the first test pilot of the Bell Lunar Landing Research Vehicle (LLRV), which was used to develop piloting and operational techniques for lunar landings. On October 30, 1964, Walker took the LLRV on its maiden flight, reaching an altitude of about 10 ft and a total flight time of just under one minute. He piloted 35 LLRV flights in total. Neil Armstrong later flew this craft many times in preparation for the spaceflight of Apollo 11 – the first human landing on the Moon – including crashing it once and barely escaping from it with his ejection seat. Death Walker was killed on June 8, 1966, when his F-104N Starfighter chase aircraft collided with a North American XB-70 Valkyrie. At an altitude of about Walker's Starfighter was one of five aircraft in a tight group formation for a General Electric publicity photo when his F-104 drifted into contact with the XB-70's right wingtip. The F-104 flipped over, and, rolling inverted, passed over the top of the XB-70, striking both its vertical stabilizers and its left wing in the process, and exploded, killing Walker. The Valkyrie entered an uncontrollable spin and crashed into the ground north of Barstow, California, killing co-pilot Carl Cross. Its pilot, Alvin White, one of Walker's colleagues from the Man In Space Soonest program, ejected and was the sole survivor. The USAF summary report of the accident investigation stated that, given the position of the F-104 relative to the XB-70, the F-104 pilot would not have been able to see the XB-70's wing, except by uncomfortably looking back over his left shoulder. The report stated that it was likely that Walker, piloting the F-104, maintained his position by looking at the fuselage of the XB-70, forward of his position. The F-104 was estimated to be to the side of, and below, the fuselage of the XB-70. The report concluded that from that position, without appropriate sight cues, Walker was unable to properly perceive his motion relative to the Valkyrie, leading to his aircraft drifting into contact with the XB-70's wing. The accident investigation also pointed to the wake vortex off the XB-70's right wingtip as the reason for the F-104's sudden roll over and into the bomber. A sixth plane in the incident was a civilian Learjet 23 that held the photographer. Because the formation flight and photo were unauthorized, the careers of several Air Force colonels