Philip Smart | Adelaide
Airbus Defence and Space has confirmed that the investigation in to the cause of the May 9 Airbus A400m crash that killed four people and injured two is now centred on the aircraft’s engine control system.
Spain’s commission for investigation of military aircraft accidents, CITAAM, said information from the aircraft’s flight data recorder and cockpit voice recorder has confirmed that three of the aircraft’s four engines froze at a particular power setting soon after take-off and would not respond to the crew’s attempts to change the power settings in the normal way.
In an attempt to reduce power the crew then set the aircraft power levers to “flight idle”, a setting usually used in deceleration and descent which provides the minimum amount of power required to maintain engine-driven systems such as hydraulics and environmental control, but not enough to maintain normal straight and level flight.
But attempts to then increase power were unsuccessful and the three affected engines remained at flight idle for the rest of the flight. The aircraft hit an electricity pylon during an attempted emergency landing.
On May 19 Airbus issued an Alert Operator Transmission requiring existing A400M operators to perform one-time specific checks of the Electronic Control Units (ECU) on each of the aircraft’s engines before next flight and introducing additional detailed checks to be carried out in the event of any subsequent engine or ECU replacement.
Later analysis has shown that all other aircraft systems operated normally throughout the flight. The investigation is continuing.
The A400M, the third built for the Turkish Air Force, was on its first pre-delivery test flight.