BA fire report suggests engine casing breach
An initial report on a British Airways plane which caught fire at a Las Vegas airport suggests engine parts flew out and landed on the runway.
The US's National Transportation Safety Board (NTSB) said the casing around a key component of the engine had been found to have "multiple" breaches.
The casing should contain any damage but spool parts, about 7-8in in length, were found on the runway.
The fire forced the evacuation of 170 people on board on emergency slides.
The plane's pilot Chris Henkey, from Reading, has said he is "unlikely" to fly a scheduled trip to Barbados, after which he is due to retire.
The plane's flight data and cockpit voice recorders are being examined by the NTSB, and the left engine is due to be shipped to experts to uncover what caused the fire.
By Richard Westcott, BBC transport correspondent
The part that appears to have broken, the high pressure compressor spool, is a circular disc that spins at very high speed.
It's designed to never break, because if it does the tough outer casing of the engine can't contain the bits of metal that will come flying out, potentially damaging the rest of the aircraft, including the fuel tanks and the hydraulic systems and wires so critical for controlling the aircraft.
Investigators need to find out how new the part was, when it was last checked, and whether it broke because something hit it, maybe a bird, or whether it was just faulty.
Dr Colin Brown from the Institution of Mechanical Engineers has told me that, although you can't rule out a bird strike at this early stage, it's "most likely" to be from a "fatigue crack".
The critical question now, is this a one-off or is it a problem that could arise in similar engines?
Flight 2276 was at McCarran International Airport, bound for London's Gatwick airport, with 157 passengers and 13 crew members on board.
The left General Electric GE90-85B engine of the Boeing 777-200 caught fire before take-off, and at least 14 people were taken to hospital with minor injuries.
The NTSB report said: "Initial examination of the left engine revealed multiple breaches of the engine case in the area around the high pressure compressor.
"Examination of the material recovered from the runway found several pieces of the high pressure compressor spool (approximately 7-8in in length)."
General Electric spokesman Mark Maguire said: "The investigation is in its early stages, and it is premature to speculate or discuss any preliminary findings.
"Investigators continue to work to determine the sequence of events that led to the damage of the aircraft and engine."
Engineer Dr Colin Brown said parts found on the runway would be examined for signs of fatigue, while the possibility of a foreign object entering the engine would be considered by looking for marks on its front fan.
Aviation safety expert David Learmount said several other engine manufacturers have had uncontained engine failures, such as the one in this case.
He said: "We shouldn't treat this as a unique incident and say General Electric is to blame.
"Most of the time you get an engine failure the casing does contain the effects but sometimes it doesn't.
"It's an issue of balance. You could make it twice as thick and twice as heavy, but air fares would go up and more fuel would be used. You could make it like a tank but it wouldn't get off the ground."
Tom Hamer, a British passenger on board the plane that caught fire, said the pilot and the staff had been "superb".
He added: "You can practice that stuff as much as you like, but until you've actually got to deal with 150 passengers who are panicking, running around, not sitting down when they're told to, grabbing luggage, jumping off slides, fire everywhere - there's no amount of training you can do to prepare yourself."
Some of the passengers came in for criticism when they were seen exiting the burning plane carrying their hand luggage.
Mr Henkey told NBC he had been due to fly to Barbados on Saturday and return the following Tuesday, "and that would be it", as he was due to retire.
But he reportedly added: "It's safe to say I'm finished flying."