The finding of negligence

The finding of pilot negligence in the wake of the Chinook accident of 1994 has excited widespread comment, most of it in the...

The finding of pilot negligence in the wake of the Chinook accident of 1994 has excited widespread comment, most of it in the form of condemnation. Hypotheses abound that seek to explain how the crash might have occurred in a way that would exonerate the pilots, or at least cast the finding in some doubt

These range from uncommanded flight control movement through engine control malfunction to control jam, with variations and other options in between. The contention is that, in consequence, the finding cannot survive the test of being beyond any doubt whatsoever and therefore should be set aside as unsafe. The case to do this is pressed with disregard for the simple facts of the accident despite the efforts made by the Ministry of Defence through countless written explanations and verbal briefings. Instead, minds have been closed to the significance of these facts and a campaign of publicity has been conducted utilising TV and press coverage of a highly selective and seriously misleading nature.

My colleagues and I have been accused of disloyalty, cover-up and even cowardice, with the clear implication that we have something sinister to hide by standing by our conclusions. That we each have a lifetime’s experience of military aviation in the Royal Air Force and that our appointments have afforded us the opportunity to examine many Boards of Inquiry appears irrelevant to our critics, some of whose accusations are defamatory. It is the nature and willful ignorance of these accusations that drives me now to break the silence we have striven to hold, as we stand by every word we wrote in reaching the judgment we did, individually and independently. This summary explains why.

The responsibilities of Command cannot be shirked. The Board of Inquiry process involves the Command chain because there is a duty to ensure that mistakes and faults of any nature are exposed, and lessons learnt so that tragedies do not re-occur. It was not acceptable for Commanders to protest insufficient evidence when, notwithstanding the absence of an Accident Data Recorder, hard, compelling, relevant evidence demanded attention and analysis. Conclusions had to be drawn, no matter how painful to families or critical of the Royal Air Force discipline for which we also held ultimate responsibility. That same evidence, taken by the Board of Inquiry with witnesses under oath, cannot now be swept aside and replaced by hypothesis, as seems to be the aim of some of those who have played no part in the formal inquiry process.

The Air Officer Commanding No I Group, the Group under which the Chinooks operated, was responsible for convening the Board of Inquiry, approving those nominated as President and Members and issuing their Terms of Reference. lt was then Air Marshal Sir John Day’s duty (as the then AOC I Group) to examine the Board’s analysis of the accident, its conclusions and recommendations, calling for comment in this process from his experienced Headquarters staff. In discharging this duty, he had the authority to accept the Board’s work in part or in its entirety.

Equally, had he considered it incomplete in any way he could have reconvened the Board, if necessary under expanded TORs. He was also bound to state his own conclusions and the action he had ordered in consequence. For this purpose, Part 4 of the Board of Inquiry proceedings document is titled ‘Remarks by Air Officer Commanding.’

In this section Sir John Day, himself a highly experienced helicopter pilot, concluded that the sortie was planned to be a low level, daytime, passenger carrying transit flight flown clear of cloud under Visual Flight Rules. Yet, when the aircraft crashed, it was flying at high speed, well below Safety Altitude in cloud (in Instrument Meteorological Conditions) in direct contravention of the rules for flight under either Visual Flight Rules or Instrument Flight Rules. On converting to Instrument Flight Rules as a result of either entering cloud or losing sight of the surface, the aircraft should have been climbed to the Safety Altitude, which had been calculated as 2800 feet Until that height was achieved, the aircraft should not have continued approaching the Mull of Kintyre.

He then amplified his opening remarks by saying that as the pilots approached the deteriorating weather near the Mull, they had 2 choices. If they intended and were able to maintain flight under Visual Flight Rules, they should have slowed down, turned away or turned back. If they planned to continue their flight under Instrument Flight Rules, they should have climbed to above Safety Altitude well before they approached the Mull. If they were forced to transition to Instrument Flight Rules because they inadvertently entered cloud when close to the Mull, they should have made a rapid climb to at least Safety Altitude at maximum power and best climbing speed, while also turning away from the Mull.

The aircraft’s avionics showed that the Chinook neither turned away nor turned back. When it was less than one nautical mile from what was to be the point of impact, a waypoint change was made. This selection on the navigation equipment caused it then to display heading and distance to the next en route fix. Specifically, the pilots changed waypoint to one 87 nautical miles beyond the Lighthouse that was their next planned turning point They did this when extremely close to the Lighthouse where the Lighthouse Keeper, who was on the spot, gave evidence that visibility was 400 to 500 metres, and in places below 20 metres.

Activity in the cockpit of this nature provided pivotal evidence of conscious, intentional pilot input. It proved that the pilots were in control of their aircraft at that moment, a fact undisputed by even our most vociferous critics. It also showed that, rather than ensure they were at Safety Altitude well before landfall, they had flown into the bad weather at low level and at speed, in the vicinity of the Mull of Kintyre where the Board of Inquiry itself had concluded that the prevailing conditions “would have required flight in accordance with Instrument Flight Rules’.

At waypoint change they were some 15 seconds from the fogbound Lighthouse and perilously close to steeply rising ground that was also shrouded in clouds. In reaching this position they had violated the rules governing flight under both Visual and Instrument Meteorological Conditions. In consequence they were in grave danger, solely through failing to exercise the skill and judgment of which they were capable and as they were trained to do. This is the definition of negligence as it applies to military aviation.

About twenty seconds after making the waypoint change and 5 seconds beyond the Lighthouse, they crashed. They hit the ground at a height of 810 feet. This was some 600 feet below the top of the Mull and 2000 feet below Safety Altitude for this sector of the planned route. Their speed at impact was calculated by the Air Accident Investigation Branch to be 150 knots. As the Air Officer Commanding-in-Chief Strike Command, it was my task to reach my own conclusions, again with access to comment by highly experienced Headquarters and Flight Safety staffs, and then set them down in Part 5, the closing section of the Board of Inquiry document. I wrote that without the irrefutable evidence of an Accident Data Recorder and a Cockpit Voice Recorder, there is inevitably a degree of speculation as to the precise detail of the sequence of events in the minutes and seconds immediately prior to impact. What emerged from the Inquiry however, was the total absence of evidence of any combination of possible minor problems, or of any major difficulty, which would have so taxed the skills of the crew that they would have had no option other that to keep flying towards high ground at speed at low level in deteriorating conditions of cloud and visibility. I said that the operating pilots could and would have avoided the accident had they followed a different course of action from the one they chose to pursue. What they should have done and what they were trained to do had been succinctly described by the AOC. Why they therefore elected to ignore the safe options open to them and pursue the one imposing the ultimate danger, we shall never know.

I concluded that all the evidence pointed towards their having ignored one of the most basic tenets of airmanship, which is never to attempt to fly visually below Safety Altitude unless the weather conditions are unambiguously suitable for operating under Visual Flight Rules.

My remarks completed the formal Board of Inquiry proceedings. The Chief of the Air Staff, Air Chief Marshal Sir Michael Graydon, then examined these in their entirety and independently. He wished to satisfy himself of the veracity of the conclusions that Sir John Day and I had reached, as it would fall on him to brief Ministers on the precise detail of a tragedy of such magnitude. Sir Michael Graydon found he was in no doubt whatsoever of the negligence of the two pilots.

No matter how much we searched for an alternative to this conclusion, our analysis of the facts rendered it unavoidable. These facts focused on three imperatives: the prevailing weather at the Mull, the speed and height of the aircraft as it flew into this weather, and the rejection by the pilots of all safe options as they approached landfall. In contrast, there is conjecture based on theories entirely peripheral to the central analysis and irrelevant to the cause of the accident. Such conjecture derives from misinformed comment on such issues as the Chinook’s introduction into service, IFF settings found in the wreckage, Boscombe Down’s software verification procedures, and the Special Forces background of the two pilots. On this last point in particular, any assertion that experienced pilots would never commit such a fundamental error is without foundation and unsustainable, as flight safety records sadly reveal. Had this been otherwise, or had we been able to identify any area of uncertainty in examining factual evidence material to the cause of the accident, the conclusion at which we arrived would not have cited pilot negligence.

Finally, it is necessary to address the hypothesis to which I allude in my opening paragraph, for the peace of mind not only of the many other families bereaved by this tragedy, but also for all that fly as passengers in modern aircraft. This is the theory our critics table of an unidentifiable major emergency. The essence of their suggestion is that in something less than the 20 seconds after waypoint change but before impact, the Chinook could have suffered a major emergency. Before impact, however, they say it must have cleared itself because it left no trace of having happened. The claim is that because such a theory cannot be disproved, it must cast a doubt over the absolute certainty of the finding of negligence.

Setting aside the one fact of fundamental importance that pilot negligence preceded the waypoint change, if the idea of some sort of fleeting emergency is argued through, it brings our finding into even sharper focus. For had the Chinook been flying, as it should have been, over the sea under Visual Flight Rules or at Safety Altitude under Instrument Flight Rules, any temporary problem of the sort described would have been safely accommodated. Ironically, therefore, far from raising a question mark over the negligence finding, such conjecture serves only to underline it.

Air Chief Marshal Sir William Wratten GBE CB AFC 15 June 2000

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