Pterodactyl Ascender
Encyclopedia
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
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.
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 wingSwept wing
A swept wing is a wing planform favored for high subsonic jet speeds first investigated by Germany during the Second World War. Since the introduction of the MiG-15 and North American F-86 which demonstrated a decisive superiority over the slower first generation of straight-wing jet fighters...
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
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
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
Horsepower
Horsepower is the name of several units of measurement of power. The most common definitions equal between 735.5 and 750 watts.Horsepower was originally defined to compare the output of steam engines with the power of draft horses in continuous operation. The unit was widely adopted to measure the...
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
Gilroy, California
Gilroy is the southernmost city in Santa Clara County, California, United States. The population was 48,821 at the 2010 census. Gilroy is well-known for its garlic crop and for the annual Gilroy Garlic Festival, featuring various garlicky foods, including garlic ice cream. Gilroy also produces...
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 engine.
In 1979 McCornack and his flying partner, Keith Nicely, flew two improved Fledglings from their base in Monterey, California
Monterey, California
The City of Monterey in Monterey County is located on Monterey Bay along the Pacific coast in Central California. Monterey lies at an elevation of 26 feet above sea level. As of the 2010 census, the city population was 27,810. Monterey is of historical importance because it was the capital of...
to Oshkosh, Wisconsin
Oshkosh, Wisconsin
As of the census of 2000, there were 62,916 people, 24,082 households, and 13,654 families residing in the city. The population density was 2,662.2 people per square mile . There were 25,420 housing units at an average density of 1,075.6 per square mile...
, where they made a positive impression on the large gathering of pilots at the EAA
Experimental Aircraft Association
The Experimental Aircraft Association is an international organization of aviation enthusiasts based in Oshkosh, Wisconsin. Since its inception it has grown internationally with over 160,000 members and about 1,000 chapters worldwide....
annual convention there. At the convention they were invited by Mother Earth News
Mother Earth News
Mother Earth News is a bi-monthly American magazine that has a circulation of 475,000. It is based in Topeka, Kansas.Approaching environmental problems from a down-to-earth, practical, how-to standpoint, Mother Earth News has, since the magazine’s founding in 1970, been a pioneer in the promotion...
magazine to fly the aircraft on to the Atlantic coast on pure ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...
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.McCornack, Jack: Ptimes, Volume 1 Number 3. Pterodactyl Limited, Winter 1979.
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
King post
A king post is a central vertical supporting post used in architectural, bridge, or aircraft design applications.-Architecture:...
, 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 7200 square feet (668.9 m²) facility co-located with the Seventh-day Adventist
Seventh-day Adventist Church
The Seventh-day Adventist Church is a Protestant Christian denomination distinguished by its observance of Saturday, the original seventh day of the Judeo-Christian week, as the Sabbath, and by its emphasis on the imminent second coming of Jesus Christ...
Monterey Bay Academy
Monterey Bay Academy
- Description:Monterey Bay Academy is located on about south of Santa Cruz, California, on the edge of the community of La Selva Beach between Manresa State Beach to the north, and Sunset State Beach to the south. The campus is directly on a beach on central California’s Monterey Bay, which is...
at Watsonville, California
Watsonville, California
Watsonville is a city in Santa Cruz County, California, United States. The population was 51,199 according to the 2010 census.Located on the central coast of California, the economy centers predominantly around the farming industry. It is known for growing strawberries, apples, lettuce and a host...
and series production of the Pfledge was commenced. The new location was ideal as it included access to the Monterey Bay Academy Airport
Monterey Bay Academy Airport
Monterey Bay Academy Airport is located near the city of Watsonville in Santa Cruz County, California, USA. This private use airport is owned by the Seventh-day Adventist Church and located on the campus of the Monterey Bay Academy, site of the former Camp McQuaide.-History:In the 1940s, a small...
. The design went through a series of evolutionary improvements, mostly involving the powerplants installed and these resulted in a number of different models.
Variants
Pfledge- The first Pfledges (also referred to as Fledges, and Fledglings) were tailless flying wings powered by a two-stroke Xenoah engine driving a 36-inch propeller. Some were also powered by a 10 hp 136 cc ChryslerChryslerChrysler Group LLC is a multinational automaker headquartered in Auburn Hills, Michigan, USA. Chrysler was first organized as the Chrysler Corporation in 1925....
two stroke engine.
Pfledge X
- The Pfledge X featured a Xenoah 242 powerplant that produced 16 hp.
Pfledge OR
- The "Oshkosh Replica" was the production version of the two aircraft that were flown coast to coast in 1979. It was powered by a GermanGermanyGermany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
Sachs SA-340 direct drive engine with a 336 cc displacement. This model sold for USD$3500 in 1980.
Pfledge 430D
- The Pfledge 430D was announced late in 1979. This model featured a Cuyuna 430D engine which McCornack helped design. The engine was a two cylinder, two stroke engine with a displacement of 429 cc and a power output of 30 hp. It weighed 64 lb (29 kg). The "D" indicated that the engine was direct drive and not connected to the propeller through a reduction drive system.
- The Pfledge 430D also replaced the twist grips with a conventional stick for roll control, while pitch remained via weight shift.
- The Pfledge 430D cost USD$3600 in 1980.
NFL
- Before the introduction of its FAR 103Federal Aviation RegulationsThe Federal Aviation Regulations, or FARs, are rules prescribed by the Federal Aviation Administration governing all aviation activities in the United States. The FARs are part of Title 14 of the Code of Federal Regulations...
ultralight regulations in 1982 the FAAFederal Aviation AdministrationThe Federal Aviation Administration is the national aviation authority of the United States. An agency of the United States Department of Transportation, it has authority to regulate and oversee all aspects of civil aviation in the U.S...
did not regulate ultralights as long as they were foot-launchable.
- The demand from conventional aircraft pilots for a version of the Pfledge that had aerodynamic pitch control instead of weight-shift led McCornack to add an elevator to the back of the aircraft, mounted on twin booms behind the pusher propeller. Because this design was "Not Foot Launchable" it was called the NFL . The design was not a production success and few were built, but the NFL paved the way for the Ptraveler and Ascender to follow.
Ptraveler
- McCornack had first installed a canardCanard (aeronautics)In aeronautics, canard is an airframe configuration of fixed-wing aircraft in which the forward surface is smaller than the rearward, the former being known as the "canard", while the latter is the main wing...
elevator on a Pfledge in 1978, but did not create a production model until 1980. The canard was operated by a side-mounted control stick. Fore-and-aft movement of the stick moved the canard and sideways movement controlled the tip-rudders. The canard was constructed with tubular spars, aluminum ribs and covered in Mylar, although some were also covered using standard aircraft fabric.
- The new model carried the name "Ptraveler", continuing the use of the silent letter “P” in Pterodactyl designs.
- The new model was powered by the Cuyuna 430D direct drive engine and was introduced in 1980 at a price of USD$3900.
Ascender
- The Cuyuna 430D powerplant was greatly improved by the addition of a 2:1 belt reduction drive, allowing larger propellers of 54 inches diameter to be used. This produced more thrust and less noise. The modified powerplant was called the Cuyuna 430R.
- Fitting the new powerplant into the Ptraveler drastically improved the aircraft's take-off and climb performance. The new model was named the “Ascender” for its improved climb rate and also in tribute to the XP-55 AscenderXP-55 Ascender|-See also:-References:NotesBibliography* Balzer, Gerald H. American Secret Pusher Fighters of World War II: XP-54, XP-55, and XP-56. North Branch, Minnesota: Specialty Press, 2008. ISBN 1-58007-125-2....
, an early canard fighter design. In 1981 a complete kit cost USD$4200.
Ascender II
- The Ascender II was an improved Ascender with evolutionary changes incorporated. It had an improved muffler, re-located throttle and fiberglass spring rod main landing gear suspension.
Psounder
- The Pterodactyl Psounder was a one-of-a kind Ascender II that was modified for an atmospheric research project at Colorado State UniversityColorado State UniversityColorado State University is a public research university located in Fort Collins, Colorado. The university is the state's land grant university, and the flagship university of the Colorado State University System.The enrollment is approximately 29,932 students, including resident and...
.
Ptug
- The Ptug was a special hang glider towing version of the Ascender II that was modified with a special rigid bridle to ensure that the tow rope stayed clear of the propeller.
Ptiger
- By adding a fiberglass fairing to the basic Ascender II airframe, along with clipping the wing by 4 feet (1 m) to a 29 feet (9 m) span, the result was a new model named the "Ptiger". With the Cuyuna 430R the aircraft was capable of 75 mi/h in level flight.
- Under the rules of the time it could not be foot-launched and Pterodactyl advised purchasers to register their Ptigers as experimental amateur-built aircraftHomebuilt aircraftAlso known as amateur-built aircraft or kit planes, homebuilt aircraft are constructed by persons for whom this is not a professional activity. These aircraft may be constructed from "scratch," from plans, or from assembly kits.-Overview:...
Ascender II+
- The Ascender II+ was introduced in early 1982 and was aimed at the physically larger pilot. This redesigned model incorporated a wider 20 ½ inch hang cage. All earlier models had a 15+3/4 in hang cage. It also had stronger upright struts and wing with 1 ¾” inch spars of 0.049” thickness, whereas all earlier models used 1 ½” spars of 0.049 inch thickness and heavier 1/8” outer bottom cables.
- The Ascender II+ sold for USD$5260 in 1983.
Ascender II+2
- The Ascender II+, with its additional structural strength lent itself to the creation of a two-seat trainer version. This was designed by adding an off-center "sidecar" frame to hold the second seat and was named the "Ascender II+2". There was no dual control installation, as both pilots had access to the single side-stick control.
- The II+2 was first marketed in the middle of 1982 at a price of USD$5560.
Light Flyer
- The final aircraft design and produced by Pterodactyl was based on the Easy Riser wing and was a tribute to the Wright FlyerWright FlyerThe Wright Flyer was the first powered aircraft, designed and built by the Wright brothers. They flew it four times on December 17, 1903 near the Kill Devil Hills, about four miles south of Kitty Hawk, North Carolina, U.S.The U.S...
. The Light Flyer introduced practical improvements over the original Wright brothersWright brothersThe Wright brothers, Orville and Wilbur , were two Americans credited with inventing and building the world's first successful airplane and making the first controlled, powered and sustained heavier-than-air human flight, on December 17, 1903...
design, such as wheeled landing gearLanding GearLanding Gear is Devin the Dude's fifth studio album. It was released on October 7, 2008. It was his first studio album since signing with the label Razor & Tie. It features a high-profile guest appearance from Snoop Dogg. As of October 30, 2008, the album has sold 18,906 copies.-Track...
instead of fixed skids, allowing taxiing. The aircraft was introduced in 1984 at a price of USD$5400, but only about five were sold.
Production
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, TexasRowlett, Texas
-External links:*...
. 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 kits available for complete aircraft in three models under the company name DFE Ultralights (Dave Froble Enterprises). 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.
Ascender III-A
- The Ascender III-A is similar to the original Pterodactyl Pfledge. It lacks a canard and pitch control is by weight shift, although it incorporates some refinements, such as nose wheel steering. The 2003 price was USD$6800.
Ascender III-B
- The Ascender III-B is similar to the Pterodactyl Ascender II with the addition of nose wheel steering and in 2003 sold for USD$7900.
Ascender III-C
- The Ascender III-C is equivalent to the Pterodactyl Ascender II+ with the heavy-duty style airframe. It sold for USD$8100 in 2003.
- Like the Ascender II+, the Ascender III-C can be fitted with a sidecar to become a two-seat trainer version.
Ascender III-T
- The Ascender III-T is similar to the Pterodactyl Ascender II Ptug hang glider tug aircraft and incorporates a bridle to fit around the propeller to attach the tow rope to.
Regulatory status
In the USA the single seat Pterodactyl models are flown as ultralightsUltralight aircraft (United States)
Ultralight aircraft in the United States are much smaller and lighter than ultralight aircraft in all other countries.In the USA ultralights are classified as vehicles and not aircraft and are thus not required to be registered or for the pilot to have a pilot licence or certificate.- US definition...
under FAR 103
Federal Aviation Regulations
The Federal Aviation Regulations, or FARs, are rules prescribed by the Federal Aviation Administration governing all aviation activities in the United States. The FARs are part of Title 14 of the Code of Federal Regulations...
, whereas the two seat models are usually registered as experimental amateur-builts
Homebuilt aircraft
Also known as amateur-built aircraft or kit planes, homebuilt aircraft are constructed by persons for whom this is not a professional activity. These aircraft may be constructed from "scratch," from plans, or from assembly kits.-Overview:...
.
In Canada all Pterodactyls are classified as Basic Ultra-lights
Ultralight aircraft (Canada)
The Canadian Aviation Regulations define two types of ultralight aircraft: basic ultra-light aeroplane , and advanced ultra-light aeroplane .- Canadian definition of ultra-light :...
.
Notable flights
Pterodactyls have been flown on many long flights. John D. (Jack) Peterson, Jr. completed a flight in a Pfledge from Long Beach, CaliforniaLong Beach, California
Long Beach is a city situated in Los Angeles County in Southern California, on the Pacific coast of the United States. The city is the 36th-largest city in the nation and the seventh-largest in California. As of 2010, its population was 462,257...
to Hilton Head, South Carolina over a period of 29 days between July 9 and August 6, 1979, with ground support. He flew the 3200 miles (5,149.9 km) distance by flying distances of a maximum of 120 miles (194 km) in a single flight. This feat was the first time that an ultralight airplane had been flown across the USA from coast to coast. Peterson’s aircraft is on display in the Smithsonian Museum's
Smithsonian Institution
The Smithsonian Institution is an educational and research institute and associated museum complex, administered and funded by the government of the United States and by funds from its endowment, contributions, and profits from its retail operations, concessions, licensing activities, and magazines...
Steven F. Udvar-Hazy Center
Steven F. Udvar-Hazy Center
The Steven F. Udvar-Hazy Center is the Smithsonian National Air and Space Museum 's annex at Washington Dulles International Airport in the Chantilly area of Fairfax County, Virginia, United States....
.
McCornack and Nicely's 1979 flight from Monterey, California
Monterey, California
The City of Monterey in Monterey County is located on Monterey Bay along the Pacific coast in Central California. Monterey lies at an elevation of 26 feet above sea level. As of the 2010 census, the city population was 27,810. Monterey is of historical importance because it was the capital of...
to Oshkosh, Wisconsin
Oshkosh, Wisconsin
As of the census of 2000, there were 62,916 people, 24,082 households, and 13,654 families residing in the city. The population density was 2,662.2 people per square mile . There were 25,420 housing units at an average density of 1,075.6 per square mile...
and onto the Atlantic coast was the second transcontinental flight by this aircraft type and was done mostly without ground support.