Bell X-14

Bell X-14
Type:	Experimental airplane
Design country:	United States
Manufacturer:	Bell Aircraft Corporation
First flight:	17th February 1957
Commissioning:	Flight tests ended in 1981
Production time:	Was never mass-produced
Number of pieces:	1

The Bell X-14 was an experimental aircraft for researching VTOL properties made by the aircraft manufacturer Bell and at the same time the first of this design.

construction

The vertical take-off properties were achieved by deflecting the thrust jet. Since essentially only vertical take-offs and landings as well as transitions (transition from hovering to level flight and vice versa) were to be carried out, the X-14 was not designed for high speeds: the cockpit was open and the tripod landing gear was rigid, i.e. not retractable. The wings were not swept, the leading edge was almost at right angles to the fuselage . The thrust jet was not deflected by variable engine nozzles, as is the case with the Hawker Siddeley Harrier , but by simple deflector plates. These steered the jet downwards by 90 ° for take-off and landing, and the angle was gradually reduced to commence horizontal flight until the speed was sufficient to generate the necessary lift on the wings. For control in hover flight, the X-14 had additional nozzles in the tail and on the wing tips, which enabled the necessary pitch and tilt movements by means of compressed air.

history

After the various VTOL and V / STOL concepts had already been tested or were being tested in the mid-1950s, the practical use of a jet aircraft with variable thrust jet was now to be tested. Bell then constructed which from a simple pattern, USAF , the term "X-14" got. There were hardly any technical innovations in the X-14, only the stability system was something completely new and was to be used in similar aircraft years later with only slight changes. The first flight took place on February 17, 1957, a pure hover flight without transition. The first vertical take-off with transition to level flight did not take place until 1958.

Numerous test flights led to a better understanding of the propulsion concept as well as the VTOL concept in general. Flight data from the X-14 program were later used to design the Hawker P.1127 , a prototype of the Hawker Siddeley Harrier. In 1969 the USAF left the only copy of the X-14 to NASA , which replaced the ASV.8 Viper engines with more powerful ones. This fact led to the renaming to X-14 A , which often leads to the wrong assumption that more than one copy was built. It was later renamed X-14 B again . After further testing by NASA, the X-14B was used as a VTOL training aircraft before being handed over to the Army Aviation Museum in Fort Rucker , Alabama . It later went to a private collection in Indiana . The last flight took place on May 29, 1981.

Technical specifications

Parameter	Data
crew	1
length	7.62 m
span	10.36 m
Takeoff mass (X-14B)	1,936 kg
Top speed (X-14B)	277 km / h
Service ceiling	not known - approximately 18,000 feet were reached during test flights
Range	480 km
Engines	X-14 : 2 Armstrong Siddeley ASV.8 Vipers with 794 kp static thrust each X-14A : 2 General Electric J85 GE-5 engines with 1,216 kp static thrust each

See also

• List of aircraft types
• List of test aircraft

Web links

Commons : Bell X-14  - collection of pictures, videos and audio files

Individual evidence

1. ↑ Description on history.nasa.gov p. 20. (PDF; 1.2 MB) Retrieved on February 11, 2013 .