LUNAR LANDER SIMULATOR

The Bell Aerosystems Lunar Landing Research Vehicle (LLRV), the Flying Bedstead, was a Project Apollo era program to build a simulator for the Moon landings. The LLRVs were used by the FRC, now known as the NASA Armstrong Flight Research Center, at Edwards Air Force Base, California, to study and analyze piloting techniques needed to fly and land the Apollo Lunar Module in the Moon's low gravity environment.

The research vehicles were vertical take-off vehicles that used a single jet engine mounted on a gimbal so that it always pointed vertically. It was adjusted to cancel 5/6 of the vehicle's weight, and the vehicle used hydrogen peroxide rockets which could fairly accurately simulate the behavior of a lunar lander.

Success of the two LLRVs led to the building of three Lunar Landing Training Vehicles (LLTVs), an improved version of the LLRV, for use by Apollo astronauts at the Manned Spacecraft Center in Houston, Texas, predecessor of NASA's Johnson Space Center. One LLRV and two LLTVs were destroyed in crashes, but the rocket ejection seat system safely recovered the pilot in all cases.

The final phase of every Apollo landing was manually piloted by the mission commander. Because of landing site selection problems, Neil Armstrong, Apollo 11 commander, said his mission would not have been successful without extensive training on the LLTVs. Selection for LLTV training was preceded by helicopter training.

Built of aluminum alloy trusses, the LLRVs were powered by a General Electric CF700-2V turbofan engine with a thrust of 4,200 lbf (19 kN), mounted vertically in a gimbal. The engine lifted the vehicle to the test altitude and was then throttled back to support five-sixths of the vehicle's weight, simulating the reduced gravity of the Moon. Two hydrogen peroxide lift rockets with thrust that could be varied from 100 to 500 lbf (440 to 2,200 N) handled the vehicle's rate of descent and horizontal movement. Sixteen smaller hydrogen peroxide thrusters, mounted in pairs, gave the pilot control in pitch, yaw and roll.

The pilot had an ejection seat. On activation, it propelled the pilot upward from the vehicle with an acceleration of roughly 14 times the force of gravity for about a half second. From the ground, it was sufficient to propel the seat and pilot to an altitude of about 250 feet (80 m) where the pilot's parachute could be automatically and successfully deployed. Manufactured by Weber Aircraft LLC, it was one of the first zero-zero ejection seats, capable of saving the operator even if the aircraft was stationary on the ground, a necessity given the LLRV's low and slow flight envelope.

In Armstrong's 2005 authorized biography First Man: The Life of Neil A. Armstrong, astronaut Bill Anders is quoted as describing the LLTV as "a much unsung hero of the Apollo Program". Although Armstrong had to eject from the LLRV, no other astronaut ever had to eject from the LLTV, and every Lunar Module pilot through the final Apollo 17 mission trained in the LLTV and flew to a landing on the Moon successfully.

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