Sikorsky X-wing
| Sikorsky S-72 X-wing | |
|---|---|
 The Sikorsky "X-wing" is being prepared for a test flight |
|
| Type: | Experimental airplane |
| Design country: | |
| Manufacturer: | |
| First flight: |
October 12, 1976 (as a helicopter without wings and turbofans) |
| Commissioning: |
Flight tests ended in 1988 |
| Production time: |
Was never mass-produced |
| Number of pieces: |
2 |
The Sikorsky S-72 X-wing was an American experimental aircraft that was a hybrid of helicopter and fixed-wing technology. It is counted among the combination aircrafts, but also among the convertible aircraft because of the stop protector . The S-72 was developed between 1983 and 1988 by the helicopter manufacturer Sikorsky , the NASA Ames Research Center and the Defense Advanced Research Projects Agency . The program was initially called RSRA ( Rotor Systems Research Aircraft , German experimental aircraft for rotor systems ).
The aim of the program was to combine the ability to take off a helicopter vertically with the high flight performance of an airplane in an efficient way.
technology
The X-wing took off vertically like a helicopter with its centrally driven rotor made of four rigid rotor blades . The rotor could be stopped during the flight and locked in the X position, with the rotor blades as additional X-shaped wings generating part of the lift . The main lift was provided by two rigid wings like those of a conventional airplane. In this flight phase, propulsion was carried out by two jet engines arranged on the side of the fuselage .
When operating the rotor, the X-Wing was not controlled by tilting the rotor plane using a swash plate as in a conventional helicopter . Rather, compressed air was passed through the rotor blades and blown out by means of computer-controlled valves during the rotation at certain sections of the blade, so that the corresponding lateral movement was achieved. This technological approach was followed up with the Boeing X-50 , but no longer with the tilt rotor aircraft V-22 Osprey .
history
As early as the early 1970s, ways were sought to increase the speed, performance, reliability and safety of helicopters. In addition, noise emissions, vibration and maintenance costs should be reduced. United Technologies Laboratories' Sikorsky Aircraft Division built two RSRAs in 1983. NASA's Langley Research Center in Hampton , Virginia began testing and then moved the program to the Ames Research Center in Mountain View , California for extensive flight tests.
The RSRA first flew at the Ames-Dryden Flight Research Facility in Edwards, California in the spring of 1984. These tests were used to demonstrate fixed-wing capabilities and range of capabilities.
Based on this, a new series of tests was carried out with the X-wing in 1986 and in 1987 a further developed version was created that was used to examine new rotor systems and supporting technologies during flight. NASA and DARPA commissioned Sikorsky to convert one of the original RSRAs into the new X-wing version and to provide it as a demonstration model for the X-wing concept.
The X-wing was not intended to replace helicopters or fixed-wing aircraft. It was intended for special missions that required both skills: both the effectiveness of a helicopter at low speed and the high speed of an aircraft. The mission's tactical objectives should include air-to-air and air-to-ground defense, as well as anti-submarine defense , air surveillance , electronic reconnaissance and search and rescue .
The converted X-wing was delivered to Ames-Dryden on September 25, 1986. After taxiing tests, the first flights in fixed-wing mode and without a rotor took place in December 1987. The contract with Sikorsky expired at the end of the month and was not renewed. The program officially ended in January 1988 for reasons unknown.
literature
- Peter Middleton: X-Wing scheduled to fly in October . In: Flight International . February 22, 1986, p. 18 ( online as PDF , 2.05 MiB [accessed January 27, 2013]).
- Julian Moxon: Darpa ditches X-Wing . In: Flight International . January 16, 1988, p. 2 ( Online as PDF , 1.35 MiB [accessed January 27, 2013]).
Web links
- X-Wing Research Vehicle. NASA, accessed January 27, 2013 .