The British government is facing intense pressure to reopen the investigation into the 1994 Chinook helicopter crash after a Lords committee concluded there was no justification for blaming the pilots.
A seven-month review by an all-party House of Lords committee yesterday unanimously declared that the conclusion by two RAF air marshals that the two pilots were guilty of gross negligence was "not justified" and mechanical failure could not be ruled out.
The RAF's worst peacetime accident claimed the lives of all 29 people on board Chinook ZD 576 when it crashed into the southern tip of the Mull of Kintyre during bad weather on June 2nd, 1994.
The passengers included the "top echelon" of security and police officers engaged in the fight against terrorism - 25 senior MI5, RUC, army anti-terrorist officers and civil servants who were travelling from RAF Aldergrove to a terrorism conference at Fort George, near Inverness.
The families of the two pilots, Flight Lieuts Jonathan Tapper and Richard Cook, urged the Prime Minister, Mr Tony Blair, to intervene to overturn the verdicts.
Mr Mike Tapper told the Lords committee his son had expressed concern about the safety of the Chinook Mk 2 before the flight. He insisted the only satisfactory answer was to quash the verdicts.
"A gross injustice must be righted," he said.
The Conservative Party chairman, Mr David Davies, insisted the only "honourable" course for the government was to reopen the inquiry.
The Scottish National Party said the "flawed and hurtful" verdict should be overturned.
Although the Lords committee report has no judicial basis, it will increase pressure on the Labour government to overturn the original findings.
Responding to the committee's conclusion that the RAF's "no doubt whatsoever" standard of proof for attributing blame to the aircrew had not been reached, Downing Street said it would study the report but declared it was "not aware that there is any new evidence which has come to light".
The Ministry of Defence stressed the air marshals had reached their conclusions based on the pilots' airmanship and duty of care and insisted they had met RAF investigating criteria.
"We have looked at this for eight years and it is really down to how people look at the evidence, depending on their point of view," a MoD spokesman said.
Under RAF rules at the time of the crash deceased aircrew could only be found negligent where there was absolutely no doubt whatsoever.
An RAF board of inquiry, investigating on behalf of the Ministry of Defence, concluded the pilots had probably chosen an inappropriate rate of climb to fly over the mull, which was covered in thick but patchy fog, but made no finding of negligence.
It was a view supported in inquiries by the Fatal Accident Inquiry and Air Accidents Investigation Branch.
However, in 1995 when the board of inquiry reported to Air Marshals Sir John Day and Sir William Wratten, they overruled its conclusions and found the pilots guilty of gross negligence.
They suggested it was "incomprehensible" why two experienced pilots had "flown a serviceable aircraft into cloud-covered high ground".
In its report, the Lords committee pointed out that even though new evidence had emerged since the crash, the evidence the air marshals had relied upon - in particular a flight simulation by the aircraft's manufacturer, Boeing, which did not take accou nt of the Chinook's FADEC computer system - was flawed.
Moreover, while no trace of mechanical fault was found, the air marshals had not considered the possibility that an undemanded flight control movement, contamination of the hydraulic fluid system or control jam could have caused the crash and therefore the RAF standard of "no doubt whatsoever" could not be met.