Chinook crash – the 16-year campaign to right an injustice

By Tony Collins

Chinook ZD576

The day after the fatal crash of Chinook ZD576 on the Mull of Kintyre an RAF Board of Inquiry convened.

There was little to go on: what could be retrieved from the fire at the crash site, and records of recent trouble with the aircraft type, including difficulties with the Chinook Mk2’s software-controlled “Fadec” system.

There had been so much trouble with the Fadec, in fact, that test pilots had ceased flying the Mk2 the previous day. But operational flights continued.

The crash of ZD576 left no survivors: all 29 on board were killed. There was no cockpit voice recorder. No flight data recorder. Particularly for John Cook, the father of one of the pilots, the absence of black boxes compounded his grief.

While a Concorde pilot for British Airways, John Cook led successful negotiations with the Air Accidents Investigation Branch for the installation of cockpit voice recorders on large passenger aircraft.

He recognised the importance of flight data and cockpit voice recorders to investigators and the families of dead pilots because they could show how an aircraft was performing in the moments before it crashed. A cockpit voice recorder could record audible warnings, pilots expressing concern about a possible malfunction and any unusual noises.

Without black boxes it would be easy to blame dead pilots for a major, fatal accident.

Said John Cook in 1999: “I fought to have the recorders installed and then I lost a son in an aircraft which didn’t have one.”

The campaign begins

In crashes of civil airliners the data from the black boxes often gives the best clues as to the likely cause or causes. Even when the black box data is fully recovered the likely causes of an accident can elude investigators.

So how could anyone know what happened in the moments before the crash of ZD576? In 1995, nearly a year after the accident, the RAF Board of Inquiry produced its findings.

The campaign to restore the reputations of the two pilots of ZD576, Flight Lieutenants Jonathan Tapper and Rick Cook, began.

MoD  and RAF attack their own software experts

In some ways the investigation into the crash was exhaustive. In other ways it was limited. It reflected the mindset of the RAF at the time, which was that Chinooks were needed desperately, and, if possible, in greater numbers. The last thing the RAF hierarchy needed was credibility being given to the internal concerns about the helicopter’s Fadec system, in which software controlled fuel to the Chinook’s two jet engines.

Days after the crash on the Mull of Kintyre in June 1994, a senior RAF officer expressed his frustration at the internal concerns over the Fadec.

In a signed, draft memo, the RAF officer attacked the MoD’s own software experts at Boscombe Down. He said their “ongoing stance towards the Mk2 contrasts sharply with the considerable efforts being made by the front line to bring the aircraft into service and maintain a capability”.

Boscombe Down’s attitude, he said, “does nothing to engender aircrew confidence in the aircraft”.

It was beginning to look as if the RAF would not tolerate an investigation that concentrated too much on the integrity of the helicopter and its software. But, to its credit, the RAF brought in the civil Air Accidents Investigation Branch.

The AAIB did not have a free hand, however. The limits of its investigation were agreed with the RAF. The AAIB could not simply require all relevant documents. It was up to the MoD and RAF what documents it showed the AAIB.

And the MoD supplied the bare minimum.

Documents not shown to investigators

Many potentially-relevant documents were to emerge years later, long after the RAF Board of Inquiry had been disbanded. The documents came to light, in part, because of leaks by well-intentioned insiders who were concerned that possible flaws in the airworthiness of the Mk2 were being overlooked.

Back in 1994, the AAIB’s chief investigator Tony Cable knew there had been problems with the Fadec, none of which the RAF hierarchy regarded as serious. Among the many things Cable wasn’t told was that the Superintendent of Engineering Systems at the MoD, Boscombe Down had, nine months before the crash, found flaws in the Fadec that he said in an internal memo were “positively dangerous”.

And Cable didn’t know at the time of his investigation that the MoD was suing the Fadec suppliers because of faults in the system’s software that were exposed by a ground test of a Chinook at Wilmington in the US, Boeing’s “Center of Excellence”.

When the Fadec was working properly, which was most of the time, it made the job of Chinook pilots easier: they could fly the helicopter without controlling power to the engines. When the Fadec systems were not working properly they were apt to leave no trace of a fault, and could endanger the lives of all on board, said Squadron Leader Robert Burke who, at the time of the crash, was one of the most experienced Chinook Mk2 unit test pilots.

A near-catastrophe that left no trace

Four years after the crash of ZD576, Bric Lewis, the pilot of a US Chinook, exclaimed involuntarily “Oh God” into the microphone of his headset. His words were transmitted to all on board. His Chinook was falling out of the sky … upside down.

The displays in the cockpit showed no warning lights… no evidence of any technical malfunction. Then, as inexplicably as the Chinook had turned over, it flipped back again, into a normal, wheels-down position. After it landed safely no serious fault was found.

Bric Lewis and his crew lived to provide evidence that their Chinook had turned over. If they had died in the incident, would they have been blamed on the basis that no serious malfunction capable of causing the crash had been found?

An extraordinary campaign

That the campaign to clear the names of Cook and Tapper has succeeded is extraordinary, and yet it’s not in the least extraordinary. It has been a campaign characterised by its intensity, perseverance, and the status and number of those involved.

It has been a campaign that pivoted on the tenacity of the families of the two pilots and their pro bono advisers. Some of the campaigners cannot be named.

MoD spin

The campaign has also been marked by the determination of the MoD and RAF hierarchy not to attach any credibility or relevance to newly-disclosed information.

In the words of then independent MP Martin Bell in 2001: “The MoD is being anything but straightforward… clearly civil servants are trying to spin the facts to suit the air marshals’ agenda.”

With a manipulative use of language, and an evasive but self-confident way of answering of difficult questions – sophistry exemplified – the MoD was a decisive influence on defence ministers of the last administration.

Every defence minister in the last government was persuaded that there could be only one cause of the accident, and that was pilot error. Tony Blair wrote in his own hand that the pilots were to blame.

So how did one of most grievous military miscarriages of justice in the last 100 years come to be corrected? It was thanks, in part, to the injustice’s enduring visibility in Parliament and in the media, such that David Cameron, when in opposition, promised, if elected, to launch a formal review of the decision to blame the pilots.

And only a prime minister or his defence secretary could, in effect, take the steps necessary to overturn the judgement of a properly-constituted RAF Board of Inquiry. In ordering the Philip review, Cameron proved as good his word.

Liam Fox, too, unlike defence secretaries in the last government, has shown by his actions that he is not prepared to be putty in the hands of his civil servants and RAF air marshals. All credit also to Nick Clegg for his support of the Philip review.

Did the RAF try to dissuade Cameron from holding a review?

It’s unclear whether the RAF tried to discourage Cameron from setting up a review. What is not in doubt is that, in January 2010, a few months before the general election, four former chiefs of the air staff, and a former RAF Chief Engineer, wrote to the Daily Telegraph saying they would wish to brief ministers if there were to be “yet another” review of the RAF’s decision to blame the pilots for the crash of Chinook ZD576.

In their letter, Sir Michael Graydon, Sir Richard Johns, Sir Peter Squire, Sir Glenn Torpy, and Sir Michael Alcock said the finding of gross negligence against the pilots of ZD576 was “inescapable”.

“We understand that in the event of a Conservative administration coming to power it will revisit the Mull of Kintyre Chinook accident and consider the negligence finding,” said the letter of the five knights. “Each one of us has reviewed separately the findings of the Board of Inquiry and reached the same conclusion, namely that basic airmanship failings caused this tragic accident.

“If yet another review is to take place then we would welcome an opportunity to brief ministers and discuss in necessary detail why this finding remains inescapable. In particular, it will be explained precisely why it cannot be overturned by recourse to a hypothesis for which there is no evidence and which is revealed as wholly implausible when tested against the known facts.”

Sir Michael Graydon
Chief of the Air Staff 1992-1997
Sir Richard Johns
Chief of the Air Staff 1997-2000
Sir Peter Squire
Chief of the Air Staff 2000-2003
Sir Glenn Torpy
Chief of the Air Staff 2006-2009
Sir Michael Alcock
Chief Engineer (RAF) 1994-1999
London W1

It is likely that the Philip review came under pressure from the MoD and the RAF not to question the finding of gross negligence. The fact remains, though, that nobody knows the cause of the crash. It could have been pilot error. It could have been a chain of events that had little or nothing to do with pilot error. Indeed the AAIB investigation of equipment recovered from the wreckage revealed several anomalies that were never explained.

That said Tony Cable noted that there was little evidence to be gleaned from the investigation. Cable told a House of Lords select committee on 7 November 2001: “Throughout this investigation the evidence was remarkably thin, from my point of view, I must say”.

What could have caused the crash?

There were many potential causes of the loss of ZD576. What can be said with certainty is that we don’t know why it happened, or the events that preceded it.

One of the lessons is that “evidence” from aircraft manufacturers and their subcontractors should be treated with the same scepticism as speculation about the actions of the pilots. After the crash of ZD576, the main attention of the RAF and the MoD was on the possible actions of the pilots, not on the possible behaviour of the aircraft.

Nobody in the RAF hierarchy questioned the fact that most of the allegations against the pilots were made on the basis of manufacturers’ “evidence”. If that evidence is set aside as lacking impartiality, and indeed the AAIB does not confirm the accuracy of that evidence, there is no basis even for speculation about the actions of the pilots.

One of the things the campaign for justice has shown is that the RAF hierarchy took a circumscribed investigation of equipment found in the wreckage as the basis for a case against the pilots.

Black boxes found in the debris of civil airliners are sometimes transported under armed guard to independent investigators. Manufacturers are not always allowed to look at their equipment until it has been studied independently. Yet in the case of ZD576 manufacturers’ evidence has been taken as the whole truth. An Mod lawyer at the ZD576 Fatal Accident Inquiry in Scotland in 1996 sought to persuade the Sheriff that the manufacturer’s evidence was “hard fact”.

To my knowledge there has never been an investigation by the National Transportation Safety Board, the US equivalent of the AAIB, in which uncorroborated, unchecked evidence from aircraft manufacturers been taken as hard fact.

Today, the lack of understanding at the top of the RAF over how much information is needed after crashes of civil airliners to establish the likely chain of events may help to explain why air marshals still blame the pilots of ZD576.

In their eyes, the lack of evidence of serious technical malfunction appears to mean that the pilots were in control of the aircraft. Such a simplistic assumption would not be made in a full civil aircraft crash investigation.

Justice has now prevailed thanks to the Cameron government, supported by Sir Menzies “Ming” Campbell, Martin O’Neill, and numerous other parliamentarians including Lord ChalfontJames ArbuthnotDavid Davis and Frank Field . There are too many other campaigners to name, though I make exceptions with Hooman Bassirian, Karl Schneider and Mike Simons who, at Computer Weekly, were willing to shape and publish innumerable stories in support of the Chinook campaign. David Harrison, a freelance producer  at Channel 4  News, which has covered developments since the day of the crash, first alerted me to the flaws in the Chinook Mk2’s Fadec.  Most of the documents relevant to the crash came to me from the Tapper family.

Air marshals will never accept that the pilots were not to blame. But that’s a hallmark of institutional disasters: once a decision is taken on the main cause that decision will be supported and stuck to whatever the facts. Thank goodness the Philip review, when it came to its investigation, had an open mind.


The campaign for justice for the pilots of Chinook ZD576 – Brian Dixon’s website

PPrune – hundreds of online pages of thoughtful discussion on the crash.

RAF Justice – how the RAF covered up problems with the Chinook Mk2’s Fadec.

Chinook ZD576 – report by Michael Powers QC.

Macdonald report on the crash of ZD576 – by three fellows of the Royal Aeronautical Society.

Flawed Chinook software updated after crash of ZD576.

The Chinook Fadec in-depth – by Malcolm Perks, another of the campaigners

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