Police denied access to black box crash data over concerns that pilots will be less co-operative

Investigators say pilots might be tempted to cover up vital flight information which could help make flying safer, fearing their mistakes might be made public

The wreckage of the helicopter that crashed in 2013 (PA)

Air accident investigators have refused police access to the flight recorder data from a helicopter crash that killed four oil workers, arguing that it could undermine aviation safety. They fear pilots might be tempted to cover up vital flight technical information which could help make flying safer, worried that their mistakes might be made public.

Police Scotland is seeking cockpit voice and flight data recorders held by the Air Accidents Investigation Branch (AAIB), part of the Department for Transport, from an offshore helicopter crash in 2013 that occurred just two miles from Sumburgh Airport. Rescue services saved 14 people, who were returning to Aberdeen from an oil platform.

In an unusual legal move, Scotland’s leading law officer, the Lord Advocate, wants the black box as part of an investigation into the deaths of the workers (Duncan Munro, 46; Sarah Darnley, 45; Gary McCrossan, 59; and George Allison, 57). Mandatory fatal accident inquiries are likely to be held as a result of the Crown Office’s investigations, assuming there are no criminal prosecutions.

MP Louise Ellman said the refusal was ‘disturbing’

The AAIB typically keeps black box data as privileged information to ensure investigators have the full co-operation of pilots. However, aviation legal experts say the regulations do allow for data from the black box to be disclosed where a court considers it to be in the public interest to do so.

An AAIB interim report hinted at possible pilot error.

The accident prompted a safety investigation by the House of Commons’ Transport Select Committee last year. Louise Ellman, its chair, said last night that investigators’ refusal to hand over evidence was “deeply disturbing”. She added: “The suggestion that pilots might erase data is shocking and should be investigated in its own right.”

The AAIB also argues that European regulations do not allow it to hand over such data, but the Crown Office and Procurator Fiscal Service have applied to the courts for the release of the data. A hearing in Edinburgh is due in May.

The Civil Aviation Authority is providing “limited assistance” with this application. The regulator’s most recent board minutes state: “The AAIB had refused to release this [data], citing concerns that such release would materially prejudice its ability to investigate accidents in future and might lead pilots to erase such data.”

Alistair Carmichael, the Shetland MP and Scotland Secretary, said: “I hold the AAIB in high regard, but once an investigation is completed then the release of this sort of evidence should be almost inevitable.”

Peter Lawton, the chief executive of the British Helicopter Association, said it was “most unlikely” a pilot would have time to wipe such vital information but admitted it was “a risk”. He said the AAIB was trying to ensure that “the ring of trust” between pilots and investigators was not broken.

An AAIB spokesman said: “Erasing any voice recording relating to an accident is against the law, but it is important pilots understand their conversations will only be used to assist accident investigations, otherwise confidence in the system will be eroded.”