Sikorsky S-72

Infobox Aircraft
name= S-72 RSRA


caption= The S-72 in flight without a main rotor in 1984
type= Experimental helicopter
manufacturer= Sikorsky Aircraft
designer=
first flight= 12 October 1976
introduced=
retired=
status=
primary user=
more users=
produced=
number built= 2
unit cost=
developed from =
variants with their own articles =

The Sikorsky S-72 was an experimental hybrid helicopter/fixed-wing aircraft developed by helicopter manufacturer Sikorsky Aircraft.

Design and development

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 convert|300|kn|km/h. 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 1970, first flight on October 12 1976 with the first of two aircraft arriving from Sikorsky to NASA on February 11 1979.

The X-Wing

The Sikorsky X-Wing was developed between 1983 and 1988 by helicopter manufacturer Sikorsky with NASA and DARPA funding. 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.

pecifications (S-72)

aircraft specifications
plane or copter?= both
jet or prop?= both

ref=Avia.Russian.ee Websitecite web|url=http://avia.russian.ee/helicopters_eng/sik_s-72-r.html|accessdate = 2006-12-8|title=Sikorsky S-72]
crew=2-3
capacity=
length main= ft in
length alt= 21.50 m
span main= ft in
span alt= 18.90 m
height main= ft in
height alt= 4.42 m
area main= ft²
area alt= m²
airfoil=
empty weight main= lb
empty weight alt= 9,480 kg
loaded weight main= lb
loaded weight alt= kg
useful load main= lb
useful load alt= kg
max takeoff weight main= lb
max takeoff weight alt= 11,815 kg
more general=
* Take-off weight without auxiliary jets: 8,300 kg
* Empty weight without auxiliary jets: 6,535 kg

engine (jet)= General Electric TF34-GE-400A
type of jet= turbofans
number of jets= 2
thrust main= lbf
thrust alt= 4180 kN
thrust original=
afterburning thrust main= lbf
afterburning thrust alt= kN
engine (prop)= General Electric T58-GE-5
type of prop=turboshaft
number of props= 2
power main= shp
power alt= 1,045 kW
power original=
max speed main= 200 knots
max speed alt= 230 mph, 370 km/h
* Max speed without auxiliary jets: 296km/h
cruise speed main= 140 knots
cruise speed alt= 160 mph, 258 km/h
* Cruising speed without auxiliary jets: 258km/h
never exceed speed main= knots
never exceed speed alt= mph, km/h
stall speed main= knots
stall speed alt= mph, km/h
range main= nm
range alt= mi, km
ceiling main= ft
ceiling alt= m
climb rate main= 600 394 ft/min
climb rate alt= 3,050 m/s
loading main= lb/ft²
loading alt= kg/m²
thrust/weight=
power/mass main= hp/lb
power/mass alt= W/kg
more performance=

armament=

avionics=

ee also

aircontent
related=
* Sikorsky S-61

similar aircraft=
* Sikorsky S-69
* Boeing X-50

lists=
* List of helicopters

see also=

References

External links

* [http://avia.russian.ee/helicopters_eng/sik_x-wing-r.html Sikorsky X-wing]
* [http://www.helis.com/70s/h_s72.php S-72]
* [http://www.dfrc.nasa.gov/gallery/photo/X-Wing/HTML/EC86-33555-2.html X-Wing Research Vehicle]