( dpa ) - The British Airways Boeing which crash-landed at London's Heathrow airport suffered double-engine failure during the approach, an initial report by the Air Accidents Investigation Branch (AAIB) said Friday.
The two engines on the Boeing 777 "did not respond" to a demand for increased thrust about three kilometres from touchdown, until when the 11-hour flight from Bejing had been normal, the report said.
The 136 passengers and 12 crew emerged largely unscathed from Thursday's dramatic crash-landing which left just 20 passengers with minor injuries.
Airport authorities said 113 flights were cancelled Friday following disruption caused by Thursday's accident.
The Boeing's captain, Peter Burkill, revealed that his co-pilot was at the controls when the plane came down just inside the airport's perimeter fence several hundred metres short of the runway.
When the engines did not respond, efforts by the crew to disconnect the auto-throttle and move the throttle lever manually also failed, the initial AAIB report said.
Senior First Officer John Coward was in charge of "gliding" the aircraft at low altitude above housing and a busy perimeter road before the Boeing "belly-flopped" on to grass.
The heavy impact caused severe damage to the plane's undercarriage and wings, and made the landing wheels come off.
Investigators will now have to determine why the engines failed.
Prime Minister Gordon Brown, whose chartered BA plane taking him on an official visit to China had Thursday been held up by the incident, praised the "calmness and professionalism of the captain and crew" Friday.
"Flying is about teamwork and we had an outstanding team on board," Burkill, 43, said in a short statement to the press at British Airways headquarters at Heathrow airport Friday.
The crew had demonstrated "the highest standards of skill and professionalism," said Burkill, flanked by a beaming Willie Walsh, the airline's chief executive.
Coward, with whom he had shared a curry after the ordeal Thursday evening, had done a "remarkable job," said Burkill.
The crew, led by cabin services director Sharon Eaton-Mercer, calmly and efficiently evacuated passengers via emergency chutes - without prior warning.
Burkill also thanked the passengers for their "calmness and good sense during extremely unfamiliar circumstances."
The wrecked Boeing remained in its final position across the end of the runway Friday as air accident investigators continued their painstaking examination.
Representatives from the Boeing manufacturers and Rolls-Royce engine makers were supporting the investigations.
Commentators were unanimous Friday that the 152 passengers and crew had a near-miraculous escape.
Aviation experts said the plane would have crash-landed at a speed of 160-kilometres-an hour.
They said finding the cause of the accident was likely to be a swift affair as the aircraft itself, the black box and the crew were available to investigators.