- Why this plane?: In 2004 I started thinking seriously about doing an airplane of my own design. After all the work involved in the biplane project I knew it had to be something worth the effort of another project, and needed to be unique. A brief flirtation with the idea of a rocket-powered Berkut (!) had clued me into the NAA record books, and I began researching the lower weight class altitude records. The first priority was (and is) to make a decent, controllable airplane, but the altitude record remains a brass ring worth going after. The current record is just over 30,000ft, and must be broken by 3%.
- The design: As with all maximum-altitude airplanes, the flight performance goals require a low drag-power airplane. While high-performance sailplanes and jets have low drag, their higher-speed requires higher power input to the system, either by big engines or a higher sink-rate. Altitude-optimized airplanes, on the other hand, are designed to fly much more slowly, reducing the power (which increases with the cube of airspeed) required to maintain level flight. The result is often an airplane that looks less streamlined, but is actually more efficient by virtue of the ability to fly slower. The pod-and-boom configuration was selected to maximize propeller clearance and minimize landing gear size (read: weight), and is used on other low-power airplanes (e.g. the Gossamer Condor) where the weight benefit of a separate fuselage pod outweighs the drag benefit of a nice teardrop-shaped fuselage. Other lightweight aircraft, from models to ultralights, also use it. The other design details like the slab-sided fuselage pod were driven by the simplified tooling system and inspired by airplanes like the Facetmobile (which I shared a hangar with in LA).
- Structural capability: The airplane was designed to a limit in excess of 7g, plus appropriate safety factors. While most light airplanes are sized for 3.8g or 4.4g, the low wing loading of this design makes the airplane particularly susceptible to gust loading.
- Materials: The fuselage and wing structures are fiberglass/foam sandwich construction with carbon fiber in high-stress areas. The fuselage boom is a built-up carbon fiber box beam with foam and carbon/foam bulkeads. The tail group and ailerons are aluminum tubing held together with sheet aluminum gussets, and the tail group, ailerons, and wing aft of the spar are covered with PolyFiber's aircraft-grade fabric covering system.
Aeropoxy was used exclusively for the composite parts. All three hardeners were used (30min, 60min, and 120min) depending on the working time needed. I wholeheartedly recommend this system.
All exposed composite parts were filled with PolyFiber Smooth-Prime, then primed with PolyFiber EP-420 white epoxy primer.
- Specifications:
- Wingspan: 45ft
- Height: 6.5ft
- Length: 21.5ft
- Empty Weight: 425lbs
- Engine: Rotax 503, 46hp (52 Dual Carb)
