"It may be that the aircraft don't actually NEED fixing per se.
I believe that the actual technical problems found with the aircraft are remarkably trivial, and could (should?) be worked around, improved, or even quietly acccepted.
The core, underlying problem is more serious and is related to clearance policy and to the 'philosophy' of flight safetly criticality.
The bespoke cockpit software can not be proven to the level currently required because it was written before the current Class 1 safety critical software assessment requirements came into force.
It would be fascinating to know when the new standard was introduced, and thus how much the HC3 'missed' the old standard by......
It is not that the unvalidated software doesn't work, nor has the software been shown to have particular problems. It's just that it can't be proven to the standards required.
Presumably (and I'd welcome confirmation of this) the software did meet (or would have met) the previous standard required - or that it was (or could have been) validated to those standards. Certainly some of the supposedly 'problem' displays are used without drama on other users' Chinooks and on commercial airliners. Boeing were entirely happy with the aircraft, and I'm informed (fairly reliably, I think!) that the Boscombe TPs were broadly satisfied - apart from the software validation issue.
Though the US Army did not take the aircraft back, as was once expected, this had nothing to do with any reservations about the software.
But with current requirements the flight safety critical cockpit and display software simply cannot be proven to the level which Boscombe Down are required to prove, and thus Boscombe Down will never be able to issue a recommendation for a Military Aircraft Release. Judged by the current standard, this software will always be 'unacceptable' by definition because it cannot be validated to the right level. But don't blame the TPs, Boscombe are just doing exactly what they are there to do.
A Military Aircraft Release could still be signed, of course (there are plenty of examples of senior officers going against Boscombe Down's advice - isn't that what happened when the TPs seemed to be a little over-cautious about a very remote risk of what the papers called 'catastrophic failure' on Typhoon?).
If the decision was taken to accept the hypothetical software risk then an MAR could have been signed (against recommendation) and the aircraft could have been in squadron service three years ago. But after the Mull of Kintyre, no-one is going to accept any risk on a Chinook (of all aircraft types) no matter how hypothetical or improbable that risk may be.
It's hard to see that changing.
You then have the problem that these aircraft lack much of the vital kit that all current frontline Chinooks enjoy as a result of five or so years of intensive UOR activity - a decent DAS, Cockpit Voice and Flight Data Recorder, HUMS, cockpit armour, etc.
When he opined that the a reason that the aircraft "have not been fixed to date is because the MoD were not convinced that the fix on offer would actually work", perhaps Drayson merely meant that if all of this kit were to be procured and installed (in a more permanent and robust fashion than via UOR/STF/SEM) then the underlying problem would still remain?
As to why they haven't flown? I believe that many of the HC3 qualified TPs have moved on, leaving only two at Boscombe, neither of whom are current, and leaving the aircraft unflown.
I remain uncertain as to where the aircraft are, physically - some suggest that all eight are at Boscombe (a view I incline towards), while others say that one is still in the USA.
Last edited by Jackonicko; 12th Oct 2006 at 15:08.