Bell X-2
| Bell X-2 Starbuster | |
|---|---|
 The Bell X-2 after a crash landing |
|
| Type: | Experimental airplane |
| Design country: | |
| Manufacturer: | |
| First flight: |
June 27, 1952 |
| Commissioning: |
June 27, 1952 |
| Production time: |
Was never mass-produced |
| Number of pieces: |
2 |
The Bell X-2 Starbuster was an American experimental aircraft that was intended to investigate flight characteristics in the speed range of Mach 2 to 3. It was a rocket-propelled all-metal low-wing aircraft. In contrast to its direct predecessor, the Bell X-1 , the wing and tail unit were swept. Instead of an ejection seat, an ejectable nasal capsule was installed. For weight reasons, there was no landing gear, instead landing skids were used.
development
One of the problems in trying to achieve Mach 3 is ensuring adequate stability and control of the aircraft. In addition, from around Mach 2.6 there is the so-called heat wall , in which the aircraft heats up aerodynamically to such an extent that common metals can no longer be used. To research these extreme conditions, the Bell X-2 was built from stainless steel and a copper-nickel alloy and was equipped with swept wings and an XLR25 rocket engine that could develop 11 to 67 kN of thrust in two combustion chambers . After all, the X-2 was the first aircraft to fly to the edge of the atmosphere on the edge of space.
Mission history
On June 27, 1952, the test pilot Jean L. "Skip" Ziegler carried out a first glide flight without using the engine. The X-2 was hung under a converted B-50 bomber for take-off and brought to operational height from Edwards Air Force Base . However, this first X-2 was lost in a later towing flight in 1953 in an explosion that cost Ziegler his life.
Lt. Col. Frank K. "Pete" Everest made the first powered flight on November 18, 1955 with a second X-2. On his ninth and last flight at the end of July of the following year, he set a new unofficial speed record of Mach 2.87 (3,050 km / h). The X-2 thus fulfilled the expectations placed on it, but not without problems. Everest reported that the plane was barely responding to controls at high speeds. In addition, simulations and wind tunnel testing , along with the data from its test flights, found that the aircraft would have serious stability problems once it reached Mach 3.
Some young test pilots, Captain Iven C. Kincheloe and Captain Milburn G. "Mel" Apt , were given the task of continuing the tests. On September 7, 1956, Kincheloe became the first pilot to break the 100,000 ft (30,500 m) altitude mark when he climbed the X-2 to an altitude of 126,200 ft (38,466 m).
Just 20 days later, on the morning of September 27th, Mel Apt took off from the B-50 for its first rocket flight. His mission was to follow a trajectory that made it possible to convert the available energy of the fuel carried into a maximum speed. Because of the problems identified, any rapid steering movements beyond Mach 2.7 should be avoided. Thanks to an extremely precisely maintained trajectory, he was the first person to exceed Mach 3 on this day, and finally reached Mach 3.2 (3,370 km / h) at an altitude of 19,960 m. Up until then, the flight went smoothly, but for unknown reasons, shortly after reaching maximum speed, he tried to turn the aircraft sideways while it was still flying well above Mach 3. The cause is suspected to be a slow reacting instrument display, which indicated a slower speed than the actual one. Apt may also fear he was straying too far from the runway on Rogers Dry Lake . The X-2 got into a flat spin, as Chuck Yeager had to experience almost 3 years earlier in the X-1A . Unlike Yeager, however, Apt was unable to regain control of his aircraft, and the X-2 was lost with him.
This event led to the termination of the program before the National Advisory Committee for Aeronautics could carry out more detailed investigations with the X-2. Nevertheless, it provided valuable research data on high-speed aerodynamics and extreme altitude flight conditions. The further exploration of the high-speed range was only continued with the North American X-15 .
Flight test program
Two aircraft made a total of 20 flights in the period from June 27, 1952 to September 27, 1956.
- 46-674 , 7 glide flights, 10 powered flights
- 46-675 , 3 powered flights
Technical specifications
- Crew: 1
- Length: 11.5 m (37 ft 10 in)
- Wingspan: 9.8 m (32 ft 3 in)
- Height: 3.6 m (11 ft 10 in)
- Empty weight: 5,600 kg (12,375 lb)
- maximum takeoff weight: 11,300 kg (24,910 lb)
- Powerplant: Curtiss-Wright XLR25 rocket engine 15,000 lbf (67 kN) static thrust.
power
- Top speed: Mach 3,196 (3,370 km / h)
- Summit altitude: 38,466 m (126,200 ft)
source
- American X-Vehicles: An Inventory X-1 to X-50 , SP-2000-4531 - June 2003; NASA online PDF monograph (1.10 MB)
