Cierva W.9
| Cierva W.9 | |
|---|---|
|
|
| Type: | Experimental helicopter |
| Design country: | |
| Manufacturer: |
Cierva Autogiro Company |
| First flight: |
October 1944 |
| Number of pieces: |
1 |
The Cierva W.9 was an experimental helicopter made by the British manufacturer Cierva Autogiro Company in the 1940s.
history
In mid-1943, the Air Ministry commissioned the Cierva Autogiro Company to develop a helicopter that would be competitive with the Sikorsky machines .
The prototype designed by Cyrill Pulin and Jacob Shapiro was completed in October 1944 and immediately thereafter subjected to a soil test. The first flight probably took place in the same month. The secrecy of the project meant that the first public screening only took place 21 months later. The place was the Air Pageant at Southampton Airport on June 22, 1946. On January 20, 1948, the machine suffered an accident during take-off, with the W.9 rolling to the side and causing irreparable damage to the cell structure . This led to the suspension of all further work.
construction
Like the Sikorsky R-4 and R-6A , the W.9 designed by James Weir used a single-rotor design, but differed in that no tail rotor was provided for torque compensation around the vertical axis. The main rotor system also differed from the usual design and was based on earlier theoretical and experimental work by Weir. The Aerodynamically Stabilized Rotor (ASR) was mounted on a rotating cardanic suspension . As a further innovation, a torque measurement on the rotor was introduced on this helicopter for the first time.
The three-blade rotor with a diameter of 10.97 m was powered by a 205 hp (150 kW) Gipsy Queen Six Series II six-cylinder engine. The empty weight was 1200 kg. The all-round glazed egg-shaped cockpit, a model for many later helicopters, offered space for two crew members. The control system did not use collective pitch control , instead the climb and descent were controlled only by the rotor speed. Since this procedure did not prove itself, a conventional control over the common blade adjustment was used later.
The use of the gas exhaust at the aft end of the fuselage to replace a tail rotor proved to be a failure. This concerned both the generation of insufficient counter-torque and the poor directional control. This system was also not a direct forerunner of the modern NOTAR system, as the W.9, in contrast to the modern procedure, did not use the aerodynamic Coandă effect . In the case of the MD Helicopters Explorer , for example, the forces acting laterally are mainly generated by this effect in the tubular part of the tail boom. The direct air expulsion at the end of the boom (as with the W.9) is only used to maintain directional stability .
Results of flight tests or performance values were never published by the W.9.
Technical specifications
| Parameter | Data |
|---|---|
| crew | 2 |
| length | 11 m |
| Rotor diameter | 10.97 m |
| height | 3 m |
| Empty mass | 1200 kg |
| Engines | 1 × de Havilland Gipsy Queen Six Series II six-cylinder air-cooled in-line engine with 153 kW |
See also
literature
- Ryszard Witkowski: Allied Rotorcraft of the WW2 Period , Stratus sc, 2010, ISBN 978-83-89450-97-5 , p. 72 f.
- AERO - The illustrated compilation of aviation, issue 51, 1984, p. 1427
Web links
Individual evidence
- ↑ Cierva W.9 on airwar.ru (ru) accessed on May 2, 2016
- ↑ Flightglobal April 17, 1947, p. 340