GRASS RUNWAYS: THE WHISPER OF WHEELS ON TURF KITPLANES OCTOBER 2016 ® Merlin PSA • Grass Runways MERLIN PSA • Maintenance Manuals • Weight Savings THE • Geared Drives PERSONAL • Pre-Buys SINGLE Part 2 • Trick Stick • Dynamic Balancing • Torque Plates ENGINE THEORY OCTOBER 2016 BELVOIR Direct or Geared? In the Shop: PUBLICATIONS ONE TRICK STICK • Weir’s Workbenches Versatile Air Data Probe • Torque Plates • Vise Squad WEIGHT SAVINGS • Easy Rivet Holders Do’s and Don’ts www.kitplanes.com SE No matter what you call it, SE is Dynon’s most affordable and intuitive SkyView experience ever. Dynon is excited to introduce the newest member of the SkyView family. SkyView SE is made specifically for VFR aircraft and pilots who want the most intuitive flight and engine instruments on the market. They feature simple and clear displays, with almost no menus to navigate in flight. At the same time, SkyView SE retains modern, innovative Dynon EFIS capabilities like SkyView’s revolutionary COM radio interface and 2-axis autopilot with single-touch controls. Without mapping capabilities, even the 7” SkyView SE display has a large, easy-to- read Primary Flight Display, including pilot-selectable six-pack “steam gauges”. With its simplified feature set and installation, SkyView SE is the successor to Dynon’s legacy D100 series products. The 7” SV-D600 display is priced at $1850, with the 10” SV-D900 at $3100. A complete 7” SkyView SE system with primary flight instruments starts at $3305 including harnesses. Add the SV-XPNDR-261 Mode S Transponder (with ADS-B Out) and SV-GPS-2020 GPS Receiver/Antenna for a low-cost integrated glass panel system that meets FAA 2020 ADS-B Out requirements. DynonAvionics.com [email protected] (425) 402-0433 October 2016 | Volume 33, Number 10 Flight Review 6 MERLIN PSA: The personal single. By Paul Dye. Builder Spotlight 16 THE INS AND OUts OF PRE-BUYS: Don’t buy a used Experimental aircraft without one (Part 2). By Vic Syracuse. 24 GEttING HIGH OFF GRass: Flying organically with turf runways. By LeRoy Cook. 28 CUstom MAINTENANCE MANUALS: They may not be required, but they’re essential for performing thorough inspections. 24 By Katie Bosman Krotje. 34 BaLANCING Act: Troubleshooting vibration problems in homebuilt airplanes. By Matthew Dock. 40 ONE TRICK STICK: Andrew Angellotti develops an air data probe for the masses. By Tom Wilson. 52 ENGINE THEORY: Direct vs. geared drive—one of aviation’s great debates. By Tom Wilson. 66 CompLETIONS: Builders share their successes. 72 aSK THE DAR: Condition inspections, N-number problems, removing an electrical system and transponder. By Mel Asberry. Shop Talk 58 THE NEW GUY: Documenting your build. By David Boeshaar. 60 MAINTENANCE MattERS: Torque plates. By Dave Prizio. 64 HomE SHop MacHINIst: The vise squad. By Bob Hadley. 76 AERO ’LEctRIcs: Workbench. By Jim Weir. Shop Tips 51 A BEttER RIVET HOLDER: By Eric Stewart. 63 FoLDING poRtaBLE GPS moUNT: By Jim Fleischman. Designer’s Notebook 44 STREssING STRUctURE: Places to save weight and places not to. By David Paule. 6 73 WIND TUNNEL: Wing root junctions. By Barnaby Wainfan. Exploring 2 EDItoR’S Log: Early or late? By Paul Dye. 48 CHECKpoINts: The big picture and red herrings. By Vic Syracuse. Kit Bits 4 LEttERS 67 LIst OF ADVERTISERS 68 BUILDERS’ MARKEtpLacE 80 KIT STUFF: Drawing on experience. By cartoonist Robrucha. 40 On the cover: Chip Erwin puts the single-seat Merlin Personal Sport Aircraft through its paces. Photographed near South Lakeland, Florida, by Richard VanderMeulen. For subscription information, contact KITPLANES® at 800/622-1065 or visit www.kitplanes.com/cs. KITPLANES October 2016 1 EDITOR’S LOG Early or late? Long before I wrote for aviation publications, I was doing testing—of airframes, engines, avionics, and acces- sories. Flight test was my field, and I have always been given opportunities to evaluate and give feedback on vari- ous designs and products. It is reward- ing to see changes that you suggest implemented in a design, and you always hope that they are improve- ments and accepted by the pilots that will come after you. I have never really been an “edge-of-the-envelope” kind of guy however—more like someone who looks to minimize risk and look for incre- mental improvements—and that affects the kinds of evaluations that I will accept. I have often described myself as an early adopter of things that are not When you spend a lot of time testing avionics, your panel rapidly takes on a polyglot look of different brand names and labels. What’s important is that you maintain a minimum required to keep me in the air, and a instrument set needed to safely fly the airplane. (Photo: Paul Dye) late adopter of flight-critical equipment. Most avionics are a good example of and reliability is measured primarily by grasp when you’re young and looking the former. If an EFIS, GPS, or radio gives how many hours the particular design for excitement, but when you are old up the ghost in flight, it is pretty easy has accumulated. While I always try to and looking back on some of the excit- to bring the airplane back down in one have backup plans for every conceivable ing times you’ve had, you are sort of glad piece—assuming, of course, that the contingency when I fly, new essential that they are in your past—and thankful equipment doesn’t go up in a ball of fire, equipment causes me to have backups that you’re still alive to reminisce. and I wasn’t foolish enough to make it a to those backups—or sometimes to just But deciding to buy or try new equip- sole source of navigation in the clouds. pass the chance for potentially exciting ment isn’t just a matter of personal safety; Engines, powerplant accessories, and flight testing on to someone else. it can also have a large effect on your ignitions, on the other hand, are mighty The best test pilots I know are very pocketbook or bank account. Experimen- important pieces of gear, and while I am reserved people that go out of their way tal aviation is known for radical ideas and qualified in a number of gliders, I prefer to not to experience excitement, but to the people who think them up. There are do power-off work in airframes designed minimize it. Boring people actually. The countless designs that looked like the specifically for quiet flight. The same ones that have lived the longest usu- upcoming salvation of aviation itself—yet thing is true for any part of the power ally stop after one beer, and are often they quietly faded into the background train—from the fuel caps all the way to headed home early to study for the next when reality sank in, funding dried up, and the exhaust pipes. I want those reliable, day’s flight. I know that is a hard idea to problems cropped up with no solution. Paul Dye retired as a Lead Flight Director for NASA’s Human Space Flight program, with 40 years of aerospace experience on everything from Cubs to the space shuttle. An avid homebuilder, he began flying and working on airplanes as a teen, and has experience with a wide range of construction techniques and materials. He flies an RV-8 that he built in 2005, and an RV-3 that he built with his pilot wife. Currently, they are building a Xenos Paul Dye motorglider. A commercially licensed pilot, Paul has logged over 4800 hours in many different types of aircraft and is an EAA tech counselor, flight advisor, and member of the Homebuilder’s Council. He consults and collaborates in aerospace operations and flight-testing projects across the country. 2 KITPLANES October 2016 www.kitplanes.com & www.facebook.com/kitplanes Unfortunately, the early adopters who souls? By applying some strict rules found a completely new law of physics, provided deposits, which the developer about where you will and will not finance, or of nature. In most cases, it’s used to pay for his hangar rent during spend your money, for starters. The highly unlikely. If someone presents you the design phase, never saw a product same rules apply as they do in non- with the product of your dreams, pinch in return for their cash. The frequency aviation endeavors. Learn the laws of yourself—you might just wake up to find with which this happens has always physics and know that they can’t be that yes, indeed, your dream was about astounded me, for again and again, we broken. You are not going to go 250 to turn into a nightmare. see companies both big and small give knots on 65 horsepower unless you are Being an early adopter is OK, so long as up on their seemingly foolproof ideas, be doing it pointed straight down from a you go into it willing to have the product they for airframes, engines, or avionics. great height. Electronics and software fail and to lose what you have invested, Coming up with the idea for a new development cost money—and while in both time and money. If you have to product is easy. Coming up with a design Apple can sometimes give away cell do a great deal of modification to your that promises to deliver on that vision is phones, they can do this because they airframe to install a new design, under- harder. Testing the prototype and solv- have amortized the development cost stand that you might have to do a lot of ing the inevitable problems that crop over millions of units.