BLEU's work resulted in an eponymous system for controlling airplane landings.[42] Flight Lieutenant Noel Adams made the first automatic landing on 3 July 1950 in BLEU's test plane, a Vickers Varsity.[2] After demonstrating the system's success, BLEU needed to prove that it was safe. The required standard was that any landing system could not cause more than one accident in every ten million landings.[43] BLEU's engineers continued refining the system as its test pilots made countless automated landings in the Varsity. When it was closed due to fog, they would make test landings at London Heathrow International Airport.