The Pterodactyl Ascender is a family of U.S. designed and built ultralight aircraft that were sold in kit form between 1979 and 1984 under Pterodactyl Limited and is currently being sold by DFE Ultralights. With a total production of 1,396 aircraft between 1979 and 1984 plus limited production today as the DFE Ascender III series, the aircraft has been one of the most influential designs in ultralight aviation.
Design and 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 was tailless. 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 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 EAAannual 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 and was powered by a Sachs SA-340 336 cc direct drivetwo-stroke engine. Construction of all Pterodactyl aircraft was predominantly of anodized 6061-T6 aluminum tubing, braced with swaged steel cables supported by a king post and with a sewn Dacron sail for wing covering. Fittings to join the tubing were either extruded or made from sheet and bolted together. The company was moved in 1980 from Monterey to a new facility co-located with the Seventh-day AdventistMonterey 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. Pterodactyl production commenced in 1979 and was completed in 1984, when the company was sold to a group of partners under the name "Freedom Fliers" and moved to Rowlett, Texas. The company quickly went out of business, and few aircraft were completed. McCornack was never paid for the sale of the company. A total of 1,396 aircraft were built by Pterodactyl.
DFE Ultralights
In 1991 one of McCornack's original dealers from 1978, Dave Froble, started producing parts to keep his own fleet of Pterodactyls flying. He located and purchased the old stock of Manta Products airframe parts and produced CAD drawings for the complete parts. In 1992 Froble started making parts available and later offered kits for complete aircraft in three models under the company name DFE Ultralights. These were very similar to the original Pfledge and Ascender series and were named Ascender III, with letters to designate the various models. DFE Ultralights has produced a small number of complete kits and continues to support the fleet of existing aircraft with parts to keep them flying.
Operational history
In the USA the single seat Pterodactyl models are flown as ultralights under FAR 103, whereas the two seat models are usually registered as experimental amateur-builts. In Canada all Pterodactyls are classified as Basic Ultra-lights. Pterodactyls have been flown on many long flights. John D. Peterson, Jr. completed a flight in a Pfledge from Long Beach, California to Hilton Head, South Carolina over a period of 29 days between July 9 and August 6, 1979, with ground support. He flew the distance by flying distances of a maximum of 120 miles in a single flight. This feat was the first time that an ultralight airplane had been flown across the US from coast to coast. Peterson's aircraft is on display in the Smithsonian Museum's Steven F. Udvar-Hazy Center. McCornack and Nicely's 1979 flight from Monterey, California, to Oshkosh, Wisconsin, and on to the Atlantic coast was the second transcontinental flight by this aircraft type and was done mostly without ground support.
