Families of those killed in an RAF Chinook helicopter crash in 1994 have urged the Ministy of Defence (MoD) to release documents sealed for 100 years.

Four crew and 25 passengers were killed when the helicopter went down in foggy conditions over the Mull of Kintyre in Scotland.

The helicopter was carrying leading security personnel from RAF Aldergrove in Northern Ireland to a conference at Fort George near Inverness.

Several families have written an open letter to the UK Government renewing calls for a public inquiry. The MoD says the incident was a “tragic accident”.

The crash on 2 June 1994 remains one of the RAF’s worst peacetime losses of life.

Two pilots accused of negligence over the disaster were exonerated 17 years later.

Families have called for the full release of documents that were locked away until 2094 by the MoD

Andy Tobias, who was eight when his father Lt Col John Tobias, 41, was killed, said the “secrecy” raises questions about what really happened.

Speaking publicly about the crash for the first time, he said he lost part of his childhood because his father was on a helicopter “that had been deemed unairworthy and should never have taken off”.

He said: “In my view, it’s nothing short of corporate manslaughter.

“I have tried for many years to put this crash, and my family’s unnecessary loss, behind me.

“But learning that the MoD has sealed away the archive until after all of us will be long gone seriously raises my concerns about what really happened.”

After the crash, pilots Richard Cook and Jonathan Tapper, were accused of gross negligence, but this verdict was overturned by the UK Government 17 years later.

A subsequent review by Lord Philip set out “numerous concerns” raised by those who worked on the Chinooks.

The MoD’s testing centre at Boscombe Down in Wiltshire declared the Chinook Mk2 helicopters “unairworthy” prior to the crash.

Esme Sparks, who was seven years old when her father Major Gary Sparks lost his life, said it had been a “shock” to learn about the existence of the documents.

She said: “My whole family wants answers and action because my daddy was denied his right to life – put in danger by the MoD on an aircraft deemed not airworthy.

“We are furious that the Government and the MoD is refusing to listen or to meet us.”

The open letter states the Chinook Justice Campaign – which includes most of the bereaved families – formally requested a public inquiry on October 9 2024.

This was rejected by the minister for veterans and people Alistair Carns on December 17.

A spokesperson for the MoD said: “The Mull of Kintyre crash was a tragic accident and our thoughts and sympathies remain with the families, friends and colleagues of all those who died.”