A total of 25 senior intelligence experts and four special forces crew were killed when an RAF Chinook ZD576 crashed on the Mull of Kintyre en route from RAF Aldergrove in Northern Ireland to Fort George near Inverness on June 2 that year.
The incident was initially blamed on pilot error before being overturned in 2011.
A BBC documentary last year, Chinook: Zulu Delta 576, revealed the files related to the tragedy had been sealed by the MoD for 100 years.
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In a petition, the family of the victims have urged for the full release of all documents.
They also call on the Prime Minister to undertake a judge-led public inquiry.
The families have demanded the Government introduce a legal “duty of candour” on all public bodies “so that no family ever has to battle for the truth again”.
The petition reads: “Twenty-nine people boarded Chinook ZD576 on 2 June 1994. All of them died.
“31 years later, we – their families – still have no answers.
“We have been denied truth, transparency and justice by the Ministry of Defence (MoD).
“Our loved ones were forced to board an RAF helicopter with fatal software flaws that MoD test engineers had deemed ‘positively dangerous’ and ‘not to be relied upon in any way whatsoever’.
“We know key evidence was withheld or ignored in previous investigations. Former ministers say they were misled by the MoD and doubt airworthiness issues were investigated properly.”
The family of the victims have welcomed the BBC’s decision to re-air Chinook: Zulu Delta 576 this month as they push for answers, with the first part airing on Sunday, August 17 on BBC2 at 9pm and the second part a week later.
Families of those killed in the 1994 Chinook crash (l to r front) Nicola Rawcliffe, Esme Sparks, Gaynor Tobias, Susan Phoenix, Lucy and Cleo Sparks, Jenni Balmer Hornby and Chris Cook, (l to r back) Andy Tobias, Sue Angus, Niven Phoenix and Matt Tobias, before meeting their legal team in central London (Jonathan Brady/PA)
Relatives of the 29 people who died have set up the Chinook Justice Campaign to demand “truth and transparency” from the MoD.
Dr Susan Phoenix’s husband, Ian, a detective superintendent in the RUC, was among those killed.
Dr Phoenix, 76, who lives in Portland, Dorset, said: “It was solely down to this excellent two-part BBC documentary by Fine Point Films that brought all of the Chinook Justice families together to fight for truth, transparency and justice.
“Why would files on this horrific crash be sealed for 100 years without there being something to hide, not just from the widows of those on board, but from their children, and grandchildren?
“There is something rotten at the heart of the MoD that continues, having put 29 people on an aircraft that was not airworthy, to insult and patronise us all, just as it dishonours our loved ones.
“We are determined to find out the truth and we believe the British public want that too.”
Esme Sparks was seven and her younger siblings were aged just two when their father Major Gary Sparks was killed in the crash.
A secondary school teacher, from Darlington, Co Durham, Ms Sparks said: “We are comforted by the fact that more than 25,000 people have signed our petition at change.org/JusticeForThe29 and we would encourage anyone that is sick of state cover-ups to add their names so that we can get truth and transparency.
“The Prime Minister must urgently introduce a legal duty of candour on all public bodies, including the MoD which placed our relatives on an aircraft it knew to be unairworthy, to prevent this type of unacceptable secrecy and wrongdoing happening over and over again.”
The MoD has been approached for comment.