Just One More...

Innovations May Increase
Versatility, Reliability in Aircraft Design

Some engineering projects tend to be like minor renovations to the home -- one starts out with a fresh coat of paint in one room, and by day's end, the old furniture has been sold, walls have been knocked down, and the truck with the new windows is in the driveway. David Gevers started out with a modification proposal for a small airplane, and now has a company with patents for a new aircraft of his design.

The proposed Genesis airplane is to be a six-passenger, twin-engine, pusher-prop design that is multi-configurable for landing on hard surfaces, snow or water. In the case of water landings, outrigger wheels would pivot outward to reduce drag. When the aircraft is in cruise mode, the outriggers would be fully retracted for maximum aerodynamics, while the propeller drives on the opposite ends of the outriggers move the props in direct line with the wings for improved lift. All configurations would be selectable from the cockpit during flight, without need for component changes on the ground. Ball-screw drives, driven by electric motors, will shift the various assemblies, with manual crank overrides in case of system failure.

The two engines will be installed face-to-face in the fuselage behind the cabin, driving a common gearbox from which both propellers will be spun via belt drives. Engine placement above the main landing gear transmits landing forces directly to the gear without passing through wing structures, and their positioning near the aircraft's C.G. reduces the rotational moment of inertia, improving spin control and high-speed taxi maneuvering. The belt-drive system, which helps facilitate mounting the props on pivots, is quieter than using shaft drive. Overall, the entire system provides redundant power should an engine fail, with only a reduction in total power, but no asymmetric thrust. Overrunning clutches would allow coupling or decoupling of the engines either automatically or at the pilot's discretion.

What originally set this project in motion was an idea for telescoping wings. The Genesis will offer an option for a main wing comprised of a fixed center section and two extendable outer sections, using a simple overlapping spar. Retracted, the low-drag central section permits the aircraft to reach cruise speeds of over 280 mph at 75% power. When extended, STOL performance is enhanced, with a stall speed of 63 mph. If multiple components in the wing should fail, the wing would simply stop in its present position, still leaving the plane completely controllable.

Genesis has had a long evolution, with its earliest design work dating back to 1981. According to Gevers, the time has been invested in extensive optimization changes and the performance of computer-aided analyses. The military has already expressed interest, suggesting that a 15-20 passenger version would be well-suited for moving troops into adverse areas. The next planned step is to construct a test stand for further development of the motors and the gearbox, and begin to build the first prototype aircraft.

--RM

For further information, contact Gevers Aircraft, Inc., PO Box 430, Brownsburg, IN 46112. 317-889-0319. http://www.geversair craft.com Circle 460.