After listening to the evidence given on Wednesday, 7 November 2001 I feel that there are some points which I, as a helicopter specialist, need to re-emphasise. I list these below:

  1.  Actions at the Waypoint Change. Contrary to the original MoD position, it now seems to be accepted by everybody including the MoD that at the waypoint change the crew were well within the legal limitations for Visual Flight Rules. I wish to state again that at the waypoint change the crew was not only doing nothing illegal but could comfortably turn to fly over the sea parallel to the coast. This is exactly how RAF Support Helicopters operate daily at this moment, not only when coasting in from sea crossings, but also when operating overland flying over low ground or following valleys in mountainous terrain in bad weather. Moreover the Chinook would not have had to reduce speed very much if at all from 135 kts to turn 15 degrees even assuming it was going that fast to start with. You may well have noted this from your own Chinook trip. As for ACM Day's comments about turning "belly up" to the high ground being mad airmanship; I am completely at a loss to understand it, as was every other pilot I spoke to. It is of course necessary to turn "belly up" to an obstacle to turn away from it whether you are flying a Spitfire, a Jumbo jet, or a helicopter in cruising flight.

  2.  The Simulation. I was really shocked to learn that the mathematical modelling for the simulation had been carried out using non-FADEC-equipped Chinook data. As far as I can ascertain nobody I have been associated with in this case, and I have contacted Mr Malcolm Perks in Canada, was aware of this. MoD must have known about it, but have chosen to keep very quiet. As I have pointed out, rotor speed (NR) is critical in helicopter operations, not only for safety, but because variations in rotor speed can dramatically alter the aerodynamics of the rotor disc(s) and thus their performance. By applying some "rule of thumb" empirical corrections for the difference between a FADEC and a hydro mechanical engine governing system, I believe I can explain a small part, but by no means all, the difference between the simulated and actual NR. However it is under conditions of massive dynamic change such as a last minute flare, or indeed when pilots might be attempting to regain control and putting in large corrective control inputs, that differences in rotor speed—and thus performance—would be most apparent.

  3.  In spite of Mr Cable's suggestion that this shortcoming of the simulation was probably not "all that significant" in this particular crash, I suggest that it could have been. Mr Cable has readily admitted to you and to the FAI in Scotland that he is not an expert in helicopters, especially Chinooks, and mathematically modelled simulations. I have the greatest regard for Mr Cable's integrity and know him to be an accident inspector of the highest standing and enormous experience. As a matter of professional courtesy I rang him up and told him what I had written about him. He urged me to use rather stronger wording for the first part than I have in fact used. I have stated that I don't think the simulation is "that bad", but it has enormous areas of doubt and is based on an arbitrary set of assumptions: also it does not take into account a number of potentially important variables. This latest revelation after six years, puts, in my judgement as a professional specialist in helicopter flying characteristics, a further serious doubt as to the integrity of the simulation.

  4.  On the discrepancy which I pointed out between the groundspeed postulated in the simulation and that actually found on the groundspeed indicator, which was questioned by Mr Cable in his evidence on Wednesday, 7 November (AAIB Report Bottom Page 22 Speed and Drift GS Digits 147 kts (1) and Page 61 List Ground Speed 158 kts). Mr Cable agrees that as written in his report there is a discrepancy and believes that a correction factor may have been left out when calculating 158 kts. He stressed to me again the difficulty in obtaining meaningful data in a "progressive" crash such as this one.

  5.  Wg. Cdr. J. Cooke's Statement. It really was something of a surprise to me to read Wg Cdr Cooke's statement. The meeting we had in his office could not have had the same significance for him as it did for me. I can only recollect the one meeting and that was in his office. I can remember no "casual conversation" outside the Operations Block. I can only reiterate exactly what I told you. It would probably be possible to find the two SNCOs assigned to Mr Cable—these were Sgt Tighe and Sgt Carter. They well might remember me being called away to Wg Cdr Cooke's office and will almost certainly remember me helping them and then having to stop. Should Wg Cdr Cooke have just casually mentioned that I was no longer to talk to people about the Chinook accident, I certainly would have asked him formally about continuing to help the AAIB.

  6.  Now I have heard Gp Capt (now Air Cdr) Crawford's evidence, I do not think there was anything particularly sinister about what happened. I think that Wg Cdr Cooke, who was an exceptionally zealous officer, probably read too much into his Station Commander's remarks and over reacted. However what was said, and I recall it very clearly because it had such an impact on me, certainly prevented me from putting myself up to the Board or to the FAI in Scotland. I do not think that there was any real cover up at Station level.

  7.  On a personal note I would add that I have always been known for both speaking out clearly—sometimes when it was not to my advantage to do so,—and for telling the truth. A number of "advisors" kept on telling me how difficult it would be to give evidence to a committee primarily composed of highly successful lawyers. I have not found this to be the case. All you have to do is tell the truth. It really is very easy!

Robert Burke

13 November 2001