The Civil Aeronautics Board determined that, based on the tanker's observations, Flight 739 probably exploded in-flight, though an exact cause could not be determined without examining the remnants of the aircraft.
A Xunta de Aeronáutica Civil (CAB) determinou que, baseándose nas observacións do petroleiro, o voo 739 probablemente estoupou no aire, aínda que non se puido determinar unha causa exacta sen examinar os restos do aparello.