Chinooks are used to transport people and equipment in the military
Campaigners are calling on the new Defence Secretary John Hutton to clear two pilots of blame for an RAF Chinook helicopter crash in 1994.
A review of the cause of the crash on the Mull of Kintyre, in which 29 people died, was set up by the former Defence Secretary Des Browne almost a year ago.
Some of Britain's top security experts died in the crash, along with four members of crew.
The campaigners are now seeking an urgent decision from Mr Hutton.
The BBC understands that Mr Browne, who was sacked from the post last week, was waiting for one final report from officials before making a decision.
BBC Westminster reporter Tim Reid, says the Mull of Kintyre campaigners, who include the families of the two pilots, have been left disappointed that Mr Browne has left the government.
He agreed to the first MoD review of the case at the end of last year, at the same time as a dossier of new evidence was handed over by the campaign group at Westminster.
Despite claims of computer malfunctions on board, two RAF Air Marshalls blamed the two dead pilots.
Flt Lt Tapper, 30, from Burnham Thorpe, Norfolk, and Flt Lt Cook, 28, from Church Crookham, Hampshire, were initially cleared of blame by an RAF board of inquiry.
It ruled it was impossible to establish the exact cause of the crash, and a fatal accident inquiry reached the same conclusion.
But that was overturned by two senior RAF officers - Air Vice-Marshal John Day and Air Chief Marshal Sir William Wratten - who said the pilots were guilty of gross negligence for flying too fast and too low in thick fog.
However, despite a cross-party committee of peers finding that the pilots could not be blamed, the Ministry of Defence has refused to change its mind.