Investigators play down EgyptAir explosion theory  

Cairo: The head of Egypt's forensics authority dismissed as premature a suggestion on Tuesday that the small size of the body parts retrieved since an EgyptAir plane crashed last week indicated there had been an explosion on board.

Investigators struggling to work out why the Airbus 320 jet vanished from radar screens last Thursday, with 66 passengers and crew on board, are looking for clues in the human remains and debris recovered from the Mediterranean Sea so far.

The plane and its black box recorders, which could explain what brought down the Paris-Cairo flight as it entered Egyptian air space, have not been located.

An Egyptian forensics official said 23 bags of body parts had been collected, the largest no bigger than the palm of a hand. Speaking on condition of anonymity, the official said their size pointed to an explosion, although no trace of explosives had been detected.

But Hisham Abdelhamid, head of Egypt's forensics authority, said this assessment was "mere assumptions" and that it was too early to draw conclusions.

At least two other sources with direct knowledge of the investigation also said it would be premature to say what caused EgyptAir flight 804 to plunge into the sea.

"All we know is it disappeared suddenly without making a distress call," one of them said, adding that only by analyzing the black boxes or a large amount of debris could authorities begin to form a clearer picture.

SCRAPS OF DATA

The investigators do have a few scraps of data in the form of fault messages sent by the jet in the last minutes of flight, logging smoke alarms in the forward lavatory and an electronics bay just underneath, but they are tantalizingly incomplete.

"The difficulty is to connect these bits of information," said John Cox, executive of Washington-based Safety Operating Systems who co-authored a report on smoke and fire risks by Britain's Royal Aeronautical Society.

There are too few messages to fit a typical fire, which would normally trigger a cascade of error reports as multiple systems fail, he said, and too many of them to tie in neatly with a single significant explosion.

Investigators will also need to understand why, for example, there was no message indicating the autopilot had cut off, progressively handing control back to the pilots as systems failed and computers became unsure what to do.

The Frenchman who headed a three-year probe into the 2009 loss of an Air France jet in the Atlantic said the data published so far appeared insufficient for any conclusion.

"I think today all the doors are still open, with probabilities practically identical," said Alain Bouillard, a former investigator with France's BEA air accident investigation agency who is now an air safety consultant.

"What we don't know is whether these messages are at the origin or the consequence of whatever happened."

An Egyptian team formed by the Civil Aviation Ministry is conducting the technical investigation and three officials from the BEA have also been in Cairo since Friday, with an expert from Airbus, to assist.

Egypt has deployed a robot submarine and France has sent a search ship to help hunt for the black boxes, but it is not clear whether either of them can detect signals emitted by the flight recorders, lying in waters possibly 3,000 meters (10,000 feet) deep. The signal emitters have a battery life of 30 days.

While a search for black boxes gets under way, investigators must make a database of debris and understand how currents may have shifted in the five days since the accident. The Egyptian team is also expected to look at maintenance and pilot records.

Although government officials have acknowledged the need for international assistance, the U.S. Navy said Egypt had not formally requested American support beyond a P-3 Orion surveillance aircraft, which was deployed on Thursday.