Ali Abedzadeh, the chief of Iran’s Civil Aviation Organization, wrote in a preliminary report on the crash that both of the plane’s black boxes have been damaged, with physical damage visible.

«Both devices have been damaged by fire and the accident. There is the memory parts in both devices, however, physical damage is visible on them,» the report wrote.

He added that the aircraft first rose to an «altitude of 8000 feet» before disappearing from the radar screen, and the aircraft hits the ground.

There were no radio messages from the pilot before it crashed, Abedzadeh wrote. It appeared the plane was heading westward from the airport, and when problems occurred it turned right, and crashed as it attempted to return to the airport, he added.