A 320-ton jumbo jet collapsed at Heathrow on Sunday while engineers were carrying out maintenance work.
No-one was injured when the nose of the Boeing 747 crashed to the ground as landing gear folded.
British Airways is investigating why safety pins, which should have secured the landing gear, apparently failed.
The plane, belonging to EVA Air of Taiwan, had been due to leave the west London airport on Saturday, but was delayed by hydraulics problems.
Passengers were sent to a nearby hotel while BA engineers checked the hydraulics systems.