Nimrod MR4 vs P8
EAP86
Fully agree. The extract available is by no means complete and it isn't clear if all the issues apply to all aircraft; but it does say they were only identified after production commenced which is why I mentioned concessions and permits. My main concern is why so late in the day?
The dilemma faced by MoD procurers is that Controller Aircraft mandated 00-970 and the 05-series in all aircraft related contracts, but the Aircraft Project Director has the authority to deviate. He may apply engineering judgement. I can't recall those who held that position on Nimrod, but in the 90s MoD (a) appointed APDs who were not engineers, and (b) allowed non-technical staff below them to self-delegate, which led to a lot of conflict. We shared our 2 Star, the man with management oversight, whose job it was to assess the top 10 risks every month. This is why the Public Accounts Committee demanded his name at a hearing in about 2000. MoD denied knowledge of who he was; presumably both were unable to read the MoD telephone directory. Everyone in AbbeyWood knew, because he had just issued an edict that basic safety could be traded out in favour of time and cost, while making a declaration in the Release papers that the safety criteria had been met. Many jumped on that bandwagon.
Fully agree. The extract available is by no means complete and it isn't clear if all the issues apply to all aircraft; but it does say they were only identified after production commenced which is why I mentioned concessions and permits. My main concern is why so late in the day?
The dilemma faced by MoD procurers is that Controller Aircraft mandated 00-970 and the 05-series in all aircraft related contracts, but the Aircraft Project Director has the authority to deviate. He may apply engineering judgement. I can't recall those who held that position on Nimrod, but in the 90s MoD (a) appointed APDs who were not engineers, and (b) allowed non-technical staff below them to self-delegate, which led to a lot of conflict. We shared our 2 Star, the man with management oversight, whose job it was to assess the top 10 risks every month. This is why the Public Accounts Committee demanded his name at a hearing in about 2000. MoD denied knowledge of who he was; presumably both were unable to read the MoD telephone directory. Everyone in AbbeyWood knew, because he had just issued an edict that basic safety could be traded out in favour of time and cost, while making a declaration in the Release papers that the safety criteria had been met. Many jumped on that bandwagon.
I hesitate to enter an arena filled with those who have personal knowledge of the MOD system and how it works (or perhaps more importantly, how it is supposed to work), but fools rush in...
It has been postulated here that had MRA4 release been carried out under the "laissez faire" pre MAA system it would have gone ahead and the aircraft entered into RAF service, with tuc's list+ to be worked through thereafter no doubt. The UK would have retained a Maritime Air Capability instead of losing it, with an aircraft of great potential enhancing a retained and famed capability.
Far more likely an outcome though would be yet another tragic airworthiness related fatal accident thread posted on this forum. A random shuffle of the Swiss cheese slices would align the pathway of predicted and predictable consequences and yet another disaster would be traced back (though not by existing official means) to the reckless actions of certain RAF VSOs 30 years ago and of the cover up ever since.
To be fair to the MAA, though they will not/cannot admit to that systemic damage to UK Military Air Safety, they do have a weapon of last resort, which is to ground fleets that the RAF feel able to do without. Hence the Air Cadet gliders extended "pause", and that of MRA capability. What of other fleets? What of the replacement fleets to those grounded? Grounding is not a viable policy, only a completely independent Regulator is. Unless and until the UK has an independent Air Regulator and Air Accident Investigator, both of the MOD and of each other, a cloud will hang over every UK fleet. The airworthiness related fatal air accident threads will continue to be posted here and UK Military Air Capability compromised.
The cover up must end!
Self Regulation Does Not Work and in Aviation It Kills!
It has been postulated here that had MRA4 release been carried out under the "laissez faire" pre MAA system it would have gone ahead and the aircraft entered into RAF service, with tuc's list+ to be worked through thereafter no doubt. The UK would have retained a Maritime Air Capability instead of losing it, with an aircraft of great potential enhancing a retained and famed capability.
Far more likely an outcome though would be yet another tragic airworthiness related fatal accident thread posted on this forum. A random shuffle of the Swiss cheese slices would align the pathway of predicted and predictable consequences and yet another disaster would be traced back (though not by existing official means) to the reckless actions of certain RAF VSOs 30 years ago and of the cover up ever since.
To be fair to the MAA, though they will not/cannot admit to that systemic damage to UK Military Air Safety, they do have a weapon of last resort, which is to ground fleets that the RAF feel able to do without. Hence the Air Cadet gliders extended "pause", and that of MRA capability. What of other fleets? What of the replacement fleets to those grounded? Grounding is not a viable policy, only a completely independent Regulator is. Unless and until the UK has an independent Air Regulator and Air Accident Investigator, both of the MOD and of each other, a cloud will hang over every UK fleet. The airworthiness related fatal air accident threads will continue to be posted here and UK Military Air Capability compromised.
The cover up must end!
Self Regulation Does Not Work and in Aviation It Kills!
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Chug, re your 2nd para.
If I came across that way it wasn't intentional. The pre-MAA approach didn't involve a MAA, the contractor was expected to certificate the platform to the satisfaction of the project office and sensible discussions about Def Stan compliance could be undertaken. It's probably worth saying that the Def Stan is an imperfect beast. Some parts are first class (eg escape systems), some parts are a bit behind the state of the art (inevitable with newer technologies) and other important aspects of design aren't covered at all. Into this scenario steps the MAA, it is sensitive to the circumstances which caused it to come into existence and some members of its leadership were away from their comfort zone. What could possibly go wrong?
As it happens, I believe that the contentious issues could have been discussed in an adult way if the will existed but the imposition of punitive cost savings on MOD by the new government meant that the technical aspects could be used to mask the Cameron\Osborne involvement.
EAP
If I came across that way it wasn't intentional. The pre-MAA approach didn't involve a MAA, the contractor was expected to certificate the platform to the satisfaction of the project office and sensible discussions about Def Stan compliance could be undertaken. It's probably worth saying that the Def Stan is an imperfect beast. Some parts are first class (eg escape systems), some parts are a bit behind the state of the art (inevitable with newer technologies) and other important aspects of design aren't covered at all. Into this scenario steps the MAA, it is sensitive to the circumstances which caused it to come into existence and some members of its leadership were away from their comfort zone. What could possibly go wrong?
As it happens, I believe that the contentious issues could have been discussed in an adult way if the will existed but the imposition of punitive cost savings on MOD by the new government meant that the technical aspects could be used to mask the Cameron\Osborne involvement.
EAP
The MAA came into existence as a result of lessons learned thanks to Haddon Cave. Any lessons learned would have been of very dubious value as his report falsely described the period in which the Air Safety system was subverted by RAF VSOs as a "Golden Period" and instead named SOs (ie 1* and below) as responsible at a later date for Nimrod airworthiness shortcomings.
As for Safety Systems, Sean Cunningham's had no published Safety Case and it killed him. It had no Safety Case because those engineers within the MOD whose job it was to ensure that it had one were got rid of, and their knowledge went with them. To admit that would reveal the subversion that led up to it and the illegal actions of those VSOs. That is presumably unacceptable, so the cover up continues and the MAA remains compromised together with RAF airworthiness.
As for Safety Systems, Sean Cunningham's had no published Safety Case and it killed him. It had no Safety Case because those engineers within the MOD whose job it was to ensure that it had one were got rid of, and their knowledge went with them. To admit that would reveal the subversion that led up to it and the illegal actions of those VSOs. That is presumably unacceptable, so the cover up continues and the MAA remains compromised together with RAF airworthiness.
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I know that, but the price of second hand A320s / A340s nowadays probably means that they can be bought, have all the kit wheeled on board, holes drilled where required, painted grey, flown until they fall to bits and thrown away, and replaced with another. I'd guess that'd still be a cheaper way to get a capability than what MR4a cost, even if it is 'wasteful'... An old airliner is probably, what, a couple of £mill at most?
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But a number of comets and electras DID suffer in-flight structural failures in airline service depositing their occupants in the ocean/prairie,PDR. The same can't be said of 737 or 320 with the exception of one very high-cycle 737 (Aloha). On what basis was the 320 judged less robust than 737? I'd have thought there wasn't much to choose
Early Comets suffered structural failures at cruise altitude due to the (then) poorly understood behaviour of metals under cyclic loadings. The 737 and the Comet 4 (on which the Nimrod structure was based) were designed later when there was a better understanding.
But all of that is irrelevant, because the fatigue failures were associated with the pressurisation stresses of high-altitude cruise. The ruggedness assessment you refer to concerned manoeuvring stresses at a few hundred feet over a storm ocean. IIRC no Nimrod ever suffered a structural failure during these manoeuvres. This was (at the time of the RMPA ITT) cited as a cardinal mission requirement, and none of the modern airliners were deemed rugged enough to meet this requirement.
In the subsequent P8 procurement the RAF were simply told that there was no available aeroplane that could do this role, so they would need to accept that this mission was no longer possible; they would have to use the sensors from medium altitudes instead. That's why the P8 is now an acceptable platform where it wouldn't have been before. AIUI there is still a "spirited debate" over whether two engines are sufficiently safe even without the low-level mission. No doubt that will be addressed in its MAR recommendations.
PDR
But all of that is irrelevant, because the fatigue failures were associated with the pressurisation stresses of high-altitude cruise. The ruggedness assessment you refer to concerned manoeuvring stresses at a few hundred feet over a storm ocean. IIRC no Nimrod ever suffered a structural failure during these manoeuvres. This was (at the time of the RMPA ITT) cited as a cardinal mission requirement, and none of the modern airliners were deemed rugged enough to meet this requirement.
In the subsequent P8 procurement the RAF were simply told that there was no available aeroplane that could do this role, so they would need to accept that this mission was no longer possible; they would have to use the sensors from medium altitudes instead. That's why the P8 is now an acceptable platform where it wouldn't have been before. AIUI there is still a "spirited debate" over whether two engines are sufficiently safe even without the low-level mission. No doubt that will be addressed in its MAR recommendations.
PDR
I don't own this space under my name. I should have leased it while I still could
msbbarrat, I attended a wedding back in 1974 and was at a table with a wg cdr who was cock-a-hoop having just bought East African's VC10s for peanuts. I think it was 6 figures. I think it cost many millions to actually certify them as safe to fly.
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ALL the contenders, PDR are modified civil airliners, and none of the original designers would have been principally concerned with low level performance. While it's true no nimrod suffered structural failure (other than resulting from a catastrophic fire!) given the tiny number in service versus the thousands of 737's and 320's that's not a big claim statistically and hardly justifies your emotive point about dead aircrew
Last edited by ShotOne; 26th May 2017 at 20:17.
Somewhere way upthread it was explained why a civil airliner designed in the 40s/50s had much greater structural margins than one from more modern eras. And of course the Nimrod wasn't just a comet with a bomb bay - there were significant structural differences - especially in the wing root and C/S area (aside from anything else it needed to be different to fit the Nimrod's Speys rather than the Comet's Avons (the spey having 25% greater diameter and 35% more length).
PDR
PDR
Last edited by PDR1; 26th May 2017 at 21:07.
Somewhere way upthread it was explained why a civil airliner designed in the 40s/50s had much greater structural margins than one from more modern eras. And of course the Nimrod wasn't just a comet with a bomb bay - there were significant structural differences - especially in the wing root and C/S area (aside from anything else it needed to be different to fit the Nimrod's Speys rather than the Comet's Avons (the spey having 25% greater diameter and 35% more length).
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Shot One
do you work for Boeing?
Only one structural failure in a B737?
What about the rudder defect that took down at least 2 and probably 4 aircraft, along with others that survived the same issue?
do you work for Boeing?
Only one structural failure in a B737?
What about the rudder defect that took down at least 2 and probably 4 aircraft, along with others that survived the same issue?
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If we'd been discussing all causes rather than structural failures, yes I'd have mentioned those two (out of @9,500 737's flying!) But then in fairness we'd also have had to mention that two out of 49 Nimrods were destroyed by inflight fires plus a third very near miss (XV235, 2007)
No, I don't work for Boeing, indeed I posed the question of why the process that selected P8 dismissed the 320 as insufficiently rugged
No, I don't work for Boeing, indeed I posed the question of why the process that selected P8 dismissed the 320 as insufficiently rugged
Last edited by ShotOne; 27th May 2017 at 05:16.
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three out of 49 Nimrods were destroyed by inflight fires
note Bomb Bay fire St Mawgan, hull loss, but crew safe...
...and there were also several more near misses the don't generally get a mention. Like the MR1 in the US that had a sustaining fire in the radio crates, but was in the circuit, so it got put out on the ground.
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TOFO: Not sure XV257 really counts as a hull loss due to fire... she flew after her St Mawgan escapade! At least not without a bit of a stretch, reasoning that if the fire hadn't happened, she wouldn't have been selected for conversion to AEW3 (conveniently being fully repaired in the process) and hence wouldn't have been in the hangar at Woodford when the roof collapsed on her... which did finally cause hull loss!
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257 was Cat4 at St Mawgan. Once repaired on site, it was ferried to Woodford, subsequently declared Cat5 and sat outside for years until scrapped in the 90's AFAIK. It was not one of the 11 Aew3's - that project ended in 86 round about the time257 would have made its one and only flight post-fire.
249 was another that apparently had underfloor burning (without being destroyed) after being back converted to R1 (to replace 666).
249 was another that apparently had underfloor burning (without being destroyed) after being back converted to R1 (to replace 666).