Followed you around? Strange, other threads show the reverse. You flatter yourself, I wouldn't waste any malice on you. What I have done, when you've posted your silly opinions on subjects of which you know SFA, is to respond. You can be an amusement at times, but mostly just a bloody annoyance. Try http://www.pprune.org/tech-log/44210...lp-needed.html Full deck comes (very much!) to mind ....

I'll leave you lot to re-define engine failure. DREG, a word of advice - leave any response until it's worn off.

DERG:

Recall when you perceived my committing (nearly) the same offense? I'd like to know what you eat for breakfast that affects you so.

All the same, best to check six... :ooh:

forget has been on site for 12 years, and has thousands of posts. I have seen some incisive and thoughtful work of his, anyone can be brash, or impatient.

Fear the laid back pilot, eh?

Engine Life in Hours
 

:suspect:Pax Romanis..yes Bear, thank you, AGREED:cool:
Barit1 I thought me and you were reconciled?

So are RR aerospace turbines generally sub standard compared to GE/EA et al.?

This evidence from elsewhere on this site:

"RB211-535 19,000 hours average time to first shop visit, The RB211-535E4 achieved the world record for on-wing life without removal for over 40,000 hours over nine years in operation for a 757."

RR has such a tip top reputation here in the UK in keeping with the above statement.

And generally:

"Most engine removals are for deteriorated thrust rating or EGT margin. Modern engines are getting towards 30,000 hours on wing and if I remember corectly the old Concorde Olympus were more like 300!"

Then from Turbine D we have this: Edelweiss incident

"DCA04IA002"

"Both engines were Rolls-Royce Trent 772-60/16 turbofan engines and were installed on the airplane when it was delivered new from Airbus on November 21, 2000; neither engine had been removed or overhauled since they were installed. Both engines had accumulated 15,169 hours time since new (TSN) and 2,348 cycles since new (CSN)."

Note: RR have limited the T972 to 70 cycles total life

and here from the guys in the shops

http://www.pprune.org/engineers-tech...gine-mtbf.html

Moreover these airliners are not dropping out of the skies, I see them often on the 6 500 mile hike from central Europe to the W Coast of N America spinning their silken contrails as they battle the western winds. This has been going on for 45 years or more beginning with the B707, never a deviation from the steady progress across the sky

Despite the fact that GE appears to have the advantage of newer technology and access to better academics, RR are not done yet.

Engine Life - Hours verses Cycles
 

DERG

Don't get too hung up over hours representing engine life. The best measure of aircraft engine life performance is cycles, that is, how many cycles are accumulated on wing before the engine requires removal and overhaul. It would be expected that engines on an extended range aircraft flying 10-14 hours routes would accumulate hours rapidly but cycles less so and would stay on wing longer compared to an aircraft that does short flights of 2 hours or less, but with 6-8 multiple flights per day.

Hours are easily understandable by the average person and quite a few advertisements cite long hours accumulated (bragging rights) before engines come off wing.

Even TBO (time between overhaul) cycles vary between operators using exactly the same aircraft and engines. It depends on general operating conditions, high altitude airports, or hot, dry, dusty conditions (desert airports), exposure to sea salts (corrosion), e.g., airports near the sea.

The exception to this would be gas turbines used in electrical power generation or natural gas pumping. There, hours, really defined as years, are the important factor. There are no cycles to speak of. Turn it on, take it up to operating speed and expect it to run 20 years with little attention if the designs are good.

Indeed. had a chance to work at a power station here in Cali. JT8Ds. Fire and forget. Simple designs, robust build, and constant monitoring. The secret was to scrub intake air to nil fod. The cleaners were changed often, and the fuel was inspected daily. In its niche, the Turbine is a brilliant workhorse.

Service Life in this incident is pretty much a red herring, imo.

Safety is the salient issue, not economy. The first picture of the 972 off wing showed the absence of the EEC. Anybody know where that little beauty ended up?? For it is here that the failure is found. Any engine will blow up when run under heavy load with compromised condition. The Kill Switch killed the kit.

Industrial Turbines
 

There are 28 companies who make industrial turbines. I think it is interesting to see how RR sits in this application.

In terms of mechanical drive generators only one company makes a model that produces more power than RR. That of course is GE.

"The Kill Switch killed the kit" Yeah...

Perhaps we are at some cathartric point in the course of technology. At RR we have a bunch of people who cling on to the 1950s because they just can't find the right road to take. They do their best to make it happen and suddenly events take them right back to the days of the Comet.

The young engineers are used to making the virtual world real. Then suddenly the ghost of the past wakes up and says "We tried that in 1949"
The Hughes corporation comes to mind.

Anyways time for some entertainment....to date THE BEST proven load carrier on the planet...
YouTube - The Steve Miller Band - Jet Airliner Boeing 747 Take offs (Watch in HD)

I rediscovered the link below which was contained in the previous thread from the PPrune rumor mill before the topic was moved to the Tech area. There are likely many now participating in this present thread who haven’t read this very interesting and revealing interview of a senior ck pilot who was onboard QF32. It’s not often “we the public” get to read or hear in such candid fashion the particulars of such a momentous event - litigiousness being what it is at least in the US.

For instance, I had forgotten (see previous post) there is an engine fuel shut-off feature associated with the cockpit “fire” buttons.... I don't know if that also includes the pylon valve but would presume so. The pilots were surprised to discover, however, that #1 was literally OOC. In line mx., when these systems are “tested” in hanger or on the gate there are no engines running, so who’d know if a particular s/o redundancy would actually be functioning or not? Bottles would be disconnected and what could ECAM tell you that you could believe? There was such severe damage out there in that wing that possibly no amount of redundancy engineering would have saved the day anyway.

The whole thing will probably be made into a movie soon.

http://www.aerosocietychannel.com/aerospace-insight/2010/12/exclusive-qantas-qf32-flight-from-the-cockpit/[/URL]

If the link doesn't work you can find it archived (I believe) at aero's site...

Living in Hope
 

This failure is something I am hoping the ATSB will address. If the safety authorities are to be respected they need to enforce something as basic as this.

I think some are getting too hung up on this. There is "redundancy" in the engine shut off, AFIAK there are 2 physically separated electrical circuits to do this, and in this event, both got cut.

To create "a tragedy", seems therefore to require 4 very unlikely specific events:

1. A failure that is uncontained (as here, unusual and has to be addressed)
2. >1 fragment that causes damage elsewhere (I saw somewhere design assumes 1 fragment)
3. These 2 (or more) fragments fortuitously cutting the separate redundant paths of an important system
4. That system's failure then leading to a signifcantly increased safety problem.

If you over-concentrate on "shutting" an engine down, you end up with engines shutting themselves down of no accord - a far greater, IMHO, safety issue :sad:
We had 3 of 4 "unlikely" events, P of the 4th is small?

Or look at it another way, if you over-emphasise the need to shut engines down, then maybe Airbus could have designed the shut off curcuits to "self monitor", and if both circuits were cut, to shut down the engine. Sound a good design? Maybe, but in this case it would have given them a double engine failure :{

A manual shut off valve? (in the pylon?) - OK, maybe a good idea, but really enhancing flight safety? In both the quoted cases, once an engineer is in place to operate it, everybody was, or could be off, and well clear anyway.

I suspect the ATSB will look at it, but I disagree they will place strong recommendations on addressing it. As an airline pilot, I am wary of too many "safety systems" being too cleaver - they usually cause more problems than they solve. I am "nervous" of the software in the Trent that can "shut the engine down" without warning / pilot control.

QF32 had a major problem with its monitoring and fuel control vv shutdown in the first place. Problem solved (?) with new software. #2 should have shutdown well before Burst. That was danger enough to have brought down this flight. Two cold engines on one side is not a good thing. I am with you, losing #1 due auto shutdown would have been not good. The Burst caused the very real worry of loss of this flight. So to answer the Burst with more "Automatic Shutdown" seems contra sensible. The EEC and monitoring programs were at fault. Looked at from a failure trail pov, the Burst was secondary to cocked up controls at the outset, No?? There is a fair amount of attention being paid the Data Entry Plug and its interface with the two channels of the EEC I'd wager.

"I suspect the ATSB will look at it, but I disagree they will place strong recommendations on addressing it. As an airline pilot, I am wary of too many "safety systems" being too cleaver - they usually cause more problems than they solve. I am "nervous" of the software in the Trent that can "shut the engine down" without warning / pilot control."

If the ATSB cannot mandate this VITAL shutdown device
they are superflous to the industry..

All it needs is an external valve that rescuers can access.*

*NOTE: Colleagues on this thead have correctly pointed out this would be impossible due to the danger of access a running jet engine.. OK lets call it a MASTER OFF switch. It is ridiculous that telemetry can "read" these engines 12k miles away yet we cannot turn 'em off.

A valve that a groundperson could reach would be (have to be?) positioned within reach on the engine or pylon. By the time QF32 was on the ground, danger of in flight fire was by definition not possible. The fuel leak was at the forward spar near the Fuselage, and interior the wing. At best, #1 could be stopped with such a provision, but we know through unfortunate circumstance (TooLoose) that run on is relatively safe. Fuel fire was avoided by QF32 by mere chance, mid air, one of many fortunate blessings. One could even argue that because #1 ran on, fuel was removed from the penetration area of the wing, perhaps forestalling a mid air fire. IMO.

If you think QF32 #1 engine continued running is a problem, consider this:

Fighter aircraft with inlets behind the cockpit, belly landing, disabled pilot unable to "pull the plug" on operating engine. How do you safely rescue the pilot? :ooh:

I have not followed this thread to the detail of you / some others.

However, what you/others seem to be saying here/previously is that there is software in the Trent that can shut the engine down automatically. Such software failed in this case to act, and was rapidly modified post event. That such software exists was "news" to me, and I would be nervous unless it was 100% bullet proof. It should not be there to "protect" the engine, but solely to prevent "in extremis" failures that will result in serious uncontainned failures. Else there is a risk it mirrors: - the day we get engines auto-shutting down unnecessarily is a bad day... automation gone too far.

Complete and utter waste of time, safety-wise. If the recuers can reach the engine, they will have got the pax out first. Little safety benefit, might save a bit of fuel / noise and get aircraft moved earlier, maybe save an airframe. But not people.

Disagree 100%, suspect we'll leave it at that ;)

In general, I agree with you, auto shutdown of an engine by a computer is not a good thing.

Focusing only on the #2 engine (the one that failed), it was operating in auto-thrust mode. The EEC apparently detected a un-commanded reduction in N2% and immediately called for increased fuel flow thereby increasing the N3% eventually to 98% before reducing fuel flow. By then, it was too late to prevent the eventual disintegration of the IPT disc due to overspeed.

IMO, I suspect the EEC was reprogrammed to view reduced N2% and the start of increased N3% as a problem and the need to reduce fuel flow, not increase it. This may have saved the day, possibly. However, reducing fuel flow is not an auto shutdown, the decision to shutdown the engine is and should be the flight crew's decision.

The ATSB job is to investigate set forth the causal factors and make recommendations.

They are not regulators nor should they mandate changes that may be impractical.

Once the full report is released I'm sure that knowledgeable safety experts will support practical changes.

This thread is suitable for discussion of facts and points of interest.

Is there anything newly released out there:?

rollercoaster
 

Reading myself after several days of absence through the meanwhile placed 75 posts, I got a bit the feeling of a rollercoaster. There are - as usual one is tempted to say - many well founded posts with useful information. But there were - once again - amusing attempts of a peeing competition recognizable, who and where and on which side of the pond the best engines are made. Finally I reconned also some useless baloneys. Thought we are a rather professional circle.

That all reminded me to Murphys law, not the short version but the one Robert Murphy, Ed´s son has passed on:

"If there's more than one way to do a job, and one of those ways will result in disaster, then somebody will do it that way."

I believe excactly that killed engine #2 on QF 32.

I also think that it is the centre point the discussion in this thread has disclosed. I believe that those possible root causes or contributing causes identified can be listed this way.
- vibration of unexpected strength and probably unknown origin
- problems with the oil system
- probably problems with the bearings
- known and probably also in this model existing problems with oil vent tubes
- unexpected problems with stiffness or strength of the support structure of
bearing chambers

One word to the idea of an external switch somewhere close to the engine or pylon. I would like to meet that hero that is willing to get so close to a running engine of that size to activate that switch.
Another word: I emphatically agree in the reluctancy of NoD to rely on a "fully automated robot". In my opinion any computer or automatic device can be only as good as the brain that has desighned it (s.a. Murphys Law).
Therefore any artificial intelligence needs a human brain controlling it.

Just been advised that A380 VH-OQD on QF32 LHR - SIN has diverted into DXB. Not the same a/c as that involved at SIN, but obviously some problem that made the crew decide on this precautionary diversion.

U415967
 

Well, you call it unsubstantiated rubbish, many of the participants in this thread - as the top line says - call it Rumors !!
Could be that all these many entries - the collection of thread 1 and thread 2 approaches about 2500 !! - are apain in RR´s neck. As usual they would have preferred to run this in the "noble" and silent way they usually handle these cases. Okay with me and many others, but to think independant fortunately has not yet become forbidden in this free world.
So as you seem to have a deeper insider knowledge to the case, feel free to "teach" those "unknowing".
And by the way, a bit more personal information than just "Seattle" would be of great help to balance the base of knowledge.

I suspect that if your location (Seattle) is accurate, you may very well be an RR employee, on assignment at Boeing, probably in support of the Trent 1000 on the Boeing 787. A clue is your use of the word "rubbish". In the States, we seldom use this word, but the word "refuge" or more commonly, "garbage".

With over 2500 posts, this thread is in reaction to a very, very near tragedy on the Qantas Airbus A-380 given the catastrophic failure of the Trent 972 engine. It is also a reaction to Rolls Royce's response to this event. The silence from Rolls Royce has been deafening.

Some of us have been in this aviation business for all our working careers in one role or another and because of the deafening silence from Rolls Royce, we speculate as to the cause/causes of this Trent 972 failure, whether or not there were specific indications that such a failure would eventually transpire, and whether or not corrective actions have actually taken place that don't require repeated inspections at short intervals among other things.

So, this thread is what it is, like it or not from your perspective. You can contribute but perhaps that may not be in your best interest, so the "silence is deafening" route may be your best alternative.

Glad we got this one point cleared up! :ok:

Now for the rest? :confused:

RR need only satisfy their current customers, regulators, potential customers and the investors.

The investors need only seek out technical based opinions beyond this from independent experts.

Since such experts are not in evidence in this thread (name, title, bio) then the technical design-redesign opinions expressed here are only to impress the browsing reader.

U415967
 

'Having spent sometime reading this thread for the first time I am very disappointed by the amount of unsubstantiated rubbish that is spouted. RR have played this close to their chest publicly, but do any of you know what they have been doing with the airframers/airliners and authorities. Thought not.

Bearfoil, DERG, annex14 etc. some of the junk you are spouting as fact is unbelievably wrong. Anyone that believes your rants should think again.

Bearfoil where do you get your facts from, do you know anything about engines/EEC's, DEP's you posts are some of the worst I think I have ever read.'

I am saddened to read your post.

Perhaps if you followed this thread from the start you may have realised that there have been many genuinely knowledgeable and respected contributors who share a genuine concern for safety, and seek to identify the physics of the QF32 failure in order that 468 pax and flight crew might never be similarly endangered.

This forum is very unique in that it brings together those who fly the planes, and those who contribute to their construction and who advance the technology. This can only be good and potentially of enormous value, because no matter what our age - we can never cease to learn.

Of course in a public forum, there is bound to be a certain amount of 'noise'. But i think the pilots and engineers here are well able to filter that out? And in any event is there something bad about throwing thoughts around? I think it's called 'brainstorming'?

I think that perhaps I speak for all to say that you are welcome here if you believe you can contribute to the discussion and to an improved understanding in a positive way.

Personally, may I thank those who sit up front, and those who are engineers in whatever capacity on the ground for their constructive and well considered thoughts shared here.

Thank you for your very thoughtful post. Indeed, there are some of us that are trying to understand what caused the engine failure on the Qantas Airbus A-380 in the interest of passenger safety. Unlike some of the posters that imply that only the stockholders, investors, regulators and potential customers be satisfied, I believe the users, the paying passengers besides the flight crews also need to be completely assured of the safety after a near catastrophic event, such as this one, that occurred. It has nothing to do with how far we may be removed from current technology as some have suggested but the honesty in dealing with what has taken place and assurances that it is not going to happen again. The problem is not with the aircraft, in fact, it saved the day. The problem is with the lack of assurance from the engine manufacturer that the problem has really been completely solved going forward. As I see it, I have yet to see any believable assurances, especially with remarks such as this from the very top of the organization:

Now we know this not true, there have been at least two, one occurring on August 30, 2010, out of San Francisco, a Trent 700 engine, also on a Qantas aircraft.

Re-arranging the deck chairs on the fore-deck, while the band plays on in the main lounge to comfort the stockholders, is not what this is about.

There is enough credible information on both sides of the pond to suggest that this event was not only predictable to occur at some time, but also preventable. It is with this in mind that we explore what happened and attempt to assemble some thoughts, ideas and our experiences as to the sequence of events leading to the failure and postulating what may need to be done to keep a replay from occurring.

It is nice that some of us are willing to share in this forum, while others, perhaps with even more knowledge, are willing to play the "I know more than you do, but I am not saying" role.

Thanks again,:ok:

Not quite. It was QF74, a 747/RB211; IPT detached from the shaft, but shed its blades (ripping case open) before reaching burst speed.

The other related case was a T1000 on test bench, early Aug. 2010 IIRC.

Yes, well, that's what has been under discussion here. The subtle undertone of this thread deals with how not fully understanding these "newer technologies" and how they actually work in the real world can affect commercial air trans as we know it.

Let me qualify myself. I don't work in the aviation industry, I'm not a pilot.

Now, to take you to task for some of your earlier and rasher statements regarding the quality of this thread and those who drive it.

This thread has been both fascinating and an education for me as I have followed the discussion; the many contributory posters (bear, turbine, loma, et al) have brought forth valid information as well as insight.

Frankly, to walk into this discussion and call most of it rubbish or garbage does not add anything to its value, and if that is the best contribution you can make, I would suggest that you hold it for a cocktail lounge somewhere and argue over designer cocktails with those who haven't put a lot of effort into trying to discern exactly what caused an engine, one of the most-touted engines, of a 5-star engine builder to self-destruct on the wing of a Qantas flagship aircraft.

Before you decide to reply with some snarky comment to this post, I suggest you re-read this thread and all the links found herein. You might at that point decide that you were in fact completely wrong in classing most of this discussion as refuse.

Cheers!

Now, where, exactly, did I write that?

(for those who wish to fact-check, and for u415967 to review, this is the post...)

Yes, you're quite right. The authorities are the ones designing engines, airframes, and infrastructure. And building all of it.

And the authorities never, ever have to enlist the help of outside talent - like engineers, experienced line mechanics, et cetera.

There is a God!


Carry on, guys - and thanks for the discussion so far!

Junk
 

"Bearfoil, DERG, annex14 etc. some of the junk you are spouting as fact is unbelievably wrong. Anyone that believes your rants should think again."

The most unbelievable fact is how the RR management took the junk as presented by Oxford University and used it in a way that resulted in endangering the public. When the public buys a ticket to ride on these aircraft they do not believe they are entering a lottery.

The BBC interviewed an aerospace analyst last week who stated that "RR know they have a problem". Then we have the article in the THE ECONOMIST, a weekly once noted for its objectivity, that reads more like some thing from THE INVESTORS CHRONICLE.

Now as far as the claim that some of us are partisan, we are biased toward GE or RR..well I for one have learned enough on this thread to make an educated guess just which engine I would trust my life with. Those of you who cannot make a judgement yet should reread this whole thread.

RR are taking a hell of gamble with people who place their trust in the T900s with their lives, not money as in the stock market, with life and limb. You think this is hyperbole...?

All 4 Trent 972's working perfectly. :ok:

Very good news Trent!

Barit

The stuff that the military do and the stuff the civil avaition does are connected intrinsically but are incomparable in terms of day to day routines. Is that not obvious Barit?

The problem arises when the UK Ministry of Defence people find themselves at the whim of Adam Smith. They suddenly realise that they have a bunch very greedy people to please, many with the morals of a rattle snake.

Indeed the public they once "served" are now seen as pawns in a game.
Of course Airbus, RR and almost all the big aircraft manufacturers have some income from military projects. These people are given only parts of the picture for reasons of security.

What they do not realise is that civil aviation has no "state secrets". In this sense firms like QuintiQ are immature and still unconnected with civil responsibility. viz. LITIGATION

Moreover we have evidence that the academics they employ readily provide them with ammunition to make probalistic projections about mechanical devices they really know SFA about.

Not military hardware, a civil airliner with over 450 people on board flying over populated communities.

OPEN TO FORUM

Some of you maybe asking IF the manufacturers know everything about the aircraft they sell.

This link is interesting:
AvioConsult - Aircraft Expert and Consultant - Home Page

This will take a couple of hours to fully digest but is well worth reading.

CF6-45/50 Uncontained Failures
 

Good information on other uncontained failures. They can occur more frequently on engines that are nearly 40 years old and for one reason or another, are not well maintained. Now, I don't want you to think that I am making this up or a "sciolist" as you like to put it. So here are the facts, read on:

AD Aimed At Delinquent CF6 Operators | AVIATION WEEK

By the way, the CF6-45 engine was designed for the Boeing 747-100SR (short range), especially for ANA and their short routes inside Japan. Just thought you would like to know.

Thanks for the information Trent 972

Presumeably it had to divert back and then round over Saudi.

Glad it was a paperwork issue and nothing technical :ok:

I wasn't counting the Trent 1000. The second one I was referring to was this one: http://www.ntsb.gov/ntsb/GenPDF.asp?...04IA002&rpt=fa
FAA Airworthiness Directive
During 2004, an incident was reported involving uncontained multiple intermediate-pressure (IP) turbine blade release on a Trent 700 engine. The blade release was the result of an overspeed of the IP turbine rotor that was initiated by an internal fire in the high-pressure/intermediate-pressure (HP/IP) bearing chamber. Post-incident analysis and investigation has established that blockage of the HP/IP turbine bearing oil vent tube due to carbon deposits was a significant factor in the failure sequence. The Trent 800 has a similar type design standard to that of the Trent 700 and has also been found in service to be susceptible to carbon deposits in the oil vent tube.

Rolls Royce and The Economist.
 

Readers will note that THE ECONOMIST ran a very subjective and somewhat biased story about the future of RR.

Rolls-Royce: Per ardua | The Economist

It is no suprise to learn that a non executive CHAIRMAN of RR is: SIR SIMON ROBINSON

"Appointed to the Board in 2004 and appointed Non-executive Chairman in January 2005. He is the founder member of Simon Robertson Associates LLP and a non-executive director of HSBC Holdings plc, Berry Bros & Rudd Ltd, and The Economist Newspaper Limited.

He is a director of The Royal Opera House Covent Garden Limited and a Trustee of The Eden Project and the Royal Opera House Endowment Fund. He is the former President of Goldman Sachs Europe Limited, a former non-executive director of the London Stock Exchange, Invensys plc (formerly BTR plc), Inchcape and a former chairman of Dresdner Kleinwort Benson."

HSBC is one of two clearing banks for RR.

Futhermore HELEN ALEXANDER a non excutive director of RR also has connections with THE ECONOMIST:

"Appointed to the Board in September 2007. Helen Alexander was Chief Executive of The Economist Group from 1997 until July 2008, having joined the company in 1984. She has an MBA from INSEAD. She was Managing Director of The Economist Intelligence Unit from 1993 until the end of 1996"

Source:
Rolls-Royce Group plc
65 Buckingham Gate, London SW1E 6AT. Company number 4706930,
UK VAT number GB 345 8860 22.

what do you want to say, really?
 

U415967:
looks like you may have not spent too much time reading all this forum before starting to write ;)
And possibly that is why RR is currently at 3rd iteration (C) of the solution for fixing the T9 - right? So who was accepting the previous iterations? RR by itself or the authorities? I understand thay you are aware that the authorities would not exist if not the big companies who do operate on this market. Just read what Derg has posted a moment ago about 'unbiased' opinion by the economist..

in your reading you must have somehow omitted some of the French reports where raison d'etat was definitely more important than other facts ;) - see Habsheim and recent Concorde crash...

If you really know more than prove it or quit writing unsubstantiated opinions.
I am sorry but we are trying to stick to discussing the problems with Trent 900 and not healing some sore personal egos ;)
History has proven that those who really know either keep doing or keep quiet
Welome to PPRuNe :)

Derg:
exposing such information to public poses a threat to national security :ugh:
Now you can understand why some countries do close internet access at all - remember what some BIG money makers say - big money like it quiet.
:}:}:}


thanks for this info :ok:

DERG
 

Nice background information, one could have expected such a vitae.
However, allow me to remember you to the saying that "caution is the safer part of bravery".Or with other words, I fear that you are opening another "broadside".
So better lets exchange these kind of info in pm´s or mails ??
And as barit1 has stated in another context - always check your six;)

Hahah they will send the UK FSB after me?
 

Thanks for your concerns. I was born on the west side of the iron curtain and I uphold the values of freedom. The day we become scared is the day we have lost that freedom. 165 million people died in war last century and another 469 people almost died as a consequence of this nonsense with the RR engine. Nah...these folks do not scare me.

Sorry for the delay, here is a summary of EEC controls re: shutdown in flight. (T9).

The engine protection system is incorporated into the EEC. Its hardware performs the following functions:

LP and IP Rotor Overspeed protection.

LP Turbine Overspeed protection.

Thrust control malfunction protection.

EEC monitors LP and IP compressor shaft speeds (N1, N2). this is done via a Phonic wheel on the shaft of each, forward of the Ball bearings. If speeds of these shafts are above an indexed value, the engine is shutdown. The LP Compressor shaft is also compared constantly with LP Turbine module, and if discrepant, the engine is assumed to have had a shaft loss, and the powerplant is shutdown.

Thrust Control Malfunction (TCM)

EEC monitors engine thrust, both Turbofan Power ratio, (TPR), and N1 Speed. If either exceeds commanded values by an indexed limit, TCM prot operates by reducing Power, or it will shut the engine down, depending on Airspeed and altitude. Flight Controls Primary Computer (Prim), provides a discrete signal hardwired to the EEC active channel, which then allows engine shutdown.

Each channel of the EEC has a hardware protection which is separate from all other EEC functions. Comparators determine if an overspeed or TCM have passed threshold; if a fuel cutoff or reduction is set, Programmable Array Logic (PAL) functions alert the opposite channel, and if both channels agree, a signal is sent to the protection motor in the HydroMechanical Unit (HMU).

If in degraded operation, (power supply or processor failure), shutdown can be commanded by one PAL.

One other thing. The LP and IP shaft speed is sensed by Phonic wheels, the HP shaft speed is derived from the actual RPM sensed at the Alternator, off the Gearbox drive. The EEC settles on Fuel flow by sensing the RPM of the N3 ONLY. This seems counterintuitive, but may circuitously explain why the engine, at the threshold of Burst, was given additional Fuel.

Seems relatively Human exclusive to me.