The black boxes of EgyptAir flight MS804, which crashed into the Mediterranean on 19 May, are expected to continue emitting signals until 24 June, says the Ministry of Civil Aviation. It is hoped that if recovered the black boxes, which contain flight data recorders, will help investigators determine the cause of accident. The ministry also confirmed that the plane turned 360 degrees before it disappeared from radar screens. Investigators say radar imagery obtained from the Egyptian military confirm earlier reports, based on Greek and British radar data, that the plane swerved in mid-air before crashing.Immediately following the crash Greek Defence Minister Panos Kammenos said the aircraft “made swerves and a descent ... 90 degrees left and then 360 degrees to the right” after it entered Cairo FIR (flight information region). The Ministry of Aviation's statement also confirmed that a member of the United States' National Transportation Safety Board (NTSB) will be joining the investigation team.The plane's engines were built by a consortium led by US firm Pratt & Whitney. The country where the engines were built is often invited to take part in air crash investigations although it is not compulsory. A technical expert from the maker of the plane's black boxes, Honeywell International, has also been invited to join. EgyptAir's Airbus A320 crashed into the Mediterranean, killing all 66 people on board, during a flight from Paris's Charles de Gaulle Airport to Cairo. Last month, Al-Ahram daily published a document from the Aircraft Communication Addressing and Reporting System (ACARS) which showed that the plane transmitted “11 electronic messages” starting at 2109 GMT on 18 May. The first two messages indicated that the engines were functioning properly. The third message, which was sent at 0026 GMT on 19 May, four minutes before the plane vanished from radar, revealed a rise in the temperature of the cockpit's right-side window. Though the plane continued to send messages for three more minutes before dropping off radar screens, investigators say the information sent is insufficient to determine the cause for the crash. Earlier this month a French ship picked up signals from what is believed to be the black boxes from the EgyptAir plane. France's Air Accident Investigation Agency, the BEA, which is advising Egypt on the underwater search, says that to recover the black boxes investigators will need to pinpoint the signals to within a few meters and establish whether the pingers are still connected to the recorders.Once the batteries of the black boxes have expired they will no longer emit signals, making their recovery next to impossible. Without the black boxes, the final moments of the ill-fated plane, and the cause of its loss, may never be known. France dispatched a naval survey vessel — La Place, based at Porto Vecchio in Corsica — on 26 May to assist in the search for black boxes. The ship arrived in the search zone on 30 May. The vessel is equipped with three detectors designed to locate signals transmitted from the plane's flight recorders, which are believed to lie around 3,000 metres underwater. The torpedo-shaped detectors can be lowered a kilometre underwater and can detect signals up to four kilometres away.
