Obituary: Milton Thompson

Milton O. Thompson, test pilot: born Crookston, Minnesota 4 May 1926; married (five children); died Lancaster, California 6 August 1993.

MILTON THOMPSON was one of the unsung heroes of aviation, a member of the tightly knit test-pilot fraternity whose story was so memorably told in Tom Wolfe's book The Right Stuff. Thompson spent most of his working life at Edwards Air Force Base, in Mojave Desert, California, about 80 miles north of Los Angeles. For 37 years, he endured the extreme temperatures and barren terrain of tumbleweed and salt flats to become involved in many of the United States' most prestigious and dangerous flight research projects. During the last 18 years he held the position of Chief Engineer at Nasa's Ames-

Dryden Flight Research Facility at Edwards.

Milt Thompson was born in Crookston, Minnesota, in 1926. He began flying with the US Navy as a trainee pilot at the age of 19. He served as a naval pilot during the Second World War, with duty in China and Japan. After six years of active service, he entered the University of Washington and graduated in 1953 with a Bachelor of Science degree in engineering. During his college years, he remained in the Naval Reserves and continued to fly whenever possible, not only naval planes but also crop dusters and forest-spraying aircraft.

Thompson's next two years were spent as a flight test engineer with Boeing Aircraft Co in Seattle. Much of his time was spent flying the B-528 bomber, the world's largest aircraft. When he moved to Dryden in 1956 as an engineer, it was under the control of Nasa's predecessor, the National Advisory Committee for Aeronautics. Two years later, Thompson was assigned to the pilots' office and began a 10-year career as a research pilot.

Between 1959 and 1968 he participated in some of Nasa's most important aerospace projects. As one of 12 pilots to fly the X-15 rocket plane, Thompson soared at speeds in excess of 3,700mph to altitudes of 40 miles - the edge of space. He experienced the exhilaration of riding the world's fastest flying machine on 14 occasions.

In 1962 Thompson was involved in test flights of a dummy Gemini space capsule slung beneath a Rogallo wing or paraglider. Nasa hoped to use this invention to bring its Gemini astronauts back to dry land rather than ocean splashdowns, but the concept was soon scrapped. Nevertheless, his expertise was noted by the US Air Force, which enrolled him as the only civilian pilot to take part in the X-20 Dyna-Soar programme.

The intention was to launch a reusable winged orbiter on top of a Titan rocket. The vehicle would then glide back to Earth for a horizontal landing an a runway, much like the modern space shuttle. Thompson's prospects of becoming an astronaut were cut short in December 1963 when the project was cancelled before the first X-20 was built.

His disappointment was short-lived, as he soon became involved in other programmes intended to stretch the bounds of existing knowledge. One of these involved using the F-104 Starlighter to air-launch a rocket containing a high-altitude research balloon and to carry out drop tests for a new parachute system while flying supersonically at 60,000 feet.

While continuing his X-15 flights, he began to take part in a very different programme to fly a wingless craft known as the Manned Lifting Body. The first prototype, the M2-Fl, was built by a gliding enthusiast named Gus Briegleb, and was constructed of plywood around a welded tubular structure.

In contrast to the multi-million dollar X-15, the cost of this strange-looking craft was a mere dollars 30,000. In the absence of its own propulsion, the half cone-shaped aircraft had to be towed into the air behind a Pontiac convertible driven at speeds of up to 120mph.

After exhaustive low-level testing by Thompson, the small glider was considered ready to be towed to an altitude of around 12,000ft by a transport plane before being released. In August 1963, he was the first to experience its hair-raising 30-degree flight path angle - 10 times steeper than the glidepath of a normal airliner.

After completing the first dozen tow-flights, Thompson was able to hand over to other pilots, including the X-15 pilot Bill Dana and the legendary Chuck Yeager. By July 1966, Thompson was ready to make the first flight in the prototype M2-F2, a heavyweight metal lifting body dropped from beneath the wing of a B-52. The flight nearly ended in disaster as he moved the controls in the wrong direction and had to struggle to overcome a loss of control while plunging towards the surface at 15,000ft per minute. Thompson solved the problem by letting go of the stick, realising his error, and readjusting the control device.

On his fifth flight of the M2-F2, he demonstrated the ability of the ungainly craft to perform a 360-degree spiralling descent before landing, a manoeuvre which is now used by the space shuttle. He later described how he practised for this event after climbing into one of Nasa's F-104 jetplanes. 'By putting the landing gear down and the airbrakes fully out, and pulling the engine throttle right back to idle, you could make the F-104 come down as fast as the lifting body vehicle.' He was named outstanding test pilot of 1966 for his flights on the M2.

After a near-fatal crash by the pilot Bruce Peterson in May 1967, the entire project was in jeopardy. Thompson spent a considerable amount of time in Washington DC trying to ensure the continuation of the programme. The outcome was the construction of an improved lifting body known as the M2-F3.

In 1968, he became director of flight projects, in charge of the aeronautical programmes at Dryden. As such he had oversight of the most advanced and secret aerospace projects in America. In 1975 he was appointed Chief Engineer, a position which he retained when Dryden was incorporated with the Ames Research Center at Moffett Field, and which he still held at the time of his death. His account of the X-15 programme, At the Edge of Space, was published this year.

(Photograph omitted)