Short SC1
| Short SC1 | |
|---|---|
 Short SC1 XG900 at Farnborough Air Show |
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| Type: | VTOL experimental aircraft project |
| Design country: | |
| Manufacturer: | |
| First flight: |
April 2, 1957 |
| Commissioning: |
Flight testing ended |
| Number of pieces: |
2 |
The Short SC1 was the first British fixed-wing - VTOL AIRPLANE. Worldwide only the Bell X-14 carried out its maiden flight in front of the SC1 as the first flat-riser . Fundamental investigations into the use of an aircraft by VTOL were carried out with the experimental aircraft.
history
First VTOL trials in Great Britain
The first practical tests in Great Britain with turbo jets as lift engines for vertical take - offs were carried out by Rolls-Royce in 1953 with a "thrust measuring rig" ( Rolls-Royce Thrust Measuring Rig ). The device was also jokingly referred to as the "flying bed frame". Two Rolls-Royce Nene were installed opposite one another in the frame; the exhaust gas jet was deflected downwards by 90 ° in three jet pipes in the center of gravity of the frame. Compressor bleed air , which was blown down through pipes on the four sides of the frame, ensured the position control in all three axes. The first flights of the two models built took place on August 3, 1954 and August 1955, respectively.
First lift jet engine
The chief scientist at Rolls-Royce Dr. Griffith was so convinced of the practical usability of a direct-acting lift jet engine that managed without jet deflection and the associated loss of thrust that the construction of a specially adapted version began as early as 1949. A thrust-to-weight ratio of 8: 1 or 9: 1 was believed to be feasible. The Soar test engine led to the world's first practically usable vertical lift jet engine, which was designated as the RB.108 . In 1955, the RB.108 actually achieved its 8: 1 thrust-to-weight ratio with a thrust of 9.9 kN (2000 lb).
Tender, order placement and construction
In September 1953, the Ministry of Supply issued the specification ER.143, the requirements for the design and construction of a VTOL test aircraft. The aircraft should be able to perform a vertical take-off with its jet engines alone, to accelerate to the normal aerodynamically supported flight condition, to decelerate again to a stationary hover condition and to perform a vertical landing.
In early 1954 Short's proposal PD11 (Preliminary Design 11) was selected as the most promising and construction of the SC1 began. The aim of the work was to design the smallest possible cell to accommodate five engines, fuel and the pilot. Early on in the design detailing, the Royal Aircraft Establishment (RAE) required the ability to quickly switch between automatic and manual controls. Three parallel channels were built in to control the servomotors. In August 1954, the official order for the construction of two machines was given (factory numbers 1814 and 1815, RAF registration XG900 and XG905).
In the spring of 1955, construction of the first prototype began and was completed in November 1956. Since initially only conventional take-offs and landings were planned, only the tail engine was installed. This completed its first successful test runs on December 7, 1956.
testing
The first taxi tests conducted by short chief test pilot Tom Brooke-Smith began on December 17th. For the maiden flight, XG900 was brought on board SS Copeland and with subsequent road transport from Belfast to Boscombe Down . The first conventional flight took place there on April 2, 1957.
The second prototype was equipped directly with the lifting engines, which could be swiveled 35 ° forwards and backwards. On September 3, 1957, the first static runs of the engines took place. The first still tied hover in Sydenham near Belfast took place on May 23, 1958. However, it then took another five months before the first untethered hover could take place on October 25. Only then did the XG900 receive its lift engines after being returned to Belfast.
At the first public demonstration of the SC1 at the 1959 Air Show in Farnborough, the planned vertical take-off failed, as the grass lying there was first blown away from the freshly mown meadow and then collected on the grille above the engine inlets, sucked in by the lifting engines. This resulted in such a severe loss of performance that it was no longer possible to take off. The first complete transition of an SC1 took place on April 6, 1960 on the Bedford base of the Royal Aircraft Establishment. XG905 crashed during testing on October 2, 1963, killing pilot JR Green. The cause was the failure of a gyroscope in the control system at a low altitude. Despite immediately switching to manual control, Green was no longer able to regain control. After the machine was rebuilt, both aircraft did not resume test operations until June 1966.
Whereabouts
In 1971 both prototypes left Bedford. XG900 was first shown at the Science Museum and then brought to the Fleet Air Arm Museum in Yeovilton , where it can be viewed today. The XG905 is located in the Ulster Folk and Transport Museum .
construction
The SC1 was a single-seat low -wing aircraft that was designed as a tailless delta aircraft (without a horizontal stabilizer). The vertical takeoff weight was a maximum of 3495 kg (7700 lb). The drive for vertical flight consisted of four vertically installed Rolls-Royce RB.108 jet engines and one RB.108 in the tail for forward flight. The vertical engines were arranged in pairs next to each other in the middle part of the fuselage, so that the thrust resulting almost went through the center of gravity of the aircraft. They could be swiveled around the transverse axis of the machine to change the direction of the thrust vector. The stern engine was installed at an angle of 30 °, as the lubrication system of the RB.108, which was designed for vertical operation, did not allow a horizontal installation.
The position control in all three axes was carried out in hover flight via control nozzles, the bleed air (around 10% of the thrust) was blown out of the four lift engines at the nose, tail and wing tips. The tanks were arranged at the front of the wing nose and as sack tanks between the two main spars of the wings.
The SC1 had the first fly-by-wire system used on a VTOL aircraft. Initially, a Folland lightweight ejection seat was installed, which was later replaced by a Martin-Baker Mk.-4-Zero-Zero seat. The inclination of the fixed landing gear could be adjusted on the ground. For the conventional take-off, the landing gear legs were tilted forward.
Technical specifications
| Parameter | Data |
|---|---|
| crew | 1 |
| length | 9.10 m |
| span | 7.16 m |
| Wing area | 13.18 m² |
| Empty mass | 2720 kg |
| Takeoff mass | 3495 kg (VTOL), 3650 kg (STOL) |
| Top speed | 296 km / h |
| Range | 240 km |
| Engines | four Rolls-Royce RB.108s , one RB.108 for level flight, power 9.7 kN (2130 lb) each |
See also
literature
- Barry Jones: Short's Early Risers , Airplane Monthly, May 1994, pp. 12-19
- CH Barnes: Shorts Aircraft since 1900 , Putnam Aeronautical Books, 1989, ISBN 0-87021-662-7
Web links
- Brief History Recap (accessed March 13, 2010)