Pterodactyl Ascender - Development

Development

The Pterodactyl designs have their roots in the Manta Fledge hang gliders of the 1970s. The Fledge was designed by Klaus Hill and produced by Manta Products in a series that ran from the Fledge I to the IV, with numerous sub models designated by letters. The Fledge series were of a "rigid-wing" type, as opposed to the predominantly “flex-wing” hang glider designs then common. These designs all featured weight-shift pitch control and tip-rudders for yaw and roll control. The tip rudders were controlled by control-bar sliders which deployed one tip rudder at a time to create a yaw. The glider's swept wing then translated the yaw into a matched rolling motion. The Fledge series were considered to be high performance hang gliders during their production run in the 1970s.

California inventor Jack McCornack took the Fledge IIB wing and designed a tubular assembly that replaced the Fledge's hang glider seat with a reclined pilot seat, wheeled landing gear and engine mount for a pusher powerplant. The aircraft used a mouth-controlled throttle, as both hands were used on the tip rudder twist grips which were retained from the Fledge. The aircraft had no canard or tail and was a true flying wing. Power was supplied by a two-stroke Xenoah engine of 16 horsepower driving a 36-inch propeller. This new design, named the Pterodactyl Fledgling, was first flown in 1977. It is also referred to variously as the Pterodactyl Fledge and Pfledge

The aircraft was first publicly displayed at an ultralight fly-in at Gilroy, California in 1978. McCornack formed Pterodactyl Limited to produce an improved version of the design, designated the Fledge X powered by the Xenoah 242 16 hp (12 kW) engine.

In 1979 McCornack and his flying partner, Keith Nicely, flew two improved Fledglings from their base in Monterey, California to Oshkosh, Wisconsin, where they made a positive impression on the large gathering of pilots at the EAA annual convention there. At the convention they were invited by Mother Earth News magazine to fly the aircraft on to the Atlantic coast on pure ethanol supplied by the magazine. The flight from coast to coast was one of the longest trips of the period and garnered much attention for the start-up company.

Limited production of the version flown to Oshkosh started in the fall of 1979. The model was called the Pterodactyl Pfledge OR (Oshkosh Replica) and was powered by a Sachs SA-340 336 cc direct drive two-stroke engine.

Construction of all Pterodactyl aircraft was of similar material, predominantly anodized 6061-T6 aluminum tubing, braced with swaged steel cables supported by a king post, with a sewn Dacron sail for wing covering. Fittings to join the tubing was either extruded or made from sheet, connected with aircraft AN bolts. The sails came in a wide variety of colour combinations.

The company was moved in 1980 from Monterey to a new 7,200-square-foot (670 m2) facility co-located with the Seventh-day Adventist Monterey Bay Academy at Watsonville, California and series production of the Pfledge was commenced. The new location was ideal as it included access to the Monterey Bay Academy Airport. The design went through a series of evolutionary improvements, mostly involving the powerplants installed and these resulted in a number of different models.