Sergeant George D. Scheid of Utah, Sergeant Aaron D. Shank of Maryland, Technical Sergeant James H. Turk, Jr., of Texas, and Sergeant William J. Wagner of New York. 7 June English Electric-built Handley Page Halifax BMk.II, serial V9977, crashed on a test flight from RAF Defford carrying a secret H2S radar system at 16:30 hrs at Welsh Bicknor, Herefordshire, killing the crew and several EMI personnel on board, including Alan Blumlein, pioneer of television and stereo audio recording. Blumlein, together with Cecil Browne and Frank Blythen, all from EMI, were attached to the Telecommunications Research Establishment (TRE) at the time of the accident. Also killed was Geoffrey Hensby of the TRE. While flying at a fire starts in the starboard outer engine. Unable to extinguish it and by then too low for a parachute escape, while attempting to reach an open area to put down the fire burns through the outer main spar at low altitude causing the outer wing to fold and detach, whereupon the aircraft rolls almost inverted and impacts the ground. The aircraft's highly secret cavity magnetron is recovered the next day by a TRE team from RAF Defford led by Bernard Lovell. An investigation into the cause of the fire by Rolls-Royce concludes that an insufficiently tightened inlet valve tappet locknut during maintenance caused the inlet valve to drop, where it was hit by the rising piston and broken off at the stem, allowing burning fuel to enter the rocker cover whereupon it quickly spread. V9977 was one of only two Halifaxes fitted with H2S, the other being the Handley Page-built Mk II, R9490, used for trials of a klystron-based version of the system, developed for security reasons due to the difficulty of self-destructing a magnetron should its carrying aircraft come down over enemy territory. The crash of V9977 wiped out almost the entire H2S development team, delaying its introduction to the extent that Churchill had to be informed. 8 June Goodyear prototype G-Class Blimp, G-1, purchased 23 September 1935, in constant use until it is lost in a mid-air collision on this date with L-Class Blimp L-2. The two blimps were conducting experimental visual and photographic observations during a night flight off of Manasquan, New Jersey. Although twelve people were killed in the crash (one survivor), the G-1 had demonstrated her capabilities as a trainer and utility blimp. As the Navy needed additional training airships