'Dangerous' software warning before Chinook crash killed 29

An internal Ministry of Defence document written nine months before the tragedy in 1994 said the engine control computer software was "positively dangerous".

Written by experts working for the MoD's aircraft testing centre at Boscombe Down, it points to serious concerns with the software, warning of "catastrophic effects".

The report said the 174 deficiencies found in the software meant the pilot's full control of the engines "could not be assured".

The document has reignited the debate over the cause of the accident on June 2, 1994, which killed 29 people including 25 senior military, police and intelligence officers.

The helicopter, which flew from Belfast, was transporting the group to a security conference at the Fort George military base in Inverness when it crashed in thick fog on the Mull of Kintyre. Their deaths were described at the time as a "catastrophic loss in the fight against terrorism".

An official RAF inquiry concluded the aircraft was airworthy and found the two pilots guilty of gross negligence, saying they were flying too low and too fast.

But three subsequent inquiries since have found the cause of the crash inconclusive.

Inquiries in the House of Commons and the House of Lords found the verdicts of gross negligence were unsustainable.

Yesterday, campaigners demanded the special forces pilots on the Chinook, Flight Lieutenants Jonathan Tapper and Rick Cook, be cleared of any wrongdoing.

Flt Lt Tapper's father Mike said the new evidence was a major advance towards what he has been fighting for for almost 12 years. He said it was a "question of honour" now to see his son's name cleared.