The Transcendental Model 1-G was an experimental American tiltrotor prototype of the 1950s. It was a single-seat aircraft powered by a single

piston engine A reciprocating engine, also often known as a piston engine, is typically a heat engine that uses one or more reciprocating pistons to convert high temperature and high pressure into a rotating motion. This article describes the common featu ...

, 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 A cantilever is a rigid structural element that extends horizontally and is supported at only one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a canti ...

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

flat-four engine A flat-four engine, also known as a horizontally opposed-four engine, is a four-cylinder piston engine with two banks of cylinders lying on opposite sides of a common crankshaft. The most common type of flat-four engine is the boxer-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 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 Tricycle gear is a type of aircraft undercarriage, or ''landing gear'', arranged in a tricycle fashion. The tricycle arrangement has a single nose wheel in the front, and two or more main wheels slightly aft of the center of gravity. Tricycle g ...

was fitted.Norton ''Air Enthusiast'' 2005, p. 46.Bridgman 1955, pp. 318–319. The aircraft's rotors were controlled with

cyclic Cycle, cycles, or cyclic may refer to: Anthropology and social sciences * Cyclic history, a theory of history * Cyclical theory, a theory of American political history associated with Arthur Schlesinger, Sr. * Social cycle, various cycles in soc ...

and

collective A collective is a group of entities that share or are motivated by at least one common issue or interest, or work together to achieve a common objective. Collectives can differ from cooperatives in that they are not necessarily focused upon an ...

controls as used by a

helicopter A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...

, for use in helicopter mode, while conventional

aileron An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement around ...

elevator An elevator or lift is a wire rope, cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or deck (building), decks of a building, watercraft, ...

s and a

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally aircraft, air or watercraft, water). On an aircraft the rudder is used primarily to ...

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 The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Signal ...

(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. A second, improved, Transcendental tilt rotor aircraft, the , 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 . On July 20, 1955, ''N2704A'' suffered a control system failure causing it to crash into the

Delaware River The Delaware River is a major river in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. From the meeting of its branches in Hancock (village), New York, Hancock, New York, the river flows for along the borders of N ...

. Although the pilot escaped with only minor injuries, the aircraft was wrecked. 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 Transcendence, transcendent, or transcendental may refer to: Mathematics * Transcendental number, a number that is not the root of any polynomial with rational coefficients * Algebraic element or transcendental element, an element of a field exten ...

, 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 The Republic Aviation Corporation was an American aircraft manufacturer based in Farmingdale, New York, on Long Island, New York, Long Island. Originally known as the Seversky Aircraft Company, the company was responsible for the design and produc ...

.Norton ''Air Enthusiast'' 2005, pp. 48–49.

Specifications (performance estimated)

Notes

References

* * * {{refend

External links

Transcendental Model 1G
''vstol.org''
Transcendental
''helis.com''
photo
Tiltrotor aircraft 1950s United States experimental aircraft 1-G High-wing aircraft Single-engined twin-prop tractor aircraft Aircraft first flown in 1954