Sikorsky S-72
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The Sikorsky S-72 was an experimental hybrid helicopter/fixed-wing aircraft developed by helicopter manufacturer Sikorsky.
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[edit] RSRA
The Rotor Systems Research Aircraft (RSRA) was developed by Sikorsky for NASA and the Army. Configured with rotor, wings and auxiliary jets, the RSRA allows testing of new rotor concepts at speeds up to 300 knots. It could fly like a helicopter with a wing and jets, or as a fixed-wing aircraft without a rotor.
The RSRA was a unique pure research aircraft developed to fill the void between design analysis, wind tunnel testing, and flight results of rotor aircraft. The joint NASA/Army project began in December of 1970, first flight on October 12, 1976 with the first of two aircraft arriving from Sikorsky to NASA on February 11, 1979.
[edit] The X-Wing
Intended to take off vertically like a helicopter, the craft's rigid rotors could be stopped in mid-flight to act as X-shaped wings to provide additional lift during forward flight, as well as having more conventional wings.
Instead of controlling lift by twisting its blades as more conventional helicopters do, the craft used compressed air fed from the engines and expelled from its blades to generate a virtual wing surface, similar to blown flaps on a conventional platform. Computerized valves made sure the compressed air came from the correct edge of the rotor, the correct edge changing as the rotor rotated.
The X-Wing name was probably inspired by the fictional X-Wing starfighter from the Star Wars movies (with the first movie premiered in 1977), but in this case because of its 4 bladed rotors' ability to double as a x-shaped wing.
[edit] Specifications (S-72)
This aircraft article is missing some (or all) of its specifications. If you have a source, you can help Wikipedia by adding them.Data from Avia.Russian.ee Website[1]
General characteristics
- Crew:
- Length: ft in (m)
- Wingspan: ft in (m)
- Height: ft in (m)
- Wing area: ft² (m²)
- Empty weight: lb (kg)
- Loaded weight: lb (kg)
- Useful load: lb (kg)
- Max takeoff weight: lb (kg)
Performance
- Never exceed speed: knots (mph, km/h)
- Maximum speed: knots (mph, km/h)
- Cruise speed: knots (mph, km/h)
- Stall speed: knots (mph, km/h)
- Range: nm (mi, km)
- Service ceiling: ft (m)
- Rate of climb: ft/min (m/s)
- Wing loading: lb/ft² (kg/m²)
Crew: 2-3, engine: 2 x General Electric T-58-GE-5 turboshaft, rated at 1045kW and 2 x General Electric TF-34-GE-400A turbofans, 4180kg of thrust each, main rotor diameter: 18.90m, wingspan: 13.74m, fuselage length: 21.50m, height: 4.42m, take-off weight without auxiliary jets: 8300kg, empty weight without auxiliary jets: 6535kg, take-off weight with auxiliary jets: 11815kg, empty weight with auxiliary jets: 9480kg, max speed without auxiliary jets: 296km/h, cruising speed with auxiliary jets: 258km/h, max speed without auxiliary jets: 581km/h, cruising speed with auxiliary jets: 370km/h, ceiling: 3050m
[edit] References
- ^ Sikorsky S-72. Retrieved on 2006-12-8.
