DozyWannabe

Although a fan blade broke on this engine, it was actually the stage 1 LP compressor blade that was the problem:

Analysis of the engine from the crash determined that the fan blades (LP Stage 1 compressor) of the uprated CFM56 engine used on the 737-400 were subject to abnormal amounts of vibration when operating at high power settings above 25,000 feet (7,600 m). As it was an upgrade to an existing engine, in-flight testing was not mandatory, and the engine had only been tested in the laboratory. Upon this discovery all 99 Boeing 737-400s (since G-OBME had crashed) were grounded and the engines modified. Following the crash, it is now mandatory to test all newly designed and significantly redesigned turbofan engines under representative flight conditions.
This unnoticed vibration created excessive metal fatigue in the fan blades, and on G-OBME this caused one of the fan blades to break off. This damaged the engine terminally and also upset its delicate balance, causing a reduction in power and an increase in vibration. The autothrottle attempted to compensate for this by increasing the fuel flow to the engine, however the damaged engine was unable to burn all the additional fuel, with much of it igniting in the exhaust flow, creating a large trail of flame behind the engine.

Thanks annex14 for the read

Ok flights are full i.e. 60 t payload. All engines are "C" build and flights will be twice a day in the near future as it was prior to the incident

If you look at the date of print, mid December. It was an eternity ago in this saga as I don’t think many staff involved in the T900 project had any leave over Christmas. There has been much correspondence between the 2 companies (RR & QF ) since.
RR has blessed a list of QF engines capable to do the flights at thrust ratings required.
If the 75 cycles rule with 2 LAX departures a day is applied to QF with a fleet of 9 it would need to re-engine in a little over 330 days. With the current availability of 5 LAX approved aircraft a re-engine would be required in 190 days. 20 engines after 190 days flying ??
. RR cannot make engines or modules quick enough to cope with this demand.

Some pruners mention the IP coupling. Yes it is inspected for wear every 100 cycles.
Has anyone changed an engine yet due to coupling wear? Probably not ,due to the new engine builds being compulsory fitted but RR now has dozens of engines to draw data from regarding the wear. I guess we shall see which part RR redesign first?

Hiya. Actually there was an engine change due Spline wear, but the Brass at RR call it an oil fire, not specifically Spline Smoothies. #2. QF32.

Given what's known, and your perspective, it is at least a good guess that RR have mitigated the cause of Spline damage by acceding to Inspections, as to my way of thinking, they are eating canal mud on LAX SYD.

No, not really. They have mitigated the focus on the actual problem by eating a swap/strip/rebuild at an agreed interval. This interval is Qantas' schedule, and EASA/ATSB mandates, with input by RR. Most expensive, but the alternative is a re-design to eliminate Resonance discovered in 972 test, but ignored because it was a "family tradition" to mimic previous test and banked approvals via certificates in the dusty files.

Who throws in the towel first?? I think RR will keep eating. They cannot retool and recertify, and "Continued Airworthiness" via a Permanent AD is too, what, Public??

There is precedent for engine swaps, Bolty, dozens of them. The Firm dog chewed a relaxed inspection interval by convincing EASA that the Splines would be "just as well" investigated with "averaged" crest wear at abutments instead of a mandated strip search at "worst case wear" involving but one Spline per Coupling set. This is in the Public AD divulgences, and speaks volumes.

Oil is hot because the engine is light, floppy, and viscous deficient with time in case of approved oils. The FOHE also does a crap job of cooling the oil when Fuel is Warm, just after launch, just as it does a crap job of heating Fuel when the engine is cold soaked, and the Oil is cold soaked, (At Altitude, or long CDA) or missing, due bypass to Air cooled Route in the Oil Path. It's all in there, and the Splines are complicit, but only as the canaries, just as the Bearings, Oil Tubes, and Oil system are likewise.

That is a very interesting set of comments. I've been intending to put up some information about splines, spline design matters, and my thoughts on vibration related to splines. I just wanted to find an example that backed up those thoughts, and I found it a couple of days ago. It was a 7th harmonic vibration in the particular example. A high harmonic is what I was thinking. As hard for me to find such a report as it was for them to find the 7th harmonic.

Looks like you have decoded the recent reports on Qantas actions and comments. I read a set of several over on Flight Global this afternoon. Apparently we both now believe that every 75 take-offs from LAX four engines are going to be scrapped (or very substantially rebuilt?). So this will have to take place back at the real factory, not at the two special RR-900 qualified shops out in the field, no?

Eureka. EASA cannot allow averaged wear format any longer, and must revert to single case (5mm crest) strip. No one strips an engine and then does not replace parts on reassembly. The Parts? Every Spline has a sister, and that means both stub Shafts of IP and LP modules. If there is an upgrade in any thing pertinent to the AD, the FAA will get a smell, and that means everyone will know. Let's get further into the strip and r/r. All rotating mass will be affected by the resonant's dirty work, so who calls the replacement relative to time in service, wear gross clearances, and risk/benefit verse Capital outlay?? His is a very pivotal role. Bearings, Splines, Labyrinthines, Carbon residue in the FOHE, vent pipes, clean? replace? Will the Magnetic chip sensors tell a tale? Oil Pump (both) plus scavenge pumps, filters?? To get the eight modules apart, and then not rebuild sufficiently means doing it again with off wing and replace with new engine or park the Whale? How long? The numbers quoted as costs to Rolls are ridiculously low. Qantas will not pursue their suit (and give up those nuts in the vise??) Haste makes waste. IMO

Disclosure and honesty are the shortcut to healing all mistakes. The other way is exhaustive, expensive, and potentially lethal. Collective Pride.

Swarf in the oil
 

I have seen a report where one of the Qantas T972s had metal chips on the magnet trap SEE BELOW Glad OE has posted!

This is the type of metal trap we are talking about
Vibro-Meter Magnetic Chip Detectors and Chip Collectors

In fact the 900 series is the first to have a chip detector that sends messages back to base. It is detailed, along with the other sensors on the engine here..
http://www.ingenia.org.uk/ingenia/is...e39/Waters.pdf

and moreover
Ingenia Articles

Qantas A380 engine had problems before explosion
6.12.2010 (Sydney Morning Herald)

It's been revealed that the engine that disintegrated on a Qantas Airbus A380 near Singapore last month had earlier been taken off the aircraft to fix another problem.

The Australian newspaper says investigators have revealed that the engine was only refitted in February.

An Australian Transport Safety Bureau report released last week shows the No 2 engine was originally fitted as the aircraft's No 4 engine but was removed last year after metal was found in a chip detector.

Chip detectors are often a permanent magnet used to gather metal fragments, usually from lubrication oil.

The relatively new engine had performed just 3419 flight hours and 416 landing and take-off cycles at the time.

The engine was sent to a Singapore workshop certified to maintain and repair Rolls-Royce engines in September last year.

Engineers found spalling in a low-pressure compressor bearing and replaced the bearing assembly. Spalling occurs when flakes break off from a larger component and is usually associated in mechanical systems with high-stress points.

The low-pressure compressor is a different part of the engine than the one that failed in the dramatic Singapore incident.

The repair was completed in December last year. The engine was fitted to the aircraft on February 24 and had completed a further 2895 flights.

There is a Vickers Electric Master Chip Detector, which is installed at the combined scavenge return inlets (At the entrance to the Scavenge Filter), and nine Muirhead Vatric screw in Detectors at the inlet of each of:

Front Bearing Housing
Internal Gearbox (HP Rotor)
Internal Gearbox (Rear)
HP Turbine Bearing Chamber
IP Turbine Bearing Chamber
LP Turbine Bearing Chamber
Intermediate and Lower Bevel Gearboxes
External Gearbox
Centrifugal Breather

Ferrous metal is entrapped and conducts electricity across two poles in the detector.
If chips are in the Master, a specific screw in can be checked to ID the type of metal and from whence it came from the nine locations from the scavenge. Bits in Oil are of course, not good.

DERG

Are you referring to an ACARS prompt? Or a Total Care Alert at Derby?? Because the Vickers Electric Master Chip Detector sends a message to the cockpit, but ten minutes after landing. Metal in the master is what alerts the install of magnet probes by Mx to install smaller detectors (The Muirheads) in the nine scavenge ports before next flight, since normal operation of this engine (T9), has the Vickers only installed. Each smaller unit allows for narrowing down the location of the disintegrating part.

BEAR I don't know

this might tell us
Ingenia Articles

I'm using the Engine Manual. (TRENT 900) The manual is specific as to manufacturer of the Oil Debris sensing kit. Specifically, the Master Chip Detector is Electric, it uses a current of electricity to find ferrous bits in the detector (It is not a permanent magnet). The Vickers 'Electric' Master Chip Detector. The Muirhead Vatric Screw in Chip detectors are permanent magnet type units.

The replacement of the Bearing in the LP Compressor was discussed by Old Engineer some time back. I think it was determined that replacing the bearing was a good thing, but did not (rather obviously) solve the main problem, the Harmonic, which caused the bearing to fail in the first place. RR is back into replacing parts rather than admit the true problem and have to either scrap or redesign and re-certificate the 900.

In the ATSB prelim report there are pics of the graph plots of engine parameters. One of them is labelled "Oil Chemistry". If that includes a value for solid debris I do not know. Does anyone know please?

You're losing me, DERG. Solid metal bits does not sound like it obtains to Oil Chemistry. IMO. Night.

Indeed
 

Agreed Bear. But after this event anything is possible!:\

THE MORAL ISSUE

The fact that people on the ground know more about the engines than the crew on the aircraft is UNBELIEVABLE.

The fact that this aircraft was designed for long distance oceanic and transcontinental routes inherently means that any communication system that relies on standard HF and VHF communications is flawed.

The Bayesians have been used to provide Rolls Royce with a cost monitoring tool with no regard to life and limb at the critical time.

This is the issue here. All the documents are focussed on $$$$ reduction.
Not safety.

What part did Sir John Rose play in this?

He saw exactly what was happening and decided he wanted no part of it.
It is one thing to use statistical methods for cost prediction but quite another to play the deity with the public. He left the company.

Good for him.

Here is the history of the #2 engine prior to failure from the ASTB report:

Take a look at the engine parameter chart again, you may want to print it out to see it better. The bottom graph is title "oil quantity", not "oil chemistry".

IMO, I think it more important for the ground mechanics to know that metal has been detected in the oil after each flight, or not, as is the setup on the A-380's. Chip detectors are there to signal the existance of wear in one or more of the bearings and it is up to the ground personnel to investigate and locate the source, not the flight deck crew. Think about it.

DERG

The Executive executes, he/she implements, enforces, and Leads. The Leadership may be Blessed, or not, and 'one monkey don't stop no Circus'.

Politics has as its main objective to distract, to Puff, to Bamboozle. Corporate Politics are no different. There is more Cachet than Cash, Eh? Personnel are interchangeable at the highest levels. The Board is the secret to navigation of troubled waters, and firing or resigning are popular arrows in the group's quiver.

Stock Price, Brochures, and Numbers. Engineering has become a supporting player.

Now that "Q" has passed, Rolls is at the mercy of Three Piece jackals who understand more about Money and Illusion than Oil and its Perfusion.

Turbine D

Thanks, very much, Sir. Cockpit alert for metal bits is as you say, "Huh"??
ACARS is the venue for maintenance, and even Total Care takes a minute to find out the good/bad news. If the ECAM shows metal in the Vickers, (Ten Minutes after wheels on), the mechanics start to decowl and place the Muirhead Vatric Magnets in Place, to narrow down the Trail. The a/c takes off again, next landing Sherlock and Watson get to work. Each magnet plug has a check valve so as to not spill oil in removal, the plot was well thought out in the first place. It is not so desperate as it sounds.

Correction?? I think there was a September amendment which allowed Rolls to average wear of the Splines as a Coupling UNIT instead of Strip if ONE Spline was found with minimum Crest Metal. The "Crest" had 2.65 mm of showing metal at its crest on assembly, and EASA and Rolls determined .5 mm was bad enough to warrant an off wing strip and "replacement". Later (September) Rolls was excused from the "hardship" of strip in favor of a more lax regimen wherein all Splines were measured, and strip was commanded if the "average" wear was .5 mm. Then comes November 4th, 2010, etc. etc.


just sayin'

Turnbine D Yes thanks I see now, my eyes have seen better days.

Bear That does not stop us seeking the truth though.

Heads up..here we go again: another oil loss and anther loose oil coupling.

NEW ENGINE EVENT IN FLIGHT ON FEB 15 2011

Investigation: AO-2011-026 - Partial power loss - Airbus, VH-OQC, near New Delhi International Airport, 15 February 2011

and
Qantas A380 finishes London flight on three engines – Plane Talking

"According to Qantas the issue that affected the engine has also been found on a Rolls-Royce powered A380 flown by another airline (meaning either with Singapore Airlines or Lufthansa) and it is one which has been raised with the engine maker and is neither the same nor as serious as the issue which saw the disintegration of an engine on QF32 shortly after leaving Singapore on November 4."

Quote from ATSB "During the cruise the crew observed a gradual decrease in the oil quantity for the number 4 engine. As a precaution the engine was reduced to idle for the remainder of the flight.
A subsequent engineering inspection found that the fitting of the external HP/IP oil line had less than the required torque. The investigation is continuing."

My thanks to a colleague on Australian Thread on this site poster"TBM-Legend"

All I am is SLF. That's all. (That's all ?!?!? Well I'm damned important to me and my family !!)
So I don't know much about all this. Except it worries me quite a bit. When I board a plane I think I am entitled to expect the engines will stay in one piece. Usually they do. Maybe this Qantas debacle is a total oddity. But some of the stuff being unearthed by the incredibly clever people on here gives cause for concern. The more I read the worse it gets.

I would like to think that when something as immensely important as an airliner engine is designed and built everyone involved is issued with a list of "bear these firmly in mind in this order" reminders.
Reliability
Robustness
Dependability
Serviceability
Inspectability
Dismantleability
Repairability
Monitorability
Controlability
Transportability
blah blah blah and ending with
Minimum fuel burn
Minimum weight
Minimum cost.

Having built the engine pop it on the scales to see what it weighs, screw it to a wing and see if it works and how much it drinks. And those numbers get written on the box lid. Bobs your uncle.

Perhaps with the 900 they had the list upside down and built a flimsy under-strength flexible wobbler that wore out too quickly and shook itself to bits. Shortly they'll be inspecting the things so often they'll never take off.

And my unhappiness with only two engines over oceans instead of four has gone up a ratchet or four.

Don't SHOUT at me I'm only SLF. I'm entitled to my worries.:uhoh::eek:

Hell YES Flapping Madly your views are welcome and valid. What you posted in the vernacular is what most of us are thinking.

TURBINE D

Can you think of the last time a licensed engineer did not tighten up an oil joint properly?

You think his mobile 'phone went off and distracted him? I am REALLY struggling with this excuse.

Seriously...an oil coupling on a unit that already has a history of oil pipe issues?

Look at this flight level...






At 38k feet with one on idle? Light load? Other three on 97% throttle?

Insufficient Torque. Fancy that. A 972 with loose bits about. The very same Stub Pipe, then. Someone in Derby is in serious Denial, or worse. Nothing to see here, move along. Please put the KoolAde down. Does any one continue to doubt this powerplant shakes itself to the Danger Zone?

It is a big engine, and carries twenty eight quarts of OIL. Total, per engine.

Time.

The needle and the digital indicator are normally GREEN. When the EEC senses FOUR QUARTS LEFT, the signal on ECAM PULSES.

The largest Three engine Airliner in the world, ever. Sorry 411A. TRITOPS??

Bear When this hassle began, and Qantas punted the A388 out of Europe toward the Far East, it often returned back to London with some issue or other. They decided to continue to London in this case too.. At first I thought the Aussies were xenophobic, but I just read a comment over on another website that adds up. You know there are not a lot of airports that can handle this size of aircraft. Then what do you do with 470 passengers say in Dnyepetrovsk when the hotels only hold 200?

Then of course there is the $50k plus hotel bill!

Rock On!:cool:

Question
 

If an engine has a vibration problem, and it is found that

does it necessarily follow that

Just wondering.

Er. Rubbish! So does the GE90 and has done since the beginning! It has also saved a few inflight shutdowns too, enabling a timely removal.
Mind you the last one I had had so much debris on it the chip counter couldn't add it all up!

picky perkins

Any admission of a "Vibration Problem" opens up a double container (Maersk Line) of Worms, obviously. No vibration (unaddressed) can be called a "Novelty".

A Pint says the chap who ticked the Box at 48 ft/lbs. will swear he did, and another Pint says He will not even be Interviewed, not even by RR (Plausible Deniability).

What of the Bench Monkey who belched whilst counterboring that horrid Pipe??

Same tick, different box. No Interview.

just sayin'

Curioser and Curioser.

When a oil tube joint is found loose, it would be natural to assume it wasn't tightened properly during original assembly by the assembly mechanic. That is the obvious and it could be true. It may not have been that it was the assembly mechanic, not tightening it to specification, perhaps his torque wrench was out of order, so the wrench was the culprit. But the history of this particular engine is not be so clear to us. The engine was originally assembled sometime in 2008, so it probably was a Mod A. So during its life, so far, it was probably disassembled and reassembled at least once and maybe twice in going from Mod A to Mod C. But then again, maybe this particular joint wasn't involved during these changes. But then again, there is the not so obvious.

Could it be possible that as a result of making the changes from A to C, a vibration problem (noted in QF32's stub pipe failure, at least partially due to fatigue instigated by vibration) has moved up stream, so to speak? In simple terms, is vibration still affecting an oil supply line to bearings at this engine location, only now on the outside of the engine? Did a properly torqued oil line connection vibrate loose over a period of time? A real possiblility, we will have to wait to see.

This gets more fun as it goes along. Turbine D that was a fabulous answer!:} Thank you!

Now the only question I have is just how they were able to manitain level at 38k feet on three engines. Anybody?:confused:

This saga is becoming more like a Walt Disney Cartoon everyday.

Somebody should hire these Bayesian people as a circus act. Better still we could have a Jerry Springer special. Airbus vs. The Rest.

Me and you Bear would be security..hahah:E

You put together a good list of attributes for a jet engine. Just have to add, check the bolts and fittings twice for proper torque and I think you got it!:)

Then there is the matter of ratcheting up or ratcheting down. As I type this to you at 8:20 PM US EST, here is a partial listing of the airplanes flying this evening in the world:

332 B-737-800
322 B-737-700
293 A-320
274 B-757
232 B-777
213 A-319
171 B-747-400
160 B-767-300
139 CRJ-100
139 ERJ-145
120 CRJ-200
119 B737-300
71 A-340

And the list goes on to include freighters, other commuter jets and biz jets.

And finally,

9 A-380

So if you take out the B-747's and the A-340's (and the nine A-380's), the world flies on two engine aircraft very successfully. So, I would not ratchet up 4 but down 4. ;)

As a matter of interest, think of all the fuel being used at the moment, and tomorrow, day or night it will be the same.

Another EUREKA moment
 

This problem is less complicated than we thought.

What we need are MORE vibration sensors. Then we need the soft and hard ware to filter them. Then we need more satellite links to tell the folks on the ground.

The crew do not need to know about nasty bits in the oil so that idea is out the window. They have enough to do as it is.

No..we need another two may be three sensors in the key places. We could then give the Bayesians more data to make better betting conclusions.

Really the cost of adding more sensors is negligable compared to the cost of ignorance. So our pals in accounts can sleep well knowing that the extra few pennies spent...and believe it is pennies...will return a very handsome plus on the warranty costs.

Go forth with this idea and prosper RR we wish you well :)

Not too sure about peppering the case with additional Vibe Transducers. Ninety Nine percent of all vibrations produced by this powerplant are known, and catalogued. Even the one percent is not the problem. The problem is a specific and transient Resonant. There is a reason the problems eventuate at specific Thrust, AoA, and Temperatures.

I brought this up on the BA038 thread, relative to fluids Stall at TOGA chat. I also injected it early on in this thread, (Actually the original). The FOHE is a candidate for failure both in cooling/heating capabilities due its position on the Fan Case. Here, the unidentified (though known) Harmonic wreaks its damage in a trail of Wear to all parts in the Core. The OIL Stub Pipe, the Frames, the Fasteners, the Shafts, the Discs, and the Blades. There was an AD for HP airfoil cracking in 2007 for this engine, and no critical part is immune. A reduction (or increase) in Thrust demand might lessen its effect, but will not eliminate it, save in Operational Profiles only.

By the time a Vibration Transducer causes the EEC to relax its demands, the event is merely the last in an increasingly alarming trail of chronic wear. The answer is not even to identify this transient, (this has been done), but to eliminate its cause. This means that an otherwise perfectly serviceable powerplant has a fatal flaw, a self sabotage that needs a re-design. IMHO.

Why don't RR just start whistling tunelessly while staring into the distance in a distracted manner and deny all knowledge of the 900 which looks like it will cost them a fortune in constant running repairs or litigation.

"Trent 900 ? what's that then? Not one of ours"
"Yes it damn well is it's on the A380"
"Nah can't be. It's two 800s on the outside ends and two 1000s as inners innit?"
"Yes it is now but the A380 started with the 900 and one blew up"
"Don't recall that and it won't be in the official history"

Are the other engines that RR make not capable of being slung on the A380?
Or would the cost to the airline be about the same as fitting GE engines?

Car makers used to produce the occasional lemon (before computers came along) so maybe this is an RR lemon.

In the opinion of the learned gentlemen on here is the engine fundamentally flawed for some reason that other Trents are free from or are the modifications really going to sort it once and for all?

I thought these things were tested to the nth degree before they entered service not after. :(

Well, may as well earn some revenue whilst exploring the "nth degree".

Let's close the circle. Resonance can float a massive Shaft making tens of thousands of Horsepower. Can it "Freeze" (Fluid Stall) a few kilograms of Fuel in the FOHE by virtue of the device's location adjacent this Massive Resonance Maker, otherwise known as the Fan?? I say Yes, and cause synchronous Cavitation in both Engine's Mechanical Pumps as well?? Again, Yes.

Boeing, RR, and the FAA (via NTSB) were unable to produce water Ice in Fuel replicating the vaunted "Fuel Ice" problem of The TRENT 700 in BA and NorthwestAL incidents/accidents. A fuel Path is no less a Shaft than a Steel one. Can Resonant energy "suspend" a Fuel "PLUG" in transit?? Again, I say yes. The AD was to cut down the protrusions of the tubes, ex-tubesheet. However, also commanded were reductions in Thrust to ostensibly "Melt the Ice Plug". Wait, the Engines ran at reduced Thrust after the Cavitation. Right, the Pumps were Toast, and what allowed the Power was Gravity Feed. There was that "Knocking" sound heard by Pax as well. Was that the noise of liberated Fuel Lines rapping on the case??

Funny how a reduction in Thrust also terminates the Resonant.........

I'd like to suggest a newer way to entertain the TRENT problems. Rather than isolating each problem from the Whole, (As in shifting Thread to Spotter's), the best way is to consider the TRENT as "Family", and the problems as siblings, not some easy to marginalize "lone Wolf" that can be marginalized by RR and its puppies into irrelevance.

dons Kevlar

The "nth degree" reveals itself, not when you are looking for it, but only when the circumstances that trigger it, co-join to announce its presence.

Whether its resonance, cavitation, 'ice-making' through unforeseen expansion, or fire due to faulty seals / fractured lube oil lines, its the critical "nth degree" that conspires to trap even the most savvy. Simply design to prevent it. Yep, but you have to appreciate what those conditions might be, before you can even start thinking of a programmable routine that will identify a problem.

So, ultimately there will always be a "nth degree" lurking to bite you in the b:mad:m when least suspected.

In the case of QF32, from the moment that climb thrust was set, an abnormal "trend" was apparent in the monitored conditions of No.2 when compared with the averaged data monitored from the remaining three engines. A simple comparison routine would have revealed a potential "nth degree" was developing at least a minute before the proverbial hit the fan.

There isn't another RR engine that would perform the A-380 task, but there is an engine (partly made by GE & partly made by P&WA) on some A-380's, the GP7200. Emirates and Air France's A380's have been in service for sometime using GP7200's.

From an Airbus ceremony in Toulouse, France, December 2010:

“The GP7200 engine has been performing very well on the A380,” said Alain Flourens, Airbus Executive Vice President, A380 Program. “We congratulate the Engine Alliance on its 100th Engine milestone and look forward to many more engine deliveries to come.” The GP7200 powers the Airbus A380 aircraft, and the 100th engine is destined for Korean Air's first A380. The airline is expected to take delivery in May 2011. There are 19 GP7200-powered A380s in service. EA launch customer Emirates began operating the aircraft in August 2008 and received its fifteenth A380 on November 30. Emirates is Airbus' largest A380 customer with orders for 90 of the super-jumbo aircraft. Air France entered service with the GP7200-powered A380 in late 2009 and has four A380s in its fleet and eight more on order. Other GP7200 customers, in addition to Korean Air, include Etihad Airways, Air Austral and International Lease Finance Corporation (ILFC).

Taking Up The Slack?
 

Could GE/P&W provide enough engines to replace the RRs in a reasonable time?

The GP7200.This is not good reading for RR then:-

Trent 900 vs. GP7200: Competitive pressures getting too hot? The k2p blog Bit of a morbid article .

Or. Was the Trent 900 that disintegrated just a rogue engine and while other copies may have problems and need close attention they are generally behaving themselves. And as time goes by and operating experience increases this incidence will assume its correct importance in the scheme of things.

This and the other thread have been immensely interesting and instructional. Do the guys at RR and Airbus read it do you think?

Turbine D
Please explain to me why the 800 or 1000 would not be suitable. They have as much thrust if not more. What makes the 900 the only RR engine for the A380 ?
Thank you. (Remember I'm only SLF):)

mm43

Hi. the Trend (T?) was monitored, but keep in mind the EEC must command different settings for each engine to get normed Thrust across the wing. Also, to make a statement such as that means we need to fault the Aircrew for acting late. They did NOT. The EEC commands the engines, to include Monitoring. Each DEP is different, but only in Memory, it is tailored to each powerplant individually, due each engine's "personality" after Test.

Your statement is open ended, did you mean the "Monitoring" was not done (By Crew)? Or did you mean the Monitoring was done, but too late for the crew or the EEC to act (The Machine).

This engine may have Three completely failed Shafts, but the EEC will "Make Up" an RPM to send to the cockpit for the LP and IP, and pour fuel by the actual RPM of the HP Rotor. I am not kidding, and I apologize for bringing up the "Dilemma".

Smilin' Ed

You are jesting, No?

Turbine D

Emirates speced the GP briskly, without so much as a nod to Derby. Some have said they knew something......

Flapping Madly

k2p blog have a bit of an attitude re: RR. (Who, Me?)

No, I'm not jesting. Re-engining with GE/P&W could not be done overnight or even within several years. It's not like asking McDonald's to take up the slack when a nearby competitor goes out of business.

Hmm... It is exactly like asking MacDonalds to take up the slack for a foundering competitor.

Eliminating the T9 on the Whale would be the Death Knell for RR.

Not that they don't face it already.

It is a long discussion, and I've had it before, Rolls couldn't sell Cracker Jacks Charms if they lost the TRENT. The only reason the 9 would be terminated is if it kills someone. There is no "Out of the Blue" any longer. The AD's spoilt that bromide. The latest cage of #4 972 (Qantas) may be non survivable. There are no lemons in Aviation, only metallic Cyanide Pills.

Hiding in innocence of new limits (Comet), or even loss of wings (C5-MIL) the game is up. Rolls knows why, and in desperation to maintain a facade, is pretending like it is a "Mystery". "New and Unknown Fuel Characteristics"?? "Misbored Pipes" ?? Faulty Bearings, etc. etc. The Public seems docile because they are ignorant. When they find out they've been had, the "World is not Enough".. just sayin'

Flapping Madly

I think the bottom-line to this question is SFC (specific fuel consumption). When Airbus decided to examine the possibility of building a new long range transport, larger than the B-747-400, Airbus went to work internally on the design. They came up with everything new, especially the wing. As part of this wing development they tested various designs and eventually tested the best candidate with various nacelle designs, before settling on the final nacelle shape and size. Then they went to the engine suppliers with a recipe of ingredients they needed, particularly to achieve the maximum range goal of the aircraft. The engines had to:
- Produce 70K lbs. of thrust with some growth potential
- The engines had to fit inside the designed nacelle
- The engines had to have a SFC capable of delivering the maximum range plus minimum reserves.
- The engines should not weigh more than "X" and it must attach to the pylon at these points.
- And there were many more technical requirements such as noise.

Pratt and GE were unsure of the market size and neither thought they wanted to spend $2B US to develop an engine in a marketplace that could be divided up three ways. No one had an engine that met Airbus' requirements. So Pratt and GE decided to form a new company (Engine Alliance) and take the best of the PW4000 and the GE90 and come up with a design to meet requirements.

Rolls Royce decided to develop the Trent 900 with some technology coming from the previous family of Trents, some new features.

And IMHO, this is how it got started. The biggest challenge was SFC, especially for Rolls Royce. Traditionally, 3 spool engines (Trents) are shorter than two spool engines (GE or PW) and when contained in shorter nacelles, overcome a deficiency in SFC compared to a longer engine that has good SFC. But the Airbus A-380 has longer nacelles aerodynamically matched to the new wing.

So if you look at SFC:
GE90 SFC (SLS) 8.30 mg/N-s (cruise)
Trent 882 SFC (SLS) 15.66 mg/N-s (cruise)

Cruise at altitude is where most of the fuel is burned in long range flights.

The Trent 800 probably wouldn't meet the SFC target.

So the GP7200 uses a GE90 core with a PW fan and LP turbine.

Rolls Royce had a big challenge and needed all the best of the new technology to narrow the gap, and for the most part new technology worked with the Trent 900 to meet the SFC target.

The Trent 1000 came along later specifically designed to meet the Boeing 787
Requirements and as such, may not meet the A-380 requirements.

This represents my best estimations of this and it could be wrong
(disclaimer).

Bearfoil;

It wasn't apparent to me that I was implying the crew should have monitored for the trend. No, the trend monitoring would have revealed the abnormality IF the EEC had a routine for doing so.

At this stage, it is after the fact. Done before, may have provided a different set of facts.

Bear:
It could also impact Qantas and anyone else who is dependent on the long-range fuel specifics promised by RR for the A380. If the T9s and other large RR engines keep having catastrophic failures (or having to be shut down due to impending failure), and fuel prices continue to escalate, everyone, airlines, EADS, and RR will suffer. We may be on the threshold of the scenario put forth in the k2p blog where one engine supplier inherits a monopoly.