Tucano Replica: If You Can’T Own an Original, It’S the Next Best Thing

Error Chain: Loss of Control in a Cassutt KITPLANES

MAY

2016

Tucano ® Replica • Sherwood Tucano Ranger • Com

Radio Replica Guide • ECO Autopilot • Firewall Layout • Sealants • Error Chain—LOC The Next • LED Taxi

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Blades ECO-nomical Autopilot May 2016 BELVOIR inexpensive and Effective

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PUBLICATIONS Com Radios in Review • Fix for a Sticking Valve • The Right Sealant Built in Britain • Counterbores TLAC Sherwood Ranger www.kitplanes.com

May 2016 | Volume 33, Number 5 Flight Review 6 Flying Legend’s Tucano Replica: If you can’t own an original, it’s the next best thing. By Luca “Luke” Perazzolli. Builder Spotlight 12 Built in Britain: The Light Aircraft Company’s Sherwood Ranger. By Geoff Jones.

18 eco-nomical Autopilot: And now for an autopilot that’s completely different. By Paul Dye.

32 sT and-alone VHF Radios: Our market scan reveals plenty 44 of models with advanced feature sets and space-saving designs. By Larry Anglisano. 44 eRRor Chain: Expectations—You don’t know what you don’t know. By Dave Holmgren.

50 engine Theory: Oil system design—Exploring the components that keep your engine alive. By Tom Wilson. 67 c ompletions: Builders share their successes. 74 a sk the DAR: Converting a Taylorcraft to E/A-B, rebuilding and modifying a Rans S-9. By Mel Asberry. Shop Talk 24 Fixing a Sticking Valve: It may not be overly complicated, but it’s not for the faint at heart. By Mike Bullock.

38 Fi rewall Layout: The chess game. By Paul Dye. 56 Best Practices: Choosing the right sealant. By Dave Prizio. 62 Home Shop Machinist: Counterbores. By Bob Hadley. 78 Aero ’Lectrics: Call me a taxi (light). By Jim Weir. Shop Tip 55 Right-Angle Deburring Tool: By Larry Larson. Designer’s Notebook 75 Wind Tunnel: A bit about blades. By Barnaby Wainfan. 6 Exploring 2 Editor’s Log: On with the shows! By Paul Dye. 64 cHeckpoints: Back courses and billy goats. By Vic Syracuse. Kit Bits 4 Letters 69 list of Advertisers 70 Builders’ Marketplace 80 kit StufF: Drawing on experience. By cartoonist Robrucha.

12 On the cover: From Italy, Flying Legend’s retractable-gear Tucano replica soars through clear blue skies. Photographed by Edwin Borremans. For subscription information, contact KITPLANES® at 800/622-1065 or visit www.kitplanes.com/cs. KITPLANES May 2016 1 Editor’s log On with the shows! Spring is here (or will be when you aviation with those who may very well reaching children with clueless parents read this) and with it comes the “flying become our future. who indulge their kid’s wishes to make season”—at least for those in the north- The big shows, like Sun ’n Fun or footprints on the wings of the nearest ern climes whose hangar doors have AirVenture, are a great place for people airplane, hang on props, or kick away at been frozen shut for several months. Of to mingle with airplanes. This is, admit- wheelpants to see if they are solid. course, those who live in places where tedly, both good and bad. First, the Public events are a double-edge sword the seasons never change have been good: We have all seen the fascinated for aviation—a great way to bring in the burning everyone else’s share of avgas stare in a young child’s eyes as they new, yet possibly dangerous to people all winter long. But statistically, spring look at the gleaming airplane and see already involved. The important thing is is when pilots start shaking off the rust the handsome pilot who has recently that we have control over how we react and getting out more—and that means stared death in the face while dogfight- to, and interact with, that public. I have going to fly-ins and the big shows to ing with the clouds. Seriously, though, met many a homebuilder who says, “I will mingle with others of their kind, as well many of them just have that fascination never go to a public fly-in event again. as the general public. Sometimes the with airplanes that makes them want to The last time, I had to yell at those little destination isn’t a formal event, just a reach out and touch them. And equally kids who wanted to touch my airplane bunch of different airplanes converging seriously, this is a golden moment to and get them back behind the ropes or on a favorite lunch spot or fly-in break- grow our community—by giving them a the fence!” OK, I understand that need fast. But either way, it is not uncommon chance to have a friendly and fascinating to protect the airplane. But let’s put our- for those on the other side of the airport interaction with something that could selves into the mind of that kid. We have fence to be interested in our planes, and take over their lives and set them on a been taken by our parents to see some- this gives us an opportunity to share path to the sky. However, there is a bad: thing that they tell us will be really neat.

Big shows, like Sun ’n Fun or AirVenture, are a great place for people to mingle with airplanes.

Paul Dye retired as a Lead Flight Director for NASA’s Human Space Flight program, with 40 years of aerospace experience on everything from Cubs to the space shuttle. An avid homebuilder, he began flying and working on airplanes as a teen, and has experience with a wide range of construction techniques and materials. He flies an RV-8 that he built in 2005, and an RV-3 that he built with his pilot wife. Currently, they are building a Xenos Paul Dye motorglider. A commercially licensed pilot, Paul has logged over 4800 hours in many different types of aircraft and is an EAA tech counselor, flight advisor, and member of the Homebuilder’s Council. He consults and collaborates in aerospace operations and flight-testing projects across the country.

2 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes We see bright, shiny, inviting things, and those interested, and if they have fur- we reach out to touch them—only to be ther questions or interest, they can get yelled at and threatened by a complete in touch with you. stranger—an adult stranger who makes (Oh—the key to good behavior by us feel really bad. The young mind asso- children is in their parents’ hands. Most ciates punishment, abuse, and embar- kids are wide-eyed sponges, willing and rassment with aviation, and we have lost waiting to learn. They don’t know how to that person to our community forever. behave, so they follow their elders’ lead. Certainly, our airplanes need to be If you see a kid behaving badly, don’t just protected, and if you find yourself at a yell at them; interact with the parents, and crowded field with a reaching public, get them to keep the kids under control. you have two choices: Stay with your It’s often the parents who have encour- plane and interact with the crowds in a aged the bad behavior in the first place, way that answers their questions, gives so reprimand the responsible party.) them safe access, and has them leaving Let’s encourage new starts—not make with a positive experience. Or get in the aviation unfriendly and unwelcoming. airplane and leave so that you don’t have We don’t want to be the last generation to interact. Either works to protect your that knows the joy and excitement of airplane, and frankly, leaving might be personal aviation. We have a responsi- better for our community than interact- bility to the future to turn the sparkle in ing in a negative way. Some of us just a child’s eye into a set of wings and the aren’t people persons—and that’s OK, rapture of flight. so long as we recognize it. But let’s face it—every indication is that the pilot pop- Respect Each Other ulation is shrinking, there are few new Oh yes—while we’re on the topic of starts, and we are aging rapidly out of airshows and fly-ins, here’s something the cockpit. We need to grow this com- to remember about helping out your munity, not shrink it by turning people fellow aviators. When someone lands away. Yes, part of the allure of aviation is and taxies in at a fly-in event, it is not its exclusivity, but we will go extinct if we uncommon for them to have a crowd don’t let new blood into the game. gather outside the airplane even before We need to be encouraging, wel- they shut down. I can’t tell you how coming, and nurturing when it comes many times I have taxied to a tie-down to those interested in joining this and then had the greeter try and talk to remarkable community of aviation. me through the closed canopy while I Homebuilders play a big part in being am still trying to shut down the avion- ambassadors for the breed. Let’s face ics and record the flight time on my it—we have cool airplanes, and we love kneeboard or airplane log. Usually, they to show off our work! The key is to show are saying, “Welcome to the show!” But them off not just to community mem- that welcome is lost in the distraction. bers, but to those who will respectfully Other times, it is just a friend who rec- enjoy them regardless of who they are. ognizes the airplane and wants to say hi Respect is a two way street, so take the before everyone else. Distractions such time to show them how to treat your as a premature greeting disrupt a pilot’s airplane, and hopefully they will respect flow and can cause them to miss somewhat you have built. A friendly interac- thing—like accidently leaving the mags tion makes a far better memory than a hot, or forgetting the master switch. cold shoulder or a reprimand. Do your friends a favor—leave them By the way, does your airplane have alone until they open the cockpit door a business card? It is so easy and inex- or canopy, take off their headset, and pensive to have picture cards made up give you a welcoming shout. It only these days, why not give it a thought? takes an extra minute to let them wind Just find a nice picture of your plane, add down from the flight, go through their a little contact information, and carry a normal procedures, and be ready to handful in a pocket. Hand them out to greet the world. J

Photo: Louise Hose KITPLANES May 2016 3 EDITORIAL Editor in Chief paul Dye [email protected] Augmenter Tubes on projects to get them flying, and that the Managing Editor mark Schrimmer I read the article, “Exhaust—Expelling greater aviation community needs to help Art Direction Dan Maher the Remains,” in the January 2016 issue. you out!—Ed. Editorial Director paul Bertorelli I found it very interesting, but did not Contributing Editors larry Anglisano, Marc Ausman, see a word about augmenter tubes like Caveat Emptor roy Beisswenger, Chuck Berthe, David Boeshaar, LeRoy Cook, those used on my Apache Geronimo. I was excited to note the Hexadyne robert Hadley, Dan Horton, Kent Tarver P60 in the most recent issue of the louise Hose, Amy Laboda, Dave martin, Sid Mayeux, David Paule, KITPLANES® Engine Buyer’s Guide Dave Prizio, Dean Sigler, Dick Tom Wilson responds: Ah, we meet at the [February 2016]. I was curious to know starks, Eric Stewart, Vic Syracuse, barnaby Wainfan, Jim Weir, intersection of Exhaust Blvd. and Cooling how development of this compact tom Wilson. St. We’ll cover boom tubes in the cooling 4-stroke engine was progressing and Web Editor Omar Filipovic system story. But I’m glad you wrote in, what aircraft currently use it. It appears Cartoonist Robrucha as the only augmenters I was aware of are there aren’t any. ADVERTISING on Beech T-34 and Twin Bonanzas, plus A visit to the web address provided Sr. Advertising Manager Chuck Preston the Grumman Goose (I think). Now I can shows the site hasn’t been updated since 805/382-3363 2002. An hour spent surfing the web [email protected] Google Apache Geronimo and see what you’re talking about. failed to produce evidence of a single BUSINESS OFFICE aircraft currently flying with this engine. Belvoir Media Group, LLC 535 Connecticut Avenue Greetings from Belize A few old pictures of mock-ups and the Norwalk, CT 06854-1713 I’ve read your magazine off and on over company demonstrator aircraft were EDITORIAL OFFICE the past few years. I’m a 22-year-old crop located. It looks like there is little likeli- 535 Connecticut Avenue duster pilot living in Belize, Central hood of purchasing and receiving a com- Norwalk, CT 06854-1713 America. I’ve been working on an Ultra plete Hexadyne P60. [email protected] Pup kit from Preceptor Aircraft lately. Mark McKeeman CIRCULATION A friend and I started it some years ago Circulation Manager Laura McMann before I went to the USA for school and You’re right Mark—the Hexadyne is an SUBSCRIPTION DEPARTMENT flight training. He died before I could example of a design that has been out 800/622-1065 get back home, so now to honor his there on the fringes for a long time. For www.kitplanes.com/cs memory, I’m building the airplane. Your P.O. Box 8535, Big Sandy, TX 75755-8535 our Buyer’s Guides, we try to list as many For Canada: Box 7820 STN Main, London, ON N5Y5W1 magazine and web site have been a good engines (and airframes) as we can, so that resource for me, so I want to say thank people looking for information can find at REPRINTS FOR PUBLICATION AND WEB POSTING AVAILABLE you! I’d also like to know if there are any least some reference that will lead them to Minimum Order: 500 kit aircraft builders my age out there that additional resources for research—even Contact Jennifer Jimolka, 203/857-3144 I can possibly get in contact with. if we know that the design has been dor- Hugh Wade mant. In some cases, this has lead to resur- gence of interest and the reinvigoration of Change of address? Thanks Hugh. It is easy for those of us a design. Missing issue? Subscription Question? in the United States to forget that there We do believe that all of our readers are homebuilding enthusiasts all over should do their own research on anything Visit www.kitplanes.com/cs. the world that have to work more or less they are looking at to buy, and trust that Or call 800/622-1065 from the U.S. and Canada. alone and without easy access to parts and they are smart enough to determine for hands-on help. It’s a good reminder to themselves how viable the design and com- Foreign 903/636-1112 or fax 203/857-3100. know that there are folks like you working pany might be.—Ed. J

Web site Information: General homebuilt aircraft information, back issue availability, online directories ordering info, plus a Kitplanes® article index and selected articles can be found at www.kitplanes.com. Unsolicited manuscripts: are welcome on an exclusive basis, but none can be acknowledged or returned unless accompanied by a stamped, self-addressed envelope. No responsibility is assumed for loss or damage to unsolicited material. Kitplanes® (ISSN 0891-1851) is published monthly by Aviation Publishing Group, LLC, an affiliate of Belvoir Publications, 535 Connecticut Avenue, Norwalk, CT 06854-1713, Robert Englander, Chairman and CEO; Timothy H. Cole, Exec. Vice Pres./ Editorial Director; Philip L. Penny, COO; Greg King, Exec. Vice Pres./Marketing Dir.; Ron Goldberg, CFO; Tom Canfield, Vice Pres., Circulation. Periodicals postage paid at Norwalk, CT, and at additional mailing offices. Copyright ©2015 Aviation Publishing Group, LLC. All rights reserved. Reproduction in whole or in part is strictly prohibited. Printed in USA. Revenue Canada GST Account #128044658. Canada Publishing Agreement #40016479. Subscriptions: One year (12 issues) is $29.95 U.S. $41.95 in U.S. funds in Canada, includes GST. $41.95 in U.S. funds for Foreign Surface Mail or $57.95 in U.S. funds for Foreign Air Mail. Single copy price $4.99 U.S., $5.99 Canadian. POSTMASTER: Please send address changes and subscription inquiries to: Kitplanes®, P.O. Box 8535, Big Sandy, TX 75755-8535, or Canada Post: Return undeliverables to P.O. Box 2601, 6915 Dixie Rd, Mississauga, ON L4T 0A9 or call 800/622-1065. Kitplanes® is a registered trademark of Aviation Publishing Group, LLC.

4 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes We hear you. Introducing the Garmin GTX 345 series of transponders. ADS-B Out and optional WAAS position source and ADS-B In. Displays on select Garmin avionics, portables and tablets using Garmin Pilot and ForeFlight Mobile. And the same footprint as most existing transponders. Learn more at Garmin.com/ADS-B.

31987 GTX 345 - iPad-7.875x10.5-Kitplanes.indd 1 2/18/16 7:48 AM Flying Legend’s Tucano Replica

If you can’t own an original, it’s the next best thing. By Luca “Luke” Perazzolli

6 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes In the Experimental aviation world, when we think of replica airplanes, what usually comes to mind is a classic fighter from WW-I or WW-II. The replica covered in this article also has military origins, but is something entirely different. The Embraer EMB 312 Tucano is a low-wing, tandem, turboprop trainer that was originally developed for the Brazilian Air Force in 1979. Since then, the aircraft has been used by numer - ous air forces around the world, and a light-attack version, the EMB 314 Super Tucano, is still in production. Flying Legend, an Italian company, has developed an all-metal Tucano replica that is 70% actual size and looks almost identical to the original. But don’t let the turboprop-like exhaust stacks fool you. The replica is actually powered by a Rotax engine. It can also be built with fixed or retractable landing gear. With fixed gear and a 100-horsepower Rotax 912 ULS, the Tucano meets LSA requirements, provided that The Tucano replica (bottom) looks amazingly similar to the original. You won’t find ejection gross weight is limited to 1320 pounds. seats, but a ballistic parachute is available as an option. (Top Photo: guillaumepaumier.com, CC-BY.) When licensed as Experimental/Ama- teur-Built, gross weight can be increased (see sidebar), which boosts power to main Italian light aircraft show, Cielo to 1433 pounds with aerobatic load lim- 130–140 horsepower. You can probably e Volo, is held at Ozzano Airfield near its of +6/-3 G at this weight. guess which version I wanted to fly for Bologna, more toward the center of Performance is significantly enhanced this report! Italy. I contacted Flying Legend CEO with retractable gear and more power. Franco Rummolino, and we agreed to The “official” engine choice for the First Impressions meet for a demo flight the day before E/A-B version is a turbocharged 115-hp Italy is a long country going from north the show opened. Rotax 914 UL. But there’s also another to south. I live in the far north, and Fly- My plan was to fly to Ozzano in my option—a Rotax 912 ULS fitted with ing Legend is based in Caltagirone, on Van’s RV-8. Unfortunately, thunder- Flygas Engineering’s supercharger kit the island of Sicily, far to the south. The storm forecasts put me in my car for 2.5 hours of driving. As it turned out, that was a good decision. When I returned home that evening, I spent the last 100 miles driving through the worse weather and rain of last summer. I arrived at Ozzano 30 minutes before the Tucano replica touched down with company test pilot, Italian Air Force retired colonel Francesco “Ciccio” Moraci, at the controls. Franco was in the back seat as copilot. They had departed at 8 a.m. from Caltagirone, did a lunch stop in Rome, and arrived at Ozzano after a flight of 520 nautical miles at 3:30 p.m. Looking at the Tucano replica for Typical drawing from the construction the first time, I immediately noticed manual that you can download from the that the aircraft is sleek and well pro- company website: www.flyinglegend.it/en. portioned. Painted military gray, it has

Photos: Flying Legend and Luca Perazzolli KITPLANES May 2016 7 Crating a kit is an art. Notice the framework securing the wings and Quickbuild Tucano kits are built on jigs at the factory. In the back- horizontal stabilizer in the crate. Other parts are also carefully packed. ground is a replica Hawker Hurricane, built from a Flying Legend kit. nicely tapered wings and a generous company owned by Franco Rummolino aviation enthusiasts, combined with the right-side tilt canopy. The front cowl and Giacomo Bandiera. With exper- unique look and impressive performance section definitely gave me the idea that tise in steel laser cutting and industrial of their aircraft, made the idea of a down- the word “replica” is important to Flying design, and a great passion for avia- sized Tucano look promising. Legend—two faux turbine exhausts let tion, they decided to enter the LSA and you dream that the aircraft is powered Experimental markets. But what type of The Kit by the Embraer EMB 312 Tucano’s tur- aircraft would they build? The Tucano replica uses traditional boprop engine. With the company’s expertise in metal construction techniques. Pre- Since this was the first time the three high-tech metal-cutting machines, it punched parts are fastened together by of us had met in person, after walking was a given that the airframe would be the builder using pulled rivets, while around the airplane, we decided to sit made from aluminum. But the spark most of the structural parts are assem- at the airfield restaurant to get to know for building a Tucano replica came from bled at the factory with solid rivets. each other and discuss Flying Legend the famous Brazilian Air Force forma- The kit is divided into several sub-kits: and the Tucano replica. tion team, Esquadrão de Demonstração empennage, wings, fuselage, flight con- Aérea (the Smoke Squadron), and their trols, landing gear, fuel system, resins The Idea blue, yellow, and green Embraer Tuca- (cowling, wingtips, fairings, etc.), can- Flying Legend was established in 2010 nos. The team’s popularity, especially opy, and engine mount. The kits can be and is part of Barum Group, a financial with Latin American and Brazilian ordered together or individually. All hardware is AN/MS and mea- surements are in inches. The fuel tanks hold 13 U.S. gallons in each wing, and are made by M.E.RIN, an Italian company that specializes in anti-explosion bladder fuel cells. The electro-hydraulic retractable landing gear was designed to look as close as possible to the original. The mainwheels are 6 inches in diameter with a differential brake system, and the nosewheel is 4 inches in diameter. Like all of the steel components, the engine mount is powder coated. The aluminum parts are treated with Alodine at the factory. The engine cowling, spin- ner, wingtips, and other fiberglass components are made with vinyl ester resin. Flying Legend worked extremely hard to make the replica cowling look as close Tucano replica quickbuild kit. All the aluminium parts are treated with Alodine at the factory. to the original Embraer front section as

8 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes The prototype is equipped with conventional round gauges, but The author receives a preflight briefing from Flying Legend CEO builders can install whatever avionics and instruments they prefer. Franco Rummolino (left) and test pilot Francesco Moraci (center). possible. Besides the faux exhaust stacks, cockpit, and the Infinity stick grip made for a pilot taller than me. Starting the the shape of the front intake scoop really me feel at home. The controls are easy engine is standard for a Rotax 912. The does make the replica look like its pow- to reach and in a natural position, and cabin was a little noisy, but headsets ered by a turboprop engine. there’s a red T-handle for the safety took care of that problem. The canopy is ready to be riveted or parachute near each seat. Brakes are independent with nosewheel glued to the frame. Like the original The panel in the company prototype steering. As I started to taxi, the nose Tucano, the rear seat is raised to pro- is equipped with conventional round felt a little heavy, so I wanted to stay vide better forward visibility for the gauges, but there’s plenty of space for light on the pedals as we taxied on the guy or gal in back. The rear seat also has all the newest bells and whistles. The macadam surface. Taxing visibility stick, rudder, and throttle controls. And landing gear switch and standard was very good, and there was plenty of speaking of controls, the ailerons and three indicator lights, along with the ground clearance for the prop. elevator are connected to pushrods, and electric prop controller, are on the the rudder is controlled with cables. left in a good position for handling. Flying the Tucano The four-point harness was more than After checking all systems and cycling Preflight enough for the mission. the electric prop, I lined up for takeoff The first thing I did was read the flight With Francesco seated in back, I on Runway 21. Temperatures and pres- manual to become familiar with the closed the right-hinged canopy and sures were good, and flaps were set to plane. I also received a thorough brief- noted there was adequate headroom one notch (15°). With the fuel pump ing from Francesco, the company test pilot, to be sure I understood the limits and configurations necessary for each Squeezing More Power from a Rotax 912 ULS phase of flight. The Tucano replica I flew has Flygas Engineering’s centrifugal compressor mounted to a Rotax It was 87°F as we walked on the 912 ULS. Instead of the usual 100 hp, the engine now produces 130 to 140 hp, depending on ramp to the plane. Ozzano Airfield’s the amount of boost. elevation is 105 feet msl. Humid- Even though Flygas Engineering originally developed the supercharger for UAVs (unmanned ity was 60%, winds were 8 knots, and aerial vehicles), Flying Legend has enough confidence in the system to install it on the the sky was clear. Together, Francesco company’s Tucano replica demonstrator. and I weighed 356 pounds. With the The core system is a centrifugal blower connected to the engine by a pulley installed on the Tucano’s empty weight of 873 pounds crankshaft. It produces its maximum manifold pressure of 43 inches at sea level, and the boost is and 20 gallons of fuel, we were at 1349 controlled exclusively via throttle and engine rpm; there’s no E.C.U. or any other electronics. Sys- pounds, well below the maximum take- tem lubrication is totally independent from the engine with a dedicated pump, filter, and tank. off weight of 1433 pounds. The supercharger kit contains all necessary components: centrifugal compressor with pulley, We preflighted the aircraft using the drive belt, mounting brackets for the compressor, oil tank with oil pump and filter, oil pressure standard checklist and made sure the valve, hoses, low oil pressure alarm switch, fuel pressure pump, adjustable regulator for fuel red “Remove Before Flight” streamer pressure, airbox, cylinder spacers to lower the compression ratio, and eight spark plugs. was removed from the pitot tube. A Besides additional horsepower at altitude, other advantages include lower EGTs (for the small step in front of the left wing, along Rotax, about 1300°F at 5800 rpm) and no backpressure in the exhaust manifold. The system with holding onto the roll bar, gave me weighs about 14.3 pounds and is priced at $6,800. For more information, visit www.flygas.info. easy access to the front seat. It’s a roomy —L.P.

KITPLANES May 2016 9

Flying Legend Tucano Replica

Kit Price . . . . . $67,900 (Engine, prop, instruments, ...... avionics and paint not included) Number flying (at press time) ...... 4 Powerplant . .Rotax 912 ULS with Flygas supercharger Propeller ...... 3-blade, electric Powerplant options . . . . Unmodified Rotax 912 ULS ...... and 914 UL

AIRFRAME Wingspan ...... 27 ft 7 in Wing area ...... 107.6 sq ft Length ...... 23 ft Height ...... 7 ft 11 in Fuel capacity ...... 26 gal Maximum gross weight ...... 1433 lb Pods under each wing serve as interesting baggage compartments. They’re great for Typical empty weight ...... 873 lb touring, but not for speed. Each pod holds up to 27 pounds. Typical useful load ...... 560 lb Full-fuel payload ...... 404 lb later, I saw three red lights as the At this weight, the aircraft showed Seating capacity ...... 2 wheels came up into the wells. Reach- positive static longitudinal stability, PERFORMANCE ing 300 feet, I retracted the flaps, not- positive long period dynamic longitudi- Cruise speed ...... 137 kt ing no appreciable pitch change. With nal stability (damped in less than three Maximum rate of climb ...... 1250 fpm the prop set at 5500 rpm, we were phugoids), and static directional stabil- Stall speed (landing configuration) ...... 35 kt climbing at 65 knots and 700 feet per ity after a rudder pulse. Stall speed (clean) ...... 40 kt minute. The aircraft felt solid, and vis- Next it was time to check stall charac- Takeoff distance ...... 490 ft Landing distance ...... 590 ft ibility was great. teristics. I first tried clean at idle power. Glide ratio ...... 10:1 We leveled out at 2000 feet due to The break came at 40 knots and was

Specifications are manufacturer’s estimates and are based on the controlled airspace. With engine rpm at straightforward and gentle, with no wing configuration of the demonstrator aircraft. 5000, the airspeed indictor showed 110 drop. In the landing configuration, with knots. I decided to get a feel for the con- full flaps and gear down, the stall came at on and engine rpm at 5700, I progres- trols: Rudder response was prompt and 35 knots. Stick shaking was evident and sively added power for takeoff. Small harmonized, and the roll rate was slow, provided good warning. Recovery was rudder force was applied, and it was easy but precise. Pitch felt too light. A little prompt with forward stick movement, to track the centerline. In less than 700 rudder input was required during turns. and only a small amount of altitude loss. Feet (about 12 seconds) we were air- The trim action is predictable and posi- The first Tucano replica prototype was borne at 45 knots. tive. I noted a little backlash in the stick painted to match the Tucanos flown by I lightly tapped the brakes before action, but Franco told me that this has Esquadrão de Demonstração Aérea, the retracting the gear. About 8 seconds been resolved in the production kits. Brazilian Air Force formation team.

10 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes Faux turboprop exhaust stacks let you dream that the Tucano replica is powered by the The retractable landing gear is strong same type of engine that’s found in the real thing. enough for well-maintained grass fields.

Leveling out, we saw a cruise speed Summing up the flight, the airplane Conclusion of 120 knots. We had two baggage feels solid, is pleasant to fly, and has out- Flying Legend may be new to the Exper- pods under the wings, so I’m pretty standing visibility. I found a few issues imental market, but their strength is a sure that a faster cruise speed is pos- that I discussed with Franco but, as well-designed replica aircraft that looks sible. With such light pitch forces and noted earlier, the aircraft I flew is a pro- incredibly similar to the original and is the pods installed, I preferred not to totype, and he assured me that every- a pleasure to fly. There are four Tucanos check the VNE speed (178 knots), so I thing is fixed in the production kits. currently flying, including one fixed- started a left spiral to enter the pattern gear LSA. The staff has a strong passion on the downwind. Kit Price for flight, so I’m sure they will be mak- Running through the checklist for The Tucano airframe kit is best described ing small improvements to the kit and landing, I lowered the gear and flaps as a quickbuild, since much of the work the design as more aircraft are completed with little perceptible trim change. has been completed at the factory. The and they gain experience with the type. After turning final, I was stable at 60 kit is currently being evaluated by the Flying Legend is serious about knots with full flaps (35°). There was FAA and is expected to be fully compli- entering the U.S. market and recently a 6-knot crosswind component, but ant with the “51% rule.” opened a new facility in Archer City, directional control was a piece of cake. Included in the price of $67,900 USD Texas. For more information, visit I gently landed on the maingear, slowly (€60,430, depending on the exchange www.flyinglegend.it/en. J lowered the nosewheel, raised the flaps rate) is the complete airframe, including Luke Perazzo Luke for takeoff, and was off for another two M.E.RIN anti-explosion bladder Luca “Luke” Perazzolli earned his run. On the next landing, I stopped in fuel cells. An optional safety kit with pilot’s license in 1989 and has logged about 650 feet. Brake action was suffi- a Galaxy GRS ballistic parachute and more than 1000 hours in 25 cient and once again, the airplane was double activation bars is available for different types of aircraft. He very easy to land. I proceeded to taxi $7,600. Engine, propeller, electrical sys- currently owns a Van’s RV-8 that he back to our parking space and shut tem, instruments, avionics, and paint are built in 2010. Luca flies aerobatics down the engine. not included and are up to the builder. and is a mountain glacier pilot, with ratings for snow and uphill landings. He is also an LSA instructor, Italian EAA technical counselor, flight advisor, DAR, and Experimental aircraft flight test pilot. He is currently involved in three new Experimental aircraft building projects and two restorations: a Piper L4-H and Stearman PT-17. Luca also teaches flight testing, metal

ll building, and aircraft electrical systems for the i i Italian EAA.

KITPLANES May 2016 11 Built in Britain The Light Aircraft Company’s Sherwood Ranger. By Geoff Jones

Hurricane, Lancaster, Mosquito, rural county of Norfolk, driving because The Company Spitfire, Moth—all iconic British thunderstorms and heavy rain are rak- In addition to selling kits, TLAC also designed and built aircraft, and all from ing the skies. I’m looking for TLAC’s builds complete aircraft, a new depar- an era when such design and construc- headquarters and factory at the quaintly ture for this type of aircraft in Great tion skills burgeoned. Postwar, there named Little Snoring airfield. I’m also a Britain. Paul is formally trained as a has been very little to match these, as stone’s throw away from Her Majesty The production engineer and joined the Great Britain’s general aviation aircraft Queen’s country residence at Sandring- family chemical production company industry swelled, then imploded. This ham. I spy a former WW-II control tower in the early 1980s until he sold up to was no more true than in the light air- and a windsock—I’ve arrived at Little pursue his flying and aircraft-building craft industry, including homebuilt air- Snoring airfield, the shadows and echoes hobby on a commercial basis. Paul craft and kit designs. Then in 2003 The of war-time DH Mosquitos long gone, brings his huge professional, industrial, Light Aircraft Company (TLAC) was but a large, modern building with a bustle and production experience to TLAC, founded in Norfolk, England by Paul of aviation activity is in front of me. I have and although from the outside it may Hendry-Smith and Ivor Smith. arrived at the focus of the current revival appear as a small cottage industry, Fast forward to June 2015 and I’m driv- of Great Britain’s light aircraft manufac- from the inside it is 21st century, state- ing down the verdant, leafy lanes of the turing industry, TLAC. of-the art, with its directors knowing

12 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes the traumas of running a profitable and successful business. Throughout my visit to TLAC, I am continually reminded that quality manufacturing is important. Many pro- cesses and components could be done more easily and cheaply, but the TLAC ethic is quality—and quality never goes out of fashion. They are now approved by the CAA in Part M, Sub part F, G, and I (Maintenance) up to 5.7 tons for fixed- and rotary-wing aircraft, and have recently been awarded A.8-1 and A.8-9 approvals, which enable them Paul Hendry-Smith, managing director of TLAC with a Sherwood Ranger XP. to manufacture light aircraft. They also have “DoA” and “PoA,” which are microlight) that fits the U.K. sub- of three, plus Paul. Like any modern design and production approvals with 660 pounds (300 kilograms) maxi- design center, it has large computer flight test authority. mum takeoff weight category. screens that display the end product of Besides the swarm of Pipers and Cess- All three aircraft have convoluted his- the Solid Works CAD software they use nas at TLAC for maintenance, as well tories, but all are now under one stable for designing structures, assemblies, and as being the U.K. agency for the Oratex roof with common TLAC production components, from full airframes down fabric covering system, their current methods and integrity. One of the main to simple brackets. Also used is Pro- portfolio includes three basic aircraft features they have in common is wing Engineer software, which does the basic designs, all of which are available in kit folding. Paul believes that with the stress analysis work. TLAC has stripped form, or as factory-complete aircraft: ever-increasing cost of hangars, an air- their three designs back to basics. • Sherwood Ranger—a tandem, two- craft with easily folded wings—with no They keep the “good” where it exists, seat biplane (formerly the TCD Sher- control disconnection—will appeal to a but replace other parts with new and wood Ranger). large number of pilots. improved designs as they develop them • Sherwood Scout—a side-by-side, to meet the stringent U.K. requirements two-place high-wing (formerly Touring the Factory for kit aircraft. the Escapade). My visit starts on the top floor of three Most of the rest of the top floor is • Sherwood KUB—a small, single- that comprise TLAC’s facility at Little taken up with Sherwood Ranger pro- seat SSDR (single-seat deregulated Snoring. The office here has a staff duction, with two of five fabricators working away here. I scratch my head and wonder whether this is a Cold- itz Cock scenario, with Rangers being launched into the air from the dizzy heights of the factory top floor roof. “No,” says Paul, “look at the area in the center.” Glancing in that direction, I see an innovative lift that takes complete aircraft and components down to the intermediate and ground floors, aircraft carrier style. To one side of the top floor is the bonded store, of which Paul is under- standably proud. In here is over $150,000 (£100,000) worth of aircraft components, most of them manufac- tured by TLAC at Little Snoring. “We draw from here for factory-complete aircraft manufacturing, or as we com- pile components for a customer before Looking down on TLAC’s lower floor demonstrates the benefit of folding wings on all shipping a kit. We make as many of three of their models in order to maximize hangar floor space. these components as possible ourselves,”

Photos: Geoff Jones and courtesy of TLAC KITPLANES May 2016 13 A sheet of GL.1 ply emerges from the three-axis 8x4-foot CNC router machine used for Ply sheets with CNC-routed ribs ready to profile cutting. Here a sheet of Sherwood Ranger fore-ribs emerges. go into a kit package. he explains. I spot a stack of wooden There are more composite compo- just arrived so that kit production for ply sheets that have been CNC-routed nents in the TLAC designs than in the Kub and Scout can ramp up on with the outlines of ribs, fillets, gussets, previous manifestations. One excellent the middle/intermediate floor. A buck and other parts. “These are so that the improvement is a one-piece compos- (mold) for the new overhead aluminum builder just has to ‘pop’ the parts out ite decking for the entire cockpit area fuel tank for the Ranger had recently when they are ready to build. It’s just like of the Ranger, a great idea to prevent been completed, and the first-off tank is the balsa-wood kits we made when we scuffs and damage when getting in and just being final TIG welded, while Paul were kids,” Paul tells me. Another large out of the finished aircraft. A fabricator explains that they no longer use plastic rack of trays has an amazing selection of is making a small cut in one of these as for fuel tanks. fasteners, nuts, bolts, etc., most of which I pass him, and I’m gratified to see that Paul also proudly shows me the are aircraft AN grade, although TLAC he is using a vacuum extraction for the three-axis CNC machine used for mak- use some nice mushroom-head bolts to cut fragments and dust, which keeps ing engine mount components, the jig secure seats; these are metric, as they the aircraft and shop floor spotlessly for producing Kub fuselages, and the couldn’t source ones they liked from the clean. TLAC subcontracts their com- three-axis 8x4-foot CNC router they AN fastener program. posites from a local company whose use for profile cutting wooden ribs TLAC has had great difficulty sourc- main business is supplying the motor on the ply sheets. He also notes that ing sufficient quantities of good spruce sport industry—they are beautifully TLAC has moved to a new cold-weld for rib caps. Apparently most supplies are and accurately made. MIG weld system throughout their fac- now being channeled to China. Instead, As we continue through the factory, tory for steel components, instead of albeit it ten percent heavier, they now use it’s obvious that TLAC has made a large the TIG weld most people use. “MIG Douglas fir from Canada, which is 20% investment in tooling, CNC machines doesn’t produce as much heat in the stronger than spruce. All the ribs for all and jigs. A new CNC tube-profiling tubes as TIG. As a result, the fusion three designs are made from GL.1 ply. machine with lights-out operation had in the welded joint is stronger, and the

Upper fuselage surfaces, including the neat composite cockpit Fabricators use heat guns to shrink Oratex fabric on Sherwood area decking, of a Sherwood Ranger. Ranger control surfaces.

14 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes Note the higher vertical tail of the newly re-designed TLAC Scout, TLAC also exhibited the Kub at the Popham Microlight Show. shown here at the Popham Microlight Show in the U.K. strength of the original tube is retained. none of the directional instability expe- A Classic Biplane The MIG system doesn’t take any lon- rienced in similar kit aircraft types. Since acquiring the rights to the Sher- ger to complete either,” says Paul. The TLAC Kub prototype is also wood Ranger, TLAC has sold 52 exam- Our next stop, the hangar on the here, a work in progress, previously with ples. Five of them are factory-complete ground floor, is where the test flight a Hirth F33 engine, but now being ret- aircraft, and the remainder are in kit examples of the three current TLAC rofitted with a new Italian-designed form. There are examples flying in most models are kept. It was also busy. I’m engine, a 36.5-hp two-stroke Polini, European countries, Japan, Thailand, shown the significant changes to the which is very light and comes with dual South Africa, and three or four are Scout design that TLAC has made to ignition. It has already been used in sev- under construction in the USA. One give better handling and improve the eral single-seat aircraft, including the builder is actually building his Ranger strength of the landing gear. There’s an Belite, and has its origins in the Italian kit in the TLAC factory, and Paul told option for double- or single-brake cali- motor scooter industry. Paul is hopeful me they are considering that option as a pers, and the tire size can be increased that with the Polini, the lack-luster per- future development of their business. to 26 inches, if required. The test-flight formance of the Hirth-powered Kub Four different models of the Sher- aircraft also has enlarged rear control will be much improved. wood Ranger are available: surfaces compared to earlier examples, That brings us to the Sherwood • ST—conforms to U.K. microlight regu- and Paul says the Scout’s new flaps Ranger, which is TLAC’s current main lations not exceeding 990 pounds/450 produce more lift. The cockpit is also focus. Like the Scout and Kub, the kilograms maximum takeoff weight. slightly wider, four inches more than a Ranger has been greatly improved since • XP—identical to the ST, but a “Group Cessna 172. All of this gives a comfort- the design was first introduced (see side- A” aircraft with a 31.5-inch/800-mil- able cruise with precise controls and bar, “An Airplane Named After a Pub”). limeter shorter wingspan.

KITPLANES May 2016 15 An Airplane Named After a Pub With origins dating back to the 1980s and the first popular microlights (for U.S. and Europe read ultralights) in Great Britain, the Sherwood Ranger had a checkered career until TLAC took over the design rights in 2007. It was originally the work of Russell Light from Worksop, Nottinghamshire, who had previously part-designed the single-seat microlight biplane, the Tiger Cub 440, of which about 100 kits were built. The Tiger Cub was a basic open-cockpit microlight with a 55-hp Fuji-Robin EC44PM 2-cylinder, 2-stroke engine. But what The comprehensive panel fitted to Owen Pope’s Sherwood Ranger gives a “period” look. made it unusual is that it was a biplane (Photo by Owen Pope) (most other microlights were monoplanes) and that it had folding wings. Russell and • XP Aero—a stronger version of the There are several kit options for the his company, Tiger Cub Developments XP cleared for single-pilot aerobatics. Sherwood Ranger, which means that (TCD), later went on to design the larger, • DST—Includes a ballistic recov- customers don’t have to invest heavily in two-seat Sherwood Ranger kit aircraft, ery ’chute and a higher 472-kilograms/ the complete kit at the outset. As with again with folding wings, and which first 1038-pounds maximum takeoff weight. many kit manufacturers, TLAC sells a flew in October 1992. It was named after TLAC favors using the Belgian tail kit for builders to cut their teeth on, Russell’s local public house in Worksop, D-Motor, which makes the empty followed by a “basic” firewall rearward The Sherwood Ranger. weight with basic equipment installed kit or a “fast-build” fuselage kit. And The aircraft had a constant-chord wing about 540 pounds (245 kilograms). finally, there’s a “fast-build” wing kit. with single aluminum spar and drag struts, Other engine options include the Rotax a plywood-covered D-box leading edge, 582, which is lighter at 474 pounds (215 Ranger Builders and Pilots spruce ribs, and fabric covering. The fuse- kilograms) and the Jabiru 2200, which is There are about 17 examples of the Sher- lage was constructed of aluminum tube heavier at 572 pounds (260 kilograms). wood Ranger currently flying on a regu- with ply formers and spruce stringers cov- Besides providing the ability to fit lar basis in Great Britain. One of the first ered in fabric. It came in two versions: The a wide range of engines, TLAC has to fly, built by Ben Chester-Master in ST featured a 64-hp Rotax 582 and a maxi- improved handling in the flight con- 2000 with a Rotax 582 engine, has been mum takeoff weight of 1000 pounds (454 trols, developed a different wing assem- sold in Italy. Early builders all talk of the kilograms), and fitted the British homebuilt bly, and made folding wings standard. inevitable difficulties with kit supplies of category (known as Experimental in the They’ve also incorporated a much higher these first examples, but all say they are U.S.). The LW was a microlight powered by a standard of machined components and Built by Kevin Crumplin from a TLAC kit in 50-hp Rotax 503, with a maximum takeoff made structural improvements by using Great Britain, this Sherwood Ranger is now weight of 860 pounds (390 kilograms). a better/stronger gauge of steel tubing: owned and flown by Owen Pope. TCD produced drawings and semi-kits, L113 aluminum seamless drawn. (Photo by Owen Pope) with several builders embarking on construction. One aircraft was built in Rolling Hills Estates, California, by Dan Nelson and was displayed at Sun ’n Fun in 1997. Russell died prematurely, and the design rights to the Sherwood Ranger were acquired by well-known British homebuilder Dudley Pattison. An aircraft accident prevented Dudley from fully real- izing the business potential of the design, and it passed through several owners, but with no progress, until TLAC acquired the rights in 2007. —G.J.

16 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes everything. Also, the way the aircraft is designed means that the assembly process is simple and standard. And once you get used to TLAC’s build meth- odology, it is repeated throughout the aircraft, and you’re then on a roll.” He praises Paul and his staff for their help- fulness. “You can ring them any time with any question and nothing is too much trouble,” he says. Registered G-DANB, the first flight of Danny’s Sherwood Ranger was for 30 minutes on June 10, 2015. He says the aircraft handling is excellent, and all he had to do was tweak the rudder slightly Patriotic tail colours for Danny Baker’s newly completed TLAC Sherwood Ranger. to overcome a need for continuous right (Photo by Danny Baker) rudder. Once a trimmer was installed, this was rectified. Paul told Danny, “It glad they persevered. I spoke to Kevin plenty of room in the cockpit, even should fly straight out of the box,” and Crumplin, who has built two Rangers, with a big Irvine fleece and leather fly- Danny confirms that it did. Although an early example supplied by Russell ing jacket on.” not as fast as other aircraft he’s used to, Light, and a more recent TLAC kit. He Another British builder of the when he lands after each flight, he has a reluctantly sold both to concentrate on TLAC Sherwood Ranger is heating huge grin on his face—and in the end, restoring and flying DH Tiger Moths. and ventilation engineer Danny Baker, that’s what the Sherwood Ranger is “The Sherwood Ranger is a brilliant lit- who has been a Private Pilot for many really all about. J tle airplane,” Kevin told me, “a delight to years, but wanted something different. fly and because of this, I kept the second The Ranger is his very first homebuilt For more information visit www.g-tlac. example—fitted with a Jabiru 2200— project. He completed the TLAC kit com or call +44 (0)1328 878809. for a long time before reluctantly selling in about one year, working weekends it to Owen Pope in 2014.” and evenings only, which in his own Owen Pope’s Sherwood Ranger was words, “Is not so bad!” Danny wanted GA in Great Britain having its annual Permit to Fly renewal an open-cockpit biplane with fold- Although there is very little indigenous when I caught up with him at his Hen- ing wings, important because he flies light aircraft production in Great Britain, stridge, Somerset base. He was taking from a private airstrip and could easily general and light aviation are flourishing, the opportunity to change the previ- fold the wings, load the aircraft onto a despite the best efforts of former govern- ous finer pitch (39) two-blade propeller, trailer and bring it home during spells ments and the EU to bureaucratize GA out which only allows a maximum 2400 of bad weather. The choice of designs is of the skies. As a measure of the kit aircraft rpm with a Jabiru 2200 engine, for a very limited in this category. The Sher- population, there are currently about 400 coarser pitch (34) Hercules two-blade wood Ranger ticked these boxes, and Van’s-designed RVs flying in Great Britain, wooden prop that he is sure will give since the aircraft has been completed, and many, many more other types. The better performance. Danny says it takes about 10 minutes Light Aircraft Association (LAA) adminis- Owen only has about 170 hours to fold the wings and get the aircraft ters and oversees the construction of most total time and flew a single-seat Taylor onto a trailer. homebuilt and kit aircraft in Great Britain, Monoplane before acquiring the Sher- He also says that the TLAC build using a Permit to Fly system on behalf of wood Ranger. He describes the Ranger manuals are very comprehensive, with the CAA (Civil Aviation Authority). There as “excellent—very light, responsive TLAC printing and issuing all the are 2600 LAA Permit aircraft now flying and stable, particularly when compared drawings as large format ones. The kit and a further 1500 under construction. If to the somewhat ‘twitchy’ Monoplane. comes complete with everything to you’re in Great Britain at the beginning of It will take off in no time, and with a build the airframe, but you then have September, make a beeline for the LAA’s 50-knot approach virtually lands itself. to buy the options such as cowlings, big, annual fly-in at Sywell, Northants, However, it’s no good for wheel land- coverings, engine, instruments, etc. where many of these homebuilts, ings because its light tail has a tendency After building his Sherwood Ranger Experimentals and other Permit aircraft to bounce, and I’ve learned not to use Danny says, “I can see why TLAC does types gather for the LAA’s popular annual the brakes until the aircraft is almost this as there are so many options, it air rally. stationary. I fly by myself, and there’s would be impossible for them to supply —G.J.

KITPLANES May 2016 17 ECO-nomical Autopilot

And now for an autopilot that’s completely different… By Paul Dye

Forty years ago, when I had the money world is TruTrak Flight Systems, based The aileron control tab is simple and easy to rent an airplane fancy enough to sport in Springdale, Arkansas. Company to install. The servo mounts to a close-out actual upholstery, it was not uncommon founder Jim Younkin started out in the plate installed like an inspection cover in the aileron. for those Cessna 172s or Piper Arrows aviation business as the father of the to have autopilots installed in the panel. Century series of autopilots, but later Targeted to cost right at $1,000, the ECO The only problem was, we never dared developed the earliest digital units under does just a few things—and does them use them. The primitive technology used his own company. The DFC, Altrak, very well. As an autopilot, it carries out in those days did not work well (or at all) Digiflight, Digiflight II, and Sorcerer are those three basic functions—heading in a rental fleet. If you engaged them, found in countless Experimentals, and hold, nav track, and altitude hold—and they were as likely to roll you inverted or have been joined recently by the newer most of the time, who actually needs more take you someplace you didn’t want to Vizion units—all of which are amazing on a VFR cross-country? (If you just have go as they were to actually help out on a when it comes to flying an airplane in to have the airplane do a teardrop entry to long cross-country. smooth, bumpy, or IFR conditions. But a hold while descending and capturing a The digital revolution has changed as capability has increased, so has com- new altitude, TruTrak will still be glad to all that, and nowhere as much as in plexity, and the current owner, Andrew sell you one of their more capable units.) Experimental aviation. Modern auto- Barker, had an urge to build a simple, But this box does more than just pilots can fly just about every aspect of inexpensive, two-axis autopilot for those provide an autopilot. Barker is a firm a cross-country flight—including the who only need it to do a few things: hold believer in doing something to decrease approach and holds if necessary—bet- a heading, hold altitude, and hey—while, the number of accidents caused by loss ter and more efficiently than their flesh- you’re at it, can it follow the magenta line of control—pilots simply getting outside and-blood operators. on my GPS’s moving map? of their comfort zone or envelope. The One of the leading dedicated autopi- The results of this desire are now avail- ECO is designed to provide full-time lot manufacturers in the Experimental able in the ECO autopilot from TruTrak. automatic envelope protection (AEP).

18 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes More Than an Autopilot While Barker’s dream to provide a simple autopilot for a low price might seem grand enough for anyone with a simple VFR airplane, there is far more to the ECO concept than just flying the airplane while the pilot enjoys the view and manages the flight. Heeding the current call by the FAA to do something about the continued high rate of Loss of Con- trol (LOC) accidents, Barker realized The entire autopilot controller fits in the control head and takes almost no space in the that this simple autopilot had all the panel. Combined with the tiny servos, it adds less than a pound to the average aircraft, depending on the amount of wire needed. hardware necessary to give the casual pilot a little help now and then—all it Basically, it helps warn the pilot of over- Installing the servos in the control would take was a little software, since banking or getting into a high- or low- surface is simple: TruTrak supplies the mechanics were already in place. pitch situation. a template for you to use for cutting a With both roll and pitch channels Remember when you first flew with rectangular hole the proper size, then available for control, it was simple to an instructor, and they might have given you install nut plates around the perim- envision that you could let the system you a little help by keeping two fingers eter, much as you would for an inspec- sense current bank and pitch attitude on the stick, adding just a touch of pres- tion hole. The servo itself is mounted to regardless of whether or not the autopi- sure to nudge you back in the right a cover plate, and the plate screwed on lot was engaged, and if pre-set limits for direction? This is exactly what the ECO to the hole. The pushrod exits through either axis were exceeded, give the system does; it provides a little restoring effort a slot cut in the skin, extending out the authority to move the airplane back to the controls when it senses the pilot is the back of the mounting hole. Prob- toward center. The system is, by default, flying outside of a defined attitude box. ably the longest part of the installation armed to help the pilot anytime it is will be running wires through the wing powered. It can be disabled at any time Architecture and Installation and to the tail (this is when you will be with the simultaneous push of two but- The ECO is very different from most cur- wishing that you ran a string through tons if the pilot would rather not have rent autopilots because it uses small high- a conduit when assembling the wings the help, and the actual limits at which quality R/C servos and piano-hinge trim because you could use it to pull those it starts to help the pilot are adjustable. tabs to “fly” the control surfaces, rather wires now.). Now the argument over airplanes that than moving control cables and pushrods Adding the control head to the panel protect the pilot from himself is an old directly. The control head fits a 2¼-inch is just as simple: Cut or find a 2¼-inch one, debated anywhere two or three pilots hole and is about an inch thick. It needs hole, add power and ground, and run get together over adult beverages. The power and ground, plus a serial GPS a serial data line from your GPS. The phrase, “If it ain’t Boeing, I ain’t going,” input. Three wires go to each servo, and ECO will listen to steering commands is a well-worn dig at the Airbus line of air- the servos can be embedded in the control from any GPS that is tracking to a way- craft that have built-in envelope protec- surface or mounted externally. This is a point—simple as that. tion as part of their fly-by-wire software simple add-on to an existing plane. The tabs are actually nothing more than a wide piece of piano hinge, sized lengthwise to match the authority needed for the size of airplane on which they will be installed. On the RV-10 we flew for this test, the tabs were about nine inches long. Riveted to the tab is a control horn, and this is connected to the servo via a simple pushrod. The servo itself is mounted to a plate in the control surface—one aileron and the elevator each need a servo for two-axis control. The tabs are pop-riveted to the trailing edge, much in the fashion of a fixed tab that you bend to correct for ECO servos are easily mounted to a close-out plate with aluminum angle. When the plate an out-of-trim airplane. is installed, the servo will be inside the aileron or elevator.

Photos: Paul Dye KITPLANES May 2016 19 The ECO control head fits in a 2¼-inch TruTrak president Andrew Barker preflights the aileron servo and tab before a demo flight. hole (here it is installed in an adapter plate) and has a highly readable color display and just two buttons. the force felt is simply one of an out-of- while pitch is the current parameter, trim condition—easy to override in just he admits that to prevent the standard design. The truth is that almost all fly- about any light single you are likely to stall/spin scenario, AoA would be supe- by-wire systems have some sort of protec- find. As stated earlier, it is more of a tiny rior to the other two. Currently, the tion—the only question is how hard it is push back, as one might get from a good ECO does not sense any air pressures, for a pilot to override it if they determine instructor trying to nudge an inattentive and adding either an airspeed or AoA that it is being applied inappropriately. pilot back to the straight and narrow. sensor would require additional hard- For those on the side of understanding Even as a fan of pilots having complete ware—but it is something that he is the benefits of a protection system, but control, I found the AEP to be gentle considering to make it more useful in who want to be the final authority on and a nice feature. I’d probably set the all potential LOC scenarios. We think what the airplane does, the ECO system limits fairly wide on a typical aerobatic- that having AoA protection, at least as is good news—for it is much easier to capable machine like many RVs, but on an optional component, would greatly override than a typical engaged autopilot. airplanes designed for smaller bank and enhance the capability of the AEP to The way the system works, flying by pitch angles, I’d probably accept the keep a distracted pilot out of trouble. trimtab, when the AEP kicks in to cor- nudge closer to the standard rate turn. rect what it perceives to be an overbank As currently designed the AEP reacts Flying the ECO Autopilot condition, the pilot does not feel a sig- to excessive pitch angles, but Barker is So how does it fly? Remarkably well. nificant push on the stick, as they might still thinking this through. Pitch excur- In fact, it was hard to tell the difference with a typical autopilot servo connected sions can be determined by speed, pitch between it and the much more sophisti- directly to the control system, Rather, angle, or angle of attack (AoA), and cated Sorcerer that was also installed in Andrew Barker on Automatic Envelope Protection As long as I can remember, I have been in love with aviation. I know your life easier as a pilot, but it increased situational awareness so that doesn’t make me unusual in this industry, but unlike many oth- much that pilots knew, within just a few feet, their exact location. ers, I’ve had the fortunate opportunity for my passion to turn into a Couple a GPS with an altimeter and no longer did you have to worry career. I have been working as an engineer in the autopilot world for about flying into the ground in those many situations when it was over 15 years now—yes, I know, surprising for a 34 year old. During quite easy to do so. Controlled Flight Into Terrain (CFIT), a leading this time I have seen countless accidents and lost many friends due cause of accidents at the time, dropped drastically. There are a to loss of control (LOC). Because of this, I have made it one of my per- thousand different ways that CFIT could have been reduced, but sonal goals to help reduce these LOC accidents. While developing new moving map GPS is what accomplished this. My theory is that it technologies for Experimental aviation, I have also been participating works solely because pilots wanted the device to make their lives in ASTM F37 and F39 for several years and have had the opportunity easier, not because it made their flying safer. to work with some wonderful people developing new standards for My problem with many of the standalone products that help aviation. Working with Levil Technologies, we have developed a revo- with LOC (mostly angle of attack indicators) is that they are a hard lutionary new idea to help with LOC. It is called automatic envelope sell to pilots. Most understand the usefulness of angle of attack, protection (AEP), and it’s built into the new TruTrak ECO autopilot. but many are plagued by thinking, it won’t happen to me; I’m a I began flying just as moving map GPS was hitting the market. better pilot than that. This is why I wanted to build a safety device The amazing thing about moving map GPS is that it not only made into something that made the pilot’s life easier, like moving map

20 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes was with bumps. Any question of the authority available with 9-inch trimtabs was dispelled with this demonstration. Once established on course, we disengaged the ECO, reversed course, and did the same thing with the much more sophisticated Sorcerer. Aside from the bigger autopilot deciding to turn the other direction, you couldn’t really tell one from the other, except that maybe the ECO was just a little quicker rolling into the turn and crisper on the roll-out as well. Of course, it was easy to determine which autopilot was flying The wiring to the servos is simple—three conductors in a shield. It is very slender and by pushing on the stick to try and drive easy to secure to a hinge point. them off course. The Sorcerer pushed the airplane. We took off from our air- to hold both pitch and roll to tight stan- back directly on the control stick park runway with the envelope protec- dards. Applying minor pressure on the through the control pushrods, while tion armed, but the autopilot disengaged. stick to disturb the unit was easy, and the the ECO simply made the airplane feel There is no drag from autopilot servos in ECO just as easily drove straight back to out of trim. The ECO was definitely the the control system because there aren’t any the target values. more friendly of the two, while the Sor- connected to the control system. Barker Setting a “Direct TO” course on the cerer was a bit more insistent. engaged the Sorcerer as we climbed to Garmin 430W to a waypoint about 15 altitude, mostly to let it automatically miles behind us, we pushed and held Protect Me! trim the airplane out—a neat feature of the lateral control button to switch Next up—trying the automatic envelope the top-of-the-line full authority unit. the ECO into nav mode. As soon as it protection. We disconnected the auto- Both the Sorcerer and the ECO were engaged, it began a very nice standard pilot and began hand flying the RV-10, listening to the serial output guidance of rate turn to the right to intercept the a wonderfully solid, yet responsive, air- the Garmin 430W, so we could test them course. Because it was actually getting plane with plenty of speed. Entering a easily against each other. Once leveled at left/right steering commands to the pre- standard rate turn, I established a bank about 3,000 feet AGL, we engaged the set course line, it turned past the (now) of about 30 degrees, then steepened it up ECO and let it hold pitch and heading. I direct heading to set up an intercept to to let the AEP show its stuff. was immediately impressed at the preci- the course, then tear-dropped onto the What I found most interesting was the sion with which it did both. Even as we magenta line, again with crisp precision. way envelope protection felt. Because the passed through mountain/wind-induced During all this turning, altitude didn’t autopilot is flying a trimtab, when it sug- bumps, the ECO had plenty of authority vary by more than 10 feet—and this gests that maybe you’re getting too steep

GPS did, and why the new ECO autopilot has AEP technology built in, not optional. Envelope protection with a conventional autopilot requires engaging the autopilot servo, and the pilot no longer has direct control of the aircraft. Because the ECO autopilot uses small servos driving trim-style tabs, AEP can be done without ever taking the airplane away from the pilot. This allows the system to deflect the tab in the event that the aircraft leaves the prescribed flight envelope. The tab deflection is essentially only trimming the aircraft back in the direction to get within the desired flight envelope. Also with ECO, AEP is by default armed and running in the background, much like stability control in a car. It is my hope that the technologies we are introducing with ECO will be able to help solve the long-standing problem of LOC and, at the same time, offer increased enjoyment and ease of flight. I know that I will keep working to develop Andrew Barker began as an engineering intern with TruTrak when he was in college. He now owns the company and is intent on new technologies that not only make flying easier, but safer as well. steering it into new markets with new ideas, while maintaining a —A.B. strong position in Experimental aviation.

KITPLANES May 2016 21 in a turn, it pushes back on the stick simply by driving the airplane “out of trim.” This is a much more comfortable feeling than having a standard autopilot servo pushing directly on the controls. I flew a fairly steep military 8 (much to the chagrin of the envelope protection), and it just felt like I needed to re-trim the airplane—it was easy to do what I wanted regardless of the autopilot’s insistence that we return to normal flight. But it was also apparent that I was outside the envelope. There are many aerobatic pilots who prefer to fly with the pitch trimmed for some force. This keeps tension on the The elevator tab installs just like the one on the aileron. External servos are being considered controls and removes any “dead band” for tube-and-fabric airplanes to simplify construction. that you would feel if the airplane was trimmed neutral. This means that the Great Potential less than the cost of fixing—much less pilot is always flying out of trim to The ECO is a revolutionary product replacing—an old technology unit in some extent, and this is about how it when it comes to providing capability for any certified machine. felt to fly beyond the AEP’s designated a reasonable price. For most of what pilots TruTrak has always been an Experi- envelope. It’s not much different than do with an autopilot, the ECO is more mental avionics company, so it is excit- some older light planes that actually than enough to fill the bill—and that ing to see them turning their attention have no adjustable trim capability from bill, at $1,000, is incredibly low. Envelope to the certified market as well. Experi- the cockpit—you get used to holding a protection is a new feature to most pilots, mental aviation should inform and pro- little stick all the time. and while we expect some to poo-poo it vide new technology to the certified So, does that mean that it is easy to openly or behind closed doors, it really world; that is originally what Experi- miss the ECO’s attempt to drive you doesn’t hurt to have it. The feature can mental airplanes did. Doing so in this back into the envelope? Not really. It is be easily disabled if you really want, the case, with the ECO, could increase both definitely noticeable—but not objec- envelope can be set to whatever aggres- safety and utility for thousands of aging tionable. The great thing about it is that sive style you like—and it just might save airplanes that need new pilots—a win if you intend to fly some aerobatics, you a few lives. What’s not to like? for the entire aviation community. can press and hold both roll and pitch TruTrak’s ECO is not the first Experi- buttons simultaneously, and the AEP mental system to provide it—Garmin’s A Matter of Practical ECO-nomics function will be disabled. Now you can G3X includes envelope protection as well, In a time when most avionics are getting fly without interference from the auto- but with a different implementation. more and more capable simply because pilot. I could easily see myself disabling TruTrak plans to pursue certification we get excited by new features, the ECO the AEP for local fun flying, yet engag- of the ECO to help address the fact that is a step in the direction of economical ing it when I was IFR or flying in a high/ it is not just Experimental pilots who flight with fewer features—for a much hot/heavy situation where I could get have loss-of-control mishaps—or who lower cost. We found the ECO was able close to the edges of the envelope. might like to have an autopilot that to fly an airplane the size of an RV-10 I am sure that many of those pilots doesn’t require a second mortgage to effortlessly, and do so with the three fea- who object to the concept of envelope install. The fact that LOC accidents are tures most pilots use the most. In addi- protection (the airplane protecting the high on the FAA’s current hit list makes tion, it can look over your shoulder and pilot from himself) would find this the timing of the ECO release fortu- keep you within a pitch and roll envelope demonstration to be eye-opening and, in itous, and bodes well for a potentially that you can define—not bad insurance the end, decide that the system is really easy path to certification. Imagine all if you get busy. We’d like to see an AoA not a bad thing to have. They might those Cessnas and Pipers with rudi- module added to really improve the odds never have an inattentive moment, in mentary autopilots out there—and the of avoiding that stall-spin accident, and which case, they’ll never need to know fact that they can get some LOC pro- it sounds like Andrew Barker at TruTrak it’s there—but if it does activate, it will tection as well, for no additional charge. believes that too. Yet even while that at least serve as an attention-getter and While Barker predicts that certification is under development, the ECO is an could just save them from a distraction will increase the price by some amount, affordable alternative to a full-fledged that could lead to a serious mishap. there is still no doubt that it will be far autopilot—and yes, it flies just fine.J

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It may not be overly complicated, but it’s not for the faint at heart. By Mike Bullock

On a Saturday in early August 2015, not right with the engine. Automati- Using the rope trick to prevent the valve I was on my first instrument rating les- cally without even thinking, I pushed from entering the cylinder while being compressed. son, something I had been putting off the mixture full rich and turned on for some time. The lesson was pretty the fuel pump. My CFII looked out quickly. It was clear that the #2 cylinder straightforward—climb up to 6500 the window to point me toward York was not producing power. feet heading 360, followed by a series airport. I didn’t have it in sight, as my At 2000 feet over KTHV, the engine of ascending and descending turns mind was going a million miles an all of the sudden started performing while under the hood. Next up was an hour. I was lucky to have him in the normally again. The EGT immediately approach into Capital City Airport airplane to point me where I needed came back to normal, and the CHT (KCXY) near Harrisburg, Pennsylva- to be. Cockpit resource management was increasing slowly (from memory, it nia. After figuring out how to get the kicked in between us, and we were dropped from 350° to 190°). I glanced Grand Rapids EFIS to properly display working as a team instantly. The engine at my flight instructor, and we both the CDI/HSI from the Garmin 430W, was still developing power, and we were thought it would be better to put the we were in business. Next up was a prac- within easy gliding distance of the air- airplane down back home at Carroll tice hold, followed by a GPS approach port, just in case the engine had other County Regional Airport (KDMW), a into York, Pennsylvania (KTHV). ideas. A glance at the engine monitor short 10 minutes away if we could make As we were approaching the fix for showed what the root cause of the issue it there safely. We circled over KTHV, the hold, the airplane developed a very was: The EGT for the #2 cylinder was gaining altitude and observing the noticeable shake. Clearly something was non-existent. The CHT was decreasing engine. Things seemed fine, as all engine

24 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes parameters looked to be back in the which keep them closed until the cam- Warning Signs green. We headed to KDMW. Roughly shaft decides they should open. A sticky So, what are the warning signs to look halfway to KDMW, the engine stum- valve occurs when the valve stem can no for before you experience a full-on stuck bled very quickly. Not enough for the longer move through the guide freely, valve at an inopportune time? One thing engine monitor to notice anything, but and it becomes bound to the guide. to look for is what is known as “morning both of us definitely heard something. There are two possible ways a valve can sickness” of the engine. Morning sickness We stayed high and circled down to a be stuck. When a valve is stuck in the is when the engine is first started and there non-event of a landing. closed position, the damage most likely is a slight miss or intermittent hesitation Once back at KDMW, my friend to occur is a bent pushrod, as some- in the speed of the engine. This usually John Sannizzaro and I started to look thing has got to give. The other way, occurs when the engine is first started for the culprit of what just occurred. which happened me, was the valve was because the clearance between the valve We removed the cowling and started stuck open. stems and valve guides are at a minimum digging around the #2 cylinder. Having Lycoming Service Letter L197A, when the engine is cold. Other indica- a full engine monitor with probes on “Recommendations to Avoid Valve tions of morning sickness include colder each cylinder was vital to figuring out Sticking,” attributes sticking valves to oil than normal EGTs and CHTs for a par- where to start looking. Both spark plugs contaminants and combustion residue. ticular cylinder. In my case, I cannot recall looked to be in fine condition (E-MAG Both of these can build up on the valve any times my engine seemed to be run- on the top plug with an auto plug, Slick stem and guide and interfere with the ning rough when first started. However, mag on the bottom with a massive elec- stem’s movement. The valve not being over the last few months, I did notice the trode plug). Next up was a compression able to fully open or close causes incom- engine missing in cruise configuration test—78/80, with the slight leakage plete combustion, which in turn forms running lean of peak. While I have no coming through the rings (audible noise more deposits and worsens the issue. consequential data that this miss was an through the oil filler tube). Lycoming’s recommendations for mini- indication of a sticky valve, I can indisput- Naturally, I would be unlucky enough mizing/preventing this buildup include: ably say I haven’t had a miss in cruise since. to have an intermittent issue. But how 1. Ensuring the air filter is clean. could I fix it? 2. Regular oil changes. Prevention 3. Using quality fuel. Almost as soon as I discovered the Cause 4. Flying regularly. reason for my engine issue was a stuck An engine needs three basic criteria to Lycoming also suggests avoiding: valve, the airport locals immediately work: spark, compression, and fuel. If 5. Infrequent ground runs where the gave me their recommendations for why the spark was lost, both the E-MAG and engine is not brought up to operating it happened and how to fix it. One the- Slick mag would have stopped firing in temperatures. ory was the oil I am using (Phillips X/C the #2 cylinder. If the E-MAG quit, the 6. Long ground runs, which can cause 20W50 for the last two oil changes, other cylinders would have symptoms of overheating. before that Aeroshell 15W-50 for 150+ elevated EGTs. That wasn’t the case. 7. Running too rich. hours) was known to cause sticky valves The lack of fuel was a more likely 8. Rapid engine cooling. in Lycomings, and I should give away culprit, especially if an injector was 9. Shutting down the engine too soon, the extra quarts I have of it and switch clogged. However, from past experience, before it is allowed to cool. to Aeroshell W100. Another theory I found it to be unlikely that an injector was I should be running an additive would be clogged and then immediately Inspection in my fuel to scavenge the potential unclog. Typically when an injector gets Lycoming Service Bulletin 388C specifies lead buildup. TCP Fuel Treatment and clogged, the EGTs are elevated, the that every 400 hours (300 for helicopters) Marvel Mystery Oil were two products exhaust makes a popping sound, and the the engine should be inspected for sticky recommended to me that I should add issue doesn’t cure itself. valves, or earlier if the engine is suspected to my fuel. Lastly, it was recommended The last possibility was lack of com- of having a sticky valve. Reading through that I not run lean of peak, as it “costs pression. What could cause this is a this service bulletin goes into detail of more to fix the issues of running LOP stuck exhaust or intake valve being specialized tools to measure how much than LOP saves in fuel.” While I kindly open. An open valve during the com- play the valve stem has in its guide—oth- acknowledged and appreciated the pression stroke of the engine would defi- erwise known as the “wobble” test. For advice, the last two recommendations nitely cause the symptoms I saw. my particular issue, it was very clear that were also listed in Lycoming Service So how does a valve become stuck? I failed the test. I could barely move the Letter L197A. I believe the cause of my The valves in a typical Lycoming valve stem in and out of the guide. A few issues were a combination of running 320/360/540 engine ride through A&Ps I spoke with said it should be easy too rich on climbout, as well as a num- guides. On top of the guides are springs to move the valve in and out of the guide ber of ground runs when my airplane connected to the stem of the valves, and spin it around. was new and I was working through

Photos: Mike Bullock KITPLANES May 2016 25 Figure 1: Removing rocker shaft. Figure 2: Rocker arms removed. some issues. Nevertheless, I am going The Fix friends, several A&Ps, and research on to start adding some Marvel Mystery With all of the background of what the Internet. Proceed with caution! Oil to my fuel and keep track of any causes this issue, and the recommended tangible evidence of it helping with the inspection intervals, let’s get into the Removing the Valve Spring engine scavenging the lead better. process of fixing a sticking valve. My 1. Remove the valve cover of the cyl- process loosely follows Lycoming Ser- inder suspected of a sticking valve. Tools vice Instruction 1425A (“Suggested Be ready for some oil to drip out of Here are the tools I used to fix the Maintenance Procedures to Reduce the the top end of the cylinder. Place stuck valve: Possibility of Valve Sticking”). It is what appropriate rags around the engine 1. Spring Compressor I used on my Superior IO-360-B1A2 and a drip pan under the engine. a. Aircraft Spruce— engine to fix the exhaust valve. I highly 2. Remove the top spark plugs from p/n 12-21520 for $60 suggest you consult your engine manu- all cylinders and both plugs from b. ACS, p/n 12-00202 for $77. facturer for their recommended proce- the offending cylinders. This is c. SkyGeek sells this variety for dure to fix a sticky valve. both for safety, and it makes rotat- $150, p/n ATS3602 I must add, this job isn’t for the faint ing the propeller easier. d. Valve Wizard for $150 of heart. While nothing here is overly 3. Rotate the propeller so both valves e. Build your own from pry-bars complicated, and I found this job to are fully closed. You will know for $18 and one hour of labor! be rather easy, I also have nearly a life- this because the top of both rocker 2. Wood Dowels time of working on engines ranging arms will be closest to the pushrod a. ½ inch for compressing the from lawn equipment and car engines shroud tubes. hydraulic lifters to outboard and inboard boat engines. 4. Remove the rocker shaft. You b. 3/8 inch for tapping the valve Also, I must make it clear that I am not should be able to easily push this out into the cylinder an A&P and have no formal training with just the force of your hands. If 3. Reamers in fixing aircraft engines. All of this this is not possible, double-check Check with your engine manufac- information was gathered by talking to that both intake and exhaust valves turer for the proper reamer to use. The technical support at Superior recommended a 0.4995-inch reamer for the exhaust valve. The Lycoming specs for the exhaust valve guide diameter is a minimum ID of 0.4985 inch and a max ID of 0.4995 inch. The intake valve guides are slightly smaller with a minimum ID of 0.4040 inch and 0.4050 inch max. 4. Mechanical Pickup Tool I suggest the lighted General #70396. The LED light comes in very handy, and the tool can be had for under $10. 5. Hook and Pick Set I used Harbor Freight #93514—the smaller the better! Figure 3: Exhaust valve cap.

26 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes until the rope is pressed between the valves and the top of the piston. You might need an assistant to hold pressure on the propeller while you move to the next step. (This step may be optional depending on how stuck your exhaust valve is.) 9. Compress the exhaust valve spring with the spring compressor. The method to do this is different with every tool out there. Consult the Figure 4: Socket extension through rocker shaft. tool’s literature for the proper way to use it. For my homemade tool (see are fully closed. Note the direction I chose to use the rope method. sidebar), I inserted a 3/8-inch exten- the rocker shaft came off (Figure 1). I have read a story of how the rope sion bar wrapped in electrical tape 5. Once the rocker shaft is removed, decided to knot itself inside the cyl- through the holes where the rocker make sure the two rocker arms do inder, causing the mechanic to pull shaft was (Figure 4). This bar is used not fall out. Remove each rocker the entire jug to free the rope. If you for the valve compressor to pivot arm individually and place it in decide to use the rope method, feed around as it compresses the spring. a container. For my engine, both roughly eight feet of rope into the cyl- Compress the spring enough to gain rocker arms were identical, but inder and then rotate the propeller access to the keys (Figures 5 and 6). this may not always be the case (Figure 2). 6. Remove the pushrods from the Homemade Valve Compressor pushrod shrouds. They may be full There are a number of valve compressor tools on the market, ranging from $60 to $150. of oil, and there could also be oil that While looking at these tools, there didn’t seem to be anything all that special or unique drips down the pushrod shrouds. about them. While saving a few bucks is always a favorite pastime of mine (my airport bud- Note which side and direction each dies have given me the call sign “Halfprice”), what was more important was the quickness of pushrod is installed. getting the tool. The sooner I had the tool, the sooner I could figure out the root cause of my 7. Remove the cap on top of the exhaust engine woes and order additional tools if needed. valve. Use a pick to remove it if you After looking at some of the tools on the market, it came to me that I could make the tool cannot by hand. Try to minimize out of some pry bars riveted together and creatively reshaped with an angle grinder. The the use of a magnet whenever pos- first step was reshaping the portion of the tool that goes over the valve itself. I needed to sible. A magnet could cause parts of make a U-shaped cutout to be able to depress the valve spring, but also be able to use the the engine to become magnetic and pick set to get access to the keys. Additionally, the tool needed to be slender enough to fit in attract ferrous material, causing pre- the space where the rocker arm resides. mature wearing (Figure 3). The other half of the tool is another smaller pry bar, which is used for the valve compres- 8. The next step is to prevent the sor to pivot on the shaft inserted through the rocker arm shaft hole. The two pry bars are valve from entering the cylinder connected with two AN4 1/8-inch rivets. while being compressed. There It took about an hour to make the tool, and the parts cost $18. Best of all, I was able to use are two ways of going about this. it the same night I started the diagnostic work on my engine. While the tool worked great, One method, Lycoming SI 1425A I think if I did the full 400-hour inspection on all eight valves, I would purchase the Valve specified, is inserting eight feet of Wizard. It seems to be the best tool out there, and would make reinstalling the rocker arm 3/8-inch nylon rope through the top shaft and compressing the hydraulic lifters a piece of cake. I’ll see if I can find it on sale! spark plug hole. The other method —M.B. is using compressed air to pressur- ize the cylinder. The compressed air method involves using an adapter that fits into the top spark plug hole and has a male air hose quick-dis- connect fitting on it (one came with my ATS differential pressure tester). Additionally, the bottom spark plug needs to be installed in order to seal the cylinder. Homemade valve compressor tool is made from a couple of pry bars riveted together.

KITPLANES May 2016 27 Figure 5: Compressing spring. Figure 6: Accessing keys with compression tool. Figure 7: Exhaust keys. 10. Using a pick set, reposition and the valve stem through the exhaust keys hold the stem to the springs will rotate the keys until they are over- port with a mechanical pick-up tool. show up. One last tap and the exhaust lapping. Gently move the positon Also, you want to make sure the pis- valve should be free of the guide. I sug- of the spring in relationship to the ton is at bottom dead center to pre- gest using a mechanical pick-up tool valve stem in a way to make the keys vent any damage between the valve that has a light at the end. This was removable. Use a pick to pull the and the piston. incredibly helpful. keys out (Figure 7). 2. Rotate the propeller so the piston of 5. With the valve removed from the 11. With the keys out, the spring will the cylinder you are working on is at guide, the next step is to ream out come out freely. bottom dead center. the valve guide. The goal here is to 12. Now is the moment you have been 3. Remove the exhaust to gain access go nice and slow, and also to prevent waiting for. Check the play of the to where the valve will exit the stem any contaminates that built up on valve in the valve guide. Check how (Figure 9). the guide from being reintroduced easy it is to push it in and out of the 4. My exhaust valve stem was very tight into the engine. This is accomplished guide, as well as spin the valve within in the guide. I could push the stem by putting axle grease (Aeroshell #5) the guide. If there is any binding of the valve to the top of the guide. onto the reamer (Figure 10). Chuck noticed, you have a stuck valve (Fig- After that, I used a 3/8-inch short the reamer into a hand grip—you ure 8). If in doubt, perform a wobble wood dowel resting against the top of want to go very slow in order not test. If the wobble test passes, skip the exhaust valve. I lightly tapped the to damage the guide (Figure 11). the next section and go to Reassem- dowel with a hammer in order to assist Ream the guide slowly, turning the bling the Exhaust Valve. in the valve removal. When I realized reamer clockwise until the tip of I was getting near to where the valve the reamer can be seen through the Reaming the Exhaust Valve Guide stem would exit the guide, I used the exhaust port (Figure 12). In order 1. Once you have determined you need mechanical pick-up tool to grab the to remove the reamer, continue to to ream the guide out, the first step valve stem through the exhaust port turn it clockwise and remove it from is to partially push the exhaust valve as close to the guide as possible. After the guide. Be sure to appreciate all into the cylinder. You don’t want every few taps on the exhaust valve of the crud that comes out after you to fully push the valve into the cyl- stem, I would reposition the pick-up remove the reamer (Figure 13)! inder, as getting it back into place is tool’s claws to be closer to the guide. 6. The next step is to remove any con- difficult. The easiest way to do this You can tell when the valve stem is taminants that might have been is to drop the valve into the cylinder about to exit the guide because the left behind in the valve guide. My enough so you can catch the end of grooves on the stem from where the method for this was to push a small

Figure 8: Valve spring removed. Figure 9: Valve and guide through exhaust port.

28 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes Figure 7: Exhaust keys. Figure 10: Greased reamer. cloth rag lightly doused with carburetor cleaner (acetone or any other solvent should also work) down the guide with a dowel, and remove it through the exhaust port. 7. Using a cotton swab, I lightly coated the exhaust valve guide with some engine oil. 8. Now the fun part begins—reinstalling the valve into the guide! The concept of this is simple on paper: Insert a magnetic telescoping wand down the valve guide, grab onto the end of the stem and yank the valve back into the guide. Simple right? Well, it is that simple. However, the valve fits into the guide very tightly, and the alignment of the valve stem needs to be perfect to get it in correctly. I found the mechanical pickup tool not to be strong enough to lift up the valve to get it aligned properly. The trick that worked for me was to take a wide Popsicle stick and file a “U” into one end of it (Figure 14). The Popsicle stick can then be used to lift up on the portion of the stem nearest the piston. With a little trial and error, it took me about 5 minutes to get the valve back into the guide. Once the tip of the stem is installed

Figure 11: Reaming.

KITPLANES May 2016 29 Figure 12: Reamer tip in exhaust port. Figure 13: Buildup on end of reamer. in the guide, the mechanical pick-up 4. Install the cap on top of the exhaust The method I came up with that tool can be removed and the valve can valve stem. worked extremely well was to use be pulled fully into the guide. 5. With nearly every engine project I the engine to compress the lifters! I have read some stories of people have ever worked on, the reassembly While with the lifters full of oil using the piston to push the valve into process is easier than the disassembly. I couldn’t install the rocker arm the guide. While this has worked, it Up to this point, my old philosophy shaft, I could install a slightly is not recommended by Lycoming has held true. Unfortunately this is smaller wood dowel in place because it could damage the valve not the case with this job. The reason of the rocker arm shaft. I then and/or the guide. Just don’t do it. being is the hydraulic lifters expand rotated the engine so the valve I Take your time and prevent yourself and fill with oil. This makes install- needed to compress the lifter for from possibly pulling the jug! ing the rocker arms an impossible was open. This process used the task without first compressing the springs of the valve to exert force Reassembling the Exhaust Valve hydraulic lifters. There are two main on the lifter to compress it (it 1. The first step in reassembly is recon- ways to reduce the size of the lifters: took anywhere from 1–10 min- necting the valve stems to the valve a. Remove the lifters. This involves utes per lifter). Once the lifter springs. In order to do so, you need to removing the pushrod shrouds, has been compressed, you need make sure the valves are seated tightly then using some safety wire to fish to work fast. These guys expand to the top of the cylinder at TDC by out the lifters. Using a toothpick, back to their full size rapidly! It using either the rope trick or with you can depress the center of the would be ideal for this portion of compressed air. With the valves fully lifter to relieve any pressure in the the job to involve two people— seated, install the spring retainers, as lifter. Reinstalling the lifter, push- one person to exert hand pressure well as the cap for the exhaust valve. rod shroud, and pushrods now on the top of the rocker arm to 2. Use the spring compressor to com- gives you the ability to reinstall the keep the lifter compressed, while press the valve springs. rocker arms and rocker arm shaft. the other person rotates the pro- 3. Install the keys. For my exhaust b. Compress the lifters. I figured peller so both valves are closed. valves, the keys were not polarized. there needed to be an easier While it can be done, it can be However, double-check if your keys way by compressing the lifters. quite awkward to accomplish this are polarized and the proper orienta- I tried and failed at a number of solo. With the lifter compressed tion they should be in before instal- experiments, which ranged from and the valves closed, act quickly lation. I found this to be a tedious using Irwin soft plastic clamps to insert the rocker arm shaft. Be process to get the keys in just right. to using the force of my hand. prepared to repeat this process

Figure 15: As the cylinder nears TDC, the camshaft is exerting maximum force against the valve spring. Let it rest here for a few minutes while the hydraulic lifters compress (A). Note the wood Figure 14: Popsicle stick. dowel in place of the rocker arm shaft (B).

30 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes and not get too frustrated when it doesn’t go right the first, second or fifth time (Figure 15)! Of course, you can always compress the lifters the way Lycoming intends, by removing the push rod tube, removing the lifter, disas- sembling it, and cleaning out the trapped oil. This does take some training and time, but avoids the need for brute force. 6. If you dropped the exhaust, now is a good time to reinstall it. Remem- ber to replace the exhaust gaskets (if needed), use anti-seize on the stud threads (not too much, just a dab!) and torque the nuts down with new lock washers. For my IO-360, the proper torque value is 180 foot-pounds. 7. Reinstall the spark plugs with new washers (or annealed old washers). 8. Reinstall the valve covers. I learned the hard way on this project not to over-torque the screws with silicon gaskets. On my first attempt I ruined all four gaskets using my German torque wrench, gutentite (Good and tight!). After researching this some more, the only spec I could find on torquing valve covers with silicon gaskets was from ECI (ECI Service Instruction 03-3) which specifies the following: a. Clean the surfaces in contact with the gasket. Both surfaces must be clean of oil and debris. b. Install the silicon gaskets dry. Do not use any sealant, oil or adhesive products. c. Torque the screws to 25 inch-pounds (cold engine) or 20 inch-pounds (warm engine—100+ °F). d. Re-torque the screws after the engine has warmed above 100°F to 20 inch-pounds. I still found 25 inch-pounds to be too tight. I ended up using much less—8 inch-pounds with perfect results. With the engine back together, it’s time to do a test flight. Before you do so, pull the prop through and check the compression in each cylinder and make sure no foreign debris ended up in any cylinder. You don’t want to find this out with the starter! J

KITPLANES May 2016 31 Stand-alone VHF Radios

Our market scan reveals plenty of models with advanced feature sets and space-saving designs. By Larry Anglisano

32 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes The Trig TY-series and TT-series units utilize remote transceivers to save space. That’s a 2-inch Becker AR6201, top.

Imbedded integration has nearly watts in a 28-volt electrical system) knob, and frequency transfer button at driven the stand-alone VHF transceiver remote-mounted radios are designed the bottom of the radio’s bezel. To the to extinction. But for non-glass and sim- with dedicated panel-mounted control left of the LCD display, a frequency- pler utilitarian panels, the traditional heads wired to a remote transceiver. monitoring button allows for monitor- panel-mounted com radio lives on. PS Engineering’s PAR200A audio ing the tuned standby frequency, while Even if your primary system is an inte- panel can serve as a controller/tuner for a memory button commands the nine- grated Garmin G3X or Dynon SkyView the radio, saving more space yet. The TY- frequency memory storage bank. Visit glass suite, a stand-alone com might series remote transceiver measures 5.5 www.trig-avionics.com. make sense for emergency backup or inches long and stands 1.7 inches high, for ground ops. A dedicated com can be which should make it easy to mount in a Becker Avionics convenient for fetching clearances and variety of locations within the airframe. With its Compact Line of products, airport info without having to power up If you don’t use PS Engineering’s Becker has a two-piece com radio: The the entire panel. PAR200A, Trig’s dedicated control model AR6201. It replaces the previ- In the March 2016 issue of KIT- head is designed to fit in a standard ous AR4201 series. Like the remote PLANES®, I looked at Experimental 2¼-inch instrument cutout or any area Trig TY91, the blue on white LCD- audio panels, and in this article I’ll move on the panel that can accommodate the equipped AR6201 transmits 6 watts down the stack to the VHF transceiver. 2.4-inch-wide by 1.8-inch-high chassis of power in a 12-volt electrical system. As you’ll see, how you choose might assembly. Total system weight is roughly It also has a four-place voice-activated depend on panel real estate, whether or one pound. The controller only occu- intercom, entertainment input capabil- not you need VHF navigation capabil- pies roughly 3 inches behind the panel, ity, plus a 99-frequency storage bank, ity, and EFIS interface. which offers flexible mounting options, which will automatically store the last especially for backup. nine frequencies used. Got Space? I like Trig’s choice of rugged intercon- In addition to the low voltage warning If you’re building your project from nect hardware, which includes common system, I like that a single Becker trans- scratch and have the panel on your bench, D-sub wiring connectors. And when ceiver (that’s the RT6201 remote box) it’s time to scope out placement options it comes to wiring, consider what you can support two control heads, which for the radio’s control head. It used to be want for features based on coexisting may be useful in tandem-seat aircraft, for that com radios came in one form fac- equipment because like other mod- example. It also has a scan mode, which tor: A six-inch-wide radio stack-mounted els, the TY-series can bring significant monitors the chatter on the standby fre- chassis. Today, there are more options audio capability to starkly equipped quency. The AR6201 with 25 kHz fre- as some radios are two-piece systems, aircraft. There’s an integrated two-seat quency spacing sells for around $1,700 with a remote transceiver and a space- intercom, and for headset-free opera- and is also available in 8.33 kHz spacing. saving panel-mounted control head. This tion, the units come equipped with an Visit www.beckerusa.com. includes two models from UK-based Trig integral speaker amplifier for direct Avionics and German company Becker connection to a cabin speaker. Trig says Garmin Avionics. There is also the Dynon SV- the TY91 can even be battery operated, Long discontinued—but still sup- COM, designed to integrate with the making it an option for gliders and ported by Garmin—is the SL40 com SkyView suite. See the sidebar on page 36 other aircraft without capable charging/ and SL30 nav/com. These slim-line for more on that glass integration. electrical systems. radios were designed by UPS-AT and The controls on the radios are Garmin acquired the product line when Trig Avionics straightforward and simple, the way a it bought the company. If you own one The 6-watt Trig TY91 and higher- com radio should be. There’s a volume in need of repair, flat-rate factory repair powered TY92 (which transmits 16 and squelch knob, frequency tuning cost for each is $550.

Photos: Larry Anglisano and courtesy of the manufacturers KITPLANES May 2016 33 The current production stand-alone com transceiver is the $1,995 GTR 225, and the $4,495 GNC 255A nav/com, which is equipped with localizer and glideslope receiver. Both of these radios borrow some technology found in Gar- min’s GTN-series navigators, including the nav and com boards. Standard is a 10-watt com transmitter, and a version is available with a 16-watt transmitter. If you’re wiring your kit’s avion- Garmin’s GTR/GNC-series VHF radios have a chassis-mounted cooling fan for better ics from scratch, you’ll appreciate the efficiency in tight stacks and for hot-climate ops. bezel-mounted USB port (no need to externally wire a USB port into the har- the old-fashioned way. Still, what imme- GNC is also compatible with the Ben- ness), which is used to update the system diately impressed me about Garmin’s dixKing KN 62 and 64 series DMEs for software and also the internal database. redesigned radios is the straightfor- displaying onscreen DME data, while More on that in a minute. ward feature set. pressing the OBS key displays the cur- If you operate in hot climates, Garmin In fact, the volume control, squelch rent OBS setting and a graphic CDI. has you covered with a cooling fan inte- control, and navigation radio IDENT The interface doesn’t stop at the navi- grated into the radio’s chassis to draw control layout and functionality is bor- gation receiver. It’s the com radio inter- forced-air cooling through the unit, plus rowed from the Garmin GNS 430 and facing that makes the GNC/GTR units inlets along the right side of the GTR/ 530 navigators. Plus, frequency tuning more advanced than any radio available GNC chassis that allows air to flow is the same as it ever was—simply dial for retrofit. It starts with an internal fre- through the unit. I once powered the the frequency on the standby window quency database of airports and VOR unit for long periods of time in a packed on the right, and transfer it to the active stations. This data is provided for down- RV-10 panel saddled to a test bench in window on the left, using the familiar load on the Garmin web site and loaded a hot hangar, and the unit remained flip-flop transfer button. to the unit with a thumb drive. efficiently cool, while the cooling fan Garmin designed the GNC 255A Pressing the function key enables the kicked on when appropriate. to be compatible with a wide variety of menu structure, where you can select The radios use traditional buttons indicators—perhaps one you already the database feature to look up the air- and control knobs and an LCD dis- have installed. This includes Garmin’s port name or station ID, much like you play which doesn’t have a touchscreen. GI-106A CDI, G500/600, Aspen Evo- would in a GPS. There’s also a reverse But that’s fine by me. Even on Gar- lution PFD, the G3X, and third-party lookup feature, which fetches the facil- min’s touchscreen GTN navigators, EFIS systems that have an ARINC ity name associated with the frequency my fingers prefer tuning frequencies 429 databus. For old-school panels, the that the user manually tunes, using the database and a valid GPS position input. Further, when the radio has received data from an external GPS receiver or DME, it displays distance, speed, and time to station. Once the frequencies are tuned, the monitor function allows for listening to the standby frequency without leaving Garmin’s GTR225 com is a touch larger than the SL40 radio it replaces, but it brings the active frequency. For example, while modern amenities, including a database and onscreen facility nomenclature. approaching the airport, with the ATIS tuned into the standby, simply press the monitor button to copy the information. Both units measure 1.65 x 6.25 by 10.4 inches and are designed for radio stack mounting. Garmin also has a non-certified com radio with a feature set more suitable for two-seat LSA and Experimental air- The GNC255A navcom is a full-function transceiver equipped with VOR, localizer, and craft—the GTR200. Priced at $1,359, glideslope receiver. It’s compatible with a wide variety of OBS indicators and EFISes. the GTR200 is a descendant of the

34 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes Garmin’s GTR 200 is a non-certified com radio specifically designed for two-seat Experimentals and LSAs. It includes a built-in 2-place intercom. certified GTR225. It features a 10-watt can display a textual name of the facility transmitter, plus an integral two-place that is tuned in the active and standby stereo intercom with pilot isolation func- windows. This data is fetched, via serial tion. This can save panel space and wiring databus, from Garmin’s G3X integrated effort in simple applications. avionics and the late-model Garmin por- The GTR200 measures 1.35 inches table navigators. tall by 6.25 inches wide. The display The GTR200 makes use of a simple has a 45° side viewing angle and mea- 37-pin connector, which stretches the sures 3.0 x 0.48 inches, with a 200 x chassis 9.3 inches deep. The entire sys- 33-pixel resolution. tem weighs just shy of two pounds, A dedicated Monitor bezel key serves including mounting rack and connector for listening to the standby frequency. hardware. Download a pilot’s guide at Garmin took the interface one step fur- www.garmin.com. ther and incorporated its 3D audio function, which is found in its flagship audio Icom panels. This provides special separation With a solid reputation in the land mobile of the standby and active frequency in and amateur radio market, in addition each ear when wearing a stereo headset. to its popular and long-standing line of The 3D function spills over to the inter- aviation portable transceivers, Icom com function, too, separating the pas- makes the IC-A220 panel-mounted senger chatter from one ear to the other. transceiver, which replaced the older Adding to the full functionality of the A200 radio. Icom offers adapters for built-in intercom is automatic squelch plug-and-play with the older radio. and a pilot-controlled auxiliary input that The two-pound A220 fits in a stan- is controlled with a dedicated bezel key dard radio stack and measures 6.0 by 1.0 (this can function as a control for music by 10.0 inches. It has an 8-watt trans- input or warning systems, for example). mitter and like its portable brethren, I like that the GTR200 is highly con- comes standard with generous features. figurable, enabling one-touch access to This includes an advanced memory the 121.5 emergency frequency, intercom bank with programmable six-character music muting, plus the ability to recall channel name (it can store 200 chan- saved frequencies. nels), NOAA weather channel, plus one- A nifty feature is the on-screen volume touch 121.5 mHz emergency frequency graphic, which shows a rolling bar and access. The Dual Watch function allows the percentage of volume as you adjust you to monitor the active and standby it. Speaking of graphics, the GTR200 channels simultaneously.

Borrowing styling and technology from its land/mobile brethren, Icom’s A220 transceiver has a bright display and rugged user controls.

KITPLANES May 2016 35 The A220 uses an OLED (organic Using a serial data port, the A220 MGL Avionics LED) display, which enables a wide view- can fetch frequencies from an exter- With a factory and headquarters in ing angle and provides for high contrast nal GPS receiver or EFIS database. South Africa and a facility in Torrance, and good sunlight readability. It also has a It’s compatible with Garmin and Ben- California, MGL Avionics sells directly two-place voice-activated intercom. I like dixKing serial outputs. to the end user, in addition to OEMs. It the ANL (automatic noise limiter), which The A220 typically sells for about offers two com radios—the V6 and V10. helps to reduce noise in the receiver. Bet- $1,299 with a custom wiring har- The 6-watt, LCD display-equipped, ter yet is the dial and key lock—useful for ness—a good value, in my view. Visit $1,095 V6 fits in a standard 2¼-inch careless fingers and in turbulence. www.icomamerica.com. round instrument cutout, weighs nine Dynon’s Smart Talking SV-COM The Dynon SV-COM-C25 is an integrated VHF radio system for the volume knob and automatic squelch override control, frequency tun- SkyView suite, consisting of a panel controller (SV-COM-PANEL) and ing control, plus its own LCD display for radio status. The display has remote transceiver (SV-COM-425). The controller is available in a a useful RX/TX annunciator when transmitting and receiving. While vertical or horizontal configuration, measuring 3.53 by 1.80 by 1.27 in Dual Watch mode, the radio monitors the standby frequency for inches, while the remote transceiver weighs 12 ounces and measures transmissions while simultaneously monitoring the active frequency, 7.34 by 2.38 by 1.51 inches. allowing you to listen to both frequencies. This allows you to listen to The idea of the SV-COM is to simplify frequency tuning by synch- ATIS on standby, for example, while keeping tower tuned to the active ing with airport and navaid data, based on the SkyView’s current GPS frequency. I wish the function would enable the standby frequency position. For this reason you’ll need the SkyView optional navigation to be heard at a lower volume than the active, but you can’t adjust mapping software/aviation database, plus a GPS input, of course. the volume for each frequency independently. To help you determine Should the SkyView system fail, the com radio will still function using whether the radio is receiving on the active or standby frequency, manual frequency tuning. The SV-COM normally powers on and off with both the control panel and SkyView’s top com bar visually indicate the SkyView system, but pressing and holding the volume knob/power which frequency is being received. button manually turns the radio off and on. The smart logic doesn’t end when you manually tune a frequency. You can send an individual frequency from the SkyView’s airport When you do, SkyView will search for the closest known airport within information page, and from the system’s Nearest function. Once the 75 miles that has that frequency and automatically show that airport’s data is transferred, use the TWR, ATIS, GND, and ATC buttons on the identifier in the associated airport and station type fields on both the SV-COM control panel to send the associated airport frequencies to the control panel and top bar of the SkyView screen. For example, if you standby frequency location. manually tune 119.600 near Hartford’s Brainard Field, the associated Repeated presses of these buttons will cycle through all available airport will be shown as KHFD and the station type as TWR1. frequencies of that type, should the airport have multiple tower fre- You can also access frequencies alphanumerically. Press the APT but- quencies, for example. The system can support an external frequency ton twice and then use the concentric knob to type an airport identifier, flip-flop frequency transfer switch, for yoke or control stick mounting. and the system will access frequencies at fields within 75 miles of your Worth noting is the transfer feature can work with a variety of third- location. When the desired airport is displayed, press the dual concen- party com radios equipped with a serial database, including Garmin SL tric knob on the control panel to load the airport to the control panel. and GTR series, Icom A220, Trig TY91, and the MGL V6/V10. The SV-COM-C25, which has 25-kHz frequency spacing, is $1,295, and In addition to onscreen frequencies displayed at the top of the a version with 8.33-kHz frequency spacing is available for $2,195. SkyView display, the SV-COM’s dedicated control panel has a rotary —L.A.

The SV-Com uses a dedicated control head, but also overlays com data on the SkyView. The remote transceiver is small enough for mounting in tight spaces.

36 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes ounces, and requires roughly four inches of depth behind the panel, including its connector. A remote version—the V6R—is available for interface with the iEFIS, Odyssey/Voyager or the R2 control head. The radio accommodates two auxiliary inputs for aural alerts, plus a stereo music input, and has a four-place voice activated intercom. MGL’s proprietary VOGAD (voice- operated gain-adjusting device) automatically adjusts the microphone gain as you speak, reducing background and engine noise in the carrier. There’s also a stuck microphone alert and a PC interface for loading frequencies. The radio has two rotary knobs for volume and frequency tuning (which The MGL V6 is a space-saver, has smart user features, and automatically adjusts mic gain for tunes in large steps when turned quickly, cleaner transmit modulation. or in 25-kHz steps when tuned slowly). The V6 is compatible with the company’s The radio has a utilitarian feel and look, Consider the Wiring iEFIS system and Dynon’s SkyView for with a bright orange LED display with As you can see, the market scan reveals frequency transfer. large characters. a variety of model choices, many of The larger $1,050 V10 fits in a1 3 /8- The COM 2000 has an 8-watt which have advanced interface poten- inch instrument cutout and uses the transmitter, 15-frequency storage with tial that will require additional wiring. same VOGAD technology as the V6. user-defined alphanumeric channel iden- If I had to pick, I would favor Garmin’s But unlike the V6, the V10 doesn’t have tifiers, plus an RS-232 serial port for com- GTR200 for stand-alone com, GNC rotary knobs. Instead, pushbuttons adjust municating with EFIS displays. The radio 255 for a full-up VHF navcom, and the frequency, while volume and squelch is plug compatible with the Garmin-AT Trig’s TY91 for its price, space–saving is adjusted with dedicated bezel keys, as SL40 radio, and VAL says it meets or footprint and compatibility with PS is the frequency transfer and menu func- exceeds TSO standards. VAL also makes Engineering’s PAR200A audio system. tions. If I had the choice, I might select the the accompanying NAV 2000 VHF nav As I advised in the audio panel V6 with its intuitive and more traditional receiver, equipped with localizer and roundup, radio performance will only knobs over pushbuttons on the V10. glideslope receiver, plus RS-232 databus be as good as the interface wiring. This Both radios are available with custom for EFIS interface. It will also play on the means careful routing of the coaxial wiring harnesses, including an RS-232 VAL INS 429 electronic CDI. cable from the radio to the antenna, harness for interfacing with EFIS systems. Speaking of EFIS, the COM 2KR while also using a quality antenna See www.MGLavionics.com for more. and NAV 2KR are remote-mounted installed with the proper doubler plate com and nav transceivers that have for strength. For fabric aircraft, consider VAL Avionics limited compatibility with Dynon’s the size and quality of the ground plane If you’re trying to save space in the radio SkyView and Garmin’s G3X, and and its effect on performance. stack, the $1,125 Val Avionics COM full capability with the Advanced Last, consider antenna placement. 2000 is worth a look. At 3.25 pounds, AF-5000 series and Grand Rapids While bottom-mounted antennas it stands barely an inch tall, but requires Horizon HXr system. For more, visit might offer better performance in nine inches of depth behind the panel. www.valavionics.com. flight, they may not offer the best range while on the ground, especially when the aircraft is tucked between hangars and buildings. For a nav/com, a separate navigation antenna is required, and could require signal splitters for receiving glideslope and VOR from the same antenna. Carefully consider and accomplish The VAL Avionics Com 2000 is plug- this antenna work first, while the fuse- compatible with Garmin’s old SL40 com. lage is open and accessible. J

KITPLANES May 2016 37 Firewall Layout The chess game. By Paul Dye

38 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes When it comes to doing the firewall forward installation on a homebuilt these days, there are two kinds of builders—those who are going to follow a set of plans and those who have to go it alone. Some kits and plans are very specific and supply everything you need to create a finished, flying airplane. The first category of builders fit into this niche. And frankly, if your goal is to have an airplane to fly as quickly and pain- lessly as possible, this is the way to go. The second category of builder—the ones who are going to have to make decisions about where lots of stuff has to go in limited space—might be there If you have to design your own firewall layout, plan an early fitting for the engine to get an idea where the challenges might lie. It’s a chance to introduce your airframe to its for a couple of reasons. Some kits and new engine! plans leave much to the imagination (and believe me, I have seen some pretty from putting another thing there. And Mounting items on the firewall is far wild imaginations). Then there are the just like chess, you have to look ahead from a trivial exercise of figuring out builders who have very specific ideas of at moves and countermoves by your what fits, primarily because once you how they want to equip their new air- “opponent.” The difference, of course, put something somewhere, you have plane, and these ideas are different than is that in chess, you have an opponent drilled holes that can’t be “undrilled” those of the kit or plans designer. There who is actively trying to defeat your very easily. It is important, therefore, is nothing at all wrong with going plans. Hopefully, that’s not true in your to have a very good plan before doing off in your own direction; it is what airplane build! In the case of building, anything rash—like breaking out the homebuilding is all about. But if you the enemy is simply a piece of space, and tools. I personally like to start with a are going to go this route (by desire or certain underlying problems such as list of everything I can think of that will necessity), I suggest that you bone up on where the structure is located to support be mounted on the firewall and every- your chess playing. heavy elements, what can (or cannot) be thing that will penetrate the firewall. Why chess? Because laying out a located next to what from a thermal per- While at first, you might think these firewall is all about looking ahead. If you spective, and how tightly you can bend lists are identical, that’s not exactly put one thing here, then it prevents you wires, plumbing, and controls. true. Controls, wires, fuel lines, heater

In this trial fitting of an IO-320 to the RV-3, the author discovered interference problems The trial fitting showed that the prop with the oil filter and the engine mount that required a longer spacer. It also became control cable bracket was going to need clear that there was little clearance between the P-MAGs and the firewall. a redesign, since it hit the edge of the firewall recess.

Photos: Paul Dye KITPLANES May 2016 39 Use tape to identify spots for various items and penetrations so that When deciding where to place control cables, remember that once the engine is removed, you can remember what you decided. eyeball fittings require space for fasteners as well. boxes—they all penetrate. Other items, so firewall space is limited. The engine 4. Starter relay (the master is on the such as sensor manifolds, shunts, and oil mount is short, so the engine is very airframe side, back by the rear- coolers, might just use the firewall as a close to the firewall, making the loca- mounted battery) convenient structure on which to live. tion of large items problematic. In fact, 5. Battery cable penetration So listing everything that will live on, or the propeller governor has to extend 6. Sensor and control wiring go through, that stainless sheet is a good behind the plane of the firewall, neces- 7. Sensors for oil, fuel, and manifold place to start. sitating a recess in that location. The pressure recess in itself removes “acreage” that 8. Ammeter shunt Priorities might be used for something else, and Now there are additional items that Next comes prioritization—what do makes it even more important to do we’d like to have if we can fit them on: you really need, and what would you some careful prioritization. 1. Heater box (it gets cold at altitude like to have. Sometimes you are going to Given the up-front choice of a con- in the winter) have to make decisions that trade items stant-speed prop, here’s what we need to 2. Inverted oil system (we want this off the list. These are things that you have to make the airplane flyable: airplane to be capable of zero- really want to have on the airplane, but 1. Engine controls (throttle, prop, G aerobatics) might have to give way to things that are mixture) Note the two lists: one required, one essential. Let’s use my RV-3 project as an 2. Fuel line penetration desired. It is important to organize your example. The RV-3 is a small airplane, 3. Brake line penetrations thoughts this way, and get started with the

Sometimes you have to get creative with control cable routings—as with the prop governor control on this RV-3. So long as you maintain minimum bend radius, Throttle and mixture controls need to be checked through their entire range of travel cables can go almost anywhere. before finalizing brackets.

40 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes Cables for CHT and EGT sensors take lots of space that might not be obvious early in the layout process. required list. But—and here is where the chess analogy comes in—you don’t want to forget about your desired list when laying out elements from the required list. In fact, you need to assume that you are going to be able to fit all of the desired items on until you just can’t figure out how to do one (or more) of them. Otherwise, you might get a little careless in allocating space and take up more room than you really need for the required items. Think in terms of preserving large acreage as much as you can. Crowd things together (within reason—think maintenance!) to avoid being wasteful of the one important commodity—firewall space. Let me remind you at this point that we have not actually used any firewall space. This is, so far, a thought exercise. Like staring across the board at your chess opponent, you aren’t actually making any moves. You are imag- ining them one at a time to see if there are any flaws in your plan: If the prop cable comes through here, then the throttle can go through there. But if I put the throttle there, then I will not be able to route the fuel line through that same spot because it can’t be bent that much—and anyway, it will be too close to the exhaust pipe. You get the idea; those are the kind of exercises you have to go through as you develop the layout. Think Three-Dimensionally Probably the biggest mistake that you can make when laying out firewall

KITPLANES May 2016 41 components is to think in only two dimensions. Don’t forget (as in my example above) to think about where things go (and come from) after they leave the firewall itself. There are specific minimum bend radii for hoses and control cables, and you also need to think about where things can be secured. Get- ting fuel and oil lines too close to a hot exhaust doesn’t even sound good—and it is indeed bad for reasons of vapor lock (much less safety). Not only is it easy to forget clearances between specific items floating in front of the firewall, there are things that you probably haven’t even thought about—the exhaust pipe hang- ers, for instance—and what about the fuel One major challenge when choosing mounting locations is to allow room for future pump overflow line? These things need to maintenance. This solenoid is just barely reachable with the engine in place. exist, and when you lay out your firewall components, they can have an impact. three dimensions, and then figure out is going to go. “Check,” as they say in One final thing that you want to how you are going to install the nut- chess. At some point, you have to find consider before picking up the tools is plates and other fasteners. Uh oh, this a move you can actually make—and whether or not you actually have the is beginning to make my head hurt! that might open up the playing field a room to use the tools! It is (again) easy And we haven’t quite yet gotten to the little to make the next move easier to to come up with a layout that is close to desired list, have we? see. By carefully picking away at the impossible to execute—planning for a Firewall layout gets complicated things where you have no choice, or bolt hole where you can’t get a drill for because we have so many things that where the choices are obvious, you take instance—at least not without remov- could get in the way four or five steps away unknowns, and leave the remaining the engine or the engine mount. down the line. There are “chicken and ing field of options smaller. And in this So now we have yet another layer of egg” problems as well. You need to plan case, that’s a good thing. the chess game to consider: the ability that a hose is going to be somewhere, Only once you have nailed down the to actually build what we plan. Figure but you can’t know for sure where it will must haves can you turn your attention out where things fit on the firewall, be until you have the hose. But you can’t to the items you’d like to have. Now, figure out the clearances needed in build the hose until you know where it do you really want to trade the cabin heat valve for inverted oil? Hmm… how much do I want to travel with the airplane versus use it exclusively for aerobatics in the local area—on warm days? Are there other options for either (heated seats for instance, or what some folks call a “half-inverted” system— something good for ten seconds or so of inverted flight)? Maybe re-evaluating your initial requirements, or looking at alternatives to solving them (a heated snowmobile suit?), can shed a different light on the topic. It never hurts to look because you still haven’t drilled any holes…right? (Put down that drill!) Making Your Move In chess, you hold all of the possible moves and countermoves in your head Modern sensors are much smaller than they used to be, allowing for tighter mounting. until it is time to touch a piece and put A sensor manifold like this one keeps them all in one place. it where you want it. Fortunately, we

42 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes Don’t forget room for heater hoses! This picture also shows how an inverted oil tank can be attached to the engine mount instead of taking up space on the firewall itself. ...and leave your engine don’t have to salute that same rule in monitoring to EIS. the workshop. Making sketches (I sug- Trusted with everything from 2-strokes gest pencil and an eraser, rather than to turbines for over two decades. ink) and putting bits of tape on the firewall where you think things should go are a couple of techniques you might consider so that you don’t lose track of FLY IT your brilliant solutions. The tape idea like you stole it... can be taken even further by using cut- outs of the devices that are going to occupy the space (just as many do when www.grtavionics.com • (616) 245-7700 laying out their instrument panel). Bet Proud sponsor of Tiger Airshows and airplane “thief” extraordinaire, Hotwire Harry! you never thought that playing with paper dolls would be a useful adult pastime, did you? While I haven’t really suggested any particular design solutions in this Print and Digital article (I didn’t intend to), I hope that I have at least illuminated the process required to come up with a solution, and suggested questions that you need to ask in order to come up with a winning game plan. Laying out a firewall is fun if you like to solve puzzles, but don’t let it stump you into inactiv- ity and a failure to finish. Know what you really need versus what you want, take the time to examine lots of different options, and don’t commit to any course of action until you have seen it all the way through to the end. Unlike chess, you are not playing against an opponent—and it would be silly to Either Format – Great Savings! checkmate yourself. J Subscribe Now at www.kitplanes.com/subscribe

KITPLANES May 2016 43 Expectations You don’t know what you don’t know. By Dave Holmgren

I’m not sure quite how to start. It’s not when I jumped off a roof on a really Next was drug interdiction aviating really a “there I was” story, but it does windy day with a sheet tied to my ankles for U.S. Customs, follewed by a trans- have elements of that. Maybe it’s more and hands. That didn’t work too well (I fer to the Air Guard, where I flew the of a guardian angel tale. Maybe a close was young). Then in June 1972, Popu- C-26B, EC-130E, and then a “light call and how did it happen? Let’s go with lar Mechanics ran a big story on hippies twin” for a provisional special ops that. While racing Formula 1 aircraft in in California building and flying hang squadron out of Hurlburt Field. Along the AirRace 1 series in Tunisia, I had gliders; I had to be about the only kid in the way, I flew some contract post main- a really, really scary thing happen. I’m Jersey dumb enough to try it. That didn’t tenance test work and a couple of con- tickled to be able to talk about it. The work too well, either (I was young). tract fighters—ended up with over 120 info about this is obviously all over the I did a lot better with airplanes—got combat flying missions and some really Formula 1 community. They’ve asked me my private at 18, went to Florida Tech, good friends and memories. I’m retired to spread the word, and the incident has earned more ratings, taught flying, and and fly for a major airline now. And already led to one racer finding a flight flew jumpers on weekends till graduation. along the way, I met and married the control deficiency that might otherwise I joined the Marines, got to be in one of most patient woman in the world. have been missed. Maybe someone else the last flight school classes to fly the Light aircraft flying has always been will get something from this, too. T-28B, then jets in the T-2C and TA-4J. a passion. I fly hang gliders, paragliders, I’ll back up. I’ve been fortunate After carrier quals and earning my wings, kitesurf, and skydive, but Experimental enough to be able to fly for a living pretty I flew the mighty OV-10A/D Bronco aviation? That really gets my motor run- much my entire life. My flying started until I left Marine Corps active duty. ning. I’ve owned a VariEze with a friend,

44 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes Last Lap Player in the pit hangar at Reno. Catching small problems here can prevent big problems from happening during a race (left). Chemtrails—isn’t that a secret? The placard is just for fun, but the reminder at the top of the panel is good for all pilots (right). and now have my Thorp T-18 and an But these are Experimental aircraft. An aside here: Racing is awesome, Ultimate 10-200 single seat bipe. But Proven design or not (and the Cassutt air racing even more so. I’ve seen it sug- I’m not (yet) a builder. is a very well proven design that’s super gested that every pilot ought to try air Well, that’s enough about me; let’s strong), they are home built—but not racing. I disagree. Air racing is very talk more about airplanes. A friend by me, so I just didn’t know everything demanding mentally, some risk toler- asked me if I wanted to race his Cassutt I really could have/should have known ance is required, and you really have to at the Reno Air Races. It’s pretty flat- about it. be able to do your own risk analysis every tering stuff to reach that point in your Hey, Paul Dye flewLast Lap Player day, every minute, every second you fly. career where people ask you things like last year and wrote about it. It’s been Your health and future are in your own that. How do you answer? You say, yes! flying for quite a while. But hidden in hands—and no one else’s—the whole And that is where the (almost) accident there, behind the seatback and under time. Thereis a wealth of knowledge chain began. the floorboard, something that just available to help answer questions; a I’ve always been spring loaded to that didn’t get looked at was a ticking time pylon racing seminar is offered (and answer, and may just still have a bit too bomb! Of course I know that the PIC is required for rookie racers) every June much of an invulnerability/invincibility the one responsible for determining if a at Stead Field to acquaint pilots new thing going on for my own good. You plane is safe to fly, but just how much is to racing with what is asked of you as want me to fly your airplane? Great! a PIC expected to know about his air- a racer and pilot. But—you’re the one Let’s go! To jump ahead again, my cur- plane? If the answer is an unequivocal with your butt in the seat, and it requires rent answer might be more like: Great! everything, then I might just be guilty of a lot of attention to detail and an ana- Let’s go take a good look at it! missing something. lytical nature to be able to deal appro- But I digress. This was a great oppor- priately with every little thing that pops tunity. Cassutts are an absolute giggle Off to the Races up at 50 feet above the ground while to fly, extremely sensitive and respon- My rookie season at Reno was great, and you’re full throttle and trying for every sive. Astronaut and World Unlimited I was offered the opportunity to fly the little tenth of a knot while attempting Warbird champion race pilot Hoot same plane this year in the AirRace 1 to fly a smooth, predictable line. Then Gibson has ranked the Cassutt as one championship series. The airplane there are seven other racers around you of his two absolute favorite airplanes owner saw a benefit to his company and depending on you to do just that. You to fly. I knew the owner/rebuilder of generously allowed me to monopolize need to stay in the smooth air and be the airplane pretty well, and I know the his plane for another five months or so. able to deal with wake turbulence that quality of his work. It’s good. He’s told I bought a new (to me) race engine and can invert you in a second. Oh, and let’s me everything he’s done with it both got Craig Catto to build a super-duper not forget that your motor is spinning before and after a hangar fell on it. (You race prop. (I wanna go fast.) The pro- ungodly revs and making a lot of heat can read about that in KITPLANES®, moter paid to ship the planes over to in ways Continental never intended. If September 2014.) We’ve torn the plane Tunisia and back on a boat, I got time you happen to be ADD like me, you may down together and reassembled it. I’ve off from work, and the incredibly sup- find that nothing brings you “into the done everything you’d see and do in a portive wife and kids said, “Sure Dad, moment” in quite the same way. The rest normal condition inspection. do what you gotta do.” of the world just falls away. Zen much?

Photos: Dave Holmgren; Ground-to-air photos: Jane Jarvis KITPLANES May 2016 45 Reno race planes come in many sizes and levels of complexity, but they all require There is little margin for error when on great attention to detail during construction and maintenance. the course with other planes.

Anyway, be on your game if you want to oil delivered to the airport was almost a getting schooled by these two all week try this. OK, back to the story. complete show stopper. on the course in practice and heats. So, there I was, flailing to get the With the plane ready to go, it was time Yeah, I’m talking about you, Justin and plane together in Monastir. I was a racer for lots of practice laps. Several of us hot Phil…respect. without a team initially; I didn’t know dog racer dudes made multiple forma- But I’m a pretty quick study (at least I enough to ask for the help that was tion low altitude flights along the beau- think I am), and on this day, had a faster offered me by other racers. I thought tiful Tunisian beaches to wake up the airplane than they did—thanks again to they had enough to do getting their own town. By now I knew the airplane and Catto Propellers. My fangs were out, I planes ready. its handling quite well, and life was good! wanted to pass them so bad I could taste I finally got the pointy end and wings it. Fifty feet (maybe) above the deck, and tail and stuff all oriented properly. Race Day coming down the front stretch about Eventually, two awesome mechanics All was going great in Tunisia. I finally 220 mph and seconds from passing, I (they call them engineers in Europe) got the motor spun up nice and fast, and realized that what I had been telling took me under their wings and things was settling down on course. And then… myself was turbulence from other racers smoothed out considerably. I had a few Halfway through the Silver semifinal for—I don’t know, half a lap maybe— fuel delivery issues, and those got sorted on Sunday, I was closing on two planes was really something else. out, too. Note to self: Next time, bring with much more experienced race pilots My ailerons felt sloppy. What spares for everything! There is no general than I. They had better tactics, better should have been millimeters of stick aviation in Tunisia. Just getting aviation positioning during passes; I had been motion had become inches. When

Dave Holmgren and Last Lap Player at the Reno Air Races. (Photo: Jane Jarvis)

46 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes a racehorse start, so lighter is faster, and I weigh considerably more than minimum jockey weight.) Besides, how much good does a ’chute do for you at 50 feet above the ground, right? Wrong! That would have been a very good time to rudder the plane over the Mediter- ranean, jump, and give it back to the insurance company. With no ’chute, that option was off the table. There is no pitch, rudder, or aileron trim in a Cassutt—pretty much nothing that doesn’t add speed, so all I had at that point was a well-balanced air- This broken weld effectively disconnected the control stick from both the ailerons and the elevator, leaving nothing but rudder and throttle to control the aircraft. plane with a good rudder and a running engine. I considered ditching, clear that awareness finally sank in, my race I could feel it everywhere, and the stick water looking like a better place to go ended because things like that just moved aft from its normal position, than the deep mud of the salt ponds sur- don’t get better. So, I eased back on the about four inches toward my gut. That, rounding the airport on three sides. But stick (when you climb above 250 feet on in a Cassutt at that speed, usually yields either of these choices would likely end the course, that’s recognized as a May- about six G. But the nose did nothing at by giving both the plane and myself to day) and zoomed to about 1500 feet, all, just stayed there. the insurance companies. I didn’t like using very minimal control motions. I At that moment, I immediately those options much, especially since knew something was wrong but didn’t regretted my decision to save 20 pounds taking my hand off the stick to pop the know what. I turned downwind and of gross weight by leaving my para- canopy in preparation for ditching— then it got scary. The plane wentclunk. chute in Utah. (Formula 1 planes do and destroying normal airflow over the

KITPLANES May 2016 47 No homebuilder sets out to make a poor weld, but no one is perfect, as evidenced by the separated mixer assembly on Last Lap Player. This should be sobering to builders as well as non-builders who depend on other people’s work. Never assume that critical parts are good—inspect them closely for defects or corrosion. tail in the process—did not seem likely settled down toward the runway, I fig- able to respond a little—at least while to end well. Since the nose seemed to be ured I was still likely to crash. But with on the ground with no air loading. The pointing pretty much ahead instead of nothing to stop me in a hurry (no water, second clunk and resultant nose drop down, and the airplane turned OK with just concrete to slide on), I realized my were probably due to—despite my best rudder only—hey, it was flying, and I’m survival chances had just increased efforts to freeze the stick—a little more a pilot. So I decided to try to land it. exponentially. I think I started laugh- back pressure unconsciously applied Doing what I could to not point ing, wondering what the spectators and when I nursed the power back a little. toward congested areas in case of fur- crew thought of my display of landing This caused the broken piece to slip ther failure, I turned base. Going about prowess as the first touchdown (prob- farther along the torque tube. If I had 160 indicated, I allowed it to get pretty ably at 120 or 130) yielded a monster stayed down on the course even one low, probably 250 feet or so shortly prior bounce. I corrected with power, took more turn, 20 seconds longer…well, I’m to the turn to final, (normal touchdown another huge bounce, power, bounce, really glad I didn’t. speed is about 80 mph indicated for a power, until it finally slowed enough to The torque tube combining aileron wheel landing, and being a racer, it’s stay on the ground. and elevator inputs had never been pretty clean), while trying to absolutely Clearing the runway and taxiing in welded properly. A lot of metal, but no freeze the stick where it was so things to my waiting crew, the chief hand sig- full-depth weld, it was a time bomb might not get worse. naled, WTF, mate? I didn’t know, but hidden with metal and paint. Over the I started squeezing a little power off, was relieved to be safely down. 20-ish years since the control assembly thinking that overshooting the run- had first been built, it had deteriorated way might be bad, too. As I did that, Luckiest Day of My Life and became weaker each time the aile- it got worse. Another clunk and things My guardian angel was watching that rons were applied. I’ve been told that started happening fast. The dang stick day. My wife gently suggests I may want this has occurred before in the Cassutt, came right back to my crotch, and the to give the poor guy a few days off; it’s but I can’t tell you when or to whom. nose dropped. Not a lot, but such that been quite a year. Afterwards, my crew chief Roy took the I figured about 5–8 seconds ’til impact So what happened? You’ve probably assembly back to his home to work on it, into the salt ponds. My left hand moved already skipped ahead to the pics—I and was able to clean, NDI, and reweld the throttle forward a little, then a lot, would. That area behind the seat, below the assembly with a nice stout gusset. It and the airplane started accelerating— the floorboard, hid a bad weld. You can- ain’t failing there again. toward the water. not see that without removing both I had a German master welding It was probably only a second or two the seat and floor. The sloppiness I felt instructor and aircraft builder look over before the nose responded, but it seemed on my last lap on the course was me every weld on the entire fuselage in Spain a lot longer. Although the nose drop working the little remaining metal on prior to assembling the plane there. It was subtle, the engine pitch change was the joint almost to the point of failure. worked great in Spain during the second quite obvious. The nose came back up, That failure came with the first clunk race of the series (no stress during that and I moderated the pitch with power— on downwind. Due to the weight of the test flight) and in Reno, allowing me to easy stuff now, then ruddered it around combining arm resting on the torque finish a respectable 6th place overall in to final. Yeah, I overshot; sue me. As it tube, the ailerons may have still been the three-continent series.

48 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes Here’s the thing: Even if I had seen Again, expectations. Reasonable, but in something was wrong (remember my it, I would not have known what was this case, faulty. I don’t blame him or his saying problems don’t usually get better going on. Anyone who knows welding work at all. I’m so glad it failed where on their own?) and being able to respond would’ve spotted the problem imme- and when it did. Any of a zillion other properly, was key to the good outcome. I diately, but not me. As a flyer, not a places for it to go could have resulted in a could’ve recognized it a few seconds ear- builder, there are a lot of skills I have much worse outcome. lier, but a few seconds later? Wow, I do not not developed, builder vision (that’s like that thought. Expectations can kill, not a thing, but you know what I mean) What Did I Learn? or at least allow complacency to develop. chief among them. Plus, as mentioned First, I did some things right. I’ve always These are Experimental homebuilt air- earlier, my expectations were that the heard to fly the airplane as far into the craft. There’s a lot of good things that go airplane would be safe to fly, and that crash as possible. That’s good advice. with that—you know that as well as I— I would be the most dangerous com- I fully expected to die right then, but but don’t trust blindly that just because ponent I was likely to encounter. So, I with a little (OK, a lot of) luck and an an aircraft has been flying properly, it will didn’t look hard enough. unwillingness to stop trying, things continue to do so indefinitely. The aircraft owner told me later that worked out for me. Ditching might Go deeper than you might need to when he had rebuilt the plane after the have been a smarter option, but it’s dif- when inspecting, at least once in a while. hangar collapse, he went through it stem ficult to argue with success. Before you fly it might be a good time for to stern, fixing a lot of issues along the Here’s another thing: I’m not going to that. An extra set of educated (builder) way, but allowed time pressures, and go all holy roller on you, but I do pray, eyes looking at things never hurts either. likely, expectations to shortcut things and my prayer before each race has been Take advantage of your local EAA bros. before he got to taking the floorboard to ask God to watch over all the rac- Take a welding class at community col- and seat back off to inspect the control ers and to give me the wisdom to make lege. And lose weight if you need to, but assembly. He said he thought that it was good decisions. I believe that prayer was dude, wear your ’chute! likely one of the last items built, and answered. Your mileage may vary. I’d love to fly your airplane, thanks that the builder would have polished his At the very least, being able to rec- for asking! Let’s go take a good look at it welding skills by the time he got there. ognize, when the pressure was on, that and tell me all about it, OK? J Kitplanes subscriber alert! several of our Kitplanes subscribers have received what appear to be “renewal notices” or “automatic renewal notices” from a company known as preMier subscriptiOn serVice, 5star subscriptiOns, rapiD MaGaZine cOllectiOn, MaGaZine billinG serVices, publisHer’s billinG serVices, circulatiOn billinG center or other similar names. Addresses for these firms include Dallas, tX; lincoln, ne; Omaha, ne; san luis Obispo, ca; salt lake city, ut; White city, Or and prescott, Fl. These firms have nOt been authorized by us to sell subscriptions or renewals for Kitplanes and we cannOt Guarantee that any order or payment sent to them will be forwarded to us. Kitplanes does nOt offer a subscription term of more than 2 years, nor do we retain your bank account information. if you see an offer for 3 or more years or if you receive a notice that references your subscription anD your banking information, it is nOt an authorized offer. We urge you to report these notices to us, as well as to your state’s attorney General and better business bureau. any offer you receive that does not bear our company logo or corporate/customer service address or 800 numbers should not be considered approved by us. the only autHOriZeD inFOrMatiOn for Kitplanes is: toll free via telephone 1-800-622-1065, Dial america renewal telemarketing, or www.kitplanes.com/cs Our texas customer service center: 1-800-622-1065, pO box 8535, big sandy tX 75755 Or our corporate offices at: belvoir Media Group, llc. aviation publishing Group 535 connecticut ave norwalk ct 06854 should you have any questions at all about mail that you receive, please contact us at our web site: www.kitplanes.com/cs or call us toll free to speak to customer service.

KITPLANES May 2016 49 ENGINE THEORY

Last month we addressed motor oil as used in aviation engines; this month Lubrication: we’ll detail the mechanical systems that store, pump, filter and cool the oil. Wet Sumps: Oil System The Motor Oil Swimming Pool Most common Continental and Lycoming aviation engine oiling systems are simple wet sump designs very similar to your car’s engine. A reservoir of oil puddles Design in the sump (oil pan or intake in Lycom- ing-speak) located at the bottom of the engine. A gear-driven oil pump sucks oil from the sump through a tube or cast-in passages known as the oil pump pickup. A suction screen in this tubing protects the oil pump from ingesting boulders fallen into the oil sump, namely chipped gears, excess casting flash, wear metal, or hardware lost into the sump by the mechanic during cylinder changes or whatever. The oil pump uses a single pair of toothed gears to suck the oil from the sump and push it through the oil filter, oil cooler, engine, and to supply the prop governor if so equipped. The oil pump is driven from the engine’s accessory section gear train, which is, of course, driven by the crankshaft. In the engine, two main oil passages—galleys—run the length of the engine and serve as oil freeways. Side passages from the main galleys feed oil to the crankshaft main bearings, the camshaft bearings, and via the hollow rocker arm pushrod tubes, out to the cylinder heads to the rocker arm bushings. Oil squirting out of the rocker arm bushings “splash” cools and lubricates the valve springs and valve stems. The rod bearings are oiled from the main bearings via passages drilled into

Lycoming engines use an aluminum oil Exploring the components drain-back tube under each cylinder to return oil from the valve springs and rockers to the sump. Rubber hose joins the inboard that keep your engine alive. end of the lines to nipples on the crankcase; By Tom Wilson those hoses are a typical leak/weep point.

50 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes the crankshaft; excess oil at the main bearings therefore travels to the rod bearings. As the oil squeezes out the ends of the rod bearings, it is flung everywhere inside of the crankcase and onto the cylinder walls. This splash oil provides the lube between the highly loaded camshaft lobes and valve lifters (tappets) and lubes the piston-to-cylinder interface, along with the piston pin- to-piston pin boss assembly. In higher performance engines, extra piston cooling is provided by special passages in the case squirting oil directly onto the bottom of the pistons. Oil extruding from the back of the Mocking up the sump and accessory cover All 360 Lycomings, including this front- rear camshaft and main bearings, along of an O-320 Lycoming serves as an excellent facing fuel servo application, dispense with some pressure oiling from the illustration of the typical wet-sump aviation with the 320’s separate oil pump pickup main oil galleys to the magneto drives, oiling system. The oil pump is the silver unit pipe and use cast-in passages instead. It provides the splash lubrication in the with safety-wired nuts in the center of the means fewer parts and more room in the accessory section to lube the gear train upright accessory section; the oil pump crankcase for other things—such as a pick-up tube is below the pump and drops longer stroke crankshaft. that powers the magnetos, vacuum into the oil sump. The four large tubes in pump, and so on. At the other end of the the sump are intake manifold runners. engine, oil is also sent to the propeller governor, which is itself part high-pres- (Lycoming) or the pushrod tubes (Conti- mist whipping around inside the engine. sure oil pump and part speed governor. nental) provide both the return oil path This windage produces drag on the rotat- The oil pump in the governor jacks the to the sump and the necessary internal ing crankshaft and connecting rods. The oil pressure into the 300 psi range, then engine breathing (movement of the air/oil piston and piston pin are direct witnesses routes the oil through the front section mist found everywhere inside the engine). to combustion heat, but their only heat of the crankshaft to the propeller where There are some take-away concepts rejection path is through the oil. That it powers a piston that controls propel- associated with the basic oil system. In junk that ends up in the oil gets spread ler pitch. If a fixed-pitch prop is used, the no particular order: Relatively little of the all through the engine unless filtered out. prop governor is deleted and a plug seals oil is found at the working points (bear- The connecting rod bearings are oiled the end of the crankshaft. ings, bushings, piston rings) at any given downstream of the main bearings; if oil Oil returns to the sump via grav- moment; most of the oil is found “resting” volume drops, the rod bearings will be ity. Dedicated oil drain-back tubes in the oil sump. There’s voluminous oil the first to know. A standard wet sump only works when upright or in positive-G flight; rolling the airplane upside down for sustained periods or going straight up or down means the oil pump cannot reach a supply of oil to pump. Dry Sumps A more sophisticated (expensive, heavy, complex) oiling system is the dry sump. Dry sump systems employ multiple— at least two—oil pumps. One of these pumps is similar to a wet sump pump in that it supplies oil under pressure to the consumers inside the engine. The other oil pump(s) are scavenge pumps; they Suction screens on O-320 Lycomings are vertically mounted at the end of the oil pump suck oil from the sump (and wherever pickup tube and are accessed from the bottom of the sump. On the O-360 shown here, the suction screen is horizontally mounted and lives behind a plug at the rear of the oil else oil might puddle, such as from the sump. The larger hole, just above the screen on the sump mounting flange, is the oil valve covers or accessory section). These pickup passage where it communicates with the accessory housing. scavenge pumps are running all the

Photos: Tom Wilson KITPLANES May 2016 51 time, and instead of letting the oil gather in a sump, the oil is scavenged immediately to an oil tank outside of the engine. The pressure oil pump is fed from the oil tank and oils the engine exactly as the oil pump does in a wet sump engine. Dry sumping offers powerful advantages. For starters, much more oil can be carried in the oil tank without creating excessive windage. This means fewer hot trips through the engine for any given drop of oil, so the oil inherently runs cooler and does not get as dirty as fast. Given a flop tube inside the oil tank, the oil supply pump always has a ready Two gears in a housing are the essence of the typical wet-sump aviation oil pump. Gear oil supply no matter the aircraft’s orien- rotation sucks the oil from the sump on one side of the gears and pushes the oil through tation to gravity, although in practice the engine on the other side. Scoring from debris wears the gears and the housing, cost- most engines still oil best upright. Also ing oil pressure and flow as the clearances open up. This current style gearset uses one important, the scavenge pumps suck the nitrited gear (“N” visible on one tooth) and one carburized impeller (“C” too faint to see here). Gear materials or finishes are purposely mismatched to reduce wear between them. windage from the crankcase, thus releas- ing power otherwise wasted on rotat- WW-II V-12s. Furthermore, our low- sump because the liquid oil is now pud- ing the crankshaft assembly through a rpm engines don’t waste too much power dling at the “top” of the crankcase. Even thick oil mist. Piston ring sealing is also on windage losses, so the efficiency gain better (worse?), oil pours out the breather. more positive due to the negative crank- to dry sumping is limited on a run-of-the For Lycomings, the popular Christen case pressure. The oil sump or pan can mill general aviation engine. system was the result. An add-on sys- be smaller because it need not hold an tem external to the host engine, it pro- appreciable volume of oil. This makes Inverted Oiling vides an additional oil drain back from the engine a little slimmer and can facili- With the postwar popularity of aerobat- somewhere on the top of the engine tate a smaller airframe frontal area. ics, an add-on inverted oil system was (typically the stock breather location Dry sumping has traditionally been needed to help conventional wet sump atop the accessory case), plus a two-way too expensive for Lycomings and mod- engines when turned upside down. valve using a pair of heavy ball bearings ern Continentals. Rotaxes use it as a When that happens, oil flow and pressure free to slide in a tubular passage, along matter of course, as do helicopter Lyc’s is lost immediately because the oil pump with an oil separator tank that also con- and Continentals, plus radials, and the pickup draws only windage from the tains a gravity-driven ball valve. As the

Oil pressure regulators are all simple spring-and-ball valves that open at a set Angle-valve and parallel-valve Lycomings with turbochargers come stock with piston oil pressure. Early regulators lived under squirter valves for increased piston cooling. The squirters thread into a crankshaft the closed end cap at left and were disas- bulkhead so their spray hits the piston underside near mid-stroke. They definitely work; sembled for adjustment. For years, the engines retrofitted with them need a larger oil cooler to maintain the same oil tempera- externally adjustable style with the castel- tures. A tiny ball-and-spring valve inside the squirter nozzle closes oil flow at low oil lated nut has been stock. It’s much more pressure to avoid excessively lowering oil pressure at idle. Continentals use a small pipe convenient to adjust. with no valve for the same job.

52 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes Rotax engines are dry-sumped and Compare the filtering area of the pleated paper element inside the oil filter at right therefore store their oil in a vertically to the simple oil screen at left—it’s not even close! The old school screen lives in the mounted round tank separate from the canister-like casting at left in the background. engine. Oil enters the tank on a line tangent to the outer wall. This swirls the supplied during sustained inverted or are a huge oiling improvement to some oil to deaerate and cool it. negative-G maneuvers. Such systems hapless Lycoming tasked with powering airplane rolls inverted, the ball bearings really don’t do much in downward a Pitts through an outside loop. in the 2-way valve seal off the upright oil vertical or sustained sideways (knife pickup and open the inverted pickup, edge) flight. They also port a negligible Pumps, Filters and Things while the ball valve in the separator amount of oil into the separator tank With that overview of the three com- tank keeps liquid oil from running with each transition from upright to mon lubrication systems, let’s more out the breather. The oil pump is thus inverted flight. That said, such systems closely examine a few oiling subsystems

KITPLANES May 2016 53 Piston-powered helicopters mount their engines vertically, with Minimum oil temperature is controlled by the Vernatherm, the accessory case down. This requires dry sumping and a two- shown here with the oil filter adapter it is often threaded into. The stage (one scavenge, one pressure) oil pump. As this exploded Vernatherm expands with heat; at its set point it expands to close view illustrates, a dry-sump pump is typically two oil pumps in one off the passage bypassing the oil cooler, thus shuttling hot oil housing separated by a plate. through the cooler. and parts, starting with the oil pump. Oil Pressure Relief Valve: Because a host of aftermarket valves—fit a Considering they’re bathed in oil, you’d oil pressure varies with temperature, screw-adjustable mechanism to speed think these things would last forever, rpm, bearing wear, and modifications the process. but they merely live a long time. Eventu- to the oiling system (larger oil coolers Lycoming’s oil pressure recommenda- ally clearances open up where the gears or adding hose length and hose fittings tions are typically between 65 and 85 psi rub on the pump body, and the gears lowers oil pressure), there is a need to at cruise rpm, and at least 25 psi at hot themselves sometimes pit and wear so regulate oil pressure. Also, to provide a idle. Given the low engine rpm, this is much you’d swear they were processing safety margin and accommodate field higher pressure than your car because gravel. Pumping efficiency is reduced by modifications, oil pumps are typically in aviation, the crankshaft bearing areas the larger clearances, so expect to replace of much greater capacity than normal are vastly larger, so there is a need to flow the pump during a major overhaul. Also, operation demands. All this means is generous volumes of oil for cooling, plus back in the mid 1990s, there were Air- an oil pressure relief valve is provided. a necessity of overpowering G loads in worthiness Directives on Lycoming oil A simple spring-loaded ball-and-seat accelerated flight. pumps to replace sintered iron and alu- valve, the pressure relief valve opens Oil Thermostat:Oil temperature is minum gear sets; this is an excellent AD when pressure rises too high, venting regulated by a thermostat, most often to keep current on. some oil flow back to the crankcase. referred to as the Vernatherm after its Remember that while oil pressure is The oil pressure relief valve is adjust- manufacturer. Typically these are set to necessary, the volume of oil flow—typi- able. On earlier models this is via shim- close at 180–185°F, at which point oil cally a Niagara-like 7 to 12 gallons per ming the spring, changing to a different is directed to the oil cooler. Oil flow to minute—is even more critical. rate spring, or both. Later valves—and the cooler is controlled because cold oil Embedded Oil Ever seen video of a huckster who drains the oil out of a car engine, then He also reports a customer will occasionally put a new engine in an drives it around the block with no apparent damage? That’s because of aerobatic plane, fire it up, and immediately take off in a maximum- the superior mouse milk additive he’s hawking, or so he says. Hooey! The effort climb. Oops. This puts high load on the crankshaft thrust bearing truth is, the engine lives because oil has embedded itself into the pores (a plain bearing the crankshaft pulls against when the prop is making of the engine’s aluminum, iron, and bearings, so just enough lubrication thrust in a direct drive engine), and because the thrust bearing is splash remains to support the lightly loaded engine for a short period. lubricated and relies heavily on embedded oil during maximum load, We’ve personally tested this theory in flight by having our oil cooler the bearing can fail under these new conditions because oil hasn’t had burst and pump all 12 quarts overboard. We flew 10 minutes with a chance to soak in the bearing or crankshaft. Metal grit ensues, that falling oil pressure and two minutes with zero oil pressure with no dam- grit travels throughout the engine via the oil, damaging every interface age. Our engine shop (Ly-Con) confirms they’ve seen numerous similar it comes to, and many of the larger chips embed in the main and scenarios with no engine damage. Aerobatic pro Sean D. Tucker is a Ly- rod bearings, where they grind on the crankshaft. Before you know it, Con customer (they rebuild his Lycoming-based 540 every year—even you have a brand new, very worn out engine. The point is, give a new or though it’s just fine), and he once lost an oil line and flew about seven overhauled engine a little running time to soak oil into its pores before minutes back to the airport at reduced power with zero oil pressure, standing on the gas. And if you have an in-flight oil loss, reduce rpm/ also with no damage as confirmed by an engine teardown. power and get on the ground pronto, but don’t panic. At least not for But, as Ly-Con owner Ken Tunnell says, “Oh, they’ll run seven or eight the first seven minutes. minutes and not hurt anything—but they won’t run 15 minutes!” —T.W.

54 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes doesn’t lubricate well, and the oil cooler can be harmed or burst by the high oil pressures generated by cold oil. Oil cooling systems must be sized to accommodate the hottest expected temperatures, such as high-power settings in summertime. Naturally, this is too much cooling for low-power winter cruising, even with the Vernatherm open. Thus it may be necessary to blank some of the air flow to the oil cooler with a plate in winter. Filtration: For some reason oil filtration seems a great subject to start fights Never forget the oiling system is also a major part of the engine’s cooling. This two-cylinder over, but the basics are pretty simple. Hirth exemplifies this maxim via a disproportionately large oil cooler. It’s necessary The old oil screen system is lousy, catch- because the Hirth oil cools the upper cylinder head and has a gear reduction prop drive. ing only about 60% of junk 80 microns or larger. Common aviation spin-on oil We’ll also say some aftermarket oil valve (additional to the main oil bypass filters snag more like 35 micron debris, filters are advertised on their merit valve that sets overall system pressure). so a filter offers an immense oil-cleaning to filter down to single digit micron Cold oil is too viscous to pass through improvement over a screen. Some sources levels. This is great, but does reduce the oil filter, so the bypass opens until say nine times better filtering! Older oil flow volume while not address- the oil pressure drops; very fine filters engines not yet retrofitted with an oil fil- ing lead and sludge contamination, so mean this bypass valve would remain ter really ought to be. If you want more oil change intervals cannot rise with open considerably longer, defeating the convincing, oil change interval specifica- them. Also, not all oil is filtered all purpose of finer filtration. tions rise from 25 hours to 50 hours when the time because the oil filter mount is Next month we’ll examine engine moving from a screen to a filter. provided with a spring-loaded bypass cooling. J

Right-Angle Deburring Tool SHOP By Larry Larson TIPS

Most of us have a threaded drill kit. Mine has an assortment of common bits like #40, 1/8 inch, etc. It also has a mini chuck and an extension. All the components are threaded 1/4-28. Most of us also have a speed deburring tool with an extension. It’s also threaded 1/4-28. Hmm. I see a pattern here. Recently, I was deburring the longerons and really needed a right- To connect a right angle attachment to a speed angle deburring tool to save my back. Necessity is the mother of inven- deburring tool, you’ll need to use a die to cut ¼-28 threads at the end of the attachment’s shank. tion, they say. I just so happened to have a right-angle attachment, but it didn’t fit the mini chuck. One 1/4-28 die and a few minutes cutting threads on the right-angle attachment’s shank, and I had exactly what I needed. The right-angle attachment connects directly to the handle of the speed deburring tool. Put the deburring bit into the business end of the right-angle attachment where a threaded drill bit would normally go and deburr in comfort. The combinations here are endless. Use your imagination. Thread a deburring bit into the right-angle attachment, The threads only take up a little of the shank, so the right-angle attach- connect a speed deburring handle, and you now have a ment can still be put into a standard drill chuck for the usual needs. J right-angle deburring tool.

KITPLANES May 2016 55 BEST PRACTICES Choosing the right sealant. This is the beginning of a new series are not meant to stifle creativity; they examples of wonderful products that on best practices in Experimental air- are instead meant to help you avoid do some jobs well, but are not appro- craft construction. In other words, it trouble as you build the airplane of your priate for others. Sealants must take is a series about the right way to build dreams. Build your creativity on a foun- into account the parts to be sealed, the an aircraft by employing the best prod- dation of good experience and good medium being controlled, and the envi- ucts and techniques currently available engineering. That is what “best prac- ronment in which this takes place. Each to us. The goal is to enhance the safety tices” is all about. Create the aircraft of of these factors bears on the best choice and reliability of our aircraft by build- your dreams, but don’t let the use of ill- of sealant for a particular job. ing them to the best standards we can. suited products or techniques turn your Since mechanical failures in Experimen- dream into a nightmare. Sealants for Fuel and Oil Lines tal aircraft far exceed those of certified We begin with sealants. This is a broad There are a few important things to aircraft, we must admit that we have topic that ranges from fuel tank sealants remember when it comes to oil and fuel some room to improve. I hope that this to thread sealants to firewall sealants and line sealants in airplanes. Use an appro- series will be a step in that direction. more, so this article will also be rather priate sealant on any fittings with pipe Over the course of this series, there wide-ranging. Here we have some great threads. These are tapered threads that may be disagreement as to what con- go into things like engine cases and oil stitutes the best practice in some area, coolers. These threads will have desig- or a good product may get overlooked. nations like 1/8-NPT or ¼-NPT. The NPT If you think you have a better idea or a stands for National Pipe Thread. They will better product, I encourage you to let leak if a thread sealer is not used. Only me know about your concerns. The goal apply sealant to clean fittings that are free is to pass along good information to our of grease, oil, or other contaminants. readers, wherever it may come from. Do not use sealant on the flare end of In many cases there are also multiple AN fittings. These fittings do not seal at options that are equally acceptable. I will the threads, but rather at the flare. Simi- try to point those out as we go forward. larly, do not use sealant on Swagelok or Lastly, there are some things that you compression fittings. The threads do not just shouldn’t do and some products, do the sealing with these types of fittings even though they may be good for other either. Some fuel systems use these fit- things, that are not acceptable for the tings as do most pitot/static systems. task at hand. Red RTV is a good example. The fittings that allow oil lines to con- It is great for sealing leaks in baffles, nect to the oil cooler and the engine acces- but lousy for sealing pipe threads and sory case have pipe threads (NPT) where firewall penetrations. A single bead all around the threads of they go into the cooler or engine case. this fitting is sufficient to properly seal it. Not to be lost in all of this is the fact There is no need to use more. Note how Use a thread sealant on these fittings. The that we are talking about Experimen- the sealant has been kept away from the sealant should be specifically for use with tal aviation. These recommendations first two threads and the end. fuel and oil and it should be designed to

Dave Prizio is a Southern California native who has been plying the skies of the L.A. basin and beyond since 1973. Born into a family of builders, it was only natural that he would make his living as a contractor and spend his leisure time building airplanes. He has so far completed three—a GlaStar, a Glasair Sportsman, and a Texas Sport Cub—and he is helping a friend Dave Prizio build a fourth, an RV-8. When he isn’t building something, he likes to share his love of aviation with others by flying Young Eagles or volunteering as an EAA Technical Counselor. He is also a licensed A&P mechanic and a member of the EAA Homebuilt Aircraft Council.

56 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes ethanol resistant. It works at temperatures up to 400°F. A small tube makes it easy to apply and will seal more fittings than anyone will have in one airplane. A cure time of 24 hours makes it less than ideal for maintenance use where a quick return to service may be required. Both of these sealants are preferable to EZ Turn for high-pressure applications such Do not apply as brake line fittings. sealant to this Apply sealant to Permatex 59235 also works well for air- AN flare fitting. this pipe fitting. craft assembly. It is fuel, oil, and ethanol resistant, and works at temperatures up work in the temperature range of up to of Fuel Lube, is a good choice. It with- to 400°F. Parts can be repositioned for at least 300°F. Sealant should be applied stands temperatures up to 600°F, can up to 24 hours after initial installation to clean threads (male end only) in such handle motor oil and gasoline including due to its longer (72 hour) cure time. This a way that it covers the entire diameter of avgas, and it does not deteriorate in the makes it great for initial assembly, but the fitting, but does not come in contact presence of ethanol. EZ Turn has a proven not as good for maintenance where such with the end of the fitting or the first two track record in aviation use, is readily an extended return-to-service time may threads. There should be enough sealant available from aviation vendors such as be unacceptable. It too comes in a small on the fitting so that some of it is pushed Aircraft Spruce, and a small container will tube that makes it easy to apply and will out as the fitting is threaded in, but not so last you a lifetime. Its only negative is that seal more fittings than most airplane much that it flows all over the surround- it is very sticky and can be messy to work builders will ever encounter. ing area. As a rule, most people use too with. On the other hand, its stickiness can Please note that pipe dopes and much, but too much can be cleaned up, lend itself to some “off label” uses such thread sealants made for water pipes whereas too little won’t allow the fitting as temporarily sticking washers together, such as those available at your favorite to seal properly. The point that must be sticking a washer to a nut, or sticking a home store are not appropriate for avia- emphasized is that no sealant should get nut to the end of your finger as you reach tion use. They are designed for water inside the fitting or on it in a way that it into a tight spot. pipes, not fuel and oil lines. I must also could get inside. Sloppily-applied sealant Two other products worth consider- mention that RTV sealant is not a thread can get into fuel injectors, carburetors, or ing are Permatex 59235 and Loctite 567. sealant. It should not be used in fuel or small oil passages and do major damage Both of these products are readily avail- oil systems for sealing threads or any- including stopping the engine. able online, but may be hard to find at thing else. Safety dictates that you use Of the products currently available, EZ your local retailer. Loctite 567 is a great a product that is designed for the task at Turn, which is the functional equivalent sealant for use with fuel or oil, and it is hand, not just whatever is handy at the

EZ Turn is so sticky that it works well to temporarily stick a washer This is a good indication that just enough EZ Turn has been and nut to the end of your finger. This can come in handy when applied. A small amount of sealant has been pushed out of the trying to reach these items into tight spaces. This is definitely an fitting all the way around the threads. “off label” use, but one that can really come in handy.

Photos: Dave Prizio KITPLANES May 2016 57 Always check the “Use By” date before applying any sealant. Expired sealant should be FlameSafe FS 1900 sealant being applied properly discarded to avoid accidental use of expired product. to the joint between the firewall and mounting flange of a Glasair Sportsman. moment. Please use the right product for sensor or carburetor. But there are some Sealants for Engines your application. When in doubt, call the aviation vendors, Pacific Oil Cooler for In every case, the engine manufacturer’s product’s technical support help line. one, who routinely use Teflon tape, so it overhaul manual or other relevant ser- Before we leave the topic of thread obviously can be used appropriately. The vice literature should guide your deci- sealants, we need to talk about Teflon important thing is to never let the tape sion regarding the proper sealant to tape. My initial thought was to simply cover the end or the first two threads of be used for assembling and/or replac- say, “Don’t use it on, in, or near an air- a fitting. The bottom line is, you can use ing various engine components. For plane, ever.” The reason for that is that it Teflon tape, but there are better choices example, Lycoming has very specific rec- is so easy to misuse, leaving a tiny strip available to you, so save the tape for your ommendations for sealing engine crank- of tape in a place where it can clog a plumbing around the house and use case halves and the crankshaft oil seal fuel line or oil line or lodge in a fuel-flow something else on your airplane. (see sidebar). These recommendations Sealing a Lycoming Lycoming has specific recommendations for sealing engine crankcase halves and the crankshaft oil seal. These can be found in Lycoming Service Instruction 1125D and 1324C. Key points are covered below. However, you should refer to the actual Lycoming instructions for complete information.

Lycoming Crankcase Sealants— From Service Instruction 1125D POB No. 4 is the preferred sealant for Lycoming engine crankcase reassembly. It should only be applied to one half of the crankcase. Apply a thin film of POB sealant on the outside mating surfaces, as shown. No build-up is permissible. Visibly, where sealant is properly applied, it will produce a wet appearance on the machined surface. If it does not have a wet appearance, reapply. Note that this sealant is used primarily to hold the silk thread in place. Be certain to wipe clean all inner edges of any excess sealant. Also, ascertain that no sealant has come in contact with the bolt holes or any surface other than the shaded areas shown. RTV-102 or Loctite 515 may be used as the only approved alternates to POB No. 4. They too are to be applied to only one half of the crankcase. The application instructions are the same, except that no silk thread should be used. cleaned with acetone or MEK solvent. After it is cleaned, apply a layer of Lycoming Crankshaft Seal Sealants— Dow Corning 737 Neutral Cure Sealant prior to installing the seal. Pliobond From Service Instruction 1324C #20 may be used as an approved alternate. Dow Corning 737 requires 24 When installing or replacing the crankshaft seal on a Lycoming engine, hours to cure, but Pliobond cures in 15 minutes. the surface of the engine case where the seal will sit should be thoroughly —D.P.

58 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes should be heeded. Substitute products may or may not yield suitable results. Don’t even think about assembling an engine without the overhaul manual. When applying sealant to engine parts, especially any parts that will be inside the engine case or exposed to the inside of the case indirectly, it is vital to prevent excess sealant from intruding into the internal spaces of the engine. Excess sealant can clog oil passages and lead to engine failure. This has happened more often than you might think.

Sealants for Firewalls The firewall between the passenger compartment and the engine compartment has a vital function, namely to keep the heat and flames of an engine fire away from the occupants of the airplane for as The gap left in the firewall from the brake fluid line coming from the reservoir needs long as possible. The FAA says a firewall an application of 3M Fire Barrier 2000+. It will be difficult to get the caulking gun into position, but this hole needs to be sealed up. should contain a 2000°F fire for at least 15 minutes. That is why most firewalls are Recommended sealants include Flame- as these, including proper eye protec- made of stainless steel instead of much Safe FS 1900 and 3M Fire Barrier 2000+. tion, gloves, and good ventilation. Always lighter aluminum. To maintain the integ- These sealants are rated for prolonged consult the manufacturers’ literature rity of such a firewall, a sealant rated for exposure to fires. Aircraft Spruce carries for proper use and handling, including 2000° is also required. This means that the 3M product and Glasair Aviation spe- proper surface preparation. sealants such as Dow Corning #736 Red cifically recommends and sells Flame- Flamemaster CS 1900 was once RTV are not going to get the job done Safe. Be sure to clean surfaces thoroughly popular with many builders, but it has because they are rated at 600°F maxi- with MEK before applying these sealants. become hard to get, and honestly, it is mum and 500°F continuous. Red RTV has Needless to say, use proper precautions not rated for continuous exposure to its uses, but this is not one of them. for handling solvents and sealants such 2000°. On that basis I would not recom- mend it. However, I am not here to pick a fight with any kit manufacturer. Care- fully consider the recommendation of the maker of your kit and then make an informed decision after consulting the relevant information. For those of you building aircraft that you wish to register under the ELSA rules, you must use the products approved by the manufacturer and should get their permission before using any substitutes.

Baffle Sealants At last we find the proper use for Dow Corning #736 Red RTV. Sealing baffles in the engine compartment is a job made for red RTV silicone sealant. It is easy to apply and hardens fairly quickly. It sticks well to baffle material, engine baffle Here 3M Fire Barrier 2000 is being pumped into a piece of firesleeve that is used to make seals, and engine cases if the surfaces a fire-resistant firewall penetration for wires. Be careful not to pump too much material are clean. Use it to seal small gaps and into the sleeve and make a big mess. plug small holes in baffles and seals. A

KITPLANES May 2016 59 wetted finger will work nicely to smooth days prior to sealing if possible. Clean Glasair for more specific instruction on out freshly-applied sealant. It can be the surfaces to be sealed with acetone using SilPruf for installing windows. It messy though, so mask off areas to or MEK immediately prior to sealing, and has a long and excellent track record in remain clean and be careful. Use plenty use a non-lint-shedding cloth, not paper Glasair airplanes. As with any of these of paper towels to wipe up excess mate- towels. Use enough tank sealant so that products, the use of expired SilPruf is rial as you go. As with other sealants, be it squeezes out along the entire length strongly discouraged. sure all surfaces are clean before apply- and both sides of each rib, but try not ing. Red RTV has not held up well over to have large amounts of extra mate- General Remarks time as an adhesive to bond baffle seal rial that will only add to your cleanup. There are many fine sealant products material together, so it is not recom- Refer to Van’s instructions for applying on the market today. Some of them are mended for that use. fuel tank sealant if you are building an particularly well-suited for use by aircraft RV-type aircraft. They have a lot of expe- builders. However, a product that may be Fuel Tank Sealants rience with this material and should be fine for one job may be exactly wrong for PPG Pro-Seal PS 890 B2 is the standard regarded as the best source of informa- another. Take the time to do the research aircraft fuel tank sealant in use today. tion about its use. required to identify the right product for Van’s Aircraft recommends and sells By the way, fuel tank sealant is not suit- the job you are doing. a similar product (Van’s part number able for sealing firewalls—it’s flammable. Sealants have shelf lives that are lim- MC-236-B2) by Flamemaster. Both prod- Nor is it suitable for any other use in the ited. Never use a sealant that has gone ucts are two-part sealants specifically engine compartment. past its labelled shelf life or has been designed for the construction of wet- improperly stored. Failure is likely, and wing fuel tanks in aircraft. They do an Sealant and Adhesive it will be your fault. Discard any expired excellent job if properly applied, but for Windows sealant products immediately to avoid careful surface preparation is of para- Glasair Aviation recommends GE Sil- inadvertent use. Surface preparation mount importance. Good ventilation, Pruf SCS2000 sealant and adhesive for is vital for the successful application of eye protection, and gloves will make installing windows and windscreens in any sealant. Consult the manufacturer’s the application safer and cleaner. By the their aircraft. It is also useful as a gen- literature to see what cleaning solvents way, this stuff gets everywhere, so old eral-purpose sealant for places such work best with the product you are clothes should be worn. Surfaces must as the intersection of the fuselage and using. Generally, a volatile organic sol- be absolutely clean and unoxidized. gear legs. It remains flexible over time vent such as acetone or MEK will work Remove the protective coating from and comes in a number of colors, but well, but do not assume that these will Alclad aluminum no more than three it is generally not paintable. Consult be best in every case. Read the literature and see what is recommended. All of this material is available online to anyone who wants to look for it. If you are struggling to find the right product or its proper use, don’t be afraid to email or phone various sealant manufacturers. It has been my experience that they are usually more than happy to help steer you in the right direction. Eye protection, disposable gloves, and good ventilation are always a good idea when using any chemical such as these sealants. For safety’s sake print out the MSDS for each product you bring into your shop or hangar and put it into a notebook you can keep handy. Quickly read it over before you file it away to see what the exposure risks are and how to deal with them if they occur. You will probably never need to use it again after that, but if something hap- Dow Corning #736 Red RTV works well to seal small gaps in baffles. It can be messy to pens this information can be very valu- apply, so be prepared with some paper towels. This product is not recommended for able to a first responder who may come sealing threads or firewalls. to help you in case of an accident. J

60 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes

Home Shop Machinist Counterbores. Counterbores are used to recess screws or bolts below the surface of a workpiece. Counterbores might be considered a relative to countersinks [“Home Shop Machinist,” March 2015], but practically speaking, they are entirely different. Unlike countersink cutters, counterboring requires a dedicated tool for each size and screw head style. Why counterbore? Two reasons come to mind: First, to eliminate protuberances that might present a chafe risk (such as against hoses or wire bun- dles). And second, to save weight through the use of shorter bolts and screws. (Every little bit adds up, right?) A typical “standard” counterbore set for English thread hardware consists of seven cutters for screw thread sizes 6, 8, 10, ¼ inch, 5/16 inch, 3/8 inch and ½ inch. One critical distinction with this set is the cutters are marked to the correspond- ing screw size. In other words, select Counterbore sets (front left, and back) typically cover a basic range of sizes for standard socket head screws and bolts. Counterbores with interchangeable pilots (front, right) offer the ¼-inch counterbore for use with a the flexibility to create “custom” counterbores or to use the bits as guided reamers. ¼-inch socket head cap screw. Important note: The clearance drill for the counterbore pilot is 9/32, not ¼ inch. Refer to the accompanying chart for examples of the clearance drill requirements, bore depths, and diameters for common Eng- lish thread socket head cap screws. The depths indicated provide a flush-to-surface installation, which is purely optional or dependent on the application. Some- times the base material may not be thick enough for full flush, or there may be aesthetic reasons to have the screw head protrude above the surface or go deeper. Every home shop should have a basic Clearance drill requirements, bore depths, and diameters for common English thread set of counterbores. The set of seven socket head cap screws.

Bob Hadley is the R&D manager for a California-based consumer products company. He holds a Sport Pilot certificate and a Light-Sport Repairman certificate with inspection authorization Bob Hadley for his Jabiru J250-SP.

62 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes Cutaway view of typical counterbored Counterboring is simple: Drill the clearance hole (left), install the counterbore bit (center), holes. set the depth stop, and make chips (right). shown in the opening photo sells for around $50. Bits with interchangeable pilots cost more, but are not a necessity for day-to-day work, and can be pur- chased as needed when you need to make a “special” counterbore. A good example would be for counterboring a hex head bolt. The counterbore needs to be relatively large to allow space for a socket wrench (see photos). Another special application would be when you need a closer fit than the typical generous clearance hole provided by standard A typical flush counterbore socket head cap screw installation (left). The generous counterbores. An example would be to clearance hole (right). tap threads in a counterbored hole. Yet another application is to use a counterbore bit as a piloted reamer; it’s a quick and easy way to enlarge an existing hole. I recently had to change six ¼-inch holes to 3/8-inch holes on a propeller crush plate for my Jabiru. I could have used a twist drill, but a piloted counterbore is much easier. Using a ¼-inch pilot in a 3/8-inch counterbore, I was able to enlarge the holes to 3/8 inch with spot-on accuracy and in less time than it took to type this paragraph. To Making a counterbore with clearance for a socket requires an interchangeable pilot. do the same job with the same accuracy with a twist drill would have required that I first line up each hole using a ¼-inch dowel or drill bit, clamp it to the drill press table, change the bit to a 3/8- inch drill, and repeat the process for the other holes. A final note: Freshly machined counterbores have knife edges that must be deburred. Deburring the clearance hole might take some effort or a special tool to get at, but it should be deburred as well. For deburring tips see “Home Shop Reworking these ¼-inch holes to 3/8 inch on this Jabiru crush plate “freehand” using a Machinist,” June 2015. J counterbore with an interchangeable pilot.

Photos: Bob Hadley KITPLANES May 2016 63 CHECKPOINTS Back courses and billy goats. This month I thought I would share missed approach to Runway 4 would not As I briefed the approach, I set up my a couple of experiences, one from my be any fun, if even possible. instruments for the new back course, and short stint of airline flying and one from Just as soon as we finished brief- I dialed in the inbound course on my HSI. a personal trip, which continue to drive ing the ILS 4 approach, we were given We were descending on the downwind home the importance of understand- a descent and the usual hand-off to now and just about to turn base toward ing your aircraft’s systems and decision Albany Approach. Remember I said this the FAF. The captain tells me it is a back making. It was a dark and stormy night was a busy trip? It was about to get even course, and I need to turn my HSI around (just kidding!). It was a typical muggy day busier. We were just about to turn right 180 degrees. I politely tell him, “No, that in the Southeast with the usual pop-up on the high downwind to the ILS 4 when is what the REV switch on the autopilot thunderstorms. These storms can wreak the controller said, “We just had a big panel is for.” We are now beginning the havoc for a while, but soon dissipate. wind shift with a level 5 thunderstorm turn to base leg, and he is adamant that It’s always best to wait them out or go northeast of the airport. Expect the back I turn my HSI around. We go back and around them. I really hate being put in course 22 approach.” Yikes. I immedi- forth a bit, and in my head, I’m hearing a the position of racing them to a destina- ately turned left, continued the descent little voice telling me the accident record tion, but that’s exactly the scenario that and aircraft approach configuration, and will say the crew was confused. But I am we would find ourselves in on this trip. briefed for a back course approach. We not confused and am getting upset. Not are all proficient in a back course, right? good. I tell the captain we will go right Back Course at Albany And to top it off, the view out the win- through the localizer this way. I yield to It was a short leg from Atlanta, Georgia, to dow showed a really black wall in the command authority and now have my Albany, Georgia, a distance of about 130 direction we were headed. The race was hands solidly on the control yoke. nautical miles. In a jet, it is very short, less on to get to the FAF (final approach fix) Then it happens. We did fly right than 20 minutes. As a crew you are really before the thunderstorm. It was going to through the localizer and at the same busy from takeoff until touchdown, and I be close, but it did look promising. time, we hit a wall of water, turbulence, enjoy these legs more than others, as I’m not really fond of long hours in cruise. (I’ve never been one much for sitting around watching things. I admire the guys who fly the long hauls, but I know I probably wouldn’t be happy doing them.) This was my leg, and just as soon as we leveled off after a quick climb to 19,000 feet, it was time to brief the approach. The ATIS said to expect the ILS to Runway 4, so that was the approach we briefed, and I was happy to see they were using Runway 4. Why? For the entire trip, we were watching a very nasty thunderstorm on the radar that was east-northeast of the Albany Here is Homer on final approach after intercepting the back course from the DME arc. The airport and moving toward it. Certainly a high terrain to the right is the reason for the arc; the VOR sits on top of the big hill.

Vic is a Commercial Pilot and CFII with ASMEL/ASES ratings, an A&P, DAR, and EAA Technical Advisor and Flight Counselor. Passionately involved in aviation for over 39 years, he has built 10 award-winning aircraft and has logged over 8000 hours in 70 different kinds of aircraft. Vic Vic Syracuse had a career in technology as a senior-level executive and volunteers as a Young Eagle pilot and Angel Flight pilot. He also has his own sport aviation business called Base Leg Aviation.

64 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes Good to be on the ground in Homer. You can clearly see here why flight up a pass can be deadly. Lucky for us, icing conditions were high that day, allowing IFR flight out of danger at 10,000 feet.

experienced in a jet. We broke out a little lunch (the sun was now shining) and had a above minimums and landed in a wall of great time with the simulator as I brought water with a crosswind that was within 1 my PC with me. First, I set it up the way Look closely at the approach plate and knot of our allowed maximum. the captain had asked me to do on the you will see the transition from 3900 feet The captain was really cool. As we inbound flight, using a reverse inbound to sea level while executing the arc and were taxiing into the gate, he looked at course on the HSI. We both watched as it final approach. It’s almost a cross-country flight by itself. Be patient. And don’t forget me and said, “You have really great situ- faithfully duplicated the transition through to cancel IFR. One pilot forgot and other ational awareness.” I was thankful for the the localizer. I then reset the approach to pilots were left holding for almost an hour. compliment, but mentioned we should the inbound course on the HSI and armed go to lunch and discuss it, since it was our the REV switch on the autopilot panel. and it became dark as night. I’ve seen last leg for the day. He agreed, and then The autopilot correctly captured the local- the inside of a thunderstorm once a we sat at the gate for almost 20 minutes izer and flew the approach. The captain long, long time ago and don’t care to see before we could deplane the passengers, was very gracious, thanked me, and said one again. I immediately disconnected due to the ferocity of the storm. he just learned something new. We both the autopilot and told the captain I had One of the things I really liked about agreed that there always seemed to be the controls and was manually flying the ASA was that they gave us a simulator for something to learn when it comes to fly- approach. I proceeded with an aggres- our PCs that did a fantastic job of repro- ing, and with the right attitude, we can all sive turn back to the final approach ducing the cockpit of the RJ. All you had gain valuable lessons while we continue course, just as the tower inquired if we to do was point and click with your mouse to build our experience. went through the localizer. We quickly and you could actually fly an entire trip answered we were correcting. So here I including the approach. I made great use Back Course at Homer was, hand flying a back course in some of it whenever I had an assigned route that It was a few years later before I saw of the worst turbulence I have ever I hadn’t flown before. So off we went to another back course, and it was even

Flight low over the water can be done safely, but be prepared When the view is so pretty, it can be tempting to continue. It to turn around and know what the forecasts are calling. This is is best to hug the right side of the valley and turn around. No the Cook Inlet on the way to Anchorage. telling what is around the next bend.

Photos: Vic Syracuse KITPLANES May 2016 65 more complicated. It was the localizer DME back course with an arc to the FAF at Homer, Alaska. I was in my RV-10 this time, and even though I hand flew it, I felt like we were cheating as the syn- thetic vision coupled with the moving map was more like a video game. And it would have been fun, if it hadn’t been for the tragedy that had occurred just a few hours earlier with one of our group’s airplanes, resulting in three fatalities. The NTSB report has been published (NTSB ID ANC13FA058), and you can read about it online at http://tinyurl.com/zsvvxva. For me, it was truly watching the luck finally When the view looks like this up the valleys, with obscuration due to clouds, it is best to stay along the river routes in the valleys. The mountainous terrain rises very run out for someone. steeply, and there is not always room to turn around. Alaska is terribly unforgiving of any carelessness or recklessness, and it is home to Mount Denali, the highest peak of our landing at Healy River. To this day definitely home to the proverbial “billy in North America. It’s not only very beau- I don’t understand why some pilots want goat in the clouds.” I know, because in tiful, but it is large enough to create its to push the weather just because they our three trips to that beautiful part of own weather. On this day the ceilings got away with it earlier. the world, we have gone by the billy were at 1500 feet on the south side of As we approached Homer, it was pain- goat (really Dall sheep) at eyeball level the pass going into Anchorage. The key ful for me to listen as ATC communicated as we flew down the canyons on clear here is that the elevation through the with some of the pilots as they strug- days. On this particular day, we were pass is over 2400 feet. I voiced my con- gled with the localizer DME back course part of a 14-airplane caravan traveling cerns about heading into that pass and approach into Homer. We even heard in two separate 7-airplane groups, and was told by the leader to not worry—just ATC issue a couple of low altitude alerts, I was leading the first group, known stay low and follow the river. That’s how which just added to the stress from as the fast group. The owner of the it always worked! Yikes. The alarm bells the earlier incident. One newly minted business was flying in a Beech Baron started big time. Instrument pilot from Florida thought- ahead of both parties as an advance To make a long story short, I was pre- fully requested and was granted the GPS “weather” plane. That doesn’t really disposed to not going through that pass approach. Well done! It behooves all of work out as you are flying so low in val- when we took off, and sure enough, us to really take a detailed look at our leys between the mountains that the when we got to the pass, I didn’t like trips ahead of time and at least play it out VHF radios don’t have much range. But what I saw (and neither did Carol!). I put in our heads, especially when going into it was a nice thought. my flight on the ground at the Healy unfamiliar territory. We were about six days into our ven- River Airport. From there we all filed IFR Flying in sport aviation is supposed to ture, and this leg was from Fairbanks to for the rest of the way to Homer. Unfortu- be fun and full of wonderful memories Homer, which required going through nately, I found out before I departed that that we create as we build experience. the Summit Pass in the Alaska Range, the Baron had crashed within 5 minutes Don’t forget that! J

Sometimes following the river or valley can work and is most often done. I don’t do it without understanding the forecasts, checking for pilot reports, and looking at the Alaskan webcams. It can be tempting to take a shortcut through the pass, but the consequences can be deadly.

66 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes Michael Smith’s Sonex After five years, three months, and 2360 hours, plansbuilt Sonex N439M first flew on June 21, 2014. Other than a misbehaving airspeed indicator, the first flight was uneventful, due in part to the Sonex factory flight training I received. The plane is polished to save weight and look cool, runs behind an 80-hp AeroVee engine and Sensenich prop, and includes MGL instrumentation. It was built almost completely in my basement, only going to the airport several weeks before the first flight. The plane is great for aerobatics. Many thanks go to my wife for supporting me through this adventure! Maynard, Massachusetts [email protected]

Jay Bell’s RV-7A My “almost complete” RV-7A quickbuild first flew in October 2012 following a 2½-year build, and it accumulated 98.6 hours and 5500 cross-country miles during the next 11 months. It has an Aero Sport Power IO-375, Catto prop, AeroLEDs, Dynon SkyView, Icom A210, Classic Aero interior, and Anti Splat Nose Job. Planned upgrades include paint, electronic ignition, transponder, and landing lights. Thanks to my patient wife and navigator Lynne, my son and riveting partner Ian, Mike Seager for teaching me how to fly RVs, Van’s, and other vendors with excellent products and service! Olds, Alberta, Canada

Steve Kunkle’s Mustang II After 3½ years of building, in June 2013, my plansbuilt Mustang II passed the FAA inspection. At the end of July, the test pilot took it up and all went well. I have been flying and have about 22 hours on it now. It has an IO-320 with Hartzell constant-speed prop and a Dynon Sky- View with autopilot. I’m still doing a lot of testing on the plane and myself, but at 22 squared it flies at 130 knots burning 7.4 gph. What an airplane! Thanks to KITPLANES® magazine for being a great information resource! Oley, Pennsylvania [email protected]

Bill Benjamin’s Lancair 360 In April 2012, after five and a half years, Lancair 360 N6QU finally took to the sky. A few small issues, including oil temperature heading toward 230°, shortened that flight. Adding oil cooler baffling brought the temperature down to acceptable levels. Then I had the pleasure of breaking in a newly overhauled engine at 200 knots in less than half of a 25 n.m. radius, high-density, phase 1 test flight area. N6QU is a rocket ship, but a few knots slower than her sister N3QU, which is a consistent Oshkosh race winner. I’m changing my MT prop’s high pitch to catch up. Engine is an O-360 A1A with Airflow Performance injection, Light Speed ignition, 10:1 compression, ported and polished ports. Weight is 1032 pounds. New Smyrna Beach, Florida [email protected]

KITPLANES May 2016 67 John Marzulli’s Seven-Oh-Fun After four years, three months of construction,Seven-Oh-Fun first flew on July 21, 2011. It was finally completed on July 28, 2014 when it landed at KOSH after an adventurous 3.5-day journey from Seattle. This also marked my rookie appearance at AirVenture. Many thanks are due, first and foremost to my long-suffering wife who encourages my aviation addiction. I am also thankful to Zenith Aircraft and EAA Chapter 1440, who all helped me along the way. It flies as advertised: short landings, shorter takeoffs, docile handling, and great visibility. Seattle, Washington [email protected]

Keith Hedrick’s Rans S7S After three years and a lot of help from my friends, 74VK took to the air. This is a great-flying airplane and a lot of fun to fly. Litchfield, Illinois [email protected]

Mark Lewandowski’s RV-8A My friend Jim Couch and I worked on the aircraft for about six years, and Stan Lawrence made the first flight on August 25, 2012. We did all the work, including the paint job. It is powered by a mid-time Lycoming O-360 with Hartzell constant-speed prop. Basic avionics include a PS audio panel, Garmin SL40, Garmin 327 transponder, Dynon D180 and Garmin 796 GPS. I did my transition training with Stan, then got into the Bad Penny and off I went. What a blast to fly! I would not have been able to do this without the support of my wife Sammi. Sacramento, California [email protected]

Dana Baker’s Sonex I completed my scratch-built Sonex on February 28, 2015. First flight was March 8, 2015. Sonex SN 1534 is a taildragger, and it is equipped with an 80-horsepower AeroVee engine, MGL Extreme EFIS, MGL V6 radio, Sandia mode C transponder, and Ameriking AK451 ELT. It took three years and 1450 hours to scratch build in my garden shed. California [email protected] J

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68 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes BACK ISSUES List of Advertisers O NEW eBOOK O Please tell them you saw their ad in KITPLANES® Magazine. eBook download is exactly the KITPLANES® interactive makes it quick and easy for you to receive instant same magazine as on the newsstand. information about products or services directly from our advertisers’ web sites. The difference is: ➥ Go to: www.kitplanes.com/links for a virtual shopping tour via links to their web sites. you get it now! ➥ Call the phone numbers listed below and be sure to tell them you saw their ad & in KITPLANES® Magazine. no shipping costs for e-books! Advertiser page # telephone Advertiser page # telephone Aircraft Spruce & Specialty CV4 877-4SPRUCE (a big savings for our international customers) Builders’ Marketplace Aerotrek Aircraft 71 812-384-4972 eBooks download as a single, full size, Avemco Insurance Company 23 888-241-7890 full color .pdf document which you can view Airflow Performance 73 864-576-4512 Better Aircraft Fabric 41 907-229-6792 on your desktop, laptop or tablet computer. Bearhawk Aircraft 70 877-528-4776 PDF eMagazine issues are fully searchable California Power Systems 3 800-AIRWOLF Bede Corp. 72 See Advertisement and are compatible with all Adobe Acrobat Belite Aircraft 71 316-253-6746 functions such as highlighting, page notes CubCrafters 53 509-248-9491 Beringer 70 708-667-7891 and spoken word audio. Dynon Avionics CV2 425-402-0433 Better Half VW 72 281-383-0113 O Individual monthly issues are $6.95 Garmin International 5 913-397-8200 O A compiled Aircraft Buyer’s Guide Carlson Aircraft 72 330-426-3934 Falconar Avia Inc 71 780-465-2024 is $12.95 Experimental Aircraft Association 29 See Advertisement Flight Data Systems 71 831-325-3131 Visit: Grand Rapids Technologies 31 616-245-7700 Flight Grip 72 800-204-7625 www.kitplanesbooks.com Grand Rapids Technologies 43 616-245-7700 to order Glen-L 73 888-700-5007 Ivoprop 41 800-FOR PROP Grove Aircraft 73 619-562-1268 ❏ April 2016 Thatcher CX5, Remembering Jim Bede Sr., Speed Deburring, 3D Parts Printing, Vacuum Forming Homebuilt Help 72 See Advertisement Kitfox Aircraft 29 208-337-5111 ❏ March 2016 Carbon Cub EX on Amphibious Floats, Audio INFINITY Aerospace 71 See Advertisement Control Panels, Bendix and Beyond Kitplanes® Bookstore 35 800-780-4115 Innovator Technologies 73 403-669-3101 ❏ February 2016 2016 Engine Buyer’s Guide, RV-14 Taildragger, Aircraft Wiring Mistakes, Repairing Loose Rivets Lancair International 31 541-923-2244 Kuntzleman Electronics Inc. 70 610-326-9068 ❏ January 2016 SuperSTOL Stretch XL, ULPower, On a Wing and a Whim, Fuel System Design, Aircraft Wiring Osprey Aircraft 70 See Advertisement Progressive Aerodyne 77 352-253-0108 ❏ December 2015 2016 Homebuilt Aircraft Directory, Light Aircraft Fuel System Design, Vortex Generators for Cooling Out of the Basement 73 See Advertisement Sonex Aircraft, LLC 3 920-231-8297 ❏ November 2015 Pole to Pole, Lady Bug’s Story, Viperjet, Spirit Recreational Power Engineering 71 800-583-3306 of St. Louis, How to Use Your Oxygen System Stewart Systems 43 888-356-3490 Smoking Airplanes 72 661-713-9050 ❏ October 2015 Carbon Cub EX-2, Taming the Lancair, Flying Other People’s Planes, Glass Panel Upgrade Van’s Aircraft 47 503-678-6545 Sportsman’s Market 73 800-SPORTYS ❏ September 2015 Ten Years With a Time Machine, Becoming a Test Pilot, Family Affair, The Motivated Builder TCW Technologies 71 See Advertisement Viking Aircraft Engines 41 386-566-2616 ❏ August 2015 SubSonex, 1909 Blériot XI, Carving Fiberglass, Tormach LLC 71 See Advertisement Fully Inverted Pocket System, Aircraft Wiring Zenith Aircraft Co. CV3 573-581-9000 ❏ July 2015 Searey LSX, The First Grand Champion, Wicks WhirlWind Propellers 70 619-562-3725 Aircraft Supply, APP in the Real World

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KITPLANES May 2016 73 Converting a Taylorcraft to E/A-B, rebuilding and modifying a Rans S-9. By Mel Asberry

Question: I’m rebuilding a 1942 L-2 installed larger fuel tanks, installed airworthiness inspection after a major Taylorcraft. I have to build all new a better propeller, and replaced change. Later versions allow the owner/ wood ribs for new wings and sand- the original Rotax 532 with a Rotax operator to place the aircraft back into blast all the old metal parts and 670. All work is documented in the phase I for flight testing after a major repaint them. Much of the fuselage logbooks; however, the aircraft has mod. The operating limitations cur- needs rebuilding after a crash from not flown after these mods. I plan rently in the aircraft and listed on the the last owner. My question is, can to buy the aircraft, reassemble it, airworthiness certificate is the control- it be recertified as an Experimental and paint it. I understand an annual ling document. They remain valid until aircraft so I can do all the annuals in condition inspection would be nec- they are amended. the future? essary prior to flight. Would the You are correct that the aircraft will I just finished building a Kitfox 4, original airworthiness certificate need a current condition inspection and all the wing ribs, spars, and the still be valid? If not, what would be before being signed off for flight. This fuselage were already built. All I did required prior to flight? inspection may be done by any A&P. was install the parts, cover them, Additionally, I believe some of I assume that the original phase I and it’s an Experimental plane. So these changes were accomplished flight testing has been completed and where is the difference between by individuals not listed as the signed off. If not, you will need to make building the Kitfox and the L2? builder/repairman, nor were they sure that gets done also. Answer: Unfortunately, the answer is IAs. Is there a requirement for such Nothing needs to be signed off by an no. Any work done on a Standard cer- work to be signed off by an IA? If IA. An IA is never required for Experi- tificated aircraft is considered a repair yes, will that effectively be done at mental/Amateur-Built aircraft. Any- and does not count toward “building.” the next condition inspection? one can do maintenance and/or mods. FAA Order 8130.2G is very specific on Answer: Unless the original airwor- However, only the original builder, if he this point. thiness certificate has been surren- or she is the holder of the repairman cer- Question: I’m considering buying dered, it should still be valid. As far as tificate, or an A&P may sign off on the a Rans S-9 that was built, registered what has to be done, you will need to condition inspection. J and certificated E/A-B in 2000. The read the operating limitations. There plane hasn’t flown since 2003. Since were some big changes around that Please send your questions for DAR then, two subsequent non-A&P time. The “older” operating limitations Asberry to [email protected] with owners have recovered the fabric, required that the aircraft get a new “Ask the DAR” in the subject line.

74 KITPLANES May 2016 Photo: Mel Asberry A bit about blades. In our discussion of propellers so of the engine at the proper rpm and see that the maximum propeller diame- far, we have covered basic momentum convert it to thrust as efficiently as ter hits a practical limit very quickly. As theory and taken a look at the charac- possible. The parameters available power increases, it becomes neces- teristics of the incident airflow on the to achieve this are blade area, blade sary to increase blade area and pro- blades. We now turn our attention to airfoil, blade planform, number of peller solidity to absorb the power in some more details of the shape of the blades, and pitch. the diameter allowed. blades themselves. Up to a point, increasing blade Like a wing, a propeller blade is char- Solidity chord works well. If the blade chord acterized by its area, planform, and airfoil The blades must have enough area gets too large, several problems cross section. As we have seen in previ- and pitch to absorb the power deliv- appear. The blades get heavy, and ous months, the airflow conditions along ered by the engine at the right rpm. the structural issues of joining the length of the blade vary in a much Increasing either blade area or blade a large blade chord to a practi- different way than on a wing. Accord- pitch increases the amount of power cal shank and hub get severe. At ingly, the airfoil and planform choices for the propeller will absorb, so proper this point, increasing the solidity a good propeller are different than those design involves finding the proper and total blade area of the pro- for a good wing. balance between area and pitch. If peller by increasing the number the blades have too much area, the of blades is a better design option Diameter Limits parasite drag of the blades will hurt than increasing the chord of a For most airplanes the propeller diame- efficiency. If they are too small, they smaller number of blades. ter is set primarily by a combination of tip may stall before the pitch reaches As we see on some modern Mach number and landing gear length a high enough value to absorb the turboprops, when the power considerations. On a direct-drive engine, power of the engine. gets large, a high-solidity prop the full-power rpm is set by the engine The solidity of a propeller is the with many blades is often the characteristics, and this in turn limits the ratio of the blade area to the area of best solution. diameter of the propeller. If the engine is the disk swept by the propeller. A NACA did many tests on propel- geared, the designer can adjust propel- high-solidity propeller has a large lers to determine the effects of diam- ler rpm, as well as diameter, to get to an blade area relative to its disk area. eter, solidity, and number of blades optimum design point. Tip Mach num- Theoretically, increasing solidity on propeller performance. One of ber becomes less of a limit because the decreases efficiency because the the best references on this subject prop rpm can be chosen to keep it at an blade parasite losses increase with is NACA Technical Report 640, pub- acceptable value, and ground clearance increasing blade area. In practice, lished in 1938. This is available online and propeller weight start to become this is only true if the designer has at the NASA Technical Reports Server more important limiting factors. the option of choosing the theo- (http://tinyurl.com/zzsp9lu). For extremely large propellers, blade retically ideal propeller diameter to structural considerations, both strength absorb the power of the engine. As Blade Planform and stiffness, can limit the maximum fea- we have seen, the diameter of the Ideally, we want every element of sible diameter as well. propeller is often limited by other fac- the propeller blade to be flying as Once the diameter of the propeller is tors to a lower-than-optimal size. efficiently as possible. The way to do set, the designer must come up with a Since most light airplane engines this is to design the area, taper, and blade design that will absorb the power turn at about the same speed, we can twist of the blades so that at every point

is a principal aerodynamics engineer for Northrop Grumman’s Advanced Design organization. A private pilot with single engine and glider ratings, Barnaby has been involved in the design of Barnaby Wainfan unconventional airplanes including canards, joined wings, flying wings, and some too strange to fall into any known category.

Illustrations: Barnaby Wainfan KITPLANES May 2016 75 Figure 1: Blade local airspeed at various forward airspeeds. along the blade, the blade element is the optimal lift coefficient for the blade Increasing the speed to 300 knots (J=2.1) operating at the lift coefficient at which airfoil, and the parasite losses due to changes this significantly. The tip air- the blade airfoil develops its highest lift- blade element drag would be increased speed is now less than twice the airspeed to-drag ratio (L/D). It is this ideal blade lift over the optimum. at 10% radius. coefficient that determines the optimum The solution to this is to vary the chord At low advance ratios, the tangential blade area. of the blade over its span. By adjusting velocity dominates. This causes a large the local chord, each blade element can variation in airspeed over the length Chord Variation be operating at or near its optimum lift of the blade. Props designed for low Along the Blade coefficient while producing the right advance ratios accordingly tend to have Looking at the airspeed of the elements amount of thrust to give an efficient very highly tapered blades. of the blades as a function of the distance spanwise loading of the blade. At higher advance ratios, the forward from the hub, we can see immediately The ideal loading on a propeller velocity becomes more significant. This that an efficient propeller will have a sig- changes with advance ratio because the reduces the variation of airspeed over the nificant amount of taper in the blades. variation of incident angle of the airflow length of the blade and makes the opti- The tangential component (due to prop along the blade is a function of advance mum planform somewhat less tapered. rotation) of the velocity of a blade ele- ratio. The variation of blade element air- ment increases linearly as we go outboard speed along the blade also changes with Practical Considerations on the blade. The dynamic pressure of the advance ratio. The theoretically optimum planform for air increases as velocity squared. Accordingly, there is no single “ideal” a propeller blade is often not practically If the blades had a constant chord, propeller blade planform. Each propel- buildable. Particularly for low advance- the lift on the blades would increase ler must be designed to match a specific ratio propellers, the optimum blade roughly as the square of the distance advance ratio and power input. planform has very large chords very near from the hub if the blade elements were Figure 1 shows the variation of local the root. It is difficult to get these large all operating at the same lift coefficient. airspeed along the blade of an example chords to integrate with a reasonable pro- This would make the prop excessively propeller flying at different airspeeds peller hub design, so it is relatively com- tip-loaded. The loading on the blade can and constant rpm. Our example prop has mon to see shorter than optimum chords be adjusted using twist, but this would a diameter of 72 inches and is operating on the inner portions of prop blades. cause the outboard part of the prop to at 2400 rpm. At the other end of the blade, extremely be operating at a much lower lift coef- Note that at 50 knots forward airspeed small chords in the outer portion of the ficient than the inboard portion. Only a (J=0.35), the airspeed at the tip is 7.5 blade may be theoretically efficient, but small part of the propeller would be at times the speed at the 10% radial station. they are difficult to make strong and stiff

76 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes enough to hold up in ordinary use. Also, extremely small tip chords may lead to a degradation in airfoil performance due Help us make to lowered Reynolds number. The best physically realizable propeller will almost always be a compromise between the theoretically optimum and the practically buildable. even better! Airfoils The airfoil cross-section of the blades Take our survey and enter also affects propeller performance. A to win an Aircraft Spruce gift card well-designed propeller operates with the local lift coefficient of each blade or free subscription. element at the value for best L/D of its We want to know what you like—or don’t like—about Kitplanes®. airfoil. Because of this, the operating lift But we need your help. We’d like you to take a short survey that coefficient of a propeller blade element only takes 5 to 10 minutes to complete. It will help us learn what is somewhat higher than the typical kind of stories you enjoy most, and what topics you rarely read. cruise lift coefficient for a light airplane wing. Accordingly, propeller airfoils tend Win Prizes to have more camber than wing airfoils We’re also giving away eight $25 Aircraft Spruce gift certificates and for cross-country-capable airplanes. eight 6-month magazine subscriptions. You can choose to receive Many propellers use the Clark Y or sim- Kitplanes® or one of our sister publications: Aviation ilar flat-bottomed airfoils with cambered Consumer, Aviation Safety, Light Plane upper surfaces. This was an appropriate Maintenance, IFR Magazine, or IFR Refresher. choice for props with wooden blades, Two winners will be chosen from all entries since the 12% thick Clark Y was thick every Friday between February 26 and April enough to make structurally sound, stiff- 15. So fill out the survey today. The sooner enough blades. The problem with such you enter, the more chances you have to sections is that they have relatively low win! And thank you for helping us make critical Mach numbers, and accordingly Kitplanes® even better. limit the acceptable tip Mach number of the propeller. To take the survey, visit www.kitplanes.com/survey. One of the primary advantages of early metal propellers like the Curtiss-Reed props used on the Curtiss Racers was that the metal construction allowed the designers to make the airfoils of the propeller tips much thinner than was possible with wood. This allowed the props to operate efficiently at higher tip speeds, which in turn allowed either larger prop diameters for a given rpm, or higher rpm at constant diameter. The higher diameter increased prop efficiency, while the higher rpm allowed the engines to turn faster and develop more power. On modern propellers, it is common to vary the airfoil along the span of the blades. Thicker sections are used inboard to improve the stiffness and strength of the blade, and thinner, less cambered sections are used outboard to allow the propeller to operate efficiently at a higher tip Mach number. J

KITPLANES May 2016 77 Call me a taxi (light). When last we left our newly LEDed air- both legal and safe? The feds are very “bright,” and it won’t catch fire, we have craft, we said that we would tackle the wishy-washy about landing light speci- our design done. Pretty simple and not power supply for the landing and taxi fications except FAR 91.205 (c)(4), which a lot of technical gibberish. The catch? lights. And so we will. says: “If the aircraft is operated for hire, If you land at night and hit something, As I said in the April column, switch- one electric landing light,” and even then the feds can say, “Your light wasn’t bright ing power supplies are efficient and only if operated at night. The “electric” enough,” and you are on the hook to noisy. Sure, noise can be filtered out, but part? Legend has it that one doofus pilot prove that it was. at what price? Inductors and capacitors was using a kerosene lantern hung out Since we are in the Experimental cat- are relatively large and expensive. Since in the breeze to satisfy the 1920 land- egory of airplanes, and since we can’t use most of today’s aircraft have battery/ ing light regulation…kerosene, flame, our airplanes for hire, the landing and alternator power to spare, linear regula- butyrate dope on the fabric…poof. taxi lights are strictly for our own use, and tors are my choice for ease of construc- But there is another FAR that tells us you can pretty well settle for anything tion and reliability. how we have to build airplane lights (FAR you want. In particular, I’ll show you just These high-powered (20 watts of DC 23.1383). Here you go: one design, and it will be adaptable to power, 100-watt-equivalent incandes- §23.1383 Taxi and landing lights: Each any configuration that you want: a single cent) LEDs that we are going to use in taxi and landing light must be designed landing light; a separate landing and taxi the landing/taxi lights are going to draw and installed so that: (a) No dangerous light; two landing, no taxi; two landing, about 2½ amps of juice (each) from a glare is visible to the pilot; (b) The pilot is one taxi; and so on. Just remember that 12-volt aircraft power supply. They aren’t not seriously affected by halation; (c) It you are going to spend about $50 per inexpensive ($38 each), but if you have a provides enough light for night opera- light, and each light has nine individual 2000-hour TBO engine, the projected life tions; (d) It does not cause a fire hazard in LEDs inside. is 32+ engine overhauls (65,000 hours). any configuration. With nine individual LEDs inside the Then the question becomes, how So, if we make it so the light doesn’t light, running 700 mA through each one, many of these lights do we need to be shine in our eyes, it doesn’t shimmer, it’s and with about a 3-volt drop for each

The “improved” power supply with two components, the IC and one resistor (left). The frontal view of the landing light showing all nine LEDs (the little green squares in the center of the picture) on the heat sink ceramic substrate (right).

is the chief avioniker at RST Engineering. He answers avionics questions in the Internet news- group www.pilotsofamerica.com–Maintenance. His technical advisor, Cyndi Weir, got her Masters degree in English and Journalism and keeps Jim on the straight and narrow. Check Jim Weir out their web site at www.rst-engr.com/kitplanes for previous articles and supplements.

78 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes Schematic of the “improved” power supply (left). Contrast its simplicity with the switching power supply’s original design (right). individual LED, if we run them all in series, light. Better that we spend the extra two beam. One of the advantages of an LED is we will need a 27-volt power supply with bucks on individual string regulators. that it runs cool enough to be able to use current limiting. That automatically calls Let’s worry about regulator power a plastic lens over the LED to focus the for a switching circuit type of supply, and for just a minute. If we say that the beam. By changing the optics of the lens, we said once before that we don’t want maximum voltage that the aircraft bus we can make it a flood, a flood-spot, or a to run switchers because of the noise fac- will have on it is 14 volts, and that each spot beam (33°, 26°, and 17° beamwidth tor. What we can do is buy the light con- LED string will drop 9 volts at 700 mA, respectively). Cost? About $6 per lens. figured in three rows of three LEDs each then the regulator will be dissipating Attachment structure? Glue. row, and that can be run directly with a (14 - 9) x 0.7, or about 3.5 watts. That’s If you will give me a little time (say, two linear regulator from a 12-volt supply. not a tremendous amount of power or three months), I’ll see if I can come up True, there will be the cost of two more (with excellent heat sinking, the LM317 with a trick circuit that will let you turn LM317s, but at about a buck apiece (plus can dissipate over 30 watts), but it will the lights on without a flasher, turn them another dime resistor), we’ve solved the get warm if we don’t put a minimal heat on with a flasher, and turn them off—all noise problem elegantly. sink on it. with a single switch, a single wire, and an One of my first thoughts was to use a What we may need to think about is airframe ground. single 3-amp linear regulator set for 2.4 how to mount the LED itself to get rid We also have to talk about the optional amps and run all three strings in parallel, of heat. We have 9 LEDs in the package, annoyance flasher circuit itself. Note that 800 mA to each of the three LED strings. each one having about 3 volts across it for clarity in both the April and May That was a pretty foolish idea. If one of at 700 mA. That’s 2.1 watts each times 9, issues, we did not include the flasher. I’ll the three strings were to fail, the regu- or just a little less than 20 watts. That’s a give you the schematic and comments lator would still supply the 2.4 amps to bunch of heat you need to get rid of, and for both the nav lights flasher (which the remaining two strings, 1.2 amps to as I’ve said for some time now, aluminum sounds like on-off-on-off-on-off several each string. That would quickly burn out airframe structure is your friend. times a second) and the landing light one of the remaining strings and force One of the advantages that an incan- flasher (which sounds like on……off…… the whole 2.4 amps into the last string. descent light has over a bare LED is that on……off, about a flash a second) in the That last string would get real bright for it can sit at the bottom of a parabolic single-switch issue. about two seconds and fail the entire reflector and shine its light in a pencil Until then, stay tuned… J

The three variations of lenses: 17, 26, and 33° beamwidths. The 17° lens mounted on the landing light LED.

Photos: Jim Weir KITPLANES May 2016 79 By Robrucha

80 KITPLANES May 2016 www.kitplanes.com & www.facebook.com/kitplanes