Responding to Tandemrotor
I
cannot "accept as FACT that the aircraft flew on a straight course, and a gentle climb, (perhaps even at high steady speed?) from waypoint change to impact", as all that we know is that the aircraft flew from the waypoint change to impact, without knowing what went on between those two points. The BOI "concluded that the most probable cause of the accident was that the crew selected an inappropriate ROC to safely overfly the Mull of Kintyre" and this, together with evidence of the time taken from take-off to impact, along with the AAIB's estimate of impact speed, has prompted messrs Day & Wratten to conclude, without any actual evidence, that the 2 pilots were not only negligent but to a gross degree.
However, several alternative hypotheses exist as to what might have occurred between waypoint change and impact. Some of these are bizarre and merit little attention, but there are 3 different and plausible events that have been put forward, which were originally dismissed by the BOI but which warrant closer examination:
i. A transitory control jam.
ii. A FADEC-induced engine runaway.
iii. A UFCM.
The occurrence of any of these 3 possible malfunctions could explain why ZD576 ended up striking the cloud-shrouded hillside. For what it's worth, I favour the UFCM as the most likely explanation because there is the precedent of a US Army Chinook suffering an extreme UFCM in a high-speed cruise, which resulted in the aircraft narrowly avoiding what would have been another unexplained accident. Importantly, when that Chinook was subsequently minutely examined, no evidence of any malfunction could be found. It is therefore hardly surprising that the AAIB could find no trace of any fault in the wreckage of ZD576. Eerily, the pilots of the American Chinook stated that, contrary to any logic, they had discovered that they needed to use full left pedal to be able to control their Chinook - could this explain why examination of ZD576's wreckage revealed 77% left pedal tavel? I believe that this fact alone should have caused the negligence charge to have failed a standard court test of 'beyond reasonable doubt', let alone 'beyond any doubt whatsoever'. I further believe that this eerie parallel between the two accidents was somehow missed by the BOI and the two Air Marshals. If the UFCM had occurred shortly after waypoint change, it would explain why, having selected the new waypoint, the aircraft appears not to have turned towards it. There would also have been adequate time for a manoeuvre similar to the US Army incident to have occurred.
It also seems to me that the AAIB and, consequently, the BOI and the two Air Marshals, appear to have assumed that, because ZD576 is estimated by the AAIB to have hit the ground with 31 deg of pitch, 5 deg of left bank and a flight path angle 20 deg above the horizontal, it must have been in a flare manoeuvre, trying to avoid ground impact. However, if the conditions in cloud were as poor as reported by the lighthouse keeper (15-20m), the crew would not have had sufficient time to produce the impact attitude from the Air Marshals' assumed steady climb towards icing conditions. Indeed, even if they had seen the hillside as much as 100m before impact, it seems extremely unlikely that the impact conditions could have been achieved, particularly if due allowance were made for a moment's disbelief, followed by normal reaction time. I suggest, therefore, that what has been perceived throughout as a 'final flare manoeuvre' is more likely to have been an attempted recovery from a nose-low UP (Unusual Position) induced by one of the plausible events listed above. Indeed, the fact that the aircraft impacted the ground with 5 degrees of bank could even be considered as evidence that the pilot's were not flying a 'final flare' as it would be unlikely that they would have imparted bank in that situation.
So, where do we go from here? As a result of correspondence with the MoD, I received a letter from the Armed Forces Minister, which included the final statement:
the Department is not convinced that a control jam or UFCM occurred and then cleared itself before the final manoeuvre, leaving no trace.
is not convinced?!? That tells me that neither event can be ruled out, which means that even they have doubts.
The same letter also states:
The Reviewing Officers determined that the pilots should, by the waypoint change, have slowed down and climbed to a safe height, or turned away. The fact that they had carried out neither of these courses of action pointed inevitably towards the finding of negligence.
One can argue about the meteorological evidence (or lack of it) until the cows come home, but I believe that the weather (apart from over the Mull and similar terrain) is very likely to have been perfectly satisfactory for a low-level transit at 2.5nm per minute (or thereabouts). It would be odd, particularly in the area concerned, for conditions of low visibility to be experienced outside cloud, especially with 20 kts+ of wind blowing. Indeed, the fact that the waypoint change was apparently not made until just under a mile from the coastline indicates to me that the crew was perfectly 'happy' with their situation.
So let's consider the Air Marshals' points from the quote above:
Q. Why didn't they 'slow down and climb to a safe height'?
A. I suggest that there was no need because they were flying in perfectly satisfactory weather, could see that the Mull was shrouded in cloud and were able simply to select a waypoint further up the coast to fly to. If they had climbed up, they would probably have worsened their situation by climbing into cloud or, at the very least, by losing visual contact with the landmass. Also, given the icing limitations on their aircraft, what would have constituted a safe height? Their decision to remain below the general cloudbase was therefore good airmanship (AM Wratten, in particular, is very keen on that, I seem to remember!)
Q. Why didn't they turn away [from the Mull]?
A. Again, because they didn't need to. They had good in-flight conditions, knew where they were with reference to the end of the Mull (let's not split hairs about 100m left or right of track), and had had plenty of time to make a decision about what to do having seen the cloud on the Mull. Indeed, the fact that they don't appear to have slowed down is evidence to me that the weather was good, not that they were being negligent.
I hope I have shown that the very things that have led the Air Marshals to believe that the crew was negligent could just as easily be evidence that they were making sound airmanship decisions (apparently in character with their previous flying records) right up till the point at which the control jam, UFCM or engine runaway changed a routine transit flight into a disaster.
There is no evidence of negligence and, to his great credit, the President of the BOI saw no evidence of negligence and wasn't prepared to change his verdict when pressured (allegedly more than once) by two officers 3 and 4 ranks above him. The then Prime Minister and Defence Secretary agree that a mistake has been made, Michael Howard has stated that a Tory Government would instigate a review by a High Court judge, yet something prevents Messrs Blair & Hoon (and some contributors to this thread) from seeing this as well.
I urge all who agree that the charge of negligence should be dropped, to write to their MP (House of Commons, London), copied to the Prime Minister (10 Downing St), making your views known.
(Original posted at 1650 on 16 Dec)