BA Flight Fire: Engine Doors 'Left Unlatched'

Doors on both engines of the British Airways plane in last week's Heathrow emergency landing drama were left unlatched during maintenance, according to an official accident investigation.

The coverings of the two engines - called fan cowl doors - then fell off as the aircraft left the runway, puncturing a fuel pipe on the right engine, said the Air Accidents Investigation Branch (AAIB) report .

But it is not known what caused the fire on the flight and that is still being investigated, the report said.

Flight BA762 was on its way to Oslo from the airport last Friday when it was forced to return to the London hub shortly after take off.

Smoke was seen pouring from one of the engines and the plane appeared damaged as it flew over southeast, central and west London.

The unlatching of the fan cowl doors was not noticed before the Airbus A319 took off, according to the report.

"Subsequent investigation revealed that the fan cowl doors on both engines were left unlatched during maintenance and this was not identified prior to aircraft departure," it read.

BA's maintenance is carried out by its own teams.

The detaching of the cowls also punctured the airframe and some aircraft systems and the flight crew, led by the 50-year-old captain, declared a pan emergency - not as serious as a mayday - and headed back to Heathrow.

As the plane was landing, an external fire started on the right engine and the crew declared a mayday.

"The source of ignition that led to the in-flight fire is still under investigation," the AAIB said.

The right engine was shut down and once the plane had landed "the airport fire service attended and quickly extinguished a small fire on the right engine", said the report.

The aircraft managed to land safely and the left engine continued to perform normally throughout the flight, the report said.

The engine was extensively damaged in the fire and remnants of the fan cowl doors were recovered from the runway.

The 75 passengers and five crew evacuated via escape slides, and three people were treated for minor injuries.

Transport Secretary Patrick McLoughlin said the AAIB report "contains serious findings" and the aviation industry "must act immediately to take the appropriate safety action and ensure that all lessons are learnt from what has happened".

British Airways chief executive Keith Williams has welcomed the findings, saying they are working with investigators.

"We continue to cooperate fully with the investigation team and can confirm that appropriate initial action has already been taken in accordance with the AAIB's safety recommendation to Airbus," he said.

"We regret we are precluded from releasing or discussing any additional details while the AAIB investigation is ongoing.

"We commend the professionalism of the flight crew for the safe landing of the plane and the cabin crew and pilots for its safe evacuation.

"We continue to offer our full support to those customers who were onboard the flight."

Aviation safety investigator David Gleave told Sky News it is not unusual for cowlings to fall off during the flight.

"In this case, the failure to do up the cowlings is not a terribly significant safety issue," he said.

"When the cowling fell off, yes it did damage the fuel pipe and there was a fire, but I don't think the whole safety of the plane was jeopardised because the crew were able to shut the engine down quite safely and return to land."

The AAIB report said that last July Airbus said there had been 32 reported fan cowl door detachment events - 80% of which occurred during the take-off phase of flights.

The drama temporarily closed both runways and although both reopened there were flight cancellations and delays for those heading off for the bank holiday weekend.

On Thursday, the US National Transportation Safety Board (NTSB) - which is assisting the AAIB probe - released information on its website saying that one engine shut down and the other on fire during the May 24 incident.

However, later in the day AAIB said the NTSB information was incorrect.