An investigation into a Mozambican Airlines flight which crashed in November has found that the pilot deliberately brought the plane down, killing all 33 people on board.
Aviation officials have examined evidence from the "black box" recorder of Mozambican Airlines flight TM470, which was flying from the capital Maputo to Angola when it came down in a Namibian national park on 29 November.
Experts say there were no mechanical faults with the plane at the time, and that the series of manual overrides required to make it crash showed there was a "clear intention" to do so.
The pilot, whose motives for bringing the plane down remain unknown, has been named as Herminio dos Santos Fernandes.
Joao Abreu, chairman of the Mozambican Civil Aviation Institute, said that a preliminary report from the data available showed that "there was an intention to crash the plane".
The aircraft was reported at a normal position over northern Botswana and with no mechanical malfunctions, he said, after which point it suddenly started losing altitude.
While the co-pilot was in the toilet, Dos Santos Fernandes manually altered the plane's altitude selector three times, quickly bringing it down from 38,000 feet to 592 feet, Mr Abreu said.
"During these actions you can hear low and high-intensity alarm signals and repeated beating against the door with demands to come into the cockpit," Abreu was quoted as saying by state news agency AIM.
"The plane fell with the pilot alert, and the reasons which may have given rise to this behaviour are unknown," he said.
Those the data available to the investigators do not reveal who was banging on the cockpit, Mr Abreu said it was clear the co-pilot was not in the cockpit at the time of the crash, and that he could not be held responsible.
Other indicators recorded by the black box, which was recovered and decoded in the US, showed that manual operations were used in the seconds before the fatal crash.
Mr Abreu said: "All these operations required detailed knowledge of the plane's controls, and showed a clear intention to crash the aircraft."
At the time of the incident last month, a search was launched after the local control tower lost voice and radar contact with the aircraft. It was a day later that the wreckage of the plane was found, "completely burned to ashes".
- UK Independent