The past 16 years have been cruel to Mike Tapper, as if the fates had decided it was not enough that he should lose his son in a helicopter crash on a bleak Scottish hillside. Almost since the day of that tragedy, he has been tormented by the Ministry of Defence's insistence that his son was to blame for the crash in June 1994. He has spent the past decade and a half trying to overturn that verdict. Last Monday he thought might have the evidence finally to shame the Ministry of Defence into admitting it wasn't his son's fault. Once again, however, he was disappointed.
"It's extraordinary," he said last week. "You're in a position with this government that even if you have the documents, they deny them."
His son, Flight Lieutenant Jonathan Tapper, was flying the Chinook to Northern Ireland when it smashed into a hillside on the Mull of Kintyre, killing all 29 people on board.
Almost immediately Tapper and his co-pilot were blamed, a view confirmed the following year with the publication of the official Board of Inquiry report. Air Chief Marshal Sir William Wratten and Air Vice-Marshal Sir John Day accused Flight Lieutenants Tapper and Rick Cook of gross negligence, saying they were flying too low and too fast. They were, in effect, accused of manslaughter.
"I never thought it was an accident," Mr Tapper said. He recalled he had been reading at home in Blackheath, London, when his daughter-in-law rang with the news. She had been contacted by one of the other wives, barely an hour after the crash.
"I immediately thought, 'There's something fishy here'. But I was expecting it all to come out – that there would be an inquiry that would uncover the things that were wrong with the aircraft. In my first meeting with the RAF I realised that wasn't going to happen."
His optimism had stemmed from the fact that Jonathan, 28, had already complained to him about the Chinook. RAF test pilots had refused to fly it because its computer software – meant to control the engine – didn't work. There was no manual override.
"I hadn't formed a view initially that there was anything sinister. It's only as time went on I realised the enormity of the – I don't use the word cover-up, it's too emotive – obfuscation."
As he sits at the kitchen table in his cottage in Burnham Thorpe in north Norfolk, where he and his wife Hazel moved shortly after the loss of his son, in front of him are a pile of documents. These go a long way to showing "the real possibility" that the software system was at fault and, what's more, that the RAF and MoD knew of the danger but still let the aircraft fly.
Among the pile also lie the results of three independent investigations that concluded there was no evidence for pilot error, and leaked memos that reveal that test pilots had refused to fly the aircraft because of safety concerns. All of these the MoD had discounted. Investigators are not supposed to blame pilots unless there is a 100 per cent certainty they were at fault.
On Monday came fresh evidence: new hope in the form of another MoD document. Written in September 1993, nine months before the crash, it said the software on the aircraft was so flawed it was "unintelligible", and that a "hazard analysis ... identifies the software as safety critical and that any malfunctions or design errors could have catastrophic effects".
But Air Chief Marshal Sir Stephen Dalton was dismissive. "The pilots consciously breached their operating rules, thereby knowingly placing their aircraft, passengers, crew and themselves at risk," he said. "This was the basis for the gross negligence finding."
Mr Tapper is not surprised. "You won't get anything out of the RAF, or anything out of the ministers. We're living in a Kafkaesque world. There is a real possibility that they were facing rapidly deteriorating conditions caused by the software malfunction. If they'd had clear air before them, they could probably have controlled it. But because they had the mountain ahead of them it was curtains."
He is 72, but his full head of steel grey hair and robust bearing defy his years. He should be spending his days walking over the fields or the nearby beaches with his dog. Instead he is once again recounting the experience of the loss of his son, who started flying as a teenager with the air cadets and had been selected as a special forces pilot.
"What incensed one is that with no evidence whatsoever they accused the pilots of gross negligence," Mr Tapper said. "The air marshals seemed to lose their cool and wrote in very extravagant language that it was the pilots who caused the crash."
He has no delusions about the MoD or military life: he spent his national service in submarines, and then 10 years as a reservist. He worked for Barclays overseeing defence industry accounts."I wasn't an innocent abroad," he said. "I'd got to know and saw how the MoD, and in particular the RAF, operated. And it was quite scary. The MoD would make a presentation and if you started asking questions it caused a certain amount of havoc."
The battle with the MoD has at least provided Mr Tapper with a channel for his grief and anger. But it is more difficult for the rest of his family. Jonathan's children are 15 and 17 now. It doesn't take much to imagine the pain caused not only by their growing up without a father, but also by the shadow hanging over his reputation.
Jonathan's mother, Hazel, has Parkinson's disease, something her husband is sure was brought about by the shock of the crash. "I think it has more effect on the women in the family because they're not so much in control," he says. "Almost certainly Hazel has got Parkinson's as a result of this. The consultant is certain that the first symptoms started in 1994. The fight helps the grieving process."
He remains hopeful. The Conservatives have promised to refer the evidence to a High Court judge. Mr Tapper simply wants his son's reputation restored. "That would be the end of it," he said. "It would be a relief and I'd shut down any further talk of it, because it is exhausting."
April 1994 Mark II Chinook is delivered to the RAF by Boeing.
1 June 1994 Test pilots refuse to fly the aircraft.
2 June 1994 The Chinook crashes into a hillside in the Mull of Kintyre, killing 29 people.
April 1995 The RAF Board of Inquiry investigation is published. Two air marshals accuse the pilots of gross negligence.
March 1996 Scottish Fatal Accident Inquiry verdict published. It concludes the cause of the accident cannot be determined but exonerates the pilots.
December 2000 Inquiry by the Commons Defence Select Committee finds the cause of the crash inconclusive.
February 2002 Inquiry by the House of Lords Select Committee describes the findings of gross negligence as "unjustified"; 170 MPs call for the finding of gross negligence to be quashed.
November 2007 Defence Secretary Des Browne says he will review the Chinook case.
December 2008 Browne's successor John Hutton says there is no new evidence and the original findings of gross negligence stand.
January 2010 Fresh evidence that the MoD knew of software problems that were "positively dangerous". It is dismissed by the MoD.Reuse content