The claim was made by a Chinook pilot who put forward his own theory about the disaster: a temporary control jam which put the helicopter on a fatal collision course with the Mull. He told the inquiry the RAF board of inquiry's explanation - a wrong rate of climb - had been largely based on "speculation and conjecture".
Top-ranking officers had then based on this a judgment of "gross negligence" on the two pilots involved, Flight Lieutenants Jonathan Tapper and Richard Cook.
The assertion by the Chinook pilot, who cannot be named for security reasons, led to the recall to the witness box today of the wing commander who acted as president of the board of inquiry. He said the pilot's alternative theory was a possibility that could not be dismissed, but was extremely unlikely.
He repeated his own view of the likeliest cause - that the crew put the Chinook into a high-speed cruising climb too shallow to clear the Mull. They began the climb at a point where they thought they were further away from the Mull, and slightly further to the right of it, than they were, he said.
The inquiry yesterday entered its closing stages. It will resume on Thursday, when closing submissions will be heard from lawyers.
The disaster, on 2 June 1994, wiped out the elite of Ulster's intelligence experts.
The Chinook pilot said that he believed an explanation could be a temporary 20-second control jam, perhaps caused by one or more loose articles interfering with the controls, with the crew regaining control but too late. The pilot said he was putting forward his theory not as the likeliest cause, but as a possible one.Reuse content