Air accident investigators have revealed how “unrobust procedures” meant all relevant black box cockpit voice recorder data were lost in an incident involving a Malaysia Airlines Boeing 747 at Heathrow.
The aircraft had to return to the airport after significant vibration was noted on one engine shortly after take-off for Kuala Lumpur, according to a report by the Air Accidents Investigation Branch.
During the approach to land back at Heathrow, all three autopilots disengaged, the cockpit displays and lights flickered and a series of fault messages were displayed.
There was a subsequent loss of power to some systems but the captain of the 747, with 340 passengers and 22 crew aboard, managed to make a safe landing at 11.20pm on August 17, 2012, the Press Association reported.
The aircraft had a cockpit voice recorder (CVR) – a device which can record the last two hours of cockpit conversations.
The AAIB, which classed the incident as “serious” in its report today, said the CVR continued to run for some time after the aircraft landed “and as a result all relevant CVR recordings were lost”.
The AAIB said: “The investigation determined that the operator’s procedures for the preservation of flight recording was not sufficiently robust to ensure that recordings would be preserved in a timely manner following an incident or accident.”
The report said that MAS had “expressed willingness to address this issue” and updated its procedures.
The AAIB said there had been a series of failures within the aircraft’s electrical system. The report listed action taken by Boeing after the incident.
The CVR and the flight data recorder comprise the black box equipment on passenger aircraft. The boxes are actually orange and their recovery in the case of missing MAS flight MH 370 could solve the mystery of the disappearance.