January 2014

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/247918

Contents of this Issue


Page 20 of 38

For everyday storage, the Panther's wings fold. Using a combination of Navy and sailplane technology, Dan has a setup that can go from folded to flyable in about 2 minutes. An additional plus is that the tanks can be filled when the wings are folded. Although folding the wings is the usual footprint-reducer of choice, the wings are also easily removed for hauling. The Panther can be trailered in a 7-foot by 7-foot by 19-foot-long trailer "with half an inch left side-to-side," Dan said. "From wings-of in the trailer to flyable takes two guys 15 minutes." Dan also noted that this is one of the only modern kit planes where you can get great performance by building your own engine. For about $7,000, you can have an AeroVee (80 hp) or Corvair (100 hp) engine ready to make your day. Other details show a lot of thought: The cable covers and map pockets are also stifeners. The 2-cubic-foot forward luggage compartment provides enclosed storage usually provided by the second seat. (There is also a luggage compartment, aft.) Inset, the isolator used for the automatic connection of the fuel sender unit in the wing. It's created by the 3D "printer. " WHY A SINGLE-SEATER? There is just one seat, with a five-point harness. Why, when the vast majority of light-sport aircraft (LSA) are two-place? First, a solo machine can accommodate nearly any size pilot without compromising aerodynamics. The Panther fits a wide range of pilots, courtesy of 6 inches of rudder pedal adjustment and 8 inches of seat adjustment. A single (or tandem) configuration's frontal area is constrained more by the engine than the cockpit, and the ballistics of the fuselage can be superior to that of a wider airplane, as well. This allows higher speed on lower power, which is another way of saying "economy." Center of gravity is more easily controlled (and therefore optimized). Additionally, a single-seat design in a weight-constrained class allows a lot of fuel capacity and a strong structure. Rollover protection and ballistic parachute mounts (the ballistic chute option is being developed) are built into the welded 4130 chromoly structure. Light weight also gives a light wing loading. Dan said, "We've tested a 45-knot stall at 1,115 pounds." SOME SPECIFICATIONS The Panther, available as an amateur-built "Sport" model or as an LSA, can be built as either a taildragger or as a tricycle gear on an aluminum 6061-T6 monocoque fuselage forward of the seatback, with aluminum-skinned 4130 chromoly steel tube, aft. Both models are rated for +6g and -4.4g; both incorporate four-position flaps, with up to 40 degrees of travel. The 1,115-pound LSA can carry engines of 80 to 120 hp; the Sport can handle up to 160-hp engines. The LSA wingspan is 23 feet, 6 inches, yielding just under a 12 pounds/square foot wing loading. The 1,150-pound Sport has a 21-foot, 6-inch span and consequent 13-½-pound loading. The LSA's claimed top speed of 140 to 180 mph can far exceed that of the LSA rule. Dan said, "Our intention was to Photography by Jim Koepnick Rachel and Dan Weseman. install a large engine to provide excellent takeof and climb performance, coupled with the prop to not exceed the continuous power at sea level LSA requirement of 138 miles per hour." The LSA's VNE is listed as 200, and the Sport's cruise is pegged at 160 to 200, with a VNE of 220 mph, at which the prototype has been tested. The Panther holds 27-½ gallons of fuel in two tanks; fuselage and wing fuel lines mate through quick-connect fittings. The fuel tanks are removable via nut plates, or they can be riveted—it's the builder's option. The seat sits low; there is room for a parachute, and the canopy has a quick-jettison design. A taller canopy is ofered, suitable for extra tall pilots, and opencockpit testing is underway. BUILDERS HAVE REAL OPTIONS Another advantage that light weight brings is the ability to use other engines and stay within design limits. "The airplane is EAA Experimenter 21

Articles in this issue

Archives of this issue

view archives of Experimenter - January 2014