Tandemrotor: I couldn't agree more dear boy. A meeting and soon would make for a Christmas present of some cheer but the doilies will remain wrapped for another festive season I fear. Frankly I fancy a quick climb up Ben Nevis with you but the locals don't supply it. A real privilege to be working this file, and thanks indeed for the very kind words. Sorry been so out of touch with my fingers recently. Been reading lots though.
Boslandew: Why was ZD576 in squadron service? The order to ground flying at Boscombe Down was not applied into active squadron life because the decision to ground the HC2 was framed as being a reasonable safety decision only for those attempting to expand the testing envelope with what was still an experimental aircraft.
At the time of the accident ZD576 had flown 66.5 hours since receiving the mid-life update, which had seen the installation of the Full Authority Digital Engine Control (FADEC) system.
As Parliament found: "FADEC had been fitted in a number of RAF Chinooks over the preceding years and had given rise to certain problems. In the summer of 1993 an independent defence IT contractor, EDS-SCICON, was instructed to review the FADEC software; after examining only 18 per cent of the code they found 486 anomalies and stopped the review. In October 1993 the Aeroplane and Armament Experimental Establishment (A&AEE) at Boscombe Down advised the MoD that because of the unverifiable nature of the FADEC software it could not recommend Controller Aircraft Release for the Chinook Mk 2.
Both EDS-SCICON and A&AEE recommended that the FADEC software be rewritten but this was not done, and in November 1993 Chinook Mk 2s were released into operational service, subject to certain operational restrictions on the load which they could carry and the height at which they could fly thereby avoiding icing - restrictions which had not applied to the Chinook Mk 1.
In addition intermittent engine failure captions were being regularly experienced by aircrew of Chinook Mk 2s and there were instances of uncommanded run up and run down of the engines and undemanded flight control movements (UFCMs).
"On 1 June 1994 flying tests of the Chinook Mk 2 were suspended at Boscombe Down. Squadron Leader ***, at that time Flight Commander of the Chinook Operational Conversion Unit, thought that this suspension was "connected with icing trials" and not due to FADEC difficulties (Q 484; cf MoD letter 2 Nov 2001, p 65 of HL Paper 25(ii)).
However, in comments by the MoD[16] on a paper submitted to them by Lord Chalfont, it is stated:
"Boscombe Down's decision not to authorise further trials flying in June 1994 was made against a background of several engine control system malfunctions that had occurred on the ground during start up checks, which had not at that point been explained to Boscombe Down's satisfaction by the aircraft or engine Design Authority. The necessary clarification was completed and accepted by Boscombe Down on 24 October 1994. Test flying was recommenced without any changes to the aircraft FADEC system, or any additional operating limitations. Operating flying continued within the weight restrictions applied."
The MoD continued in relation to a memo of 3 June 1994 from Boscombe Down:
"The 3 June 94 memo was an internal MoD working level document, the last sentence of which reads: "Notwithstanding the claims made in Textron's white paper, the problem remains that the product has been shown to be unverifiable and is therefore unsuitable for its purpose".
But it is emphasised that this statement arose because Boscombe Down were unable to verify the software independently using their preferred analysis, which was neither mandated nor included in the development contract placed in 1985. Contractors had carried out their own validation and the fact that Boscombe Down could not verify the software using their preferred software should not be taken to imply that there was an inherent problem with its design."
A statement on behalf of the MoD to the FAI included the following:
"As to the allegation that some pilots refused to fly the Chinook HC Mk 2 during CA Release trials at Boscombe Down, this is an over simplification of what actually happened and perhaps it would be helpful if some of the background was explained. On 7 March 1994 during one of the specified FADEC checks on the ground, the engine of an HC Mk 2 flamed out. Trials at Boscombe Down were halted while the failure was investigated.
The failure was not due to a software fault and flying resumed on 20 April. However in the period up to 2 June 1994 there were a number of incidents involving airborne HC Mk 2 of which approximately 5 were due to FADEC malfunction whilst operating in normal mode. There had also been other incidents on the ground. The MoD(PE) Project Office sought explanations of the various incidents from the aircraft and engine manufacturers but in the absence of satisfactory explanations Boscombe Down suspended trials flying."
It is clear from these quotations that at the time of the crash there were still unresolved problems in relation to the FADEC system of Chinook Mk 2s."
end of excerpt
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Much of this has appeared in previous posts, and John Blakeley's work on the engineering is splendid.
To the nub I would make three points:
1.) The Chinook Mk2 was not well understood at the time
2.) Those flying ZD576 had to assume they would lose an engine because they were restricted to an all-up weight that a single engine could cope with. This was, in part, because of an epidemic of real and false engine control warnings. (remember Rick Cook's last recorded conversation)
3.) The icing restrictions related to the oppressive CA release forced Jon Tapper and crew to elect no flyover of the Mull because the route toward WayPoint B/C (not A-B) would, in FOREcast, take them below the allowed 4C. Ironically, the limited icing clearance rules give helpful posthumous guidance: namely there was to be no overfly of the Mull because the aircraft was not up to it. Their approach transiting the water at low-level was therefore not questionable. In fact it was textbook.
So a reasonable question from a reasonable person is why risk all these passengers? The reason the Chinook was used to transport all these people was because it was the only aircraft handy to carry so many busy people, regardless of their importance, at the appointed hour.
The air transport order was taken at Army HQ, Lisburn. The total passenger manifest had been 27 but two passengers dropped out on the day. One has since died of natural causes. The other, I believe, is alive. Both cancelled for bona fide reasons, one for an ongoing security operation, the second for family reasons. He is a former RUC officer and does not talk about the issue publicly, including his views on the use of the Chinook.
With all that is known today, would ZD576 still have been used to transport VVIP pax? Surprisingly the answer in 1995 was yes, VVIPs were still flying in Mk2s.
"Lightning doesn't strike twice," a senior MoD official told me then.
He was right, but with all the stories that have emerged about the confusion and shortcomings of the fleet in the years subsequent to the crash, I sense he could have just as easily have been wrong.