The Spirit of Homebuilt Aviation I www.eaa.org

OCTOBER 2012

Replica Fun! Bill Keyes’ Stewart S-51

» 2012 Homebuilt Award Winner » Baffl ing... The Aerochia LT-1 It doesn’t have to be Homebuilder’s Corner

Checking In Flying new-to-you airplanes By Chad Jensen

I’ve had the opportunity to fl y a as much to do with the airport Flying the tri-gear airplanes fi rst number of airplanes since I’ve been environment as it does the airplane. allowed me to learn to fl y the on staff at EAA, and I’m quite pleased I went through the ground school airplanes without having to worry with the amount of fl ying that I’m able and then started training at the much about winds during the takeoff to do here. airport in the tri-gear Glastar. While and landing phases of fl ight. I haven’t I was signed off to fly the tailwheel yet fl own the taildragger Sonex or When new-to-me airplanes become Glastar solo, I did not complete my Onex, but I wouldn’t even think of available to fl y, I use the checkout training to fly Young Eagles from doing so without training. training system to transition to the airport in that airplane. Why that airplane. The term “checking one Glastar, and not the other? My challenge to all of you who check out” should really be “checking They are different. Not just in the in to new-to-you airplanes is to get in.” I’ve checked in to six different case of where the little wheel the proper transition training from a experimental airplanes over the last resides on the airplane, but they fly qualifi ed instructor. A focus at EAA year—the two Glastars at Pioneer, differently. The pitot-static system is safety of the E-AB segment of Sonex tri-gear, Onex tri-gear, RV-6A, is slightly different in each airplane, aviation. We are under the gun from and the Wag Aero Cuby. the speeds are different in the the NTSB to improve our record. pattern, and the list goes on. So EAA’s Safety Initiative is a big part of Checking in to an experimental close, yet different. that, but the biggest part of improving amateur-built (E-AB) airplane the record is you. (airplane-AB) is something no one The folks at Sonex have allowed me should take lightly. Even if you have to fl y a couple of their airplanes, and Check in before you give yourself a previous time in a similar type (I it has been a wonderful experience. chance to check out. built and fl ew my RV-7 but still took instruction in the RV-6A), they all fl y a little differently, and they all have different panels and systems.

I did my tailwheel endorsement in 2007 in a J-3. The Cuby is the experimental version of the J-3, so it’s no big deal, right? Well, the J-3 had a 65-hp engine; the Cuby has an 85-hp engine on it. Not a big difference, but they are different, and the Cuby does fl y a little differently than the J-3. I was pleased with my training in the Cuby to get me ready to fl y it regularly; it’s the airplane of choice for me! A check-in at Pioneer Airport has

On the cover: Bill Keyes’ turbine-powered S-51, Lil Stinker. (EAA photo by Jim Koepnick.)

2 NO. 2/OCTOBER 2012 Contents

NO. 2/OCTOBER 2012 I A publication of the Experimental Aircraft Association Features

» 12 Bill Keyes’ S-51T » 18 Aerochia’s First: The LT-1 When 12 cylinders just aren’t enough The plans-built grand champion at By Budd Davisson AirVenture Oshkosh 2012 By Tim Kern Departments Columns » 2 Homebuilders’ Corner » 28 Under the Cowl By Chad Jensen Baffl ing By Tim Kern » 4 E-Mail Letters and links from readers » 6 News from EAA HQ » 32 Safety Wire News from EAA Transitioning to Experimental or » 9 Flightline Unfamiliar Airplanes, Part 2 Industry News By Hobie Tomlinson » 24 What Our Members Are Building » 38 The Panther Sport Plane Light Plane World By Pat Panzera Recapping AirVenture 2012 By Dan Grunloh » 27 Hints for Homebuilders A “Holey” Saw By Cy Galley » 43 Flight Test Techniques Airspeed Basics By Ed Kolano

EAA EXPERIMENTER 3 E-Mail

Readers React PUBLICATIONS STAFF To the “new” Experimenter! Founder: Paul H. Poberezny Publisher: Rod Hightower The digital Experimenter provided a good read. Accessibility was good as well. While my specifi c interest areas are LSA, motorgliders, and ultralights in an E-AB context, the Vice President of Publications: coverage of experimental subjects (e.g., the 1/3 B-17) helps in appreciating the work of J. Mac McClellan other people. Homebuilding Community Manager: Chad Jensen Thanks for your efforts, Editor: Mary Jones/EditEtc. LLC Harold Bickford Graphic Designer: Chris Livieri EAA 567796 News Editor: Ric Reynolds Copy Editor: Colleen Walsh I really like the digital Experimenter. Keep up the good work. I’m building a Pietenpol Multimedia Journalist: Brady Lane and love articles about homebuilding. Visual Properties Administrator: Jason Toney Arden Adamson EAA 126141 Contributing Writers: Budd Davisson, Cy Galley, Dan Grunloh, Tim Kern, Ed Kolano, Pat Panzera, Hobie Tomlinson Just fi nished the “new” Experimenter and must congratulate all associated with this European Correspondent: Marino Boric enterprise…It is great! Will be looking forward to subsequent editions.

Doug Brownlee EAA 28103 ADVERTISING Display Sue Anderson Pros Jonathan Berger I like the format, the tool used to deliver, etc. Jeff Kaufman Article: Celebrating Older Homebuilts – Home run! Article: Can’t Keep a Good Plane Down – Good! Mailing Address: – Love these. And so few people know about them—why? Hints for Homebuilders P.O. Box 3086, Oshkosh, WI 54903-3086 What Our Members Are Building. Safety related articles—experimental—such as the article “Transitioning to Phone: 920-426-4800 Experimental or Unfamiliar Airplanes.” Fax: 920-426-4828 Flight Testing Techniques. E-mail: [email protected] Lack of ads—good move! Website: www.EAA.org Cons Chapter News – Keep that in Sport Aviation. Need to change your address Anything about certifi cated aircraft such as “Cessna to Change Skycatcher or have other membership Certifi cation”—what part of this is experimental? questions, call 800-564-6322 Anything about Continental Motors’ “diesel turbo” yada yada—what part of (800-JOIN EAA). this is experimental? News from HQ – Leave that for the EAA fl agship publication. If HQ is building an E-AB, EAA® and SPORT AVIATION®, the EAA fi ne, otherwise I don’t want to read about HQ. Logo® and AERONAUTICATM are registered Keep out articles about AirVenture—the most commercialized gathering of aviation. trademarks, trademarks, and service marks This is not grassroots E-AB stuff; better left to Sport Aviation. of the Experimental Aircraft Association, Inc. The use of these trademarks and The new Experimenter is a bit too much like Sport Aviation. Think about the people who service marks without the permission of build E-AB and stop writing about companies like Cessna and Continental. And I would the Experimental Aircraft Association, Inc. like to see a heavy emphasis on safety of E-AB—how can the E-AB builder make a is strictly prohibited. safer plane and improve E-AB safety overall.

Bob Dewenter EAA 773828

Send your letters or comments to [email protected].

4 NO. 2/OCTOBER 2012 I’m a Member because... EAA protects my freedom to build and fl y.

Visit EAA.org/join to become a part of the world’s most passionate aviation community.

Photo by Jeff Miller/EAA © 2012 Experimental Aircraft Association, Inc.

OCTOBER 2012 EAA EXPERIMENTER 2 News From HQ

EAA Member Donates Piper Cub Replica The EAA AirVenture Museum received a tremendous gift this summer from longtime EAA member and Air- Venture volunteer Marv Hoppenworth, EAA Lifetime 2519, of Cedar Rapids, Iowa, and EAA Chapter 33, who presented the museum with a homebuilt replica have borrowed the registration number, NC9245H, from of a Piper Cub on the 75th anniversary of William that Cub for this museum Cub.” Piper’s masterpiece. The replica aircraft is now at Pioneer Airport waiting to Marv spent countless hours building a full-size Piper be moved into the museum to truly honor Marv’s achieve- Cub replica for donation and static display in the mu- ment and generosity for years to come. Marv and his wife, seum and worked tirelessly to get it completed in time Cathy, are longtime volunteers at AirVenture, helping to for EAA AirVenture Oshkosh 2012. The replica contains make EAA’s international celebration possible. He has pro- parts from more than 20 different Piper Cubs and was vided limitless entertainment for children with his famous built in the memory of Marv’s very first airplane, a Piper pedal plane kits and plans. The pedal planes that are used Cub that he bought in 1948. “It was a Piper L4-H that I at KidVenture to entertain our youngest visitors are of purchased from the pilot, Mr. Vernon Sandrock, who Marv’s creation. To quote Marv, “There are two seasons in was flying it at the end of World War II,” Marv said. “I Iowa: before Oshkosh and after Oshkosh.”

The EAA Flight Plan begins with an introductory Young Eagles airplane ride with a volunteer EAA pilot in a GA aircraft. From there, participants have ac- cess to a free EAA student membership, the Sporty’s online course, a free fi rst fl ight lesson at a local fl ight school of their choice, and numerous scholarships available to support continued fl ight training until a pilot’s certifi cate is obtained.

Now Young Eagles will have upgraded options to further explore aviation as Sporty’s Pilot Shop makes its Sporty’s Learn to Fly Course available to all Young Eagles. The upgraded course is offered at no charge.

“Our recently introduced Learn to Fly Course gives tre- mendous fl exibility to folks starting their fl ight training,” said Sporty’s President and Chief Executive Offi cer Sporty’s Enhances Flight Michael Wolf. “The Learn to Fly Course is a modular program that gets everyone focused on the most impor- Training Program tant fi rst step—solo. Then users are given their choice to pursue a sport, recreational, or private license.” Sport pilot course among upgraded options now available to youth after fi rst fl ight Sporty’s Learn to Fly Course is delivered in new HTML 5 format, making it usable not just on your EAA and Sporty’s Pilot Shop’s partnership has allowed desktop computer but also on iPads and other more than 15,000 EAA Young Eagles to pursue aviation mobile devices. interests beyond their fi rst fl ight through Sporty’s Com- plete Flight Training Course, as part of EAA’s Flight » For more information about the YE program, Plan program. visit www.YoungEagles.org.

6 NO. 2/OCTOBER 2012 Eagle Flights

Taking Off Pilot Tom Sampson (lef ) and Michael Martinez (right) af er their Eagle Flight in Tom’s RV-7A. EAA’s new Eagle Flights ground by hosting an Eagle pilot Tom Sampson in his RV-7A. program introduced at AirVenture Flights rally a week after the They did some routine pattern offers introductory airplane convention at Twin Oaks Airpark work, including several flying rides to adults who have always (7S3). Nineteen would-be pilots maneuvers. After landing, Martinez had a desire to fly, but for got introductory rides, and five of vowed to take advantage of what whatever reason have not yet them gave their commitments to he experienced and pursue his pursued it. begin flight training and pursue a pilot certificate. pilot certificate. Members of EAA Chapter 105 of Learn more about the program at Hillsboro, Oregon, wasted little One of those future pilots, Michael www.EAA.org/EagleFlights, or call time getting their efforts off the Martinez, flew with EAA member/ 800-557-2376.

EAA Urges Participation in Annual GA Survey Every year the FAA surveys the purposes for which owners in this survey in late August. GA community to obtain accurate and operators use their aircraft. Only members who receive a information on aviation activity Survey results help determine fund- mailing are asked to complete and safety. The 34th annual Gen- ing for infrastructure and service the survey. Respondents may eral Aviation and Part 135 Activity needs, assess the impact of regula- complete the survey online Survey (GA Survey) gets underway tory changes, and measure aviation or by mail. The cutoff date for this month, seeking information on safety. The GA survey is also used survey responses is November activity occurring last year. to prepare safety statistics and cal- 30, 2012. culate the rate of accidents among The survey is the only source of GA aircraft. EAA supports the FAA in this GA comprehensive information on the activity fact-fi nding survey, and asks activities of the GA fl eet, including A sample of pilots received a post- that members who receive the sur- the number of hours fl own and the card invitation to participate vey complete it as requested.

EAA EXPERIMENTER 7 News From HQ

EAA Employees to Build a Zenith CH 750 E-LSA EAA staff members have begun work on a Zenith STOL CH 750 kit, with EAA Communities Manager “Support of the E-AB community is something I am Chad Jensen leading the project. “This is a fantastic op- committed to doing, and seeing an opportunity like this portunity for EAA to show our love and appreciation for to work with EAA on a project that will not only provide homebuilt airplanes,” Jensen said. “The response I’ve an education to their employees, but also to see a group received from interested staffers has been phenomenal!” project come together and end up in the EAA Employee Zenith President/CEO Sebastien Heintz has graciously Flying Club is something I am very proud to be a part of,” offered EAA an airframe kit for the STOL CH 750 E-LSA. Heintz said.

day, altitude, and heading of the Pilot’s Bill of Rights Beginning to aircraft if possible. Pay Dividends The EAA sees this notice and the ac- companying webpage as a very posi- FAA has issued a notice implement- the FAA website, where a pilot tive step toward the FAA’s full imple- ing elements of the recently passed who is the subject of an investiga- mentation of the law. Doug Macnair, Pilot’s Bill of Rights. Under the new tion may submit a request for air EAA vice president of government law, which received the President’s traffic data to a central point of relations, was pleased with the an- signature on August 3, pilots now contact within the agency. Re- nouncement, saying, “This is the fi rst have the right to obtain “air traffi c quests made to this point of con- tangible sign of benefi t to airmen data” relevant to an FAA enforcement tact will promptly be passed on to from our hard work on the Pilot’s Bill action from government contractors. the appropriate contractor. of Rights as we seek to improve the This includes information such as level of fairness and accountability recordings of fl ight service briefi ngs The FAA cautions that air traf- within the FAA enforcement process. from contract facilities and communi- fic data is commonly disposed of We deeply appreciate the agency’s cations with contract control towers. within as little as five days through responsiveness and support in bring- Previously, only services provided the course of normal business. ing about the new procedures.” directly by the FAA and its employees Therefore it is imperative that had been subject to such requests. pilots ask to secure this data in For additional information, EAA mem- a timely fashion and carefully bers may call Government Programs The notice directs inquiring pilots to describe the nature of the infor- at 920-426-6522 or send an e-mail to the new Pilot’s Bill of Rights page on mation sought, including time of [email protected].

8 NO. 2/OCTOBER 2012 Flightline

FAA Issues Emergency AD for Some Rotax 912 Engines The FAA issued an emergency airworthiness directive may not be manufactured to full fuel-resistant standards, affecting certain Rotax 912 series engines. The AD which could result in the degradation of the interior of requires that the pressure side fuel hose be replaced the hose and result in debris fouling the fuel system. on fuel pumps with the following serial numbers: The AD became effective on September 10. Affected 11.3117 through 11.3325 inclusive owners have five flight hours from that date to make 11.4036 through 11.4355 inclusive the prescribed repairs. EAA advises owners of Rotax 11.4516 through 11.4595 inclusive 912-powered aircraft, both type certificated and 12.0251 through 12.0270 inclusive. non-type certificated, to check the AD to determine if their engine is among those affected. For more infor- An AD from the European Aviation Safety Agency indi- mation, EAA members may call EAA Aviation Services cates that the pressure side fuel hose on these pumps at 920-426-5912.

PRA Joins FAA FA ASTeam to Represent Light Rotorcraft and Experimental Aircraft The FAA and the Popular Rotorcraft Established 50 years ago, the PRA is rotorcraft operations. Through the Association (PRA) signed a letter of the only major U.S. organization rep- FAASTeam Industry membership, the understanding creating a high-level resenting personal rotorcraft such as PRA will be able to not only create more relationship between the two organi- light-sport experimental amateur-built, safety programs but also make these zations. This agreement establishes ultralight, and certifi cated rotorcraft. programs nationally available. offi cial contacts between the FAA PRA Offi cers and Board of Directors and PRA to share national media re- The PRA has already created the fi rst strongly urge all personal rotorcraft sources, develop safety training, and WINGS safety presentations to contain owners, pilots, and student pilots exchange safety materials between specifi c information about how GA to join the WINGS and FAASTeam both organizations. aircraft can safely interact with light programs (www.FAAsafety.gov).

EAA EXPERIMENTER 9 Flightline

Bearhawk Introduces LSA Model Bearhawk designer Bob Barrows ous projects, with the fuselage and Currently, the Bearhawk LSA introduced his newest design, the tail surfaces using traditional 4130 is only available as a plans- Bearhawk LSA, at EAA AirVenture chromoly tube and fabric design. The build project, but Bearhawk Oshkosh 2012. wings are all-aluminum, fl ush-rivet- Aircraft is in the process of ed, with a single strut. Empty weight tooling up to manufacture quick- While the Bearhawk LSA looks simi- is 728 pounds, with an aluminum prop build kits. For plans, contact lar to the two-place Bearhawk Pa- and no electrics. Bob Barrows, R & B Aircraft, trol, the LSA is really a clean-sheet at 540-473-3661. For kit infor- design, with a new airfoil designed in Barrows reports an economy cruise mation, contact Bearhawk A part by Harry Riblett. The LSA’s con- speed of about 100 mph, sipping only 4 ircraft; call 877-528-4776 or struction is similar to Barrows’ previ- gph with the 65-hp Continental engine. e-mail [email protected].

STOL CH 750 Now Available as Factory-Assembled LSA Zenith Aircraft Company’s popular light-sport utility The STOL CH 750, often called a “Sky Jeep,” is design, the STOL CH 750, is now available as a factory- optimized for off-airport operations and short assembled LSA from Tennessee Aircraft Development takeoffs and landings, using fixed-wing leading LLC (Tenn-Air). The large-cabin aircraft, powered by a edge slats and other high-lift design features. The six-cylinder Jabiru 3300 engine, is being offered at the all-metal aircraft is configured with a standard introductory price of $74,900. steerable tricycle-gear configuration, with a large, high-visibility cabin. New features include available According to Pete Krotje, head of Jabiru USA, Tenn-Air has adjustable seats and a raised cabin for even more licensed the design rights from Zenair Ltd. to produce the all- head room. metal, high-wing CH 750 as a factory-assembled LSA. Tenn- Air will purchase STOL CH 750 kits from Zenith and assemble For more information, contact Pete Krotje at 931-680- them to LSA standards at its factory in Shelbyville, Tennessee. 2800, or visit the Tenn-Air and Zenith websites.

10 NO. 2/OCTOBER 2012 NTSB: Worn Parts Led to Fatal Crash at Reno 2011 Deteriorated locknut inserts that allowed trim tab attach- tation of the pilot. Seconds ment screws to become loose and induce aerodynamic later, a section of the left fl utter led to the deadly crash of Jimmy Leeward’s Gallop- elevator trim tab sepa- ing Ghost race plane at the 2011 National Championship rated in flight. The airplane Air Races in Reno, Nevada, the National Transportation descended and impacted the ramp in the spectator Safety Board (NTSB) reported. The fl utter, caused by the box seating area, killing the pilot and 10 spectators and reduced stiffness in the elevator trim system, broke the injuring more than 60 others. trim tab linkages, resulting in a loss of controllability and the eventual crash, the NTSB stated. The NTSB also concluded that “undocumented and untested major modifi cations” on the aircraft, as well as According to a news release from NTSB, the crash on the pilot’s operation of the airplane in the unique air racing September 16, 2011, occurred on the third lap of the environment without adequate fl ight testing, contributed to six-lap race as Leeward’s highly modified North Ameri- the accident. can P-51D was traveling at race speed estimated at 445 knots (512 mph) and experienced a left-roll upset and Read a synopsis of the NTSB report, including the probable high-g pitch -up peaking at 17.3g and causing incapaci- cause and a complete list of the safety recommendations.

Wicks Aircraft Supply Announces 4130 Shortage Is Over 4130 chromoly tubing, the tradi- full lengths (usually 18 to 24 to help with fabrication and fi nishing. tional foundation of tube-and- feet, depending on diameter). fabric aircraft and a substantial Special-order lengths are Wicks is currently offering a special component in landing gear, engine also available. price on one of the most popular mounts, and roll structures, is sizes—1-5/8-inch OD, .083-inch wall available again in quantity from Wicks has nearly 200 ways to tubing has been reduced from $3.79 Wicks Aircraft Supply. supply 4130—e.g., sheets, bars, per foot to $2.99 per foot (part num- strap, rod; and round, square, ber R1-5/8x083-41). Wicks’ 4130 chromoly tubing is rectangular, and streamline seamless, rather than welded, tubing. Wicks also carries 4130 Visit www.WicksAircraft.com for and is sold by the foot or by TIG fi ller and other welding supplies more information.

Lockwood Aviation Launches New Website

A new Lockwood Aviation website uses a large number of innovations to make shopping for Rotax parts easier. “More than 3,500 of the parts and supplies that Lockwood carries are now online,” said John Hurst, director of sales and technology. With more than 2,000 photos, including en- gine and airframe parts, tools, and supplies, customers can completely confi gure and purchase Rotax Aircraft engines online, including the new 912 iS.” It also has real-time online inventory. For more information, visit www.Lockwood.aero.

EAA EXPERIMENTER 11 Bill Keyes’ S-51T

12 NO. 2/OCTOBER 2012 Bill Keyes’ S-51T When 12 cylinders just aren’t enough By Budd Davisson

There is one image that, in one form or another, seems history. But not everyone can afford one. In fact, very to stick in every pilot’s mind: It’s a clear summer day, few people can, which is just as well because there are and you are screaming across the landscape, guns very few original Mustangs in existence. Still, the desire armed, the Merlin in the nose singing its tight, raucous is there, making the P-51D Mustang probably the most song, the enemy just out of sight…waiting…ready to modeled, most photographed, most chronicled fighter of pounce. But your Mustang and you are ready, too. You World War II. were born ready. It is possibly the most revered airplane of all time. So, Everyone wants his own Mustang because everyone, it would only make sense that scale modelers, who are it would seem, is in love with its looks and its place in continually increasing the size of their models, would

EAA EXPERIMENTER 13 Bill Keyes’ S-51T

eventually approach 1:1 (full size) built. Mine is the only one with the there’s not much you can do about scale. Is that what Jim Stewart did turbine engine.” scaling the pilot down. He is what when he developed the Stewart he is, and the airplane has to be S-51 in 1996? Did he design and built around him. This design dif- build a man-carrying scale model “If you have nothing ficulty is compounded by the fact of the Mustang that is approxi- around it to give scale that a 70-percent wingspan actually mately 70-percent scale in size means the cubic area available for but 100-percent scale in terms of to a Stewart Mustang, the pilot is less than half that of the excitement? Bill Keyes of Louisville, original. So a full-sized pilot has to Kentucky, thinks that’s exactly what people sometimes have go into half the space. Jim did. trouble telling it from Bill said, “The only area that from Bill said, “If you have nothing the real thing.” a distance tells onlookers that around it to give scale to a Stewart this is a replica is the very slightly Mustang, people sometimes have The Stewart S-51 is certainly one increased size of the canopy. Jim trouble telling it from the real thing. of the more ambitious homebuilt wanted this to be a two-place air- Especially those S-51s that aren’t kits ever seen. For one thing, the plane, but with a perfectly scaled fully painted, so they show their Mustang is not a simple airplane canopy, there wouldn’t be enough aluminum structure and are using to replicate because of its flow- room. As it is, it’s really only a one- the Chevy V-8, as Jim originally in- ing lines, which required multiple and-a-half place aircraft. My son tended. About 14 S-51s are currently stretch-formed skins. Also, when would fit at 14 years old, but not flying with another 20 to 30 being scaling an airplane down in size, now at 22. And, of course, the pilot

Bill Keyes

14 NO. 2/OCTOBER 2012 looks bigger than he should in com- parison to the airplane. But that’s it. You can look at it from any angle and it has ‘that’ look! It looks like a Mustang. The best part, however, is that from the pilot’s point of view, it is indeed a Mustang.”

As indicated by the sewer pipe- size exhaust stack on each side of the nose, Bill’s Stewart Mustang isn’t just any Stewart Mustang. Bill explained, “Jim Stewart originally designed the S-51 to be powered by a big-block Chevy, a 454 or larger, with a gearbox to reduce prop rpm. However, when Bob Wahl built this Power for Bill’s aircraf is a Walter 601D turbine engine. airplane back in 1999, he decided to go with a Czech-built Walter “I had flown about an hour and done 601D turbine that puts out 724 hp. five or six landings, then was taking He sold it to a friend of mine, and in it back to my home field when things 2004 I bought it. I’d always wanted went wrong. I had touched down, a Mustang and now I had one! Sort and the airplane wanted to start a of, anyway.” very slow turn. I put the engine in beta with the tail off the ground, An obvious question is “How does but I couldn’t keep it straight. Then one learn to fly a 724-horse, single- I noticed a wingtip going down and place taildragger?” I knew a gear leg was folding. This was all happening in slow motion, “I had about 150 hours of taildrag- and I had no problem keeping the ger time,” Bill said, “most of that wing up as long as possible. Then in Cubs and Huskys. I had bought I gently let it down and watched a Super Cub, then a Husky, to use as each prop blade hit the ground, in teaching my son how to fly. So, I each one making a very distinctive, didn’t have a lot of tailwheel time. unpleasant noise. Then I ground to Plus, even though I’d flown RF-4s in a halt only about four feet left of the the USAF, I’d never flown a civilian edge of the runway.” in the main spar with a shorter one airplane with that much power. My in the rear spar. Both were just checkout consisted of Brad Hood An autopsy of the folded gear outboard of the gear mount. The kneeling on the left wing while I sat showed that two problems had flap was kinked in the middle, and in the cockpit. He said something worked together to bend Bill’s air- the prop was trashed. The internal to the effect of ‘…and then you flip plane: a design change that upgrad- condition of the engine was a big this switch, turn this lever, and…’ ed the main gear trunnion axles from question, so it went out to Diemech I was really keyed up, so you can 1015 mild steel shafts to 4130 chro- Turbines in DeLand, Florida, the imagine how I felt when I taxied moly hadn’t been communicated to Walter engine experts, where it out to the end of the runway and the original builder. Plus, too many was torn down and rebuilt. Fortu- couldn’t get the canopy cranked all holes had been drilled through the nately, since it wasn’t a sudden the way shut. I had just gotten my trunnion axle for the down-lock col- stop, the internal condition was nerves under control, then had to lar. The result was a break through surprisingly good. In the meantime, taxi back, spend three hours fixing the bolt holes, which allowed the I started taking things apart. Very the canopy, then had to go out and gear to collapse. shortly I decided that if you’re go- do it again. It was double jeopardy! ing to get this far into an airplane, I was nervous, but the first part of Bill said, “The wing hit hard enough you might as well do everything the flight went without a hitch. that there was a three-inch crack you’ve wanted to do, and that’s

Photography by Tyson Rininger EAA EXPERIMENTER 15 Bill Keyes’ S-51T

Bill’s S-51 parked in the Replica Fighters area at AirVenture 2011. If you’re a fan of replica aircraf , you can learn more about the Replica Fighter’s Association at www.ReplicaFighters.net.

exactly what I did. Essentially, with “The doghouse that normally lock now works on the stick, just the help of Jerry Zollman, I rebuilt covers the radiator on the bottom like a real Mustang. With the stick most of the airplane. of the fuselage had kissed the anywhere but forward, the tail wheel ground, but just barely. I was lucky steers six degrees either direction. “I had to de-skin the entire left there because it just took some But, when you want to turn sharp, wing panel to repair the spars, judicious sanding and buffing to you push the stick forward, and the and to do that right, I took the get rid of all the scratches. That tail wheel unlocks and full swivels, fuselage off the wing and split was fortunate because those are allowing tight turns. Many of the im- the wing into its component parts all compound curved skins and not provements are the result of the work for compete access. Since the easy to replace. done by the builders’ group.” turbine burns more fuel than a Chevy, the plan was to add extend- “When we rebuilt the gear, I had Once you get an airplane apart, you ed aux and main tanks. The wings new trunnions machined out of 4130 quickly run out of excuses not to are wet, which required a lot of chromoly, but rather than through- do things, and a simple repair turns sealing and testing, then reseal- bolting it, I used cylindrical locking into a complete rehab where the ing and more testing. The first nuts that required no through bolts. owner puts some of his own DNA time around I had lots of leaks. It I’ll never see them crack again. in the airplane through sweat and was a very tedious process, but busted knuckles. it gave me a total of 140 gallons, “As long as I was working on the which is really nice. I burn about gear, I had never liked the single-fork “I figured, what the heck, I’m only 40 gallons an hour in cruise, so this tail wheel, so I modifi ed it. I made going to do this once,” Bill said, gives me a decent range with a up a new dual-fork tail wheel with a “so I completely gutted the interior good reserve. larger shock spring. The tail wheel and tore the entire instrument panel

16 NO. 2/OCTOBER 2012 out. All of it. Then I made up a new and at cruise you’re right at 380 out into a hair dryer, and it’ll blow instrument panel. Well, actually, I hp, which gives 250 mph at about your glasses and hat off.” made six of them because I either 40 gallons per hour. That’s a pretty had problems in making them or conservative setting. It’ll go a lot The allure of the Mustang is univer- found I didn’t like some of the ar- faster, but at that setting I have a sal, something that Bill enjoys. rangement. As it turns out, the first solid two-and-a-half hours with one arrangement was the one I came hour reserve. “I’m never alone at the gas pump,” back to in the end. Isn’t that always he said. “It gathers a crowd be- the way?” cause everyone on the planet seems T e residual power to recognize and like Mustangs. Bill obviously got his S-51T back in the air, at idle always gives a So it’s really fun to take it places. and in the end, knew much more about The only thing missing is the magic the airplane than when he bought it. pretty good f oat, and sound of a Merlin.”

He said, “When you go completely ground ef ect keeps it Hmmm…with all of the creativity through an airplane the way I did, up, but at 70 mph it’s EAA homebuilders seem to have, cleaning up and changing every- we’re wondering how long it’ll be be- thing to both fit your mission and on the ground. fore Bill designs an audio system that work better, it does a lot for your produces that distinctive 12-cylinder confidence in it. So, I fly the airplane “On approach, I get the first bark. As he has said, projects like his more comfortably now than I think I notch of flaps at 140, which helps Mustang are never truly fi nished. did at the beginning. slow it down; the gear is down at 125 and I’m flying downwind “As for how it flies, it’s pretty much at 100 mph. I try to have 80 to 90 Budd Davisson is an aeronautical everything you’d want in an air- over the fence and it stalls at 72. engineer, has fl own more than plane. A real fighter. On takeoff, The residual power at idle always 300 different aircraft types, and as long as you remember to preset gives a pretty good float, and ground published four books and more than right rudder trim, it’s pretty easy to effect keeps it up, but at 70 mph it’s 4,000 articles. He is editor-in-chief keep straight, and with 724 horses on the ground. Once on the ground of Flight Journal magazine and a dragging you down the runway, it’s a no-sweat operation. However, fl ight instructor primarily in Pitts/ takeoff doesn’t take very long. As when taxiing it, if you stick your tailwheel aircraft. Visit him at soon as you’re off the ground, the head around the windshield while www.Airbum.com. throttle comes back to 657 horses, S-turning, it’s like sticking your head

Photography by Tyson Rininger EAA EXPERIMENTER 17 Aerochia’s First: The LT-1

Aerochia’s First: The plans-built grand champion at AirVenture Oshkosh 2012 The LT-1 By Tim Kern

18 NO. 2/OCTOBER 2012 It’s not often that a new airplane builder has a test Len explained the plane’s flight characteristics, after pilot volunteer to do first flight and development some 20 test flights (including the plane’s first). His in- flying. But Andy Chiavetta, former nationally ranked sights are telling, both for Aerochia (Andy’s company) (number five) skimboarder-turned-raceplane builder, and for any would-be designer or builder. had the respect, advice, and curiosity of not only race partner Darryl Greenamyer (four-time Sport “I first saw this airplane as a drawing on [aerodynami- Class and seven-time Reno Unlimited champion) cist] Greg Cole’s office wall in Bend, Oregon,” said but also top test pilot Len Fox, as Andy brought Len. “When the time finally came for the first flight, his dream to the air this spring, and then to EAA Andy’s friend Darryl Greenamyer wasn’t available, so I AirVenture Oshkosh. was happy to oblige.

EAA EXPERIMENTER 19 Aerochia’s First: The LT-1

“As a test pilot, you look at a new sible for a reduction in horsepower “One way to check when you’re plane with an eye for what may from the rated 60 hp. (Andy Chia- approaching the aft limit of stabil- present a problem. With this air- vetta admits to a very quickly made ity,” Len explained, “is when you plane, all the things I thought air filter arrangement that he can’t do a standard turn, and then tighten might be problems weren’t. There wait to improve.) it up, adding g’s. You should always was plenty of rudder, plenty of have positive stick forces. If the aileron, plenty of elevator, and Additionally, the airplane has not stick falls into your lap, you don’t there wasn’t any blanking or slop yet flown with its wheelpants. have enough horizontal tail. At in the controls.” “Gear on this airplane is a huge the design aft CG, this airplane portion of the drag.” Still, Len said, has enough.” So, Len felt confident before he left “With the cruise prop, and no the ground. wheelpants, and probably down on power, it goes 129 knots.” That’s “When you’re f ying, “When you’re flying, it does just 148 mph. Oh, and the flight tests are what you want it to do: Center the being conducted in Thermal, Cali- it does just what you stick…boom!…the plane stops roll- fornia, in the summertime. Andy’s want it to do: Center ing. Good ailerons make for smiling design top speed of 150 mph seems pilots. This one makes me smile.” pretty reasonable. the stick…boom!…the

Performance, as Measured So Far Approach can be made as slow as plane stops rolling.” 65 knots. Takeoff in this light air- Len continued, “After we calibrated plane is very quick, considering its He liked the approach and touch- the airspeed indicator, we found small wing (60 square feet), lack of down, too. “The gear is in the that the stall came at 47 knots. flaps, and modest power. Len said, right place. You can flare, touch When we called Greg Cole and “On the worst day, with the prop at down on the mains, and gently let asked him what he had predicted steepest pitch, we use maybe 1,000 the nose down. It tracks straight the stall speed to be, he said 47 feet of runway.” on the ground.” knots. “With the stall strips, the airplane stalls straight ahead. The Flight Report Partially this comes as a result roll rate is about 120 degrees per of just 60 nominal horses and a second: crisp, but not twitchy.” Len noted that he felt “no strange well-sized rudder. “There is very vibrations. The throttle is smooth; little P-factor. With the controls, One of the modifications to the it’s easy to take off, easy to fly; you feel connected to the airplane. HKS engine that powers the LT-1 smooth and responsive.” Ailerons and elevator have little was to replace its twin carburetor or no free play, and there are no setup with a single carb. Len thinks So far, test flights have mapped aerodynamic dead zones; when the this interim modification is respon- the heart of the CG envelope. control surface moves, the plane moves. There’s a direct connection between the pilot’s brain and the control surfaces. Controls are light but not twitchy; they have a good centering feel. The LT-1 has the immediate reaction of a high-performance aerobatic ma- chine, but the pitch and roll rates induced per inch of stick movement are less. With a flick of the wrist, aileron response is immediate, but you get 5 degrees angle of bank instead of 50.”

Len also said it’s no effort to fly, including pulling it into and out of the hangar. “A test pilot likes a

20 NO. 2/OCTOBER 2012 At 5 feet, 8 inches tall, author Tim Kern had plenty of headroom in the LT-1. But even a 6-foot, 5-inch tall pilot had plenty of clearance for a headset. Cockpit width is 27 inches. plane that is built right, flies right, problems, but he’s got them worked Specifications and Performance and is fun to fly. This plane makes out. That’s the only criticism I’ve had, me smile.” and he’s worked them out. He’s still The single-seat plane is little, with experimenting, though, making the 60 square feet of wing like a Formula How big is that smile? “From seeing engine better, and I think he has an- 1 racer, but it’s not a racing wing. the line drawing in Greg Cole’s shop other idea, too,” possibly referring to The wingspan is 20.8 feet, and there to doing the fi rst fl ight to test-fl ying it, the turbocharged version of the HKS. are no flaps. It’s simpler that way, well, I’ve put a deposit on one.” Len and it doesn’t need them. Overall Fox, professional test pilot, will be the He continued, “The LT-1 flies well; length is just 15 feet. The world’s ti- owner of LT-1 serial number three. it’s easy to control. It handles well, niest trim tab, half the size of a stick feels good, is good. The airplane of chewing gum, is on one elevator. Darryl Greenamyer Weighs In flies fine, works fine, has good Tiny stall dams on the leading edges speed for its power.” Darryl, who aren’t any longer than a cell phone. Eleven-time Reno champion Darryl is responsible for the name “LT-1” Greenamyer had a complaint: (the meaning of which is a secret, With 18 gallons of gas in the two- “I wish it went a thousand miles an perhaps like the British “Lola” race wing tanks, minimum endurance hour faster.” He laughed and said, car name), added that it “flies the should be well more than four “I’m just used to faster machines, but pattern well; it has good low-speed hours, plus reserves. this airplane fl ies well and is easy to handling. Some may want flaps, but control.” Darryl acknowledged that I don’t see the need.” He summed Still, the LT-1 is comfortable and “He [Andy] has had some engine up: “I like it.” capable. With a useful load of 293

Photography courtesy Andy Chiavetta EAA EXPERIMENTER 21 Aerochia’s First: The LT-1

pounds, it will haul a standard Visibility was astounding. Looking the LT-1 should easily make its pilot, 15 pounds of luggage, and full ahead, even from my artificially claim of 1,000 fpm climb; the 650 tanks off a short runway. The cabin low position, was plenty adequate; fpm figure for MTOW climb also is 27-½-inches wide. That doesn’t I could just see the wings in my looks realistic. sound like a lot, but think about peripheral vision. Even with the how wide a two-place, 55-inch round fuselage dominating your Offi cial, pilot’s operating handbook– cabin would feel! (For reference, sight picture, keeping the wings style V-speeds have not been de- a Cessna 172 is 39-½-inches wide, level without relying on instruments termined, but design speeds of 120 seated two across.) should be a breeze. knots at 60 percent and full speed at 140 knots are still listed on the web- Tall pilots will fit, as well. At Yes, more compact pilots will be site. But only 129 knots have been AirVenture, one 6-foot, 5-inch able to fly the plane. Darryl, while a achieved so far. Remember, though, volunteer hopped in, and he fit, giant in the record books, is smaller there are no wheelpants on this little with headset clearance on top than I am, and he’s flown the LT-1 machine, and they’ll make a huge im- and “didn’t have to move the rudder many times. provement. VNE is listed as 180 knots. pedals” legroom. When I put my 5-foot, 8-inch frame in the cockpit, The LT-1 is aerobatic at +6/-4g, but The Plane’s Boss there was a mile of space above it does not have inverted fuel and me, and I could barely reach the oil systems. Simple, remember? Andy likes to make things out of pedals. (I wasn’t wearing a para- composite materials, and since his chute, but I was sitting on the At minimum weight and with a days as a hardcore skimboarder, foam pad.) better airbox/filter arrangement, his craftsmanship has been an

T e LT-1 is powered by the 60-hp HKS 700-E engine. T e turbine HKS engine could also be an option.

22 NO. 2/OCTOBER 2012 important contributor to his results. The fuselage is split horizontally, Andy figures that a highly expe- For a decade now, he has been the easier to install the controls. rienced builder who had never building composite go-fast parts for “It’s easy to work on at waist level built an airplane—but who has a Lancairs and other “glass” birds; [the shipping fixture is great for dedicated garage or hangar and the his modifications and parts are this], before bonding the top half ability to concentrate on building— found on virtually every Lancair on,” he added. could build an LT-1 in three months. at Reno, including that of Darryl For others, he thinks “up to a year Greenamyer, for whom Andy also Fuselage assembly itself is simple. for an enthusiastic amateur.” served as crew chief. Andy said, “You use structural ad- hesive, clecos to hold it until it sets. The design is simple and inex- Andy wanted to build his own air- Then you pull the clecos, patch the pensive. There are no machined plane, and Darryl, who knows ev- holes, and it’s done.” hinges, for instance; everything’s erybody and has flown pretty much hinged with piano hinges. Another everything with wings, was a great simple, cheap, light trick: The tubu- mentor, from the early stages right Andy likes to make lar gear legs are housed in simple through the current test regime. carbon-fiber sheaths. Darryl’s influence is there, but the things out of composite design is all Andy’s. “And the wing materials, and since Pricing is Greg Cole’s,” Andy reminded me. his days as a hardcore Andy is planning to complete the The design was to have been airframe kit for around $30,000, simple and inexpensive to manufac- skimboarder, his with deliveries to regular custom- ture, to build, and to fly. “Keep craf smanship has been ers (he’s already building No. 2 and it light. Keep it simple. Keep it No. 3) starting around Oshkosh time inexpensive,” Andy said, “and it an important contributor in 2013. Although the spinner and will be easy to build.” As many of plate are included, the kit does not Andy’s crew have noticed, keeping to his results. include the HKS engine, prop, paint, it light (about 500 pounds) makes and instruments. Yes, the 60-hp HKS it easy to maneuver on the ground The firewall-forward setup is gives plenty of performance, but and in the hangar. “One hand is all easy. HKS supplies a very ef- there is room for the turbocharged it takes to bring it out of the han- fective (and big) muffler; Andy’s version. Other engines will likely gar,” he noted. single-carb intake may remain find their way into the spacious, and become refined, or he may round cowl. Andy spends a lot of time in the opt to have the builder tune the shop, so he knows what takes stock two-carburetor setup. The Summing up, Andy told me, “My the builder’s time, and he en- noticeable black bumps on each philosophy was to make an easy gineered the LT-1 kit to have a side, near the rear and under the airplane to build and to fly; safe, af- minimum of shop time while still cowl, are cooling air exits. “I’m still fordable, and comfortable.” It looks complying with the 51 percent rule. optimizing the shape,” Andy said.. like he did it. “The molding is mostly done,” he “Right now, we have at least said. “The builder needs to do just all the cooling we need—and » For more information, visit a few small layups.” These small our tests are being flown at Ther- www.Aerochia-LT1.com. parts are easy to handle and pro- mal, California!” For now, they vide skill in composite work, which just screw on, as Andy tests will be useful down the road when various configurations. Tim Kern is a private pilot who the builder is repairing or modifying lives near Indianapolis, Indiana. his machine. Sure, there’s work. Andy said, He has written for more than 40 “As a manufacturer, we can’t different aviation magazines and “Look at the website; you can close out everything; we have also provides writing and marketing see the wing, the spars, fore to comply with the 51 percent services to the aviation industry. and aft,” Andy said. “They’re in rule. Still, this is a kit plane, not a He was key builder on two aircraft the wing when you get the kit. scratchbuilt. Don’t get me wrong; and has earned the title of Certifi ed The builder can literally start in- there’s still work to do, once you Aviation Manager from the NBAA. stalling hardware.” get the kit.”

EAA EXPERIMENTER 23 What our Members are Building

While still in the construction stage, it’s easy to see this will be a sporty airplane to f y. Panther Sport Plane

By Patrick Panzera, EAA 555743 to see its progress. Although David is – is a single-seat aerobatic aircraft Photos by Pat Panzera close to getting signed off by his DAR, with ample room for even the most he wasn’t able to make it to AirVenture robust pilot. While it’s primarily My guess would be that the average 2012. Hopefully we’ll see his fi nished aimed at the light-sport market and homebuilder attending EAA AirVenture project at AirVenture 2013. has folding wings that take two Oshkosh is probably most interested minutes to rig, the Panther also can in seeing what’s new and different. But this year we were introduced be built to exceed the light-sport Sometimes that takes the form of to something on the other end of aircraft (LSA) performance limits progress by an emerging design. In the spectrum. Although it’s also for pilots who want to have a little 2010 we were introduced to David powered by a Chevrolet automobile more fun. And although the cockpit Algie’s fi re-breathing LP1 (an all- engine (the air-cooled, six-cylinder is roomy, the seat and rudder ped- composite, Corvette engine-powered Corvair), Sport Performance Avia- als are fully adjustable so nearly speed demon) that was shown at tion’s Panther – brainchild of the anyone can fit without compromise, AirVenture; in 2011 we were privileged company’s president, Dan Weseman with or without a parachute.

24 NO. 2/OCTOBER 2012 Construction enough to be easily rolled into the rear of a 7-foot by 7-foot by 18-foot- The Panther’s wings, tail cone, and long enclosed trailer and kept there empennage are constructed from 6061 until the next fl ight – no need for a aluminum using fl ush, blind rivets. hangar or extra space in the garage. The prewelded fuselage is built from a carefully selected mix of square The Engine and round 4130 steel tubing, from seat back to fi rewall, which is skinned with Powering the Panther prototype is sheet aluminum. All critical attach the aforementioned Corvair automo- points, such as the those for the solid tive conversion reported to make aluminum (spring) landing gear legs, 120 hp from 3000-cc displacement While nearly every f ying Corvair uses a wing pin, engine mount, fi ve-point and with a yet unproven fuel injec- carburetor, Panther creator Dan Weseman is harness, ballistic chute, rollover tion system. Stock Corvair engines planning to use mechanical fuel injection. bar, control hard points, etc., are all are 2700 cc (164 cubic inches). But welded in the jig. This allows for quick Dan is no stranger to the Corvair, and accurate construction of all criti- having successfully installed one cal points, and the steel cage, with its in a Sonex that he built and (out of integral rollover bar, offers added pilot respect for the designer’s wishes) safety in the event of an accident. renamed Cleanex, as it was a clean- slate installation. The use of the Because the folding wings lie fl at Corvair in the Sonex, while gener- against the side of the fuselage while ally frowned upon by the factory, is trailing aft, hauling the Panther on a good fit for the airframe, and Dan an open, fl at-bed trailer, such as a supports this option with a full line customized, recycled boat trailer, is of the required accessories that T e integrated use of both square and round an option that’s hard to beat by those make for a clean installation for tubing, along with the simple and robust rudder of us on a tight budget. The overall those who want extra power for the pedal adjustment, show the forethought that has size of the folded aircraft is compact Sonex at an affordable price. gone into the design of the Panther.

Panther LSA Specifi cations Seats 1 Wingspan 23.5 feet Wing area 93 square feet Empty weight 650 pounds Gross weight 1,020 pounds Fuel capacity 20 gallons (in wings) Engine 110-hp Corvair (or 80-120 hp) Top speed 138-180 mph*

VNE 200 mph Aerobatic capacity +6/-4.4g

* Maximum speed in level f ight with maximum continuous power (VH): 138 mph

EAA EXPERIMENTER 25 What our Members are Building

Dan has also developed and is certified aircraft engines, and that’s planes, especially high-drag aircraft marketing a “fifth bearing” adapter what Dan accomplished with his like the Zenith 750. plate for the aero-converted, direct- simple design. drive Corvair engine that’s designed Three Different Panthers to reduce some of the troublesome propeller loads from the prop end And Dan has recently There are three different models in of the stock Corvair crankshaft. taken the Corvair the making. The Panther LSA ver- Although the stock General Motors sion has a wingspan of 23.5 feet, crankshaft is forged and in some conversion to the next can use engines ranging from 80 cases even nitrided, it was never to 120 hp, and will be offered with designed to handle the gyroscopic level by creating (and conventional gear or with a nose loads imposed by the prop, so it marketing) a new billet wheel. This will be the first of the only makes sense to increase the three offerings to fly. length of the front bearing to be crankshaf for aviation more in tune with what we find in The Panther Long LSA is the same as and automobile use. the LSA version but with extended wings and horizontal stabilizer, each And Dan has recently taken the with tapered tips. It’s designed to use Corvair conversion to the next level smaller engines, including electric by creating (and marketing) a new motors, for the most effi cient fl ight. billet crankshaft for aviation and These will be tested on the prototype automobile use. He’s even gone LSA airframe in the future, based on as far as to offer the option to add customer interest. stroke length, further increasing the displacement (and power) of The Panther Sport version will have the little horizontally opposed six- a wingspan of 21.5 feet but won’t fit cylinder to a full 3400 cc (207.5 cubic in the LSA category. It can handle inches), making approximately 134 anything from a stock 2700-cc Cor- hp at 3400 rpm, the normal speed vair to the 160-hp Lycoming O-320, for the direct-drive Corvair engine. and it will only be available with But Dan’s aim for this displacement conventional landing gear. T e 3,100-cc Corvair engine is the staple for this increase is to provide the typical design, although the airplane is tolerant of higher 120 hp at a reduced rpm, potentially » For more information, visit power, heavier powerplants; smaller, low-power upping the time between overhaul. www.SportPerformanceAviation.com/ engines can be used by those with a budget in mind. This will work well in all LSA air- panther.html.

Video of the Month George Richards of New Zealand recalls his adventures building and flying his all-wood Falco homebuilt. George shipped his aircraft from New Zealand to California and then flew it to EAA AirVenture Oshkosh 2012. That’s quite a story, too!

26 NO. 2/OCTOBER 2012 Hints For Homebuilders A “Holey” Tip Cutting holes accurately By Cy Galley

Hole saws are great; they don’t kick plywood as a guide by clamping or back and can be used in a handheld taping the plywood where you want drill. But wouldn’t it be nice to use the hole. Use the lines to center the the cut-out disk without the ugly cen- guide. Then use the hole saw without ter pilot hole? We could cut a disk the centering drill. Some hole saws for a disk brake pad. Use the saw to use the drill as a drive shaft; if so, cut inspection holes without wor- you’ll have to use a shortened drill. rying that the pilot drill will damage something behind the surface we’re The previously drilled hole in the cutting, like a gas tank, fuel lines, plywood will provide all the posi- or control cables. Other uses would tioning necessary to drill your new be to cut gussets for wing ribs and hole or create a disk without a hole inspection covers. in the center. Because you are using an outside guide, you even can saw However, you cannot just remove less than a semi-circle. the center pilot drill, as it locates and stabilizes the saw. We need If you are making several disks and something to hold the saw from have a quality hole saw, make the “walking” and wandering; some- guide from 1/8-inch aluminum. How- thing to locate the hole. ever, if you are just making disks, stack enough layers and each layer The solution is to drill a hole through will guide the next. Use a slower a piece of thin plywood, such as a speed when cutting larger disks. A scrap of paneling, with the pilot drill metal-cutting hole saw would make in place. Then use the hole in the the job easier on aluminum.

Hints for Homebuilders Videos EAA has produced hundreds of hints for homebuilders videos. You can view them all here, www.eaavideo.org/channel.aspx?ch=ch_hints. Here’s a sampling of the videos that are available.

Cotter Key Installation-Standard Method

Brian Carpenter, of Rainbow Aviation in Corning, California, demonstrates the standard method for installing a cotter key on a castle nut. Here’s the video.

Cotter Key Installation-Alternate Method

Brian next demonstrates the alternate method for installing a cotter key on a castle nut. Here’s the video.

EAA EXPERIMENTER 27 Under the Cowl

Michael Goulian’s 580-hp Lycoming-powered Red Bull racer does not let any air go wasted. Baffl ing… It needn’t be By Tim Kern

Aircraft engines, whether air cooled, The Basic Rule it. Vastly different packaging and air/oil cooled, or liquid cooled, are purpose make the cooling systems all ultimately cooled by transferring We’re not cooling engine size, look different, but the amount of their heat to the air. This transfer is compression ratio, or numbers of cooling needed at any given output so important that we tolerate cool- cylinders. We’re cooling horse- is virtually identical. ing being responsible for up to 20 power. A tiny 600-cc (37-cubic- percent of an airplane’s total drag. inch) motorcycle engine making Two Important Generalities 100 hp needs the same amount of Understanding the basics of cooling cooling as a 200-inch Continental Although the air gets colder as we helps us to understand how much O-200 that’s making 100 hp. A TSIO gain altitude, it also loses density. cooling we need and how best to 540 throttled back to 100 hp needs Less dense air carries off less achieve it. The principles are sim- that same cooling, as does a Rotax heat. Less dense air also reduces ple; execution is not easy. (Mozart, 912S at full tilt, or a 427-inch Cor- the power potential for normally it is often said, wrote simple music. vette that’s loafing along, cruising aspirated engines. Adding a turbo- You try it.) at 120 mph and using 100 hp to do charger to an existing design, even

28 NO. 2/OCTOBER 2012 when that turbo does not raise top Turbulence can be used to our of fl exible reddish silicone cloth. For output but only allows maintenance advantage, if we are aware of it and slow airplanes, this can be suffi cient; of sea-level power to some alti- exploit it. but it’s ineffi cient. tude, raises engine output at any given altitude, and thus raises cool- Pressure, both high and low, can Other approaches are to attach the ing requirements. and should be exploited in the cool- baffl ing directly to each cylinder ing design. bank. Jabiru, for instance, furnishes Drag increases faster than the formed boxes that can be ducted square of the speed (many claim With propeller planes, the amount of forward to the cowl inlets, which fi t the cube; some, more than that—it air the blades move is asymmetrical well to the cylinders and heads. Put depends somewhat on the speed in climb. We all recognize P-factor cold air in the front, and the factory- range one is discussing), but the when climbing; the same phenom- supplied ductwork carries it right to amount of heat the air carries away enon is in play when we consider the hot spots. increases only linearly with speed. how much cooling air the prop is For example, doubling the speed in- forcing into the cowl. (Did you ever It’s important to put the cool air creases drag by at least four times, notice the little blanking plate in where it does the most good, and but the amount of air going past the front of the “down blade” cylinder fins merely doubles. on many certificated airplanes? That’s why it’s there.) So, the faster we fl y, the higher we fl y, the more critical becomes the Your cooling requirements extend cooling design. to more than just your cylinders. Consider cooling your alternators, Some Important Considerations magnetos, batteries, etc., and don’t forget the oil cooler! Air separates from the surfaces it covers when the angle increases Although crude “eyebrows” work on Jef LaVelle’s Glasair topped 400 mph at Reno, partly beyond a certain point. In general many slow airplanes, an integrated due to ef cient use of cooling air in a proper plenum. terms, that’s about 15 degrees; in enclosed cowl/internal baffl ing a tube, the walls should converge system is more elegant and ever or diverge no faster than about 7 more effi cient as aircraft speeds rise. degrees each. We know that when Keeping the cooling air focused on a wing’s angle of attack exceeds its job is the duty of the inner cowl about 15 degrees, we quickly trade design, specifi cally the baffl ing. lift for turbulence; the same thing happens to any air interface. So, In “fl at” (opposed cylinder) engine when we’re ducting air in our airplanes, the simplest enclosed cowlings, gentle “ramps” are re- designs consist of an opening in the quired. However, once we know front of the cowl for inlet air, a hori- we need to break that flow (22 zontal “tray” separating the top and Tony Higa’s Pitts, set up for Reno racing, features an degrees, say, is as bad as 90), we bottom of the cowl, and an opening in internal pressure plenum inside the original cowl. can then abandon the pretense of the bottom of the cowl, to let the air keeping airflow attached, and just out. The purpose of the tray is to di- deal with the drag and build the rect the fl ow of cool inlet air through “easiest” solution. the engine’s fi ns, rather than allowing it to fi nd the easiest way out, bypass- Air cools as it expands and heats ing the engine. up as it is compressed. An extreme example is a diesel, i.e., compression The next step is to build a vertical engine, where combustible gases wall atop the tray, behind the cylin- are compressed in the cylinders ders, to concentrate the airfl ow. The until they ignite simply from the heat gap between the cowl and the top of W.G. Coppen’s Corvair-powered SA-7 gathers all its air generated by compression; no spark the metal “box” and the sides of the in the cowl and forces it through the six cylinders’ fins. plug required! tray is typically closed with a sheet

Photography by Tim Kern EAA EXPERIMENTER 29 Under the Cowl

that’s usually the cylinder heads. attaches to the top of the engine and If you can do all that, you’re halfway Continental, in fact, showed some encloses all the heads, supplying air there. The other half involves letting the experimental O-200 cylinders a few more or less equally to all areas. This air back out, while causing the smallest years ago that had no fi ns at all. They “plenum” design can get scientifi c, but amount of drag. run cool enough, but it turns out that some general principles always apply: the fi ns also serve as mechanical Obviously, the outlet should be located in a reinforcement to keep the cylinders 1. The plenum should not leak. low-pressure area. Although some cowls round. (The newest O-200-D cylin- Lost air is wasted drag. vent out the top, most use an opening on ders have much smaller fi ns that 2. The plenum should not chafe the bottom. And many of these openings taper ever smaller toward the case, against the cowl or any other are much larger than they need to be. saving about a pound per cylinder.) part of the airframe. 3. Baffl ing inside the plenum, if First, it’s not suffi cient to rely on the Better yet is to have equal pressure used, should concentrate pressure (inlet) side to do the work to all the cylinders, and one excellent airfl ow to the heads. of pumping cooling air through the solution is to build a single box that 4. The plenum should not enclose fi ns. The outlet should provide some exhaust components. Hot air vacuum (lower pressure). By making won’t cool your engine! the outlet side (below the tray) a larger 5. The plenum should have as volume than above (or in the plenum), a much volume as is practically natural vacuum can often be achieved. possible to allow uniform pres- The opening itself can be made to sure inside the cowl and to help: Many fi nd that a small “lip” bent allow maximum expansion of into the lower trailing edge of the cowl the outside air. will help create a pressure drop more 6. Inlets to the plenum should be useful than the drag it creates, like as long as possible (it some- a spoiler on the rear deck of a car. times helps to use a prop shaft “Small” is the byword! extension), and the inlets should expand as they approach the A potentially more potent pressure- plenum, at no more than a dropper can be made by exploiting the 15-degree included angle. Inlets exhaust outlets. Many Reno racers T e Junkers Tri-Motor’s No. 3 engine shows a typical need to be smooth on the inside help accelerate the air out of the cowl approach to forcing air through a radial engine. as well as outside! by “persuading” it with speedy exhaust gases. (The photos do a better job of explaining this.)

In next month’s article, look for a few special-case solutions (e.g., pusher/ seaplanes) and some traditional and not-so-traditional expedient measures (e.g., cowl fl aps, spray bars, and elec- tric fans). Baffl ing, remember, is simple. Like Mozart’s music.

Tim Kern is a private pilot who lives near Indianapolis, Indiana. He has written for more than 40 different aviation magazines and also provides writing and marketing services to the aviation industry. He was key builder on two aircraft and has earned the title of Certifi ed Bill King’s Curtiss Pusher replica uses rudimentary “eyebrow” air catchers to put more air on his Aviation Manager from the NBAA. Lycoming’s six cylinders.

30 NO. 2/OCTOBER 2012 Experience is the best teacher EAA membership connects you with more than 1,000 Technical Counselors and more than 450 Flight Advisors who provide in-person expertise on building, restoring and fl ying amateur-built aircraft—at no cost to you.

Find a Tech Counselor or Flight Advisor near you. Not an EAA member? Join today!

EAA EXPERIMENTER 31 Safety Wire

Transitioning to Experimental or Unfamiliar Airplanes Part 2 By Hobie Tomlinson

As we said last month, with the FAA and NTSB stress- Experimental or Unfamiliar Airplanes,” which was pub- ing the importance of transition training in reducing the lished by the FAA’s Flight Standards Division (AFS-800) amateur-built accident rate, we’re concentrating our on March 30, 2011. first Safety Wire columns in Experimenter on Advisory Circular (AC) Number 90-109, “Airman Transition to » To read the entire AC, click here.

32 NO. 2/OCTOBER 2012 Lancair 320

This month we continue by reviewing the transition drag. Experimental examples includes Glasairs and Lan- requirements for Family III and IV airplanes. Family III. Air- cairs. Type-certifi cated examples include the Cirrus SR-22, craft are characterized as having high inertia and/or low Cessna Columbia, Piper Comanche, and Mooney M20.

Transition Training for Family III Airplanes – High Inertia and/or Low Drag 1. Defined as airplanes that that occur too late in the land- cant range; however, unless decelerate slowly when power ing sequence. their low-drag characteristics is removed. are adequately managed, they 3. Transition hazards: will build excessive speed dur- 2. A typical accident involves a. This family of airplanes is on ing the critical flight phase of pilots misjudging their approach the leading edge of the low- approach and landing. energy, which in turn causes drag design technology. They b. Unmanaged excess speed can high, fast approaches with are beautiful, sleek, and look result in overshooting the final their associated long landings. fast even while sitting on the approach path and descent This results in overruns, or ground. These airplanes are angle, an inadvertent stall dur- worse yet, attempted go-arounds fast, efficient, and have signifi- ing a much-too-late go-around

Photography by Jim Koepnick EAA EXPERIMENTER 33 Safety Wire

attempt, wheel barrowing, aircraft to descend without large ing higher true airspeeds and in- loss of control, and run- reductions in power and simul- creased range. Aggressive and/ way excursions. taneously prevent overspeed- or abrupt throttle movements c. Also included in this fam- ing the aircraft. If the aircraft will increase the possibility of ily are airplanes designed is equipped with speed brakes, overboosting (or shock cooling) for high-speed cruise. These incorporate their correct use the engine, both of which will airplanes have relatively high into the training. Landing pat- cause severe engine damage. stall speeds necessitating high tern practice should emphasize b. Retractable landing gear sys- approach and landing speeds. proper power, correct descent tems may operate mechanically, This can be a challenge for profi le, and confi guration for the hydraulically, or electrically, or pilots transitioning from lower- approach and landing phase of may employ a combination of the performance airplanes that fl ight. Demonstrate the landing two systems. Pilot knowledge of will result in long touchdowns, distance required for different the system, including proper pro- runway overruns, and much- types of approaches in the vari- cedures for emergency landing too-late go-around decisions. ous landing confi gurations. Then gear extension, is vital. These airplanes also become practice them until successful c. Fuel systems tend to be compli- challenging when required to repeatability is ensured. There cated on complex and high-per- follow a slower airplane in the also needs to be an emphasis on formance airplanes. This leads to traffic pattern. adequate control (and a correct fuel mismanagement, as refl ect- understanding) of the airplane’s ed in the Nall Report that states 4. Recommended training for this stopping distance. almost one-third of fuel-related family includes both ground train- accidents involve fuel misman- ing and flight training. agement (i.e. fuel starvation— a. Ground training for airplanes Fuel systems tend to rather than fuel exhaustion). in this family should include be complicated on d. Performance (aerodynam- reviewing the proper power, ics) that allow the airplanes to airspeed operating limits, alti- complex and high- obtain higher airspeeds make tude, and configuration for the them less forgiving than slower specific airplane’s approach performance airplanes. airplanes. Since proper energy and landing maneuver. Train- management is a signifi cant ing should include the proper 5. Transitioning to higher-perfor- part of fl ying high-performance configuration and adequate mance airplanes can be demand- airplanes, the student must learn speed control for producing a ing for most pilots without previous to fl y “by the numbers.” stabilized descent and land- high-performance airplane experi- e. High-altitude training is required ing approach. Performance ence because of their new fl ight to fl y as pilot-in-command capabilities should be taught controls, new systems, and more (PIC) on any airplane certifi ed so that pilots are aware of the complex systems. The increased for altitudes above FL 250. Not runway lengths necessary for performance and complexity of only are there physiological safe airport operations. Deci- higher-performance airplanes requirements, but there are sion making on when to reject require additional planning, judg- also aerodynamic and handling a landing and initiate a go- ment, and piloting skills. Transition considerations that are critical around should be taught before training in these types of airplanes to safety when operating at the flight training begins. needs to be accomplished in a sys- airplane’s upper altitude limits. b. Flight training must include tematic manner using a structured This knowledge is invaluable, descents from cruise altitude, course of instruction that is admin- even when operating at altitudes pattern work, and landing dis- istered by a well-qualifi ed fl ight below FL 250. tance awareness. Training must instructor. This class of airplanes f. Turboprop transition involves include instruction in descent will involve exposure to some, or learning the different engine profi les to teach the proper most, of the following: operating procedures that distance versus altitude from a. Turbo-charged engines allow are unique to gas turbine en- which to begin a normal descent the aircraft to maintain suffi cient gines. The turboprop airplane profi le. A properly planned de- cruise power at high altitudes fl ies and handles just like any scent profi le should permit the where there is less drag, provid- other airplane of comparable size

34 NO. 2/OCTOBER 2012 and weight; the aerodynamics and experienced instructor. Full Flight Simulator (FFS). are the same. The major differ- This is due to the jet’s per- TC’d civil jets require an FAA ence is in understanding the new formance capabilities, flight flight test to obtain the re- type engine’s operating proce- characteristics, and more quired type rating upon your dures and its related systems. complicated systems. The airman certificate, as well as g. Jet transition absolutely very best transition training a 25-hour, mentored, initial requires that pilots receive for jet airplanes will be ob- operating experience period training in the specific type jet tained from a recognized train- prior to operating the airplane from a knowledgeable ing provider using a Level D as PIC.

Family IV Aircraft Family IV aircraft have nontradition- Experimental aircraft examples and the Breezy. A type-certificated al configurations and/or controls. include the Long EZ, the Air Cam, example is the Lake Amphibian.

Lockwood Air Cam

Photography by Brady Lane EAA EXPERIMENTER 35 Safety Wire

Transition Training for Family with trailing edge rudder and c. Issues Specific to Canards are IV Airplanes (Nontraditional elevator. Even though there may as follows: Configuration and/or Controls). be variations on the theme (e.g. (i) While canards offer several A TC’d airplane example is the a stabilator for the horizontal tail aerodynamic advantages, they Lake amphibian. component or a “V-tail” con- also carry some unique risks. Be- fi guration using ruddervators cause a canard lifts upward (rather 1. Defined as airplanes whose ex- to perform both pitch and yaw than downward like conventional ternal configuration is sufficiently functions) all TC’d airplanes will tails), it reduces the load carried different from traditional type behave in an expected, intuitive, by the wing (rather than increasing certificated (TC’d) single-wing, and acceptable manner. the wing’s load). This upward lift empennage-mounted tail designs b. The innovations presented in the characteristic produces improved so that they display non-tradition- experimental aircraft can include aerodynamic effi ciency, but also al handling qualities. Flight control non-traditional confi gurations makes its proper aerodynamic surfaces are different from the and controls, canards (Long-EZ), design extremely critical. typical elevator-aileron-rudder- and wing-mounted pusher engine (ii) The canard must be designed to engine/prop arrangements and/or installations (Lake Amphibians) stall before the wing stalls in order flight control systems are differ- that produce strong thrust-vector to allow a nose-down pitching mo- ent from the typical stick/yoke- effect. Other non-traditional con- ment. If the wing stalls fi rst, while pedals configurations. fi gurations include fl aperons (i.e. the canard is still producing lift, drooped ailerons – Robertson STOL there is no way to lower the aircraft 2. A typical accident scenario would conversions) leading edge slats nose and the stall then becomes involve a pilot who is unfamiliar (Helio Courier), crosswind gear unrecoverable (i.e. a deep stall). Ad- with the operation of a crosswind (Cessna 195), differential spoilers ditionally, if the canard stalls during landing gear (e.g. Helio Courier aircraft). When the crosswind gear is “unlocked,” the aircraft must be allowed to touch down in a crab. This is so that when the crosswind gear swivels upon touchdown, the aircraft will still track down the runway. (If the aircraft is “de- crabbed” prior to touchdown, with the crosswind gear unlocked, the aircraft will track off the downwind side of the runway, even though its longitudinal axis is parallel to the runway centerline. This is due to Long-EZ the fact that the crosswind will usu- ally provide enough side loads to swivel the landing gear.) Converse- (MU-2), and all-moving vertical the landing fl are, the aircraft will be ly, if the aircraft is landed in a crab tails (Mooney M20). Cockpit con- seriously damaged (or worse). with the crosswind gear locked, it trols may be a yoke, conventional (iii) A canard will typically have will ground loop-- just like any other stick, or outboard side-stick. Side- a rudder on each swept wing tip, conventional gear airplane. sticks may pivot conventionally, with each rudder only defl ecting or translate (slide) for pitch while outward. This feels natural to the 3. Discussion of transition hazards are pivoting for roll control. Throttles pilot and actually helps minimize as follows: may be on the left side, right side adverse yaw. Unlike traditional a. The external confi guration of (or both), in the center, on the fl oor, airplanes, both rudders can be TC’d airplanes follow a standard or on the ceiling (fl ying boats). The defl ected simultaneously to act as pattern using a single wing with obvious hazard in all this is the a speed brake. Because the de- ailerons (and usually fl aps) and potential for pilot misuse of the fl ected rudders change the air fl ow a tail consisting of a vertical and controls due to unfamiliarity with over the outboard wing sections horizontal stabilizer equipped the human-machine interface. (which are aft of the aircraft’s CG),

36 NO. 2/OCTOBER 2012 defl ecting both rudders simultane- confi gurations (usually pushers) and other owner/builders ously will produce an unexpected cause a reverse thrust-vector effect of your airplane model for pitching moment, as well as typi- in which increasing power pitches additional information. cally reducing aileron effective- the nose down (instead of up) and b. Flight training recommendations ness because of the disturbed reducing power pitches the nose up are as follows: airfl ow over the outer wing panels. (instead of down). Although pilots (i) Best training is accomplished (iv) Canards require a dramatic adapt to this effect, it complicates in your specifi c airplane with a wing sweep to locate the rudders maneuvers such as a rejected well-qualifi ed instructor who is far enough aft on the airframe to landing go-around. Becoming thor- experienced in the specifi c make be effective. Their dramatic wing oughly familiarity with the airplane’s and model. sweep causes a strong rolling ten- pitch-power interface is essential to (ii) Second best training source dency during any uncoordinated safe fl ight. is from the kit vendor, either fl ight. (A strong yaw-roll coupling (iii) Pilot interface with the control in your airplane or in their effect is a characteristic of all surfaces has a large infl uence on demonstrator of the same swept-wing airplanes.) Whenever workload, handling qualities, and model airplane. a slidslip is produced by rudder overall satisfaction with the aircraft. (iii) Third best training source is usage (or a wind gust), the airplane A short side-stick, which requires information from and fl ying with will weathervane back into the a lot of effort to move, will limit ma- the previous owner, if you pur- relative wind as well as roll away neuverability, and this disadvantage chased your aircraft already built. from the sideslip. (i.e. a “Dutch will grow as the airplane’s speed (iv) All training should empha- Roll” tendency which is also char- increases. Quickly fi nding the neu- size the unique aerodynamic acteristic of swept wing airplanes.) tral stick position after an airplane behavior of your airplane’s During slow fl ight, this rolling upset can also be very diffi cult with non-traditional confi gurations, tendency may be more powerful side-stick controls. as well as any pilot compensa- than that which can be countered (iv) Pilots typically enjoy a tac- tion required to safely fl y the by the ailerons alone. tile reference for their stick arm, airplane. If any of your airplane’s (v) Canard’s wheel brakes are typi- usually resting their forearm on cockpit controls are different cally operated by applying force to their thigh. Side-stick designs, from what you are accustomed the rudder pedal after the rud- without an arm rest, deprive the to, insure that you have become der is fully defl ected. This design pilot of this reference and make familiar with the advantages and saves both weight and space, but fi ne adjustments diffi cult, leading disadvantages of the design. it means that there is no braking to unwanted control inputs during Be sure that you explore your without fully defl ecting the rudder. turbulence. In designs with single plane’s handling qualities under This works well for taxiing, but side-stick between the seats, poor safe, supervised conditions. warrants consideration (and famil- implementation can limit roll con- iarity) for crosswind operations. trol due to interference with the The thought for this month is d. Other confi gurations that may cause pilot’s or passenger’s leg. “Not being known doesn’t stop problems are as follows: the truth from being true.” - Richard (i) Hand lever operation of the 4. Recommended Training is Bach, American author. So, until wheel brakes can be found in some as follows: next month, be sure to Think Right earlier Piper Cherokee aircraft that a. Ground training should allow to FliRite. did not incorporate the toe-brake the pilot to become thoroughly option. Hand brakes require the familiar with the location, force pilot to release either the stick required, displacement, and Hobart C. “Hobie” Tomlinson is or throttle control to operate the operative sense requirement the Director of Safety for Heritage hand brake lever, and it’s your of all the cockpit controls. Know Aviation, Inc., in South Burlington, arm strength that determines the your airplane’s systems, limits Vermont. He is also a Flight Advisor braking effectiveness. If brakes are and recommended procedures for EAA Chapter 613. He received cable actuated (via a single brake before you begin fl ying. Practice the 2012 Spirit of Flight award from lever), cable rigging becomes a simulated emergency proce- the Society of Experimental Test critical issue in order to prevent dures while on the ground. Pilots.. He was also named the 2012 asymmetric brake application. Consult the National CFI of the year by FAA. (ii) High-wing-mounted engine kit vender, type club members,

EAA EXPERIMENTER 37 Light Plane World

Phil Knox with the AeroMax built by members of EAA Chapter 132 from a kit donated by the manufacturer. T e AeroMax, like its predecessor the AirBike, is f own with the pilot’s legs on the outside of the fuselage, similar to a motorcycle. Welcome to… The new Light Plane World column By Dan Grunloh

Welcome to news and commentary renamed Light Plane World three AeroMax Is Back from the world of ultralights and years later, and in May 1987 it be- light planes. EAA originally adopted came Experimenter magazine. We This AeroMax displayed at EAA the light plane terminology in the still use the light plane terminology AirVenture Oshkosh 2012 by Phil early 1980s to describe the mixture on the grounds of AirVenture and in Knox, president of EAA Chapter of aircraft, including light N-num- aircraft judging because it best de- 132 in Elkhart, Indiana, was built by bered amateur-built aircraft, flying scribes the mixture of N-numbered chapter members and brought with at the time. It didn’t take long for the light aircraft flying with the ultra- it some good news. The aircraft is knowledge and skills accumulated lights from the grass strip at Air- built with laser-cut plywood parts in the homebuilt aircraft scene to Venture. We have everything from using a locking tab technology that migrate into the ultralight movement foot-launched powered paragliders speeds construction and eliminates and create “proper little airplanes,” to light-sport aircraft (LSA) like the the need for jigs and fixtures. Learn as they were called at the time. The Flight Design CT flying “down on the more about the development of the original EAA Ultralight magazine, Farm.” They’re all part of the world aircraft in the story “JDT AeroMax which began in January 1981, was of light planes. Prototype Flying in Tasmania,”

38 NO. 2/OCTOBER 2012 published in the February 2011 TEAM Mini-Max hopes people will download issue of the Light Plane World e-newsletter. Unfortunately, JDT the plans, start building, and then be motivated Mini-Max closed its doors earlier this year when the U.S. partner in to buy parts and kit components that can be the firm, John Grabber, announced ordered through the website. his retirement. The engineering and design side of the company as TEAM Mini-Max LLC, a name PDF download from its website. TEAM is based in Australia, and without that harks back to the roots of the Mini-Max hopes people will download a U.S. partner for manufacturing design. The international company the plans, start building, and then be and distribution, there would be no includes partners from South Africa motivated to buy parts and kit compo- AeroMax kits. and China. They have brought on nents that can be ordered through the board some of the original TEAM website. The AeroMax is a laser-cut Australian partner David Trump (Tennessee Engineering and Manu- kit, and plans are not needed or avail- came to the United States for a facturing) personnel, including able. David Cooper, director of U.S. meeting with many of the original Larry Israel. Their new website, operations in Niles, Michigan, said the players in the company, including www.TeamMini-Max.com, has more company also plans to reengineer one those associated with production details, a history of the TEAM air- of the earlier classic Mini-Max models of the parts and kits for the JDT Ae- craft designed by Wayne Ison, and as a laser-cut kit. roMax. Phil Knox owns the tool and a surprising announcement. die company used for fabricating Oratex Fabric on Bodacious the metal parts and laser-cutting The company is making the plans the wood components. JDT Mini- for all of the TEAM airplanes (seven When I first saw the new prepaint- Max has now been reorganized models) available free of charge as a ed fabric covering on Bodacious,

John Steere’s Bodacious started out as a Legal Eagle, but so many major changes were made that it became a dif erent airplane. It’s shown here with the wings folded, another of its unique features. T e prepainted fabric colors are Cub yellow and Fokker red.

EAA EXPERIMENTER 39 Light Plane World

the AirVenture Reserve Grand There are no paint runs, painting the German manufacturer’s web- Champion ultralight by John Steere equipment, or hazardous solvents, site, Oracover.de. The UK distribu- of Martinsville, Indiana, I thought and the method will save both time tor has a summary here, and there it was one of the top news stories and weight. Oratex has a finished is a dealer for Alaska and Canada in the ultralight area. The unique weight of 3.0 to 3.8 ounces per at www.BetterAircraftFabric.com. plane, inspired in part by Leonard square yard and should save 10 to Expect the announcement of a U.S Milholland’s Legal Eagle, showed distributor soon. fabulous workmanship and much I would argue it makes originality. See more photos by Batteries as Fuel Mathew Long here. Oratex UL600 little sense to include is a prepainted woven fabric that Something significant happened uses the same technology that has the full 5 gallons of at AirVenture, and you might have been available for years for model batteries in the empty missed it unless you talked to Dale airplanes, but it is now engineered Kramer or noticed he brought his for full-size aircraft. The red and weight of the ultralight. eLazair electric-powered ultra- yellow colors looked terrific. light to AirVenture 2012 in the 20 pounds of weight per airframe. landplane version. The ultralight Oratex UL600 is approved for air- The final cost is said to be about no longer qualifies for the addi- craft up to 600 kilograms or 1,320 the same as conventional aircraft tional 60-pound “allowance” for pounds gross weight. It is glued to covering processes after you amphibious floats as it was when the airframe with a water-based consider the cost of aircraft paints. flown here last year. It now must adhesive, then the fabric is shrunk Unfortunately the range of colors is weigh under 254 pounds empty of tight with heat, and you are done. small. For more information, go to fuel. There has been some talk and

Dale Kramer with his electric-powered eLazair, now in the landplane version, returned for a second year of f ying at AirVenture. It will f y for about one hour per charge. T e ultralight was probably the most f own electric airplane at the convention.

40 NO. 2/OCTOBER 2012 Darrell Porter showed of his craf smanship to bystanders down in the ultralight area with his wood and PVC replica Spandau machine gun for replica light planes of the First World War. T e only thing missing was a sound ef ects machine. discussions about a weight allow- sense to include the full 5 gallons based in Holden, Missouri. Darrell ance or exemption for the batteries of batteries in the empty weight of didn’t like the “toy” machine guns of- in electric-powered ultralights, and the ultralight. Dale apparently feels fered for use on the Baslee replicas, now thanks to Dale, we can better confident enough of his analysis so he decided to do it better. A kit will understand the argument that bat- of the question that he made many be sold through Robert Baslee and teries are the fuel and should not flights at AirVenture in his eLazair, Airdrome Aeroplanes. The materials be included in the empty weight. which weighs about 300 pounds are wood, PVC, and metal, and much with 5 gallons of batteries, but of the work is already completed. The There were some lively discussions much less than 254 pounds without price has not yet been determined. in front of his plane with people any fuel or other energy source. It’s not on the website yet. If interest- who thought differently, but Dale ed, call and ask. The company manu- reminded everyone there is no Mock Machine Gun for Ultralight factures kits for quite a few replica weight limit on the fuel allowed for or Light Plane airplanes, including a three-quarter- ultralights. The maximum amount is scale Eindecker ultralight ($5,495 less 5 gallons in volume, and there is no Airplane and model builder Dar- engine and paint). Learn more at limit on the type of fuel. It could be rell Porter showed his very realistic www.AirdromeAeroplanes.com. gasoline, corn oil, solid rocket fuel, mock German Spandau machine gun peanut butter, or electric batteries; at AirVenture 2012 in the ultralight Powered Parachute for Your so long as it fits in 5 gallons. Bat- area. Darrell built it for his own World Bucket List teries are different from other types War I Fokker replica, which was of energy sources in that their displayed in the replica fi ghter area. I have a confession to make. Al- weight is the same whether empty He works for Robert Baslee, designer though I have been an airman for or full. I would argue it makes little of the Airdrome Aeroplane designs 30 years and consider myself to be

EAA EXPERIMENTER 41 Light Plane World

a well-rounded aviator, somehow aside from those who flew the early of aircraft (as Leonardo da Vinci I had never gone for a flight in a designs, have actually experienced once said). Next up for me is a powered parachute. It wasn’t be- this degree of slow, open-cockpit gyroplane like those shown in this cause I didn’t like them—and flight. Many of us can slow our ul- video from the 2012 Popular Ro- I had many opportunities—but tralights, trikes, or fixed-wing light torcraft Association Convention in most of the time I was flying some- planes down to 30 mph or less, but Mentone, Indiana. thing of my own. At fly-ins, I didn’t this is completely different. We are want to take a seat away for a not hanging on the edge of a stall, If you have thoughts or suggestions newcomer who might decide to delicately controlling pitch and for this column, please send your take up flying. The years kept slip- throttle while keeping the wings comments to [email protected]. ping by, and I was still a powered level and ensuring we have plenty parachute “virgin.” of altitude for stall recovery. The powered parachute experience is Dan Grunloh, EAA 173888, Finally, a recent introductory far more relaxed. is a retired scientist who lesson with a certificated instructor began flying ultralights in an LSA powered parachute If I wanted to buy a first open- and light planes in 1982. has given me a better understand- cockpit airplane experience for my He won the 2002 and 2004 ing of their charm and appeal. spouse or another relative, U.S. National Microlight During the takeoff roll I was struck this would be it. You should try it, Championships in a trike by the extremely powerful pull of too. It’s hard to imagine anyone and flew with the U.S. World the canopy as it swung overhead. going up for a ride in a powered Team in two FAI World In cruise flight I came to the con- parachute and not wanting to get Microlight Championships. clusion that few ultralight pilots, back in the air again in some type

Dan Grunloh grinning during his f rst f ight as a passenger in a powered parachute in Kankakee, Illinois, in August.

42 NO. 2/OCTOBER 2012 Flight Testing Techniques

Airspeed Basics By Ed Kolano

I once had the privilege of flying to perform flight testing, and that 4. Equivalent an airplane that did everything involves a lot of work with air- 5. True at about 130 knots. Big deal, speeds. Last month we identified you say, because you’ve probably the various kinds of airspeeds We’re going to examine each of had that privilege yourself. The pilots should be familiar with. This these airspeeds by themselves, difference with this airplane month we’ll get into the details. then put the puzzle back together. was I did it somewhere on the That’ll put us in a good position to other side of 60,000 feet. That move on to calibrating your pitot- Observed and Indicated Airspeed put the true airspeed around 480 static system, which you’ll have to knots. Don’t plan to fly that high? do before you start collecting the Observed airspeed is what you see Doesn’t matter. data that will eventually become on the airspeed indicator. I know, the performance charts in your you thought this was indicated air- Understanding airspeed is airplane flight manual. speed. Well, it is according to FAA essential if you want to know – publications and many pilot’s oper- and you do – your airplane’s There are five airspeeds to deal ating handbooks. There’s no harm best climb speed, maximum with. They are: in doing this, because these manu- range cruise speed, and just in 1. Observed als just want you to be aware of case, its maximum range glide 2. Indicated the difference between what you speed. To get there, you’ll need 3. Calibrated see on the airspeed indicator and

EAA EXPERIMENTER 43 Flight Testing Techniques

Table 1

the published calibrated airspeeds. tor. Once you know these errors, specific pitot and static pressures You use calibrated airspeed in you can correct what you read on to the respective fittings on the your true airspeed calculations, the airspeed indicator (observed back of your airspeed indicator. so the airplane manufacturer airspeed) to what it should read These same fittings are used to wants to ensure you know what (indicated airspeed). connect your airspeed indicator you read on the airspeed indicator to your airplane’s pitot and static may have to be adjusted before you Indicated airspeed is observed lines that go to your airplane’s perform any planning. airspeed corrected for airspeed in- pitot tube and static ports. These dicator internal errors. Note: Some lines route the air pressure sensed We’re differentiating between texts refer to what you read on the at the pitot tube and static sources observed airspeed and indicated gauge (what we’re calling ob- to your airspeed indicator. Unfortu- airspeed because the airspeed in- nately, the pressures sensed at dicator itself may not be complete- the pitot tube and static sources ly accurate. FAA airworthiness You’ve probably seen are not always the real ambient standards for small airplanes call articles explaining how pressures, and an in-flight calibra- for minimum instrument calibration tion is necessary to account for error. This is the error inherent in to do this with a simple these errors. the gauge itself. Indicated airspeed is observed airspeed corrected for water manometer used Although it’s a common belief that airspeed indicator internal errors. to apply air pressure to the errors are mainly due to the pi- You can have your indicator bench- tot tube not being oriented directly tested to determine any errors the airspeed indicator. into the relative wind, for example, between what the airspeed indica- during slow flight or high angle of tor reads and what it should read served airspeed) as indicated air- attack flight, most of the problem based on the pitot and static pres- speed and the airspeed corrected comes from the static side of the sures applied to it during the bench for indicator internal errors (what system. Static ports are generally test. You’ve probably seen articles we’re calling indicated airspeed) along the side of the fuselage or explaining how to do this with a as true indicated airspeed. Too pitot tube. The object is for these simple water manometer used to much of an opportunity to confuse ports to be exposed to the ambi- apply air pressure to the airspeed it with true airspeed, so we’ll stick ent air pressure without allowing indicator. The applied pressures with observed airspeed. any ram pressure to enter. Ram correspond to appropriate air- pressure is pressure caused when speed readings. The technician Indicated and Calibrated Airspeed air is forced into the port by virtue compares the appropriate indi- of the airplane’s forward speed. cated airspeeds with the readings The observed-to-indicated bench It’s the pitot tube’s job to sense observed on your airspeed indica- test is accomplished by applying that ram pressure along with the

44 NO. 2/OCTOBER 2012 ambient pressure, but the static Because your airspeed indicator compares the port should be located such that it senses only ambient or static pressure from the pitot tube with the static pressure. This is why the static port is located where its opening is pressure, any variation in sensed static pressure perpendicular to the relative wind. can cause erroneous airspeed indications. Different flight conditions and land- ing gear and flap positions can We’ll discuss flight-test methods where this variation is minimal. cause the air pressure around the next month, but for now we’ll just That’s why this indicated-to-cal- static port to vary. Because your make the point that calibrated ibrated correction is often called airspeed indicator compares the airspeed is indicated airspeed position error correction or instal- pressure from the pitot tube with corrected for errors stemming from lation error correction. the static pressure, any variation in the pressure variations around the sensed static pressure can cause static port. Note: Certified airplane Calibrated and Equivalent Airspeed erroneous airspeed indications. manufacturers perform extensive The only way to determine these testing to find a static source loca- Equivalent airspeed is calibrated errors is through flight testing. tion or position on their airplanes airspeed corrected for compress-

Figure 1

EAA EXPERIMENTER 45 Flight Testing Techniques

ibility. This word “compressibility” you fly your airplane at 100 knots As Figure 1 shows, what you is often associated with high- equivalent airspeed at 10,000 feet, read on your airspeed indicator speed, near-sonic flight, but in this the less dense air means a lower is observed airspeed. Correct application it has to do with the air sensed pressure in the pitot sys- the observed airspeed for internal pressure in the pitot system. In tem, and that results in a lower gauge errors, and you get indicat- a nutshell, at faster speeds airspeed reading on your airspeed ed airspeed. Correct the indicated and higher altitudes, the static indicator. Alternatively, if you airspeed for installation/position pressure sensed in the pitot fly your plane at 10,000 feet with errors to get calibrated airspeed. system (remember, the pitot sys- an airspeed indicator reading of Account for high-speed and tem senses total pressure or 100 knots, your true airspeed will /or high-altitude flying to find static plus dynamic pressure) is be faster. equivalent airspeed. Correct not the true static pressure. The equivalent airspeed for density sensed static pressure is higher altitude to find true airspeed. due to this compressibility effect, T e sensed static Apply wind corrections to your so the total pressure in the pitot pressure is higher due to true airspeed to determine system is artificially high. This ground speed. causes the airspeed indicator to this compressibility ef ect, show a faster speed than the air- If all these different airspeed plane is actually flying. so the total pressure corrections sound intimidating, in the pitot system is take heart. If your flying habits The good news for most of us is we or airplane limitations keep you usually don’t fly fast enough or high artif cially high. below the equivalent airspeed enough to worry about correcting correction altitudes and airspeeds, for this error. Table 1 shows the you’ll need just two tests. The corrections that would have to be You may be familiar with airspeed manometer bench test will account applied to a sampling of calibrated indicators that have true airspeed for any errors in the gauge, and airspeeds at different altitudes. Un- indicating capability. Rotating a an airspeed calibration flight less you fly faster than 200 knots temperature scale to align outside test will take care of any installa- calibrated airspeed higher than air temperature with your pres- tion errors. 10,000 feet pressure altitude, you sure altitude on a pressure altitude can probably safely ignore this scale also rotates a true airspeed Okay, we’ve laid the groundwork correction. Note: The manufacturer scale behind the indicating needle, with this airspeed primer for next calibrates the airspeed indicator to allowing you to read true airspeed month’s topic – airspeed calibra- read correctly under standard day, directly along with observed air- tion. We’ll take a look at a few sea level conditions, so there is no speed. This simple device works flight-test methods you can use to calibrated-to-equivalent correction because aligning the outside identify your airplane’s position er- necessary when flying under these air temperature and pressure ror corrections. conditions at any speed. altitude scales compensates for density altitude. Density altitude Questions about flight testing? Equivalent and True Airspeed is pressure altitude corrected E-mail [email protected]; for temperature. True airspeed is please put “Flight Testing” in the The higher you fly, the less dense equivalent airspeed corrected for subject line. the air is. This decrease in air den- density altitude. sity affects the pressure sensed by the pitot system, and therefore, the True Airspeed and Ground Speed Ed Kolano, EAA 336809, is a reading on your airspeed indica- former Marine who’s been tor. Say you fly your airplane at Ground speed is true airspeed cor- flying since 1975 and testing 100 knots equivalent airspeed at rected for wind. This wind correction airplanes since 1985. He sea level. The pressure in your is learned by every private pilot and considers himself extremely pitot system causes your airspeed used by every pilot every time we fl y. fortunate to have performed indicator to read 100 knots. (Let’s Although ground speed has nothing flight tests in a variety of assume the corrections for indica- to do with your airplane’s airspeed airplanes ranging from tor, position, and compressibility indicating system, it completes our ultralights to 787s. errors are zero for simplicity.) If look at the fl ight speed picture.

46 NO. 2/OCTOBER 2012 EAA Employee Brian Tesch #849155 wearing Camp Shirt Plane provided by Curt Drumm, Lakeshore Aviation member #374143 EAA AirVenture Oshkosh Sea Plane Base 2012

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