Egypt is taking on two companies, one French and one Italian, to help search for the black boxes of an EgyptAir plane that crashed in deep water in the Mediterranean Sea, the airline's chairman says.
EgyptAir flight 804 crashed on May 19 with 66 people on board including 30 Egyptians and an Australian-British dual national, and nearly a week later investigators have no clear picture of the plane's final moments.
EgyptAir chairman Safwat Musallam did not name the companies involved, but he told a news conference they were able to carry out searches at a depth of 3000 metres.
The plane and its black box recorders, which could explain what brought down the Paris-to-Cairo flight as it entered Egyptian air space, have not been located.
The black boxes are believed to be lying in up to 3000 metres of water, on the edge of the range for hearing and locating signals emitted by the boxes.
Maritime search experts say this means acoustic hydrophones must be towed in the water at depths of up to 2000 metres in order to have the best chance of picking up the signals.
Until recently, aviation sources say, the US Navy or its private contractor Phoenix International were considered among the only sources of equipment needed to search on the correct frequency for black box pingers at such depths.
The US Navy said on Tuesday it had not been asked for help.
Batteries powering the signals sent from the black boxes typically last only 30 days, but the airline's deputy chairman Ahmed Adel said the search would continue beyond then if necessary, using other means to locate the recorders.
"There are many examples in similar air accidents when 30 days passed without finding the box yet ... these planes' black boxes were found," he said.
Musallam reiterated earlier comments from sources within the Egyptian investigation committee who said that the jet had shown no sign of technical problems before taking off from Paris.
He said the Airbus 320 was given a regular check by an Egyptian engineer and two Egyptian technicians at Paris airport.
"The engineer and the pilot both signed the Aircraft Technical Log which stated that the check found that all the plane's machines were safe," he said.