On touch down, the nose wheel collapsed, and the aircraft slid across the dry lake bed . . . .
Bell Aircraft, later Bell Helicopters, has had many ingenious and groundbreaking ideas over the decades. But it has also had quality-control problems and a tendency to stick with a once-bright idea long after its expiration date.
The Bell P-39, and its derivative, the P-63, were WWII fighters with the engine mounted behind the pilot. This allowed a 37-mm cannon to be mounted in the nose. The engine was the same Allison V-1710 that limited the high-altitude performance of the P-40 and early-model P-51. It needed to be turbocharged, like the P-38, but there was not enough room in the fuselage for a turbocharger. Brilliant, original idea, but poor execution. We sent most P-39s and P-63s to the USSR, where they did fine because most of the air fighting was done at low-to-medium altitude.
A Bell X-1 flown by Chuck Yeager was the first aircraft to exceed Mach 1 in level flight. But the X-1A almost killed Chuck Yeager after he reached Mach 2.44. And the X-1D made only one successful flight, an unpowered glide like the X-2 in the picture which also featured a nose-wheel collapse on landing. The second flight was supposed to be powered, but the fuel system exploded while it was still attached to the B-50 mother-ship. The X-1E program killed two pilots in fuel explosions caused by improper gaskets in the fuel lines.
The X-2 program killed three people. Pilot Skip Zeigler was killed in X-2 #2 in a captive flight when the liquid oxygen fuel exploded, also killing a crewman on the B-50. Pilot Mel Apt was killed when he encountered the same emergency--supersonic inertia coupling--that had almost killed Yeager in the X-1A. Before he lost control, he had set a new record of Mach 3.2. The program was cancelled at that point after 20 flights.
Bell got into the helicopter business early and produced the Model 47, a great helicopter made famous by its use on the TV series "Whirlybirds." As the H-13, it was widely used in Korea (later appearing in the long-running "MASH" TV series) and in the early days of the Vietnam War. The Korean Army still had some in use (I think) when I was there in 1987-88). It featured the semi-rigid rotor system I mentioned upthread. That type of main rotor is relatively simple and durable, but its limitations restrict the helicopter's maneuverability and top speed. Bell would stick with that rotor system into the 1980, with the UH-1 Huey, the AH-1 HueyCobra, the OH-58 Kiowa (military version of the JetRanger). All were limited by that rotor system. The biggest problem is the need to avoid low-G situations, in which the rotor can start teetering and tear itself off the mast. 0.5 positive G was the lowest G-loading permitted.
Bell's XV-15 tilt-rotor and production vehicle the V-22 Osprey are newer examples of the ingenious ideas. But the V-22 has had the highest accident rate of any manned aircraft in the U.S. armed forces over the last 40 years.
