Aircraft

Information on the TAM Airbus A320 accident shortly to be made available to operators will show that the crew retarded only the thrust lever for the left-hand engine during touchdown, leaving the other in its forward position.

Industry sources say the information, to be set out in a communique, shows that the crew made a normal approach to Sao Paulo Congonhas Airport on 17 July with auto-thrust selected – the aircraft operating under a ‘managed thrust’ regime – and the thrust levers in the ‘climb’ position.

For reasons yet to be explained, the pilot, in the final moments before touchdown, retarded only the thrust lever for the left-hand engine – first into the ‘idle’ position, then into ‘reverse’. This action disconnected the auto-thrust, as per its design. The failure to move the right-hand engine’s thrust lever to the reverse position runs contrary to the standard operating procedure which calls for both levers to be set to ‘idle’ and then 'reverse' – even with a thruster reverser inoperative.

It is unclear why the right-hand engine thrust lever was left in position. Newly-released cockpit-voice transcripts have notably highlighted the crew’s awareness that only the left-hand engine had an operable thrust-reverser; the right-hand reverser had been deactivated. This, however, should not have made a difference to the thrust retardation procedure.

As the aircraft began to slow after touchdown the thrust being produced by the right-hand engine remained at the level it was at when the auto-thrust had disconnected. With the thrust lever forward the spoilers would not have deployed, and the auto-brake would have similarly been inhibited.

In the cockpit transcript the co-pilot appears to state that the A320’s spoilers did not activate on touchdown and, as the situation develops, the pilots are heard to say that they cannot slow the aircraft. Flight-data recorder information indicates that the pilots repeatedly pressed on the brakes in a bid to stop the jet but did not retard the right-hand thrust lever.

• TAM A320 crash - full transcript from cockpit voice recorder