Ethiopia’s requests came following a statement by Elias Murr, Lebanon’s Defence Minister that had said that the pilot on board the flight had gone in the opposite direction from the path recommended by the Beirut control tower. "A command tower recording shows the tower told the pilot to turn to avoid the storm, but the plane went in the opposite direction," Elias Murr said, hinting at pilot error as a possible cause of the accident.
Other theories include a possible lightening strike and a possible terrorist attack
 
Flight ET409 was carrying 90 people when it lost contact with air traffic controllers in stormy weather minutes after takeoff. The flight, bound for the Ethiopian capital Addis Ababa, was carrying 51 Lebanese and 23 Ethiopians, together with two people from British and one each from Turkey, France, Russia, Canada, Syria and Iraq in addition to eight Ethiopian airlines crew members.

No survivors had been found on yet day four of the search and rescue mission.

A pilot from the airlines that asked for his name to be held tells SSI: "the Boeing 737-800 airplane is equipped with a weather monitoring equipment that can display the weather condition in the area. Our pilots receive frequent training on flying through different weather conditions even in disasters condition like engine failure and fire. Each pilot receives training every sex months on different condition”. 

“Any international civil aviation law states that cause of an air plane crush can’t be speculated until the black box is found and the correct information is gathered”, stressed Seyoum Mesfin, Ethiopia’s Foreign Minister adding that speculations would only add to the sorrow of the families of people who died.