Transcendental Model 1-G
{{Short description|1950s American prototype tiltrotor aircraft}}
| {{Infobox aircraft begin
| name=Model 1-G | image=Trascendental_Model_1-G.jpg | caption= }}{{Infobox aircraft type | type=Experimental tiltrotor aircraft | national origin= United States | manufacturer=Transcendental Aircraft Corporation | designer= | first flight= July 6, 1954 (first free flight) | introduced= | retired= | status=Prototype | primary user= | more users= | produced= | number built=1 | program cost= | unit cost= | developed from= | variants with their own articles= }} |
The Transcendental Model 1-G was an experimental American tiltrotor prototype of the 1950s. It was a single-seat aircraft powered by a piston engine, and was the first tiltrotor to fly.Norton Air Enthusiast 2005, p. 49. A single example was built, which was destroyed in a crash in 1955.
Design and development
The Transcendental Aircraft Company was founded in January 1947 at New Castle, Delaware by Mario Guerrieri and Bob Lichten, two employees of Kellet Aircraft, to develop the Model 1-G, on which they had begun design work in 1945. Their design was a small cantilever monoplane powered by a single {{convert|160|hp|kW|abbr=on}} Lycoming O-290-A air-cooled flat-four engine positioned in the fuselage that drove two 3-blade rotors at the tips of the wings via a two-speed reduction gearbox. Two {{convert|1/6|hp|kW|abbr=on}} electric motors were used to tilt the rotors, with the rotors linked by a shaft running through the wing to ensure that both rotors would be tilted at the same angle. A steel tube forward fuselage carried the single pilot, engine and gearbox, with the open cockpit positioned forward of the engine and gearbox. An aluminum alloy monocoque tail boom carried the aircraft's tail surfaces. A fixed tricycle landing gear was fitted.Norton Air Enthusiast 2005, p. 46.Bridgman 1955, pp. 318–319.
The aircraft's rotors were controlled with cyclic and collective controls as used by a helicopter, for use in helicopter mode, while conventional ailerons, elevators and a rudder were fitted to the aircraft's wings and tail to control the aircraft in airplane mode.
Development was slow owing to a shortage of funds, with the prototype sufficiently complete to allow testing on a ground test rig in 1951, although it was badly damaged later that year when the rotors disintegrated on the test bed during the first run at full revolutions. A series of contracts from the United States Air Force (USAF) allowed development to continue, and for the Model 1-G to be rebuilt into a form suitable for flight testing.Norton Air Enthusiast 2005, pp. 46–47.
Lichten left Transcendental in 1948, and, in September 1952, Guerrieri sold his interests in the company to William E. Cobey Jr., a Kellett Aircraft Corporation vibrations expert who continued the development of the Model 1-G. With some funding provided by a 1952 Army/Air Force contract for flight data reports and analyses, hover testing of the 1750 lb. Model 1-G began on June 15, 1954.Maisel, Giulianetti and Dugan 2000, p. 8. A second, improved, Transcendental tiltrotor aircraft, the {{convert|2249|lb|kg}}, two seat place Model 2, was subsequently developed by William E. Cobey Jr. but funding limitations resulting from the withdrawal of Air Force support prevented the expansion of the flight envelope, and the program was terminated in 1957.Maisel, Giulianetti and Dugan 2000, p. 11.
Operational history
The Model 1-G, registered N2704A made its first tethered flight at Bellanca Airfield New Castle on June 15, 1954, following this by the first untethered free flight on July 6.Norton Air Enthusiast 2005, p. 47. The first in-flight rotor-tilting took place in December that year, and by April 1955, it was flying with 35 degrees of forward tilt and had reached speeds of {{convert|100|kn|abbr=on}}. On July 20, 1955, N2704A suffered a control system failure causing it to crash into the Delaware River. Although the pilot escaped with only minor injuries, the aircraft was wrecked.{{cite web|title=American airplanes: Ti - Ty: Transcendental|url=http://aerofiles.com/_ti.html|work=Aerofiles|date=May 2, 2009|accessdate=September 20, 2013}}
By the time of its loss, the Model 1-G had carried out over 100 flights, accumulating 23 flight hours. Although it never made a complete transition to and from wing-borne flight, tilt angles of 75 degrees were reached during testing, with more than 90% of lift generated by the aircraft's wings. Transcendental received a further contract from the USAF in 1956, which allowed it to design and build a new tiltrotor, the more powerful and aerodynamically refined Transcendental Model 2, which flew late in 1956. US Government funds were then directed to the Bell XV-3, however, causing the Model 2 to be abandoned with Transcendental being sold to Republic Aviation.Norton Air Enthusiast 2005, pp. 48–49.
Specifications (performance estimated)
{{Aircraft specs
|ref=Jane's All The World's Aircraft 1955–56
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|crew=1
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|length ft=26
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|wing area sqft=63
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|aspect ratio=7:1
|airfoil=NACA 23015
|empty weight kg=
|empty weight lb=1450
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|gross weight kg=
|gross weight lb=1750
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|fuel capacity={{convert|14|USgal|abbr=on}}
|eng1 number=1
|eng1 name=Lycoming O-290-A
|eng1 type=four-cylinder air-cooled horizontally-opposed piston engine
|eng1 kw=
|eng1 hp=160
|eng1 note=
|rot number=2
|rot dia m=
|rot dia ft=17
|rot dia in=0
|rot area sqm=
|rot area sqft=454
|rot area note=
|perfhide=
|max speed kmh=
|max speed mph=160
|max speed kts=
|max speed note=as airplane, {{convert|120|mph|km/h kn}} as helicopter
|range km=
|range miles=
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|endurance=1 hour 30 minutes
|ceiling m=
|ceiling ft=5000
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{{aircontent
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Notes
{{reflist}}
References
- {{cite book|last=Bridgman|first=Leonard|title=Jane's All The World's Aircraft 1955–56|year=1955|publisher=The McGraw-Hill Book Company|location=New York}}
- {{cite book|last1=Maisel|first1=Martin D. |last2=Giulianetti|first2=Demo J. |last3=Dugan|first3=Daniel C.|title=The History of the XV-15 Tilt Rotor Research Aircraft: From Concept to Flight |year=2000|series=The NASA History Series|issue=Monographs in Aerospace History #17| publisher=Office of Policy and Plans, NASA|location=Washington, DC |url=https://history.nasa.gov/monograph17.pdf}}
- {{cite magazine|last=Norton|first=Bill|title=Tilt-Rotor Patriarch: Bell's XV-3 Convertiplane|magazine=Air Enthusiast|date=January–February 2005|issue= 115|pages=44–64}}
External links
- [https://web.archive.org/web/20130921061337/http://www.vstol.org/VSTOLWheel/TranscendentalModel1G.htm Transcendental Model 1G]. vstol.org
- [http://www.helis.com/50s/transcen.php Transcendental]. helis.com
- [https://www.flickr.com/photos/sdasmarchives/4822021001/ photo]
- [https://www.youtube.com/watch?v=PZqdaR2tSYE Test flights]
Category:1950s United States experimental aircraft