72-230 LLTV retired

NASA Manned Spacecraft Center, Houston, Texas 77058

FOR RELEASE: December 1, 1972

Milton E. Reim 713/483-5111

RELEASE NO: 72-230

LLTV RETIRED

"I think it does an excellent job of actually capturing the handling characteristics of the lunar module in a landing maneuver. It's really a great deal different than any kind of aircraft that I've ever flown .... "Neil Armstrong, the first moon walking astronaut told newsmen in mid-June of 1969, just after he had completed a training flight in the Lunar Landing Training Vehicle (LLTV) at Ellington Air Force Base.

Now the last moon walker, Eugene Cernan, commander of the Apollo 17 mission has completed his training in the LLTV and the vehicle has been retired. The final flight of the LLTV was piloted by Cernan on November 13, 1972. This was his 46th flight in the LLTV.

Early in the 1960s, engineers and pilots were confronted with the question of how to train to land a vehicle like the lunar module on the moon with one-sixth the earth's gravity and no atmosphere.

In order to investigate the problems associated with the terminal phase of a manned lunar landing mission, a free-flight lunar-landing research vehicle (LLRV) was constructed by the Bell Aerospace Corporation to specifications established by the NASA Flight Research Center at Edwards, California.

The first flight in the development of the research vehicle to simulate the final portion of the descent and hover of the lunar module was made on October 30, 1964, by the late Joe Walker at the Flight Research Center. Nearly 200 flights were made with the LLRV before the program was transferred to the Manned Spacecraft Center in the early part of 1967.

In mid-1966, NASA/MSC ordered three Lunar Landing Training vehicles which were modified versions of the LLRV, with deliveries commencing in December 1967. First flight of the LLTV was October 8, 1968, at Ellington AFB.

The LLTV, a wingless free-flight trainer, has a CF-700 turbofan jet engine as its main source of power for flight. The jet engine produces a maximum of 4200 pounds (1991 kilograms) of downward thrust to lift the 4100 pound (1863 kilograms) vehicle to the altitude of about 400 feet (131 meters) for a lunar landing simulation. During the lunar simulation phase of flight, the jet engine thrust is automatically adjusted to support five-sixths of the vehicle's weight as two throttleable 100 to 500 pound (45 to 227 kilograms) lift rockets support the remaining one-sixth of the weight.

There are no aerodynamic control surfaces on the LLTV so attitude control is maintained by the use of 8 small attitude rockets with a thrust of 90 pounds (41 kilograms) each.

Due to jet engine and lift rocket fuel limitations, flights are less than 10 minutes duration with the last 90 seconds of each flight devoted to the lunar simulation phase.

All prime and backup commanders of Lunar Landing missions practiced lunar module-like landings in the LLTV at Ellington AFB. Astronaut pilots include Neil Armstrong, Charles Conrad, James Lovell, Alan Shepard, David Scott, John Young, Eugene Cernan, Richard Gordon and Fred Haise.

Flights in the earlier LLRV were made by Astronauts Frank Borman, Bill Anders, Edwin Aldrin and the late C.C. Williams. Checkout flights with the LLRV and LLTVS were performed by NASA pilots at Edwards FRC and Ellington AFB. NASA/MSC pilots who flew the flight tests and acted as instructor pilots were Joe Algranti, Harold "Bud" Ream, Jere Cobb, and the late Stu Present. FRC pilots on the program were Joe Walker, Don Mallich and Colonel E.E. Kleuver, U.S. Army.

Three of the wingless vehicles have met untimely ends. LLRV No. 1 crashed on a training flight on May 6, 1968. Cause of the accident was loss of attitude control due to depletion of attitude control propellant. The pilot, Nell Armstrong, ejected with no injury.

LLTV No. 1 crashed on December 8, 1968, after pilot Joe Algranti ejected safely. This accident was caused by loss of attitude control due to inadvertent flight outside the vehicle control system capability during the initial flight test program.

The third accident occurred on January 29, 1971, when LLTV No. 2 on a routine test flight experienced a loss of attitude control due to an electrical system failure. Again, the pilot, Stu Present, escaped without injury using the Weber ejection seat system.

The LLRV was flown 83 times at Ellington AFB. A total of 439 flights were logged on the three LLTVs, with LLTV No. 3 (NASA 952), the only remaining vehicle, accounting for 254 of those flights.

At the end of the Apollo program, LLTV No. 3 will be offered to the Smithsonian Institution in Washington, D.C. for use as an exhibit in the National Air and Space Museum.

-end- December 1, 1972