Nimrod Information

[Chugalug2]

To follow up my last post and to respond to Distant Voice, I turn as ever to tucumseh, for at post 1920 (thread page 96) he says:

2. As to the maintenance issue, by now it should be clear to anyone who reads and understands this thread that the term in this context refers to ALL technical, administrative, managerial and supervisory actions supporting the objective to retain or restore an item so that it is fit for purpose. You may argue semantics, but this holistic view is the one you should take. The BAeS and QinetiQ reports make it crystal clear that the MoD has failed in this DUTY at all levels. The Board of Inquiry report and especially the reviewing officers (with the notable exception of a former Director/Maritime and Nimrod MRA4 IPT Leader – I wonder why) have agreed.

Perhaps 'non-contentious' is too much to assign to any issue on this thread, perhaps I should have said "authoritatively dealt with already". The point is surely that airworthiness provision or the lack of it is the issue here, not servicing

[nigegilb]

Ed, can you set me right on something. The BoI pointed out that a damaged section of duct insulation only reduced the temperature of the bare metal by 16deg. Do you know how much of a reduction the insulation was supposed to provide? And would this have prevented auto-ignition?

[Distant Voice]

nigegilb; As I understand the report, auto ignition came about because of the lack of insulation at the V-coupling (aft of the elbow). So temp reduction due to insulation problems did not come into it in the end.

One would have thought that when this section of piping was replaced, as it was after XV227 incident, the instruction should have been given for the insulation blanket to cover the exposed clamp.

Perhaps someone involved in the replacement programme can comment on this

DV

[EdSet100]

DV has answered the question well. I would add that there can only be conjecture about the thickness of the insulation and the size of the gap in the vicinity of the V band clamp on XV230.

NG, I don't know, as a fact, what the temperature reduction is with a brand new insulation shroud. I've seen them, in good condition on other jets, and IMHO they are not designed to protect the equipment around a pipe with 400 C air pushed through it for hours on end. To be accurate, though, the engines are normally at about 90% while the SCP is used (duct air temp will be approx 300C). There will be an occasional increase to climb power (95%). When the pipe was originally designed it's sole purpose was for use as a crossfeed air start pipe. The SCP was then added with the introduction of MR2, then the empty refuel pipes (they were sucked empty before the days of AAR) in the area of the hot pipe were pressurised in flight during AAR. As aircrew, I unwittingly trusted other folk (engineering policymakers) to keep an eye on the the safety of all this.

As a matter of interest, we actually breath the air in that pipe and other similar ducts. There are no biological or chemical filters between the engine compressors and my lungs. Should there be a safety case for this???

[Magnersdrinker]

I like your last point Ed Set , you should try sitting under an engine at max throttle and adjust the conditioning regulator LOL The vibration that shakes your internal organs as well as the crap the system throws out also the constant burning of the hands trying to check for leaks in the piping. There is no saftey procedures for this even though I dont think it can be doing the body any good. Saying that im still alive so far

[spanners123]

EdSet,
The air you breathe is taken from a low pressure tapping from the ECU, there are no filters on the system and as far as I recall, in over 20 years of aircraft maint, none of the a/c I have worked on have had filters fitted either.
You should never experience any unpleasant odours as the tapping is before the combustion chamber.
Cheers

[nigegilb]

Ed, I seem to recall reading that the Tri-Jet is the fastest tanker, requiring higher power settings for Nimrod to keep up. Would the figure of 94% be about right, thus giving the 400 deg+ temp in the pipework?

Also, and I believe this is not uncommon, the Nimrod uses engine air to actually dump fuel in an emergency. This positive air pressure is used directly in the fuel tanks. I am a pilot with very limited engineering knowledge, but is there any concern about this procedure? Where is this air tapped from?

Apologies if I am going off track a bit and also if my techy bits aren't quite right.

Finally, with a temp reduction of only 16 deg, surely the auto-ignition could have occurred anywhere the fuel was in contact with the damaged insulation?

I am not specifically referring to XV230, if you see what I mean.

[EdSet100]

Spanners,
The air that I breath comes from the 12th stage of the HP comp. To get there it passes over the oil metering pump in the intake bullet. When engine a/icing is selected on, some of the 12th stage air is routed forward and then through small pipes inside the bullet before entering the LP comp and it occasionally induces oil out from the metering pump. This air/oil mix then ends up at the 12th stage and centifugal force throws it down the HP air outlets and it eventually gets up my nose. Then we have the cold air units with their syringe full of oil in the system as well.....

NG,

Ed, I seem to recall reading that the Tri-Jet is the fastest tanker, requiring higher power settings for Nimrod to keep up. Would the figure of 94% be about right, thus giving the 400 deg+ temp in the pipework?

Yes, as the BOI confirmed, XV230's engines were somewhere between 94% and 99% at the end of the bracket, so at least 400C would have been in the pipes. Perhaps, much higher.

Also, and I believe this is not uncommon, the Nimrod uses engine air to actually dump fuel in an emergency. This positive air pressure is used directly in the fuel tanks. I am a pilot with very limited engineering knowledge, but is there any concern about this procedure? Where is this air tapped from?

The air comes from the engine LP comps. It is reduced to a much lower pressure, with most air bled overboard, before it gets into the tanks. The vent system comes under spring relief pressure at 2.5 psi and backed up by the (in)famous blow-off valves if the vent valves fail. So, the fuel pressure in the dump lines/refuel lines, is very low and does not cause us any concerns. However, a loose coupling is a loose coupling and fuel without any pressure will leak through it. But, we are quite content that the lads are making sure that the couplings are not loose.

Finally, with a temp reduction of only 16 deg, surely the auto-ignition could have occurred anywhere the fuel was in contact with the damaged insulation?

Well, it is conjecture to say how much reduction is achieved by brand new, or very old, insulation. IMHO, regardless of the thickness, if the pipe has more than 400C air in it, the insulation wouldn't stop auto-ignition if the fuel is able to remain on top of it for a minute or two.

Regards
Ed Sett

[spanners123]

Edset,
You are correct, the air is taken from the HP comp, thats what happens when I think at this time of night!

[tucumseh]

EdSet100

“As aircrew, I unwittingly trusted other folk (engineering policymakers) to keep an eye on the safety of all this”.


Quite right too. This is one area I hope the review studies.

They should ask why non-engineers are permitted to make sometimes crucial engineering decisions. It’s not unusual for an engineering project manager to spend half his time running around over-ruling decisions made by unqualified superiors.

Also, and I can only speak from personal experience, it is now nearly 20 years since a Service Engineering Authority (an IPT function nowadays) first approached me (as a PE project manager) and asked me to write a new maintenance policy for a system, as they no longer had the expertise.

There’s so much wrong with the above you could write a book. Two simple sentences contain a host of fundamental breaches of airworthiness regulations. The Service EAs used to be self reliant, with PE a fallback. A viable fallback, as PMs had to have been there and done it before promotion. But when you come to rely on the fallback, and the latter’s boss announces he doesn’t want engineers in PM posts, then the fallback becomes Industry. They, too, offloaded engineering posts and many are now employed on a consultancy basis. Consultants, by their nature, are transients. Where is the continuity of expertise today? (The Corporate knowledge which is itself a fundamental airworthiness requirement). Where is the recruitment ground for MoD project engineers who understand military aviation? Sold off, that’s where. Lining the pockets of shareholders, when we should be more concerned with stakeholders. (i.e. YOU). Like I said before, these are not revelations. Predictable, predicted and ignored.

[enginesuck]

Spanners,
The air that I breath comes from the 12th stage of the HP comp. To get there it passes over the oil metering pump in the intake bullet. When engine a/icing is selected on, some of the 12th stage air is routed forward and then through small pipes inside the bullet before entering the LP comp and it occasionally induces oil out from the metering pump. This air/oil mix then ends up at the 12th stage and centifugal force throws it down the HP air outlets and it eventually gets up my nose. Then we have the cold air units with their syringe full of oil in the system as well.....

Id be more worried about your oxy mask that I hooped.

[Chugalug2]

A call to Arms

Mike Jenvey, thank you for responding to my 'call to arms'. Yes, you are quite right to attribute tucumseh with a special knowledge of what goes wrong in the implementation of Airworthiness provision, and even more importantly a willingness to reveal what he knows on this forum, subject to the OSA and what is already in the public domain but not spelled out. What makes him do it? I suspect he is driven by his training, engineers must surely be able to empathise with his fury at seeing all the processes designed to make aircraft safe being subverted by ignorance (ie those not so trained) and worse still malevolence (those in authority who ride roughshod over any like him who try to enforce airworthiness protection into military aircraft and their systems). How has it come to such a dreadful pass? As ever the reason is simple, good men (and women) were unwilling to stand up and stop it. Why was it done? Who knows, ostensibly to save money one supposes, in a ministry renowned for its wastefulness the one process where slashing expenditure has an immediate sting in the tail was not a wise move. These are not wise people, they are ignorant single minded bullies and should have no power over such vital work which must be removed into the safe qualified hands of a dedicated independent authority established for the purpose.
What Mr Haddon-Cave, or for that matter tucumseh himself, does is entirely up to them. What is important here and now is what each of us on this thread does. If you are convinced, as I am, that further preoccupation with the minutiae of the MOD structure for airworthiness enforcement is pointless, because that structure is now completely dysfunctional, then what is to be done? I feel that we are in the position of having tried to diagnose the random and seemingly pattern less malfunctioning of an undercarriage actuating ram. Sometimes it works, sometimes it doesn't, and sometimes it starts but then stops. Others it seems have been preoccupied with flying control faults, similarly random, yet others with a variety of other bizarre symptoms. One person then questions if the right hydraulic fluid was ever used, or a cheaper but incorrect one. Do you go on concentrating on the undercarriage fault, or take seriously this latest contribution and check it out? Now I know my analogy can be shot down with ease, but I hope that what I am trying to say is understood. We, that is aviation professionals (well ex in my case) of whatever persuasion, tend to go deeply into things to discover what is wrong. In this case what is wrong is the thing itself, ie the system or rather the way in which it has become subverted. As I have said before forget the trees, look at the woods.
So to get back to my query, what is to be done? PPRuNe is powerful, especially when it talks about what is dearest to its heart. If Flight Safety isn’t just that, I do not know what is. So we should pick up on the theme that tucumseh espouses, contributing anything in our knowledge that supports his stance, calling individually for the total reform of this blighted system, supporting the call for an independent MAA, in short speak out! Is this the right thread on which to do that? I would say yes. This tragedy seems to have finally caused pennies to drop in the minds of those who should have been alert all along to this farrago, if any good is to come out of it then this is surely it. We owe much to those who perished in XV230, the very least we can do is to strive with all our might to ensure that preventable accidents like this, and far to many others within the military air fleets, are avoided in future by reinvigorating the process of military airworthiness provision, ie by creating an MAA.

[Distant Voice]

Wescam Fit

Does anyone know if cables for the Wescam camera pass through No.7 dray bay?

DV

[airsound]

Does any of this sound familiar?

The organizational causes of this accident are rooted in the......Program’s history and culture, including the original compromises that were required to gain approval....., subsequent years of resource constraints, fluctuating priorities, schedule pressures, ....... Cultural traits and organizational practices detrimental to safety were allowed to develop, including: reliance on past success as a substitute for sound engineering practices (such as testing to understand why systems were not performing in accordance with requirements); organizational barriers that prevented effective communication of critical safety information and stifled professional differences of opinion; lack of integrated management across program elements; and the evolution of an informal chain of command and decision-making processes that operated outside the organization’s rules.

Well, apart from the spelling, we might hope that this, or something not dissimilar, would be part of the executive summary that Mr Haddon-Cave QC will present as part of his inquiry.

Actually, it's from the Executive Summary of the Columbia Accident Investigation Board, after the 2003 destruction of the Shuttle Columbia on re-entry. I recommend a glance
http://www.nasa.gov/columbia/home/CAIB_Vol1.html

airsound

[Safeware]

Airsound et al,
If you want to read more about this kind of thing, may I also commend Nancy Leveson's book "SAFEWARE: SYSTEM SAFETY AND COMPUTERS" or look at her website http://sunnyday.mit.edu/
and from the papers section http://sunnyday.mit.edu/papers.html#org:

Technical and Managerial Factors in the NASA Challenger and Columbia Losses: Looking Forward to the Future by Nancy Leveson, in Handelsman and Kleinman (editors), Controveries in Science and Technology (to appear) , University of Wisconsin Press, 2007. (DOC )

This essay examines the technical and organizational factors leading to the Challenger and Columbia accidents and what we can learn from them. While accidents are often described in terms of a chain of directly related events leading to a loss, examining this event chain does not explain why the events themselves occurred. In fact, accidents are better conceived as complex processes involving indirect and non-linear interactions among people, societal and organizational structures, engineering activities, and physical system components. They are rarely the result of a chance occurrence of random events, but usually result from the migration of a system (organization) toward a state of high risk where almost any deviation will result in a loss. Understanding enough about the Challenger and Columbia accidents to prevent future ones, therefore, requires not only determining what was wrong at the time of the losses, but also why the high standards of the Apollo program deteriorated over time and allowed the conditions cited by the Rogers Commission as the root causes of the Challenger loss and why the fixes instituted after Challenger became ineffective over time, i.e., why the manned space program has a tendency to migrate to states of such high risk and poor decision-making processes that an accident becomes almost inevitable.

NEW:
What System Safety Engineering can Learn from the Columbia Accident by Nancy Leveson and Joel Cutcher-Gershenfeld, Int. Conference of the System Safety Society, Providence Rhode Island, August 2004. (PDF )
Many of the dysfunctionalities in the system safety program at NASA contributing to the Columbia accident can be seen in other groups and industries. This paper summarizes some of the lessons we can all learn from this tragedy. While there were many factors involved in the loss of the Columbia Space Shuttle, this paper concentrates on the role of system safety engineering and what can be learned about effective (and ineffective) safety efforts.

sw

[Chugalug2]

NASA v RAF

airsound and Safeware, I really cannot see the relevance of citing NASA's safety record when considering that of the RAF. In NASA's case a self regulating authority, faced with the horrific deaths of Grissom, White and Chaffee in a ground training accident preparing for the Apollo 1 mission, produced a safety regime whereby all future Apollo missions , including the ill-fated Apollo 13, were conducted without further loss of life. Having attained such an enviable record, thanks to training and financial investment, standards later slipped due to a combination of managerial pressure and financial cutbacks, culminating in the losses of Challenger (Smith, Scobee, McNair, Onizuka, McAuliffe, Jarvis and Resnik) and of Columbia (Brown, Husband, Clark, Chawla, Anderson, McCool and Ramon).
In contrast the RAF, under a self regulating authority, faced with the horrific training accidents of the early jet era produced a Flight Safety regime whereby such accidents were greatly reduced. Having attained such an enviable record, thanks to training and financial investment, standards later slipped, due to a combination of managerial pressure and financial cutbacks, culminating in....oh wait, I think I can see where you are going with this...

[airsound]

Charles Haddon-Cave, QC’s Inquiry

I understand that facilities for the Inquiry are being set up in Whitehall, but probably won’t be up & running until after Christmas. But then there will be a website and means of getting in touch for interested parties. Also, I believe that Mr H-C will be familiarising himself with PPRuNe.

So I guess it’d be best not to get in touch with him until perhaps the new year - but I do believe that once the site is up, he’ll be happy to hear from people who have something significant to say.

airsound

[Safeware]

Chug,

When an organisation with a good safety management system, properly managed and resourced, goes through a period where the rationale for setting up the safety management system is forgotten about, it sees "safety" as having no added value. If the safety culture is then cut to save costs, it isn't the suits doing the cutting that pay the price. As they say, if you think safety is expensive, try having an accident.

sw

[Tappers Dad]

Thanks for the information airsound. Needless to say I will be on the website once it has been set up, I have plenty to say. Although I am busy preparing for the pre-inquest at present.

[Chugalug2]

Safeware wrote:

When an organisation with a good safety management system, properly managed and resourced, goes through a period where the rationale for setting up the safety management system is forgotten about, it sees "safety" as having no added value

And Bingo, at last we see the woods for what they are. The reason that self regulation always fails us in the end is because it is essentially self serving. The NASA safety regime enforced after Apollo1 was just that. The whole programme, indeed NASA itself, was under threat and the answer was a total redesign of the vehicle, procedures, and the programme itself. Once all that was done, the task was essentially achieved. Safety for its own sake was not, per se, the point and other priorities, principally financial, replaced its supremacy. Without flogging the point to death an almost identical sequence occurred in the case of the RAF, its onset being the early post war accident rate of Meteors etc. The point of RAF Flight Safety is not safety for its own sake (for which it is often derided) but Force Preservation, ie to reduce avoidable losses of aircraft and crews so that they are available for operational use. Thus it is a management function, thus it can be and has been supplanted by other priorities, hence the present crisis. This is thus an unstable and dysfunctional system. It must be reformed, in particular the regulation of military aircraft airworthiness must be removed to a Military Airworthiness Authority. Operating unairworthy aircraft is not macho, it is reckless and irresponsible, no matter who does it and it has to be prevented.