The Tories have made it party policy to appoint a senior judge to review a finding of gross negligence against the two deceased pilots of a Chinook Mk2 helicopter which crashed on the Mull of Kintyre in June 1994.
David Cameron's position is that the reputations of the two pilots deserve to be reinstated. "In the absence of any overwhelming argument presented to me as Prime Minister, that is what I would do," said Cameron.
The crash of Chinook ZD576 killed all on board: four crewmen and 25 senior police and intelligence officers. It has become the RAF's most notorious peacetime accident.
An RAF Board of Inquiry found that problems with the Chinook's software-controlled "Fadec" engine control system could have been a factor in the accident.
Computer Weekly has campaigned for more than a decade, with many other organisations and individuals, for a new inquiry which could clear the names of Flight Lieutenants Jonathan Tapper and Rick Cook, the pilots of ZD576.
Software problems should have halted operational flights
No clear cause of the crash has ever emerged. New evidence since an RAF Board of Inquiry into the accident in 1995 has shown that a commanding officer at the Ministry of Defence, Boscombe Down, was so concerned about various faults related to the helicopter's "Fadec" engine control system that he asked for operational flights to stop.
His memo called "in the strongest possible terms" for a formal recommendation that operational flights of the Chinook Mk2 cease until Fadec faults were explained and corrective action taken.
The memo was dated 2 June 1994 - the day of the Mull crash.
At the time of the accident, the MoD was secretly accusing Fadec's supplier of having designed a software-driven fuel control system that was not airworthy, did not meet international safety standards and had not been tested adequately.
No details of this legal action were given to the Board of Inquiry into the crash of Chinook ZD576.
Fadec software was critical to safe flight
The Fadec software was an intermediary between pilot controls and the engines. It controlled fuel to the Chinook's two jet engines and was categorized by the helicopter's manufacturer Boeing as "flight critical".
Fadec problems included engines shutting down or surging unexpectedly, and warning lights illuminating in the cockpit.
An RAF Board of Inquiry did not rule out the possibility of a major technical malfunction distracting the crew but two air marshals, after reviewing the Board of Inquiry's report, decided that Cook and Tapper had been grossly negligent.
RAF rules at the time were that deceased crew should be found negligent only when there was "absolutely no doubt whatsoever" about the cause of a crash. The Chinook had no black boxes and parts of the aircraft were damaged by fire after the impact.
In written evidence to the Public Accounts Committee in 2000, Computer Weekly said: "In the case of the Chinook's Fadec there has never, to Computer Weekly's knowledge, been a procurement or an implementation of safety-critical software that has had such a dense history of significant problems."
Analysis of Fadec software stopped because of so many faults
In 1993 an assessment of the Fadec by defence contractor EDS was abandoned because of the large number of anomalies found - 485 after an analysis of less than 18% of the code. EDS said in a report that a potential flaw in the Fadec's main computer "may cause incorrect operation of the Fadec".
MoD IT experts at Boscombe Down wanted the Fadec software rewritten but the MoD and RAF rejected this recommendation.
Now Conservative Central Office has confirmed in a statement to Computer Weekly that it is official Party policy to review the finding of gross negligence against the pilots.
In an exchange of emails with Computer Weekly, Central Office said the Party's policy is "for the existing evidence to be examined by a senior judge with the remit of advising if such evidence is sufficient to sustain a verdict of negligence at the required standard of proof".
The Tory Party's statement means there is a clear gap in policy between the Conservatives and the present government over the Chinook accident.
Labour rejects calls for a review
Without exception, Labour ministers have rejected calls for any new inquiry over the crash. In June this year Bob Ainsworth, the Defence Secretary, wrote to Lord O'Neill, a longstanding campaigner for the Cook and Tapper families, rejecting calls for a new inquiry.
He said: "Whilst I acknowledge that you have gained the agreement of a number of your key stakeholders, I cannot agree that the suggested review would be an appropriate way forward."
Tory defence ministers Sir Malcolm Rifkind and James Arbuthnot, who had backed the finding against the pilots when they were in office, have since changed their minds.
A former Tory defence spokesman Robert Key has also campaigned for the reputations of the pilots of ZD576 to be restored.
The MoD declined to comment on what is now official Party policy over the Chinook crash. It has always supported the finding of negligence against Cook and Tapper.
The father of one of the pilots, Mike Tapper, said of the Tory policy statement: "After 12 years of totally negative response from the Labour government this has to be good news."
If the Tories win the next general election, and a judge disagrees with the finding of gross negligence against Cook and Tapper, it will be incumbent on the Party to accept the judge's decision because it had, after all, set up the inquiry.
But would the MoD accept a judge's finding, even if it were accepted by its Secretary of State for Defence? If the MoD refuses, that would raise questions of who is ultimately in control of the MoD: the civil servants and military advisers, or elected ministers.