Boeing 377-10-28 construction number 15943, original registration G-ALSA. Delivered to BOAC 28 October 1949 and operated as RMA Cathay, it made the inaugural BOAC London-New York flight 6 December 1949 via Prestwick. The accident was attributed to pilot error; that coming in high, he increased the rate of descent and flared too late, undershooting the runway by about 20 metres. The portside main undercarriage strut was thought to have collapsed and severed fuel lines, starting the fire.