British aviation lawyers have launched their own investigation into last week's Ethiopian airliner crash and are examining similarities with another air disaster less than three years ago.

Ethiopian Airlines' flight 409 caught fire five minutes after take-off from Beirut on Monday and plummeted into the Mediterranean two miles off the Lebanese coast, killing all 89 passengers and crew, including two Britons.

The plane crashed in similar circumstances to a Kenya Airways plane that came down in Cameroon in May 2007 killing all 114 people on board.

In both cases the planes were Boeing 737-800s that crashed in bad weather, at night and shortly after take-off.

Aviation experts said that each crash could have been caused by a technical fault which combined with other factors.

James Healy-Pratt, an aviation lawyer with London-based Stewarts Law, said: "Based upon our research and investigation into the Kenya Airways crash, the aircraft's spoilers and/or altimeters may have been faulty."

Attempts to find the cause of the Kenya Airways disaster were hampered because investigators failed to retrieve wreckage that could have provided vital clues. They have still not produced a final accident report.

Three British families who lost relatives in that crash launched a legal action against Boeing, the aircraft's manufacturers, in Chicago last year, accusing it of supplying a "dangerous aircraft", in an attempt to find out what caused the disaster.

Mr Healy-Pratt, who acts for the British families involved in that case and has been approached by relatives of the Ethiopian Airlines crash victims, said the delay was "extremely distressing" for the families.

He called on Ethiopian investigators to publish a preliminary report into last week's crash within three or four months and a final one within 18 months to two years, "to avoid making the same mistakes."

"It's important that families know the cause of the crash as soon as possible," he said. "We will be seeking assurances from the Ethiopians and Boeing that every effort will be made to recover all parts of the wreckage."

Lebanese officials ruled out "foul play" as the cause of the crash and initially blamed the weather. But aviation experts said bad weather alone was unlikely to have been enough to cause the crash and said a technical fault might have caused the engine to catch fire.

The two Britons on board the aircraft, which was built in 2002, were Kevin Grainger and Afif Krisht, 57, a father of six who also held a Lebanese passport and owned a haulage company based in Angola.

The Britons who died in the Kenya Airways crash were Gordon Wright, an aid worker, Anthony Mitchell, a journalist, and Stuart Claisse, an auditor.

Mr Healy-Pratt, a partner with Stewarts Law, said: "With Kenya Airways, we have a situation where 114 people died in an air crash two and a half years ago and nobody knows why.

"It's a serious air safety issue and not enough has been done to assist the families. That must not be allowed to happen this time."

The Kenya Airways plane came down in a mangrove swamp and although the official investigation team arrived quickly at the scene they removed only the plane's black box and left the rest of the wreckage behind.

"We thought there could have been some issues with the aircraft systems so we were shocked that all the wreckage was not taken away for forensic examination," Mr Healy-Pratt said.

The British lawyers have video evidence of locals on scooters riding away from the crash scene with pieces of metal from the wreckage.

The Boeing 737 is the world's most widely used aircraft. There are nearly 5,500 in service all over the world and it is estimated that one takes off every 24 seconds. The 737-800 is the newest and most advanced plane from the 737 production line.

A spokesman for Boeing said the company was assisting the investigation. He added: "It is too early to determine whether there are any similarities betwee the two crashes."

Source: Telegraph.co.uk