A Board of Inquiry investigated the crash and found it was caused by loss of power from Nos. 1 and 2 engines, both mounted on the port wing. George Ward told the House of Commons that "the four fuel tanks on the port side of the Beverley feed into a collector box from which the two port engines are fed. From the available evidence, including inspections of part of the aircraft's fuel system, it is clear that a non-return valve between No. 1 (port) tank and the collector box had been fitted in reverse and that the fuel supply from Nos. 3 and 4 (port) tanks were switched off throughout the flight." Ward continued, saying that the loss of power from No. 1 was caused by it being shut down as a precautionary measure, and the fuel starvation to No. 2 engine was caused by an incorrectly fitted non-return valve in the supply line from No. 1 fuel tank. No. 2 fuel tank had been isolated and two smaller fuel tanks in the port wing had not been selected during the flight.
