Experimenter is a magazine created by EAA for people who build airplanes. We will report on amateur-built aircraft as well as ultralights and other light aircraft.
Issue link: http://experimenter.epubxp.com/i/271000
EAA Experimenter 23 It was out of a Mooney and had been sitting in Charlie Jentus' basement for years, so it was about as rusty as an engine can get. In fact, I had to mill the cylinders of just so I could get the wrist pins out. About all I used was the case and the crank. Everything else was new. At this point, Dan Hopkins and I went to the Lycoming school in Pennsylvania to learn how to assemble and disassemble the engine. Then we assembled the engine with the help of a mechanic in northern Ohio." One of the problem areas in any high-performance airplane is getting the landing gear to retract in such a way that all of the gear doors close perfectly fl ush with the belly of the air- plane. It's the rare airplane that has tight gear doors, but Mike was determined that his would be one of them. "I played all sorts of games with the landing gear and the doors," he said. "For one thing, as designed, there is supposed to be a long, tapered bump in the wing walk, which is stif ened by carbon fi ber, by the way, for tire clearance. On mine I just faired the wheel in a smaller-than-designed bump. It looks better. "The gear doors were a real chore to get closed exactly fl ush because when you're swinging the gear in the shop, there is no air load on anything; so the exact rigging changes when the airplane is fl ying. For instance, to get the inner, main gear doors and the nose-gear door to snap shut and be nice and tight, I put in a small 3/4-inch cylinder that was actuated by an electric valve that was signaled by the up-gear switches. When the gear is up, the switches turn on the electric valve. The valve lets the hydraulic pressure actuate the small cylinder that pulls on three small cables that pull the two inner main gear doors and the nose gear door closed. On that cylinder, there is a switch and when the cylinder reaches the closed position, the switch turns of the hydraulic pump. "It's this kind of thing that makes scratchbuilding so dif- ferent than building kits. You have to love solving problems by yourself. I'll still be changing and improving stuf on the airplane until I'm 95 years old." THE GP-4 AND GEORGE PEREIRA AN ANNIVERSARY WITHIN AN ANNIVERSARY Although we are celebrating the 30th anniversary of the fi rst fl ight of the Pereira GP-4, super-fast wooden wonder, this year, what we should be celebrating is the 70th (that's right, 70th) anniversary of George Pereira's intro- duction to fl ight training. George recalled how he got started fl ying: "I was a freshman in college on a football scholarship and absolutely hated it. It was 1944 and World War II was in full swing; so I volunteered for fl ight training." In short order, George traded his college campus for a U.S. Army Air Forces base outside of Foggia, Italy, from which he piloted a B-17 on raids into German territory. When the war was over, George returned to Sacramento, California, got mar- ried, and eventually established a chain of building supply companies. George said, "I needed to be able to visit those stores on a regular basis, and they were spread over a wide area in Northern California, so I got back into avia- tion and bought a Mooney 21, which I fl ew often. In fact, out of boredom, I'd often fl y over the coast and lakes around the San Francisco Bay area. I found myself thinking a lot about how nice it would be to have a personal airplane that would let me land on the water. "At the same time, I got involved in building racing boats. These were ski-type boats using V-8s for power, so I got my feet wet, literally, in designing hulls. "Eventually, I retired out of the building supply business and spent much of my time designing airplanes, the Osprey I fl ying boat being the fi rst. The Navy even evaluated it. It appeared in a number of magazines, and I started getting requests for plans. Soon I found myself in the homebuilt plans business. At the same time, I redesigned that fi rst plane into a two-place amphibian, recognizing that an air- plane that couldn't land on a runway as well as water wasn't very practical. To date, I've sold more than 1,700 sets of plans, and lots of the aircraft are fl ying." "In the early 1980s, I decided to build an airplane for cross-country fl ying. At the time, anything that did 200 mph was considered impossibly fast, so I set that as my minimum performance number and started educating myself on what it would take to go that fast behind what then was a new engine, the 200-hp IO-360-A1A." The fi nal design was the GP-4, a sleek, tapered-wing, retractable-gear speed- ster made entirely of wood. He said, "When I looked around, I saw a lot more guys with woodworking shops rather than metal or rag and tube talents. Plus, I was very familiar with wood, so that's the way I went with the airplane. So far I've sold more than 650 sets of plans, and there are more than 55 airplanes fl ying all over the world, from Norway to New Zealand." Congratulations, George, on 30 years of helping homebuilders realize their dreams. And thanks for your service in WWII. Wanting to get all three gear doors closed as tightly as possible, Mike designed a separate system that uses a small hydraulic cylinder that is sequenced to close the doors after the gear is up. Photography by Jim Raeder E A A E X P _ M a r 1 4 . i n d d 2 3 EAAEXP_Mar14.indd 23 3 / 3 / 1 4 1 0 : 3 1 A M 3/3/14 10:31 AM