Crash cripples war on IRA: Computer or pilot error suspected after helicopter disaster kills Ulster's police and army intelligence chiefs

THE FULL magnitude of the Mull of Kintyre helicopter disaster became apparent yesterday as it emerged that the crash had claimed the lives of up to six senior MI5 officers and the most senior soldier to die in the Northern Ireland Troubles.

Together with the head of the Royal Ulster Constabulary Special Branch, they were among 29 people killed when their Chinook helicopter hit a Scottish hillside on the way from Belfast to Inverness.

The scale of the human tragedy was matched only by the loss to the security establishment, which at a stroke lost two dozen of its most valuable officers.

The RUC's Chief Constable, Sir Hugh Annesley, admitted: 'No one can pretend that this is not a catastrophic loss. It is a very, very significant setback.' Some of the RUC officers lost had more than 20 years' experience in the force's Special Branch, the leading intelligence agency in the fight against the IRA.

As the investigation into the accident continued last night, an RAF source suggested a possible cause was that the helicopter, which had been recently refurbished, was not yet cleared to fly at high altitudes. The Chinook had returned about three months ago from a Boeing plant in Philadelphia, where it had been completely refitted as part of the RAF's modernisation of its 30 Chinooks.

This total refurbishment involves the new Mark 2 craft being given so much new equipment that it requires a whole new testing programme before it is put back into full operational service.

The helicopters' operations are restricted because trials on the new computer-driven engine system and new rotor blades are still be carried out. The RAF was anxious to retain some Mark 1 aircraft at Belfast while this testing was being carried out, but was unable to do so.

The Chinook that crashed was one of those which, in certain weather conditions, are not allowed to fly high enough to cruise all the way to Inverness. The pilots were forced to operate at a low level. In addition, the pilots may have made an error, possibly through a mistake in inputting their course into the computer, which led them to fly into high ground.

In the crash, the Army lost a full colonel, three lieutenant-colonels and five majors. Six security specialists, all or most of whom are thought to be MI5 officers on secondment to the Northern Ireland Office, also died in what was an unprecedented blow to the security apparatus. The Chinook's four-man crew and its 25 passengers, one a woman, were all killed.

A senior Ulster anti-terrorist official said the Inverness conference the officials were due to attend was 'massively important'. It would have covered money laundering and the pursuit of terrorists' funds.

Questions were immediately raised about the suitability of the aircraft and the inadvisability of transporting so many key people in one helicopter.

The Secretary of State for Northern Ireland, Sir Patrick Mayhew, said the use of a single helicopter was standard practice.

Speaking after visiting the crash site, Jeremy Hanley, Minister of State for the Armed Forces, refused to rule out the possibility of terrorist involvement in the crash, but said: 'The odds are very heavily in favour of this being a tragic accident.' He hinted that the Government would act to prevent so many key officials travelling together in future. But he insisted that there was no reason to think that the Chinook constituted a risk. 'It is a very safe way of carrying people to particularly remote locations,' he said.

Acting Chief Superintendent James Guy, the local police commander, said that the pilot had not sent a distress call.

Incalculable loss, page 2

(Photograph omitted)