Leeham News and Analysis
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Leeham News and Analysis
- Dissecting Boeing CEO’s statement next new airplane will cost $50bn April 15, 2024
- Bjorn’s Corner: New engine development. Part 3. Propulsive efficiency April 12, 2024
- A350-1000 or 777-9? Part 2 April 11, 2024
- Pontifications: Boeing “transparency”–not so much. April 9, 2024
- Airbus charges and write-offs since 1999: more than €33bn April 8, 2024
Boeing faces 787 deliveries slow down with Rolls-Royce problems; earnings call April 25
April 21, 2018 © Leeham News: On the eve of the Boeing first quarter earnings call Wednesday, the company faces a slow-down in 787 deliveries at a time when it is gearing to ramp up production to 14/mo next year.
The engine issues with Rolls-Royce, resulting in grounded 787s across the globe, has had the knock-on effect of new production 787s emerging from the Everett and Charleston assembly plants without powerplants. Huge, yellow weight blocks are hung where the engines should be to keep the airplanes from sitting on their tails.
Delayed deliveries
At least five 787s in airline colors are on the Everett flight line awaiting engines, airplane spotters tell LNC. At least one in colors and two more without airline liveries are on the flight line at Charleston, a local reporter tells LNC. (Update: a sixth 787, this one for Gulf Air, rolled out of the Everett factory Friday night without engines.)
Engines from new production airplanes are being diverted to Aircraft on Ground (AOG), sources tell LNC.
As of April 18, there are 45 RR-powered 787s scheduled for delivery this year, according to the Ascend data base. The number rises to 57 next year.
Production isn’t expected to slow, but deliveries are already being affected, LNC is told—with physical evidence clear from the Gliders now parked at Everett and Charleston.
AOG and other choices
There are about 30 787s that have been grounded for up to several months. Other 787s have been redeployed, taken off trans-ocean routes and assigned to overland service where ETOPS isn’t required. Japan’s ANA, for example, is now flying the 787 domestically while its older 767s are covering trans-ocean routes.
Airlines affected include Air New Zealand, ANA, Avianca, British Airways, Ethiopian, LATAM, Norwegian Air Shuttle, Scoot, Thai and Virgin Atlantic.
Some of these airlines already arranged for replacement aircraft through wet leases (with crew) or dry leases (to be staffed by their own crews).
Related articles
- FAA severely limits 787 ETOPS
- Focus on engines for NMA-all OEMs vying for approval
- Focus on engines for NMA-Part 1
But these and other airlines are scouring the market for more aircraft in anticipation that mandatory inspections and severely reduced ETOPS (reduced to 140 minutes under some parameters and down to 60 minutes under others) will ground more aircraft. Industry officials predict the number of grounded aircraft could double.
LNC understands that the airlines identified above are look for between 30-40 aircraft from lessors and wet-lease operators.
Impact to Boeing
The impact to Boeing remains unclear. Although its leasing arm, Boeing Capital Corp., is working to source airplanes for the affected airlines, any financial impact to BCC isn’t known outside the company and may not yet be known inside.
Although it’s Boeing’s name on the side of the 787, financial penalties flow to Rolls-Royce, which announced a $500m charge related to the problem. This is only the tip of the iceberg, industry sources say. Some compare this to the development problems of the RB211 engine to power the Lockheed L-1011 in the 1960s-70s that drove RR into bankruptcy and a government bailout.
The pressing impact to Boeing—and the one relevant to aerospace analysts for Wednesday’s earnings call—is how deliveries of the new production 787s will be affected.
Observers say 787 deliveries are already running weeks, and in some cases, a few months behind schedule. The evolution into Gliders only exacerbates the problem. And observers predict the number of Gliders is going to increase.
It’s a question for Boeing CEO Dennis Muilenburg and CFO Greg Smith to address on Wednesday.
Astonishing how little the share price has been affected. RR are promising that payouts will be unaffected,as the losses will covered by reducing “discretionary spending”or vital long term investment as it’s known outside the city.
RR should have been doing more not LESS discretionary spending and this would not have happened!
Boeing should really stick RR with a massive bill. What is RR trying to do? Pull a “Lockheed” on Boeing? What I find funny is that Willie Walsh has apparently said they “considered” the 747-8 but quickly rejected it because there was no RR option…..I mean, what?! Is he serious? So he could also have 747 gliders parked at BA facilities alongside his RR powered 787s?
RR, amazingly, has had NO PROBLEMS on the A350…so far. They seem to have royally screwed up the Trent 1000. GE is likely set to be the lead on the 797, and RR will struggle for a while. If Emirates are smart, they’ll not even consider the RR option on their 787s and their remaining A380s.
RR and GE made big promises for the 787 program. Looks like they where 10 years ahead of themslves. Remember, most of the 787’s gains were due to new engine tech. Looks like AB were smart waiting for BA to debug it for them first. Was this planned?
You seem to forget that Pratt & Whitney currently have far more gliders parked up than RR powered 787’s. This issue of teething problems with new tech isn’t singular to Boeing. There has been issues with the GE engines as well as RR although of late, not as prominent. I guess that is what happens when an aircraft manufacturer pushes for a next step up in performance.
Rolls along with Pratt will at some point get these issues ironed out. and they will have fine engines. And so will GE who certainly have issues too but clearly not as steeply stacked. As for Willie Walsh…I guess the 747-8 is a great plane but the economics of having a small fleet of a GE powered 747-8’s obviously didn’t add up for him within the setup of BA like it would for another operator with no RR in the fleet and nearly all GE.
As GRUBBIE pointed out, I too am astonished at the lack of impact on the share price of RR. Unless we are missing something??
It will hurt the stock, as usual it takes time, for investment fools to accept reality.
First, they’re are obviously flaws in the regulatory (FAA and EASA) certifications to let engines with these type flaws through. Time to look at changing/lengthening the “cert” regime/rules/process! Second, given the issues, it seems crazy for the regulators not to pull the ETOPS cert, or, at “max”, limit it to 60 minutes tops! (You’ve got airlines pulling affected 787 a/c, replacing them with 767s or 330s! Heck, LATAM grounded ALL 6 of their affected 787s, and sent them 6,000 miles away for eventual service at Victorville, CA! Hello, regulators, are you really paying attention? Do they realize the media, political, and public “blowback” they’ll get, if one of these 87s goes into “the drink”?) Thrid, this is really gonna cost RR. My guess is $1B to $1.5B! Why? Reimbursement of all related costs, including replacement a/c leasing, on 390 engines? Plus to Boeing on the new build “gliders”, sitting for months, untaken? Lastly, how do you “trust” RR going forward on new technology engines like NMA engines and/or Advance/Ultrafans? (My guess is you don’t.)
All true.
I admire India for the fast action on the P&W.
Meanwhile the FAA delayed implementation for 18 months of more detailed crack inspections of CFM engines after an actual uncontained engine failure because of push back from US industry ( would be around 220 engines involved)
After the 2nd identical instance, FAA gets it done in days.
None of the RR Dreamliners affected seem to be US airlines
It is really hard sometimes to test for all vibration induced problems. Sounds that the RR IPC stg 2 vibration problem is at certian speed/altitude/temp combination. You need to spend quite some time in flight tests at these combinations of Mach no and Reynolds no hit the right vibration harmonics. The British Midlands fan blade that punctured a fuel tank had similar fan blade induced vibrations at a certian speed/altitude/temp combination.
Western Europe might need its own Arnold Army Test Center wind tunnels to test run Engines at similated altitudes with varying Mach and Re numbers as todays FEM/CFD calculations does not seem to be enough.
The unannounced part of engine orders could swing big time to GEnx, costly lesson for RR.
… or Change to 359’s with XWB84’s?!
Yep, from a dismal 40% or so to an even more dismal 20%
I was surprised that Norwegian took the RR.
Mostly its been traditional RR operators.
And the song
“Whose Sorry Now?”
I’m assuming there’s much affinity and a fairly close set of ties between Norway and the U.K.. (For example, Monarch’s maintenance sub was chosen to provide BA GoldCare on Norwegian’s 787s.) And, RR’s reputation hadn’t been nearly as damaged at the time when Norwegian placed their 87 RR engine order.
Norwegian cancelled some of its 787s a few months back, but the notification was hidden in a ‘new order’ by lessor BOC Aviation. Only this week was it revealed that BOCs order was a transfer from Norwegian.
I think the cancellation was financial related not any dissatisfaction with the 787.
Norwegian’s first 787s were “terrible teens” built for and rejected by other operators. Maybe they had no choice?
DY’s first 787 was LN102. They did not take any of the terrible teens.
RR has to pay the price of having kept the aftermarket of the Trent to a few shops they control out of greed, now when they need capacity it is not there. Lots of T1000’s and some T900’s need new blades. If something similar happened to the CF6-80C2 the shop global shop capacity is x10.
I’m reminded of the 10:1 swing to cfm from Pratt as their ongoing fiasco has impacted deliveries and operators for years at this point, in a new program likely to have a bigger long term impact on airbus than this tertiary engine for the now mature 787 is to Boeing.
https://www.bloomberg.com/news/articles/2017-08-22/pratt-s-10-billion-jet-engine-lags-ge-by-10-to-1-on-new-orders
It should be short term for P&W unless something deep and serious comes up.
Still it shows how volitile it all can be.
RR was not doing that well to start with.
What is RR’s warranty? There must be substantial warranty time left on these blades, despite being years/decades old. Maybe like the car battery I just bought: 3 years free replacement, 9 years prorated. I don’t expect answers as the contracts are all private, but speculation is fun.
How does RR charge? Most airlines probably just want to temporarily use the TENs that are diverted from Boeing’s new builds, while RR makes and fits new blades to their original engines. When the crisis is over, RR delivers the used TEN to Boeing, and gives the new build customer an appropriate discount or improved warranty.
Would Boeing & RR allow some airlines to permanently upgrade to the TENs that are diverted from Boeing’s new builds? RR may find it easier and cheaper to ramp up TEN production to let Boeing get back on its delivery schedule, than to diagnose the old blade problems, then timely make new ones.
Norwegian is going to change all the current -9s to the TEN (or were)
The 1000 is also a has been fuel wise and that is a drag on the aircraft.
Tangential question
If AB or BA announce 10 per month then what is the the annual figure?
A) 110 — includes plant shutdowns / holidays?
B) 120 — the monthly rate is the annual plan divided by 12?
Previous annual numbers pointed to Answer A.
However the diagram suggests not.
@Fat: Boeing typically increases production rates in mid-year, so you can’t strictly speaking take the output and divide by 12 to get the announced rate on an annual basis.
Steady state in the associated diagram has 2019 / 2020 / 2021 all at 168 units for the year.
So that would be 14 units across the full 12 month.
Consequently not taking into account plant shutdowns.
I appreciate that the US has different holiday patterns but I would expect to close during the year.
Christmas / Thanksgiving / summer holiday.
Auto plants usually plan work for 46/47/ 48 weeks of the year.
However they often use a 2/3 week summer shutdown to introduce new models that in turn lead to new equipment and plant layouts.
Consequently still a bit confused.
Does the B787 Assembly hall / line work 52 weeks of the year?
How does a monthly build rate cope with February and its 28 days?
Or does a month actually mean 4 weeks and the line only works 48 weeks of the year — the rationalist in me thinks yes but I am Big Auto and not Big Aero.
Does RR have one issue or two with these engines?
Have they developed a fix(s), or are they still working on it?
When is it anticipated that the fix(s) will be implemented and the 787 returns to normal operations?
@Rick: fixes are, or are being, developed. It will be until 2022 (says RR) before all engines are retrofitted. More on this comes Monday on LNC.
There seems to be a rather cavalier attitude to safety with regard to new engine development. As the engine manufacturers push the envelope as the fundamental way to improve fuel efficiency in air transport we seem to be getting a litany of problems.
The T1000 problem is the current big issue but looking at two recent uncontained failures of the stalwart CFM56 and P&W’s ongoing woes amongst others there is question over the original certification of these engines.
As the most pertinent example I see the T1000 as being a victim of hurried development to meet the original B787 timetable. But so many of the new designs are struggling when fully certified for operation
FAA & EASA & OEMs have already said as much. In the current instance, they took their time after the 2016 RR/SW blade & case failure. They are scrambling after this month’s similar failure, which establishes a pattern, and BIG legal liability.
It’s not just cavalier on safety on new engine development. As I noted above, in my first comment, LATAM pulled ALL its affected 787s off the flight line, and sent them 6,000 miles from home for storage, and eventual repair. How can the FAA and EASA, both of which should have passenger and crew safety as their paramount concerns, in good conscience continue to allow more than a 60 minute ETOPS on these a/c—if any? Ok, if that’s really so, then get their and RR’s engineers out there, in public, with full explanations on why these are reasonable risks/gambles to run on 60 minute + ETOPS. Guess what? “The lawyers” would NEVER allow it!
If they flew 6000nm on SCL to Victorville it seems they might have stayed within 60 min ETOPS.
I share your concern on the what is at least perceived as a lack of urgency and direct action from the FAA and EASA.
True, but presumably still no “walk in the park” if they were working their way up near/over the spine of the Andes the first part of the trip!
Etops only covers passenger flights.
Anyway a flight from Chile to California would have short distance to suitable airports all the way.
Could this be the beginning of some profound changes?RR will be at least chipped away at,if not broken up. Consolidation?How happy will customers be with everything in American hands?
Well, two options immediately come to mind: 1) RR “Bankruptcy II” (with May playing the role of Thatcher?); and/or 2) Safran starts to do some major work on its own, independent of GE.
It is Safran, not GE, which designed and manufactured the failed fan blade on the CFM56 engine. Besides, Safran doing major work on their own hasn’t worked out too well lately:
https://www.reuters.com/article/dassault-safran/dassault-aviation-to-drop-silvercrest-engine-contract-with-safran-idUSL8N1OD5Q3
Cessna is stopping its development of its long range Business jet that was supposed to be using Silvercrest as well.
It looks like GRUBBIE and MONTANAOSPREY are both jumping the gun. You are both so far wide of the mark.
Firstly RR is a PLC on the UK stock market. That means in times of difficulty, the board of directors can approach shareholders to come up with cash to rescue a company. If shareholders decide it is worth trying to turn around their investment then they will stump up. If not, they can allow the company to go under. At this moment in time, RR balance sheet is more than solid enough to ride this out. They are quite a diverse operation.
As a final resort, if shareholders ever did allow it to go under, the UK government has a “golden share” which enables them to prevent RR falling into foreign ownership due to national security reasons.
Of course the UK government will then have to bail the debts. Similar to how Barack Obama saved many US institutions in 2008 with a near $800BN bail out. The UK government also did this with the Lloyds TSB bank and have slowly returned it to the stock market in tranches of share sell-offs and the public purse is actually not really any worse off. So if the unthinkable happened at RR…it would go along those lines.
Isnt it strange how GE gets 18 months ‘consideration time’ since the fatigue problem was diagnosed on the high time CFM56-7C engines used on Southwest 737-700.
This is an actual uncontained engine failure which led to fuselage damage.
Rolls Royce has ‘potential’ resonance issue with its IP compressor which then ‘may lead to fatigue failure’ on the blades.
Doesnt get 18 months consideration time.
When its Boeing, GE and a big US airline like Southwest issues are downplayed so as to not to ‘scare the horses’
ETOPS and the trans-ocean, trans-polar use of 787s have something to do with it, I would guess. WN landed in 20 minutes. Quite different for 787.
WN landing in 20 minutes was lucky. There are dozens of CFM56-7B powered West Coast to Hawaii flights every day where the unlucky could find themselves 1200 miles from landing spot following a similar event.
Not an issue why action was taken with RR, but an issue why action wasnt mandatory with the 737s a year or more ago.
After all CFM issued an ‘advisory’ a year ago for what the FAA has now decided is mandatory.
We saw the American 767 which blew a turbine on its CF6 takeoff from Chicago on Oct 28 2016 ( after the first Southwest front fan un-contained failure). That resulted in a fire which destroyed the wing after the crew were able to abort the takeoff.
The recommendations and even the NTSB report have all been issued.
Yet the just as clear cut case for the CFM56 ( fatigue failure) had no NTSB report and no final recommendations for AD ( until this week)
“In 2017, CFM even asked the FAA to enact a new rule requiring those checks. But Southwest Airlines opposed the proposed change to inspection frequency, stating in a comment to the FAA that it would take longer for the airline to comply because of the number of engines in its fleet:”
https://arstechnica.com/tech-policy/2018/04/southwest-airlines-protested-airworthiness-directive-designed-to-prevent-engine-failures/
Heres the NTSB report for Oct 2016 AA 767 un contained failure
https://www.ntsb.gov/investigations/AccidentReports/Reports/AAR1801.pdf
You wont find an NTSB report for the Sept 2016 737 CFM failure.
Hello dukeofurl,
Regarding: “You wont find an NTSB report for the Sept 2016 737 CFM failure.”
The Southwest 737 fan blade failure in 2016 was on 8-27-16, not in September. See link to NTSB preliminary report below. The NTSB web page lists 8 accidents that occurred on 8-27-16, and indicates that final report have been issued for only two of the accidents. This suggest to me that it is not really unusual for final reports to be still pending 1.5 years after an accident.
https://app.ntsb.gov/pdfgenerator/ReportGeneratorFile.ashx?EventID=20160827X31134&AKey=1&RType=HTML&IType=FA
@Duke: FAA delay=Tombstone Agency. Someone has to die to get the FAA into action.
Rolls Royce may beg to differ on that.
When was the last time they had an uncontained engine failure – the Qantas A380 and there was hell to pay over that.
The Air France A380 in Sep 2017 with its GP7000 not so much , but true its a bit of a regulatory black hole due to it being over Greenland.
Then there was the high pressure compressor failure of
GE90 on the British Airways 777 at Las Vegas sept 2015
No ETOPS restrictions there ?
NTSB last update was 2015. No sign of a final report either
The current Trent 1000 restrictions are based intermediate section compressor issues. [but no uncontained failures]
I can understand all the GE fanboys ignoring GEnx issues like this ( 2 failures)
http://aviationweek.com/awin/second-genx-2b-failure-under-investigation-ge
Or this other inflight failures with Jetstar
https://www.flightglobal.com/news/articles/jetstar-787-engine-shutdown-caused-by-known-issue-432396/
Hello Scott,
Regarding: “Someone has to die to get the FAA into action.”
The FAA issued a proposed AD in response to the 8-27-16 Southwest 737 fan blade failure on 8-25-17, a few days short of one year after the incident, and solicited comments from interested parties, as required by federal regulations except in cases of emergency, with comments due on 10-10-17. Do you consider this doing nothing? What would you suggest would have been an appropriate timeline for issuing an AD on what was at that time an isolated incident for an engine with a reputation for high reliability? Do you believe it should have been issued on an emergency basis without soliciting industry feedback?
For anyone who is interested, here is a link to the Notice of Proposed Rulemaking for the AD.
https://www.federalregister.gov/documents/2017/08/25/2017-17828/airworthiness-directives-cfm-international-sa-turbofan-engines
Below is a link to the comments that were received on the notice of proposed rulemaking from ALPA, Southwest, United, Alaska, Delta, American, Qantas, RyanAir, CFM, Norwegian, and Lufthansa.
https://www.regulations.gov/docketBrowser?rpp=50&so=DESC&sb=postedDate&po=0&dct=PS&D=FAA-2017-0313
Good points, Scott. I have two, quick questions related to these high time CFMs: 1) do you think SW might revisit its recent deferral decision on Max 7s, and start retiring its highest time 700s next year; and 2) do you know the life limits on the rotating parts in these engines? (I understand the subject SW engine had 40,000 cycles, and was overhauled at 10,000 cycles.)
@Montana: Look for WN to place a large order for MAX 8s (not MAX 7s) to start its replacement program of the -700s. The order could come as early as this year. When the deliveries come is a good question.
Hello dukeofurl,
Regarding:”This is an actual uncontained engine failure which led to fuselage damage.”
According to the Notice of Proposed Rulemaking that the FAA issued on 8-25-17 in response to the 8-27-16 Southwest 737 fan blade failure, the 8-27-16 fan blade failure was contained; however, the engine cowl tore apart and this and/or other non fan blade debris cause the damage the fuselage damage.
“We received a report of a fan blade failure and inlet separation on a CFM56-7B engine that occurred during a revenue flight. This fan blade failure was contained by the engine case, but there was subsequent uncontained forward release of inlet cowl and other debris. The fracture in the blade initiated from the fan blade dovetail. The investigation, however, into the root cause of the fan blade failure is not complete. This condition, if not corrected, could result in fan blade failure, uncontained forward release of debris, damage to the engine, and damage to the airplane.”
https://www.federalregister.gov/documents/2017/08/25/2017-17828/airworthiness-directives-cfm-international-sa-turbofan-engines
According to the following excerpt from the FlightGlobal article at the link after the excerpt, former NTSB member John Goglia believes a similar failure happened in the 4-17-18 incident. What difference does it make? If you are an engineer assigned to better protect the fuselage from damage in these types of incidents, reinforcing the containment ring won’t do any good if the containment ring isn’t being penetrated and the damage is actually being caused by fragments of a disintegrating cowl or other debris that went around instead of through the containment ring.
“Like in 2016 incident, the 17 April engine explosion may not technically qualify as an “uncontained failure” – a term meaning a blade penetrated the casing around the fan, says Goglia.”
“You can see the containment ring, and it’s still on the engine,” Goglia says after viewing NTSB photographs of Southwest flight 1380. “Further back… you see the containment ring. It’s totally intact.”
The blade broke near the hub, according to the NSTB. It apparently flew forward, hitting the forward part of the cowling and causing the cowling to disintegrate into shrapnel that damaged the aircraft, Goglia suspects.
Investigators retrieved parts of the cowling on the ground 65nm (120km) from Philadelphia, the NTSB said.
“Everybody has been saying it’s an uncontained engine failure. It isn’t by the FAA definition,” Goglia says.
https://www.flightglobal.com/news/articles/analysis-faa-and-cfm-seek-to-address-complex-fan-bl-447858/
The question that I would like answered,is have airlines been finding cracks during non mandated inspections or are these 2 blade off incidents isolated?
Hello Grubbie,
Regarding: “have airlines been finding cracks during non mandated inspections or are these 2 blade off incidents isolated?”
According to the FlightGlobal article that I provided a link to above, former NTSB member John Goglia characterized the problem as rare and poorly understood.
“But it remains unclear if that proposal, had it been issued earlier, might have prevented the Southwest incident, which was caused by the poorly-understood and exceedingly-rare problem of internal cracks in the fan blades of CFM International CFM56-7B engines.
“They can’t get a good handle on this,” former National Transportation Safety Board member John Goglia tells FlightGlobal. “It’s not well understood. We can see the physical results behind [failures], but the cause and the actual mechanism that led to the failure is not so plain to see.”
The same article reports that the fan blade involved in the 4-17-18 incident may not have been covered by the proposed AD.
“But the AD might not have applied to the Southwest aircraft anyway. On the day of the accident, Southwest chief executive Gary Kelly said the engine had accumulated 10,000 cycles since a shop visit – below the FAA’s proposed 15,000-cycle threshold for urgent inspections.”
“As a matter of proportion, the CFM56-7 has accumulated 350 million flight hours with few problems, according to CFM.”
How many in flight engine failures per 350 million flight hours should be required before before the US Government wide notice of proposed rulemaking / solicitation of comments regulations are bypassed to issue an emergency airworthiness directive?
As far as I can determine from anything that I have read, the idea that the risk of the problem is related to high cycles is so far a hypothesis, based on one incident, that has yet to be proved. One can not yet rule out alternate theories, such as the problem resulting from manufacturing defects that can occur rarely in fan blades of any age. The results of the inspections done under the upcoming AD should provide some pretty solid statistics on how common the problem is, and whether additional occurrences, if found, tend to be in high cycle fan blades or instead occur randomly in low, medium, and high cycle fan blades. The big problem with designing a solution based on a preliminary guess as to what you think a problem may be, is that you may not be designing a solution to the actual problem.
Regarding: “The results of the inspections done under the upcoming AD should provide some pretty solid statistics on how common the problem is …”
Actually it is not an upcoming AD, the emergency AD was issued on 4-20-18.
http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/6de148fe35ddeddb8625827500759aa4/$FILE/2018-09-51_Emergency.pdf
Yeah, but how rare?
“It’s not well understood. We can see the physical results behind [failures], but the cause and the actual mechanism that led to the failure is not so plain to see.”
Thats seems a case of backside covering.
The ’cause’ of the failure was flagged as a fatigue failure early on.
The recommended service action was a form of inspection which could detect these hidden cracks, if they existed, before they led to failure ( thats how fatigue works!)
No one was suggesting they pull the engines from service while they look at the underlying mechanism for the cracks to start.
All they had to do was mandate the service action like they did for Rolls Royce – which didnt wait 18 months while they listened to airlines concerns.
AP,
the definition of an uncontained failure is not that clear as some want it to appear.
This is covered by FAR 33 (14 CFR 33.94 – BLADE CONTAINMENT AND ROTOR UNBALANCE TESTS.)
It is some time ago I last looked at this in detail. Since eight years I am no longer in the aero engine industry. I therefore cannot pinpoint the exact location of various paragraphs (am now at work so little time to deep dive).
Anyhow, to my recollection it is up to the engine OEM to define the blade release angle. So while it might be semantically correct to term the event on the 2016-8-27 (I find the US date format utterly confusing) as a contained failure wrt the fan(blades) as the containment ring was in fact correct, the engine OEM might have been wrong in defining the blade release angle and, hence, designed too short a containment ring.
I know from personal experience that at least one of the big three engine OEM’s is extremely rigid in defining the containment zone, to its advantage, i.e. minimal zone for lowest weight. This discussion was regarding a turbine (for an eventual TBO, turbine blade out, event) where said OEM defined the containment zone as being strictly radially outwards of the rotating hardware.
I also know from personal experience that another of the big three engine OEM’s altered their in-house design practice regarding TBO’s to extend the containment zone further aft, beyond the turbine casing. I never got to know the reason behind the change in practice, but at the time I had the impression that in-service data pushed them in that direction.
So, there might still be a design flaw, or oversight to use a less negatively stressed word,in the CFM56-7B if the CFM consortium failed to properly define the extent of the containment zone.
But this is all from memory so I think we could/should look more into the details regarding release angle etc. The more leisurely oriented researchers out there (i.e. retirees) might find the time easier than myself… 😉 But I would happy to discuss any finding.
Hello dukeofurl,
Regarding: “Rolls Royce has ‘potential’ resonance issue with its IP compressor which then ‘may lead to fatigue failure’ on the blades. Doesnt get 18 months consideration time.”
According to the 4-17-18 FAA AD on Trent engines, over the last year there have been several failures of Package C Trent 1000’s due to failed compressor turbine blades and seals, and numerous findings of cracked blades resulting in unscheduled removal. According to the AD, Rolls Royce has stated that a resonance condition exists at high thrust settings that could cause an engine throttled up to maximum continuous thrust for extended periods for single engine operations after an engine failure, to itself fail before an ETOPS alternate airport could be reached, with the probability of such a failure increased if the throttled up engine had the type of blade cracks of which there have been numerous reports. A glider parked outside an assembly plant is bad, an airborne glider far away from land, over an ocean, with several hundred people on board, would be much worse. The AD estimates that 14 aircraft of US registry are affected. If non-US operators believe the AD is excessive, they need to direct their concerns to their own national aviation regulator. Does not EASA have a similar AD?
Following are some excerpts from the FAA AD, and after the excerpts, a link to the full AD.
“This AD was prompted by a report from the engine manufacturer indicating that after an engine failure, prolonged operation at high thrust settings on the remaining engine during an extended-operation (ETOPS) diversion may result in failure of the remaining engine before the diversion can be safely completed. We are issuing this AD to address unrecoverable thrust loss on both engines, which could lead to a forced landing.”
“Over the past year, we have been aware of several engine failures of Trent 1000 Package C engines due to failed compressor and turbine blades and seals.”
“During that same period, under the management programs for those engine issues, we have been aware of numerous reports of engine inspection findings of cracked blades resulting in unscheduled engine removals. Boeing reported to the FAA that the engine manufacturer recently determined that intermediate pressure compressor (IPC) stage 2 blades have a resonant frequency that is excited by the airflow conditions existing in the engine during operation at high thrust settings under certain temperature and altitude conditions. The resultant blade vibration can result in cumulative fatigue damage that can cause blade failure and consequent engine shutdown. In the event of a single engine in-flight shutdown during the cruise phase of flight, thrust on the remaining engine is normally increased to maximum continuous thrust (MCT). During a diversion following a single engine shutdown under an ETOPS flight, the remaining engine may operate at MCT for a prolonged period, under which the IPC stage 2 blades would be exposed to the resonant frequency condition. Therefore, an ETOPS diversion will put the remaining engine at an operating condition that would significantly increase the likelihood of failure of the remaining engine. In addition, if the remaining engine already had cracked IPC stage 2 blades, the likelihood of the remaining engine failing will further increase before a diversion can be safely completed.”
“An unsafe condition exists that requires the immediate adoption of this AD without providing an opportunity for public comments prior to adoption. The FAA has found that the risk to the flying public justifies waiving notice and comment prior to adoption of this rule because unrecoverable thrust loss on both engines could lead to a forced landing. Therefore, we find good cause that notice and opportunity for prior public comment are impracticable. In addition, for the reasons stated above, we find that good cause exists for making this amendment effective in less than 30 days.”
https://www.federalregister.gov/documents/2018/04/17/2018-08127/airworthiness-directives-the-boeing-company-airplanes
Reading through the AD for 787’s with package C Trent 1000 engines that I gave a link to above, I have noticed that all it calls for is revising the airplane flight manual to restrict ETOPS operations on or before 4-20-18. It does not specify any repair or replacement work that can be done on the engines to remove the ETOPS restrictions.
“AD Requirements: This AD requires revising the AFM to limit ETOPS operation.
Interim Action: This AD is interim action. The manufacturer is currently developing a modification that will address the unsafe condition identified in this AD. Once this modification is developed, approved, and available, we might consider additional rulemaking.”
Duke, the fan blade was contained. The cowling failed due to the vibration caused by the blade-off event, and it was this debris that penetrated the fuselage/window. To be sure, the end result is a system failure that must be addressed. Doubtless the agencies will have to reset their criteria for ongoing certification and related.
The fuss about whether the failure was contained or not is a bit of a red herring – for certification purposes any failure that can lead to loss of the aircraft is defined as a hazardous failure and it must be shown that will occur less than 1 in 100 million flight hours – RR up that to one in a 1000 million by the way.
I would suggest that an air intake cowl departing the airframe presents a significant hull loss hazard to the aircraft and since there have been two such events, the probability of the next one taking off the horizontal stabilizer is uncomfortably less than required.
“This is only the tip of the iceberg, industry sources say.”
Hey Scott. Could you elaborate on this comment? What do you think is the size of the iceberg?
The next sentence: “Some compare this to the development problems of the RB211 engine to power the Lockheed L-1011 in the 1960s-70s that drove RR into bankruptcy and a government bailout.”
I am still mystified as to the reason for the near grounding of T1000 engined B787s. What makes this issue so much more of a concern for passenger safety than other engine failure problems occurring elsewhere?
And what does RR have to do to rectify matters? Is it ‘simply’ a matter of replacing the blades on the affected turbine or do complete engines have to be manufactured?
This seems to have been a slow motion car crash for RR and seems to reflect the manner in which they have overextended themselves with too many Trent evolutions at one time. The T1000 appears to have been rushed in development and critically struggling to achieve performance guarantees needing multiple PIPs.
Perhaps the ball was dropped here as performance was sought at the expense of durability. Is there a concern about subsequent developments such as the XWB or the TEN?
So far—and it’s a big “so far”—it’s not affecting the TEN or XWB. But it supposedly will affect the Trent 7000, for the new A330neos—at least to the extent of redesigning some parts for it to give “greater durability”. The problems with the Trent 1000 include stage 2 intermediate pressure compressor blade failure and resonance issues from same at very high power settings (a particular issue when needing to go over to single engine operation). RR must have been somewhat aware of all this for some time. Norwegian negotiated with RR for all NEW RR engines for all 8 of its 787-8s in 2016! Oh, and ANA also replaced 100 RR engines!
The engines for ANA werent ‘replaced’ they just underwent maintenance over 3 years period to replace some turbine blades.
Not a lot different from the GE90 for the 777 back when it was introduced – yes it had Etops restrictions too
I’ll admit I’m at least somewhat wrong, though my Reuters-sourcing (8/21/16 ANA article) goes ”back and fourth” between all new engines (Article title and ANA’s comment in same) and ALL new blades (Rolls Royce). In any event, the article does confirm back in at least mid 2016, RR must have known they had some really significant problems with their Trent 1000s, given the minimum Rolls commitment was to replace ALL ANA 787 turbine blades, after three subject ANA engine failures. Once again also, I think you really have to ask: Where were the regulatory authorities while all this was going on?
Who knows ,RR could be the first to experience this resonance problem.Perhaps the LEAP could be next in line. Imagine the mess that would make in 10 years time!
Interestingly,I have read various reports on the net of people moaning about the racket an RR powered B787 makes on take off compared to a GE powered version (ofcouse I can’t find any of them now!)I strongly suspect that they have been aware of this problem for some time and have been caught in the headlights. If they really have only just discovered this issue,then there is no reason to believe that subsequent models don’t share it.
As ever,notice how GE and P&W don’t gloat,they know that it’s tempting fate.
However, this is possibly the start of the long-awaited consolidation.
It’s a time honored agreement in the industry that you never make light of a competitors safety problems in aviation as the next time it could be you. This presumes that any safety concerns are new information to their respective manufacturers and will be corrected in short order. The a340 advertisements breached this and Boeing was furious with the famed 4 engine 4 long haul campaign. Most likely they are doing their own analysis of any similarities between their design and the defective one and determining if any proactive steps should be taken.
Hello Grubbie
I’m sorry but this “long awaited consolidation” you talk of will not happen.
RR will not fall into the hands of any non-UK ownership. As I explained in my previous post.
And yes we will probably revisit this when GE are also caught like rabbits in headlamps at some point just as P&W have too.
Here’s another, somewhat underreported RR headache: While not (yet?) a safety issue, RR is taking significant charges for apparently underperforming high pressure turbine blades on its A380-powering Trent 900s.
Says who ? Who even can measure under performing turbine blades , or do they each have KPIs
Flightglobal, 3/08/18 : “Rolls Royce takes hit on 787 and A380 blade flaws”. Third from last paragraph talks about RR introducing an extended life Trent 900 turbine blade—and further redesigns to be available in 2020. So, apparently Rolls Royce, if you can believe Flightglobal.
Just saw some GEnx software bug/s, (only effecting 787-10?).
https://www.flightglobal.com/news/articles/boeing-requests-waiver-to-avoid-787-10-certification-447937/
While engines in the news, Airbus and RR signs collaboration on the Ultrafan.
https://www.bartintl.com/news?n=3031#