Families who lost loved ones will have to wait until December for a decision on access to voice and data recorders from a North Sea helicopter crash.
A judge has ruled that Air Accident Investigators should hand over the black boxes from the August 2013 Super Puma crash off Shetland in which four passengers were killed.
Now a legal challenge has been launched by The British Airline Pilots’ Association (Balpa).
The case is set to be heard on December 1.
The pilots’ union claims disclosure would jeopardise ”the culture of honest reporting” which they claim improved overall safety.
Prosecutors have been trying to establish whether anybody could be held criminally responsible for the crash.
The Air Accidents Investigation Branch (AAIB) has the right to initial access to the cockpit voice recorder but has no obligation to give the materials over to other bodies, like the Crown prosecutors, unless they are directed to do so by a court.
In June, a judge found it was in the public interest and the interests of justice to make the cockpit voice recorder recovered by the Air Accidents Investigation Branch, available to prosecutors.
A total of 18 people were on board when the Super Puma crashed on its approach to Sumburgh airport.
Helicopter passengers Sarah Darnley from Elgin, Gary McCrossan, from Inverness, Duncan Munro, from Bishop Auckland, and George Allison, from Winchester, lost their lives.