In the past year, the Ministry of Defence has confirmed in dozens of separate letters to MPs that it is willing to consider any new evidence on the fatal crash of a Chinook helicopter on the Mull of Kintyre in June 1994.
But the families of the dead pilots say that, when new information is put forward by specialists, MPs or the media, the MoD is quick to dismiss it.
Last year, as Computer Weekly was preparing to publish RAF Justice, a 140-page report into the history and problems that beset the introduction of the Chinook helicopter's safety-critical Full Authority Digital Engine Control (Fadec) computer system, we requested a comment from the ministry. RAF Justice's source material comprised many official documents that had never been published before.
The MoD's comment took the form of a statement to the general media. "The MoD has always said that it will consider any new relevant evidence" said the statement which went on to suggest that Computer Weekly's report held nothing new.
Yet the ministry's statement was issued before it had seen a copy of RAF Justice, and indeed before the document had been completed.
Now a leaked report by three senior fellows of the Royal Aeronautical Society (RAS), the world's most eminent professional aviation body, has questioned whether the RAF was right to blame the pilots for the crash.
The MoD's response is to say that the report contains inaccuracies, none of which it specifies; that it contains nothing new; it is not an official report of the Royal Aeronautical Society; and that the MoD had been told by the society that it will not endorse or adopt the report.
Could it be that while the MoD says it is willing to consider new evidence, it is in fact closing its ears to the doubts which have been cast on the decision to blame the two dead pilots for the crash?
In the past year, the MoD has claimed that independent experts have all agreed that the pilots were to blame for the crash.
But the report by the three Fellows of the RAS - which represents the first in-depth independent investigation into the crash by any professional aviation body, is highly critical of the procedures used in the RAF Board of Inquiry - and of the decision of two air marshals to blame the pilots for the accident.
The report highlights several possible causes of the accident other than pilot error. "More recently, possible technical causes that could have made the HC2 [Chinook Mk2] aircraft uncontrollable have been identified," says the leaked report, "such as Fadec software faults that could cause an engine runaway situation at any time."
The MoD has stressed to Computer Weekly that the report has no standing within the society, but its authors have impeccable credentials. One is a past chairman of the society's Flight Operations Group, another is the current chairman, and the third is vice-chairman.
Captain Ron Macdonald, the current chairman, is an aircraft accident investigator. Past chairman Captain Richard Hadlow is a retired airline captain and an armed forces helicopter pilot. The compiler of the report, Captain Ralph Kohn is a retired airline captain and regulatory authority inspector.
Their report cites an inquiry into RAF accident investigation procedures in the 1980s by William Tench, then Chief Inspector of Civil Aircraft Accident. The "Tench" report has never been published but a paragraph from it is quoted in the document authored by Macdonald, Hadlow and Kohn.
Tench is quoted as saying that the involvement of the "Air Officer Commanding's Staff Officers and even the Commander in Chief" is an "unwelcome intrusion upon what should be the complete independence of the Board of Inquiry".
That the lessons from the Tench report were not learned by the time of the inquiry into the crash on the Mull was made clear by Lord Trefgarne in the House of Lords last year.
As the Defence Minister in 1986, Lord Trefgarne had commissioned the Tench report to review the procedures pertaining to Service Boards of Inquiry. Lord Trefgarne told the House of Lords that the RAF inquiry procedures in the 1980s were "wholly unsatisfactory".
He added that the unsatisfactory inquiry procedures in the 1980s were "applied with only few modifications" to the investigation of the Mull accident.
Macdonald, Hadlow and Kohn's leaked report reveals that Sir John Day, one of the two air marshals who reviewed the evidence and then over-ruled the inconclusive findings of the three-man RAF Board of Inquiry, actually controlled the introduction into service of the Chinook Mk2.
Day's immediate superior manager was the Board of Inquiry's other reviewing officer Sir William Wratten.
The report's authors stress that Day was responsible for "controlling" the introduction into service of the Chinook Mk2, which implies that he may have been involved or carried responsibility for operational decisions on where and how the newly-upgraded Chinook Mk2s were deployed.
But there is no suggestion that either Day or Wratten were in any way party to the procurement of the Fadec, the Chinook Mk2 or the processes by which the Chinook Mk2 was approved for safe flight. Indeed there is no imputation of impropriety against Day or Wratten.
However does this wholly answer the concerns that Day and Wratten were in a position of potential conflict of interest?
An MoD spokeswoman could not say whether Day and Wratten had the authority to recommend that the Chinook be grounded in the face of ongoing concerns about the Fadec software.
In the House of Lords last year, Lord Trefgarne said the conclusion of the RAF Board of Inquiry was "unsound". Many other Lords, more than 90 MPs from all the main parties, the former Secretary of State for Defence Sir Malcolm Rifkind, hundreds of specialists who have written to Computer Weekly and now three senior Fellows of the Royal Aeronautical Society have questioned the conclusion that the pilots were negligent.
The issue now is whether the MoD will bow to the politicians and set aside the verdict against the pilots or will continue to dismiss all criticisms of the inquiry's conclusion.
Another, wider, question is whether the MoD is the servant or the master of Parliamentarians. So far the question in relation to the Chinook accident has proved rhetorical.