Lebanese air traffic control lost contract with the crashed Ethiopian Airlines Boeing 737-800 at 9,000ft following its departure from Beirut today.
The director of Lebanon's air navigation department, Khaled Chamieh, tells Air Transport Intelligence that the aircraft departed runway 21 on a service to Addis Ababa.
Weather data shows the presence of cumulonimbus clouds and thunderstorm activity, but Chamieh says that the jet climbed to 9,000ft before contact was lost.
"The aircraft was called several times but it did not respond," he says, adding that the investigation is underway and no further information is available.
Ethiopian Airlines has ended confusion over the identity of the aircraft, confirming it was an eight-year old model - serial number 29935, registered ET-ANB - leased from CIT.
The aircraft underwent maintenance on 25 December at the airline's facilities, says the carrier, and was "declared safe and fit to fly".
Ethiopian adds that the pilot had over 20 years' experience on various types across the carrier's network.
"A team of experts from Ethiopian has arrived in Beirut and has reported that the Lebanese Government and its army, together with the United Nations security forces in Beirut, are aggressively engaged in the search efforts for survivors at the accident scene," says the carrier.
Twenty-five victims have been recovered. Ninety passengers and crew were on board the flight, ET409.