New doubts on Chinook crash ruling

This is a longer version of an article on

A former senior officer who helped write rules for RAF accident inquiries has spoken publicly for the first time about his concerns over what caused the crash of a Chinook helicopter 14 years ago which killed the aircrew and 25 VIPs.

Retired Air Commodore Derek Hine says there is too much evidence of software problems on the type of Chinook which crashed to convince him that the pilots were definitely to blame.

Hine’s comments come as the Defence Secretary Des Browne considers a lengthy file on the circumstances surrounding the crash of Chinook ZD576 on the Mull of Kintyre in June 1994.

The dossier contains new evidence which campaigners hope will lead to minsters setting aside the verdict of gross negligence against the pilots Fl Lieutenants Rick Cook and Jonathan Tapper.

Computer Weekly and important others, including Channel Four News, have campaigned for the finding of negligence to be set aside. We published a 140-page report “Raf Justice – How the RAF blamed two dead pilots and covered up problems with the Chinook computer system FADEC [Full Authority Digital Engine Control ]”.

The crash of Chinook ZD576 killed all on board: four aircrew and 25 senior police and intelligence officers. It has been described as the RAF’s worst peacetime accident.

Hine chaired an RAF standing committee in 1982 which established rules for RAF Boards of Inquiry into accidents. He wrote a rule that dead aircrew should be found negligent only if there is “absolutely no doubt whatsoever”.

Now, in his first interview over the crash, Hine has told Computer Weekly that there is too much uncertainty over its cause to meet the standard of proof required by the phrase “absolutely no doubt whatsoever”. He said the written findings of two air marshals against the dead pilots did not at the time include any discussion of the phrase.

He said he has “lost faith in RAF” because of its decision to find the pilots of ZD576 grossly negligent. “I cannot believe that the RAF would do that to two pilots. I did not think that even on balance of probability that they were negligent.”

In November 2000 the Public Accounts Committee found that the RAF’s procurement of the software-controlled FADEC for the Chinook Mk2 was flawed.

It also found that “faults with the FADEC led to doubts as to the reliability and safety of the aircraft at the time and make it very difficult to rule out categorically a technical fault as at least a contributory cause of ZD-576’s crash”.

The committee called for the verdict against the pilots of ZD576 to be set aside, which ministers have so far declined to do. In February 2002 a Lords committee investigation of the crash found that there was doubt about its cause because of the possibility of a technical malfunction, such as a jam of the pilot’s controls or a sudden engine surge, caused by the Chinook’s safety-critical FAEDC. The committee said the finding of negligence was not justified.

Hine was the commander of an RAF base, a fast jet pilot and a flying instructor. His rule for RAF boards of inquiry – which was adopted by the air force in its Manual of Flight Safety [AP3207] – was aimed at safeguarding the right of dead pilots not to have their reputations defiled unjustifiably by being incorrectly blamed for crashes.

Hine said the rule of “absolutely no doubt whatsoever” was established after senior RAF officers in the 1980s had been too quick to blame the pilots for fatal crashes rather than look harder for other reasons such as technical fault and managerial shortcomings.

He said: “There was some evidence that dead pilots were being blamed as a convenience … boards of inquiry had been closed down early and the pilots blamed. It was an easy way out.”

Hine reviewed the evidence from the crash of ZD576 and said he found it “very, very thin”. The aircraft did not have a cockpit voice recorder or data recorder.

He added that the cause would never be known but “things are coming out of the woodwork such as problems with the Chinook’s software”. He pointed out that a day before the crash flying trials on the Chinook Mk2 were suspended at Boscombe Down, largely because of the unreliability and criticality of the engine control software.

Hine said he and his committee had sought to isolate boards of inquiry from the command chain. “We tried to say that when there is an accident it is no longer the bailiwick of the commander in chief. He controls the aeroplane and its operation; he should not control the board of inquiry, nor the people who are running it because he can influence them. And this has happened in the past. I wanted independent boards of inquiry – and early on I was told we could not have that.”

On the blaming of the pilots for the crash of ZD576 Hine said: “In circumstances so sensitive as a telling verdict against the two pilots there should have been some discussion to show they had taken into account the condition of “absolutely no doubt whatsoever” and despite that had come to the conclusion reluctantly that the pilots were negligent. There should have been some discussion along these lines and there wasn’t.

“My regulation was a heaven sent opportunity to set the verdict aside because there was insufficient evidence to reach a conclusion on the cause of the accident.”

Hine pointed out that one of the pilots [Rick Cook] had told his father he was unhappy with the Chinook Mk2’s FADEC software; and several people at Boscombe Down had put things in writing which “really make things look rather bad for those who say the pilots were definitely to blame”.

Hine wrote to a committee of the House of Lords, which investigated the crash of ZD576, to say that his regulation on “absolutely no doubt whatsoever” had not been met. This is the first time he has been interviewed on the subject.

Browne’s decision on whether to accept the new evidence and set aside the finding against Cook and Tapper is expected in the next few months.


Raf Justice – Computer Weekly’s 140-page report on the problems with software on the type of helicopter which crashed on the Mull of Kintyre: rafjust.pdf

Website of a tireless campaigner for the finding of negligence against the pilots of ZD576 to be set aside

Pprune [Professional Pilots Rumour Network] – forum for pilots on the Chinook crash [several years of posts]

New doubts raised on Chinook crash ruling

House of Lords committee report on an investigation into the crash of ZD576

New disclosures will be made shortly on the crash of a Chinook helicopter on the Mull of Kintyre in 1994

Guardian report on the crash, written on the evening of the accident

Channel 4 News – Des Browne to look at Chinook evidence

MPs boost Chinook fight