Italian investigators probing a LATAM Airlines Boeing 777-300ER tail-strike at Milan Malpensa indicate a discrepancy between the take-off parameters used by the crew and those calculated by the carrier after the event.
The aircraft had been conducting a service to Sao Paulo on 9 July.
Its tail contacted the ground as it rotated from runway 35L, damaging its tail-skid, a drain mast and the tail-strike sensor.
The crew, having been notified by tower controllers of the tail-strike, opted to jettison fuel – a total of 72t – and return to Malpensa. The aircraft landed on runway 35R some 1h 10min after the occurrence.
Italian investigation authority ANSV states that the 777, which was transporting 383 passengers and 15 crew members, had a take-off weight of 328.4t according to the loadsheet.
Flight-data recorder information shows the aircraft started rotating at 153kt, in line with the 149kt entered into the flight-management system.
Some 5s after the pitch-up command, the aircraft was 8.2° nose-up with an airspeed of 166kt, and tail-strike indicators activated.
The twinjet lifted off at 180kt having scored the runway surface over a distance of 723m (2,370ft), from between the DM and DE intersections to the EM intersection.
ANSV says that, after the event, the operator conducted a performance calculation using the on-board tool, based on a take-off weight of 328.4t and an outside air temperature of 30°C.
This calculation returned a rotation speed of 181kt and climb-out speed of 186kt – higher than those obtained from the 777’s flight-data recorder – with the same 5° flap setting.
ANSV has not remarked on the discrepancy between these parameters and the recorded figures. Its findings are preliminary and no conclusions have yet been reached.
The crew comprised three pilots in the cockpit: an instructor captain in the right-hand seat, who was flying, and a captain under training in the left seat, plus a relief captain in the jump seat.
None of the 398 occupants was injured. The aircraft involved (PT-MUG), powered by GE Aerospace GE90 engines, was originally delivered to the Brazilian division of LATAM in 2012.
