Norwegian 787 blows a donk in FCO

[ManaAdaSystem]

https://avherald.com/h?article=4cb6a09d&opt=0

A Norwegian Long Haul Boeing 787-8, registration LN-LND performing flight DY-7115 from Rome Fiumicino (Italy) to Los Angeles,CA (USA), was in the initial climb out of Rome's runway 16R when an engine (Trent 1000) failed emitting debris onto the ground below. The crew stopped the climb at 3000 feet, secured the engine and returned to Rome for a safe landing on runway 16R about 23 minutes after departure.

The Mayor of Fiumicino reported 25 vehicles and 12 houses were damaged by debris falling off the aircraft, one man on the ground was hit too. The man was just frightened and remained uninjured however.

Local residents reported glowing pieces of metal rained down in the hundreds.

The airline reported the aircraft returned to Rome due to a technical problem.

Italy's ANSV have dispatched investigators on site.

Not too familiar with the engine problems on the 787, but I thought they needed to be modified? Are the airlines allowed to fly the aircraft while they wait for the engines to be modified? Or is this incident an unrelated issue?
Luckily nobody on the ground got killed.

[NEDude]

The RR engines (Rotating Rubbish...) have several restrictions on them. Many of them are cycle limited, and some versions have been restricted to ETOPS 138 instead of 180. I am sure this will place further restrictions on those junk engines. Rolls Royce and Boeing, not a great combination these days...

[Icejock]

This was an updated Package B engine...

[atakacs]

This was an updated Package B engine...
Whoops. Doesn't bode well...

[Dave Therhino]

This was an updated Package B engine...

Can you elaborate? There are about 5 different issues with those engines and I'm curious if you know what was updated on it. Thanks.

[Alwaysairbus]

I guess in the strive for efficiency that reliability has taken a hit. The alternate engine has issues too pushing current technology to the limits, the GE90 on the 777 still has regular BUG failures after 25 years, as for the MAX and now A320NEO with their stab AFCS faults, the A350 computer resets every so many days, it all reminds me of working the L1011 Tristar in the 1990's. I am afraid it looks like we are now in an industry relying on backups rather than designing safety and reliability in to the airframes and engines in the first place. I think they call it safety risk assessment.

[atakacs]

From the various picture showing up this one seems to have pretty much disintegrated. Lucky that no-one got hurt.

[Sailvi767]

This is also the same basic engine on the A330-900 modified for bleed air. It’s the only engine option on the 900 so might impact sales on a already slow selling airframe.

[swh]

This is also the same basic engine on the A330-900 modified for bleed air. It’s the only engine option on the 900 so might impact sales on a already slow selling airframe.

Nope the 787 engine problems that both GE and RR are seeing failures on are basically due to the requirements placed upon them. GE engines have also seen failures and premature replacements.

RR have said the issues on the 787 engine are specific issues related to the airframe.

There seems to be a good reason why the 747-8, 737MAX, A350, A320neo, A330neo, and 777X did not got “bleedless”. The energy needs to be extracted from the engine somehow.

[Dave Therhino]

RR have said the issues on the 787 engine are specific issues related to the airframe. I actually laughed out loud when I read that.

[Fursty Ferret]

There seems to be a good reason why the 747-8, 737MAX, A350, A320neo, A330neo, and 777X did not got “bleedless”. The energy needs to be extracted from the engine somehow.
#14 (permalink)
Dave Therhino's AvatarDave Therhino , 12th Aug 2019 05:00

Exactly. I'm not sure why Boeing went all-electric on the 787. I can see arguments for the cabin air supply, but taking 250kW from the IP turbine, rectifying it, and inverting it once again to drive the CACs surely outweighs the simple benefit of taking bleed air directly from the compressor.

The air quality seems no better (very dry) since Boeing updated the CAC schedules to minimise surging.

Likewise with the electric brakes - they seem bulkier than their hydraulic equivalents and more prone to failure.

Pros? Well, I'm a big fan of the dual engine start.

[Torquelink]

This is also the same basic engine on the A330-900 modified for bleed air. It’s the only engine option on the 900 so might impact sales on a already slow selling airframe.

Actually, the Trent 7000 on the A330-800 and -900 is derived from the Trent 1000-TEN on the 787 and the Trent XWB 84 on the A350 both of which are substantially different to the Trent 1000-A/B/C and, while not immune to some of the same issues, is likely to be far less affected.

[Out Of Trim]

A lot of folk deriding the engine without knowing what actually happened to cause it! Was it caused by FOD or a bird strike or a mechanical failure?

[lomapaseo]

A lot of folk deriding the engine without knowing what actually happened to cause it! Was it caused by FOD or a bird strike or a mechanical failure?

Well of course many like to sound knowledgeable by citing history. I just can't recall a similar event (dumped turbine blade pieces) on the B787, but I'm sure somebody will throw out something.

[ManaAdaSystem]

A lot of folk deriding the engine without knowing what actually happened to cause it! Was it caused by FOD or a bird strike or a mechanical failure?

I’ve never seen a birdstrike cause anything like this. Damage yes, but a spray of engine parts out the back? 25 houses and 12 cars damaged by falling parts. Norwegian says this is an ongoing investigation and doesn’t want to comment.
If this is a modified engine as somebody said, it’s really bad news for operators with these engines.
Add the fact that engine pairs have about the same number of hours and I for one would be reluctant to go on an aircraft with these engines.
The modifications are about fanblades/turbine blades?

[golfyankeesierra]

Add the fact that engine pairs have about the same number of hours
I heard the rumor that the first thing Norwegian does with a new plane straight out the factory is swapping one of the new engines with an old one..

[Porrohman]

I’ve never seen a birdstrike cause anything like this. Damage yes, but a spray of engine parts out the back? 25 houses and 12 cars damaged by falling parts. Norwegian says this is an ongoing investigation and doesn’t want to comment.
If this is a modified engine as somebody said, it’s really bad news for operators with these engines.
Add the fact that engine pairs have about the same number of hours and I for one would be reluctant to go on an aircraft with these engines.
The modifications are about fanblades/turbine blades?
The engine pairs don't necessarily have the same hours. There's currently a restriction on fitting two engines (of the type affected by the known problems) with more than a certain number of cycles on the same aircraft. This is for exactly the reason you are concerned about.

[ManaAdaSystem]

The engine pairs don't necessarily have the same hours. There's currently a restriction on fitting two engines (of the type affected by the known problems) with more than a certain number of cycles on the same aircraft. This is for exactly the reason you are concerned about.

Where do they get old engines from?

[Out Of Trim]

Where do they get old engines from?

I'd guess from one of their older fleet and swapped for the new one. So one older and one new on each aircraft until enough new ones available to swap out all the older ones maybe.

[Sailvi767]

Exactly. I'm not sure why Boeing went all-electric on the 787. I can see arguments for the cabin air supply, but taking 250kW from the IP turbine, rectifying it, and inverting it once again to drive the CACs surely outweighs the simple benefit of taking bleed air directly from the compressor.

The air quality seems no better (very dry) since Boeing updated the CAC schedules to minimise surging.

Likewise with the electric brakes - they seem bulkier than their hydraulic equivalents and more prone to failure.

Pros? Well, I'm a big fan of the dual engine start.

The 787 is humidified. The cabin air quality is the best out there. Pure air without the additions from the engine and a comfortable humidity level instead of near zero in other airframes.

[david340r]

I believe bleed air has to be cooled before entering the cabin, which under some conditions could condense some of the water content out resulting in the low humidity experienced (building air conditioning plants will cool air below the target and then warm it back up to ensure it isn't too humid). I'm guessing the 787 cabin compressors don't heat the air so much, so perhaps lose less moisture this way? But I can't imagine them carrying a tank of water to actively humidify the air?

[MickG0105]

No independent humidity tests have been conducted on the 787 or any other aircraft.

You're correct with regards to the Dreamliner but there has been at least one rather thorough independent test of air quality and relative humidity performed by Carlo Giaconia using an A319 flying a variety of short haul routes. His paper is here (https://www.google.com/url?sa=t&source=web&rct=j&url=https://core.ac.uk/download/pdf/53284046.pdf&ved=2ahUKEwiG-Y_hr_7jAhX9ILcAHUn5AM8QFjAEegQIBRAB&usg=AOvVaw3-iZu9B7OwiXZ_sg09_NcA&cshid=1565652223800).

[DingerX]

787s have humidifiers for flight deck and crew rest air. Something like that is being done on the A350 and 777X as well, with humidification of first and business as on option. For the most part, the cabin experience is the same.
The colder the air, the less moisture it can hold, so if you cool air with nonzero relative humidity, the resulting air will have a higher relative humidity, which is why air conditioners have dehumidifiers. If you warm air, the result has a lower relative humidity. If the air outside is -40, heating it to room temperature is going to create a very dry environment that sucks the water out of you. This has nothing to do with bleed air or electrically heated.

There's also the claim when the 380 and 787 were entering service that they're pressurized to 6000 feet, while previous gen ac are pressurized to 8000. I'll leave it to someone else to say how often their Cabin Alt climbs to 8000.

[Less Hair]

Hasn't the claim been the humidity could be set higher because of the CFRP fuselage? Like less corrosion risk or similar?

[SLF3]

Given the issues with the Trent I'm surprised this has not caused more of a stir.

Was this a mechanical failure of the engine, a precautionary shutdown, or was there an external cause?

[Ian W]

I’ve never seen a birdstrike cause anything like this. Damage yes, but a spray of engine parts out the back? 25 houses and 12 cars damaged by falling parts. Norwegian says this is an ongoing investigation and doesn’t want to comment.
If this is a modified engine as somebody said, it’s really bad news for operators with these engines.
Add the fact that engine pairs have about the same number of hours and I for one would be reluctant to go on an aircraft with these engines.
The modifications are about fanblades/turbine blades?

Perhaps it was an ingested small UAS (aka drone) so a drone strike/mid-air collision, not a bird strike.

[tdracer]

Hasn't the claim been the humidity could be set higher because of the CFRP fuselage? Like less corrosion risk or similar?

It's not 'set' higher - as Dinger noted there simply isn't much moisture in the outside air at 35k - compressing it and heating it doesn't change that regardless of how you do it.
What they were able to do on the 787 - that hadn't been done previously - was have humidifiers to improve the humidity of the passenger (and crew) air. The carbon fiber construction meant there is no corrosion risk associated with that, but the ability to add humidifiers for passenger comfort has always been there - just seldom used.
It's up to the operator as to if they bother to service the humidifiers with water between flights...

BTW, for all the problems the Trent 1000 has been having, the current generation of engines is still an order of magnitude more reliable than what was available 40 years ago. Back then, people thought a shutdown every 10,000 hours was just fine, today a shutdown every 100,000 hours is cause for concern.

[RetiredBA/BY]

What they were able to do on the 787 - that hadn't been done previously - was have humidifiers to improve the humidity of the passenger (and crew) air
.

Not true, The VC 10 had humidifiers back in the 70s . Engine driven compressors supplied the air , not bleed.

[TURIN]

Zonal driers in the crown area stops the moisture from condensing out, it is then recirculated back into the cabin to keep the humidity level above 15%.

At least, thats the theory.

Back to exploding engines....

[Viscount Way]

Indeed it did have Godfrey engine driven compressors, just like the Viscount! The VC10 ones had variable output controlled by a slide valve which often leaked huge quantities of oil into the a/c ducting. Nothing new....

[Jet Jockey A4]

6000 foot cabin at what cruising altitude in a B787?

[Meester proach]

6000 foot cabin at what cruising altitude in a B787?


All the way to the ceiling of 430

[ManaAdaSystem]

Perhaps it was an ingested small UAS (aka drone) so a drone strike/mid-air collision, not a bird strike.

When you have an engine with known issues and that engine starts to spew engine parts out the back, I lean towards a connection between the two. And that can mean really bad news for operators of these engines. If taking them off the aircraft for modifications doesn’t solve the problem...

What was acceptable 40 years ago is not acceptable today. 180 minutes ETOPS with possible dodgy engines...😮

[Whitemonk Returns]

I think people are getting caught up in Boeing spin here, our 30 year old 757s regularly cruise along at 6000 feet cabin altitude but our 737s sit at 8000 at the same level. Both use standard engine bleed as far as I'm aware

[lomapaseo]

When you have an engine with known issues and that engine starts to spew engine parts out the back, I lean towards a connection between the two. And that can mean really bad news for operators of these engines. If taking them off the aircraft for modifications doesn’t solve the problem...

What was acceptable 40 years ago is not acceptable today. 180 minutes ETOPS with possible dodgy engines...😮

Once again association does not equal causation.

Big pieces typically equate to loose larger bits which often stem from the cooler parts in a turbine. I was under the impression that the earlier publizied problem was in the hot part of the turbine.So I remain neutral in picking a cause out of a news item.

[ManaAdaSystem]

Once again association does not equal causation.

Big pieces typically equate to loose larger bits which often stem from the cooler parts in a turbine. I was under the impression that the earlier publizied problem was in the hot part of the turbine.So I remain neutral in picking a cause out of a news item.

I agree, but you can’t exclude the possibility of an additional problem with the engine.

[Porrohman]

I'm surprised how little factual information has been released about this incident, especially given the history of problems with the Trent on the 787. The only photo of the affected engine I could find had a large advertising board placed in front of it to try to prevent photos of the damage. Normally, by this stage, we would have seen photos of the damaged engine, know the variant of the engine, the number of cycles and hours it had done, and have some idea about what part of the engine had failed, even if the cause is still to be determined.

Twitter had this amusing observation; As avgeeks like @janlisiecki most likely know: BOEING = Bits Of Engines In Neighbor‘s Garden

[OMAAbound]

What about ANZ 787 that decided it needed to loose a few KG's on departure from AKL (I think it was) , didn't that shower the local community with fan blades?

[ManaAdaSystem]

What about ANZ 787 that decided it needed to loose a few KG's on departure from AKL (I think it was) , didn't that shower the local community with fan blades?

That happened in 2016, so I doubt the engine was modified.
It would be interesting to see pictures of the Norwegian FCO incident engine and how it compares to the ANZ one. Both sprayed parts out the back.

https://www.newsroom.co.nz/2017/12/07/66537/photos-air-nzs-damaged-787-engine#

[Sailvi767]

I think people are getting caught up in Boeing spin here, our 30 year old 757s regularly cruise along at 6000 feet cabin altitude but our 737s sit at 8000 at the same level. Both use standard engine bleed as far as I'm aware

Your 757’s are a bit different than ours. At the same altitude the 757 would have a lower cabin altitude because of how it was scheduled but they typically cruised much higher so the actual cabin altitude was the same. All the Boeing older airframes had the same max differential pressure. The 787 is pressurized to a higher differential pressure than earlier Boeing’s and can maintain 6000 feet you FL430.

[BluSdUp]

The more I read about RR the more I love my CFM 56s.
If it starts , it runs.
If it runs it dont melt!

Something to be said for a FrenchAmerican project!

[golfyankeesierra]

It would be interesting to see pictures of the Norwegian FCO incident engine and how it compares to the ANZ one. Both sprayed parts out the back.

https://www.newsroom.co.nz/2017/12/07/66537/photos-air-nzs-damaged-787-engine#

Answer to your question: looks a little different to me. Norwegian’s look a bit bent while ANZ look serrated.
But I am no expert so look for yourself on the updated Avherald page (https://avherald.com/h?article=4cb6a09d&opt=0)

[ManaAdaSystem]

Answer to your question: looks a little different to me. Norwegian’s look a bit bent while ANZ look serrated.
But I am no expert so look for yourself on the updated Avherald page (https://avherald.com/h?article=4cb6a09d&opt=0)

Of the two, the ANZ one looks more like a possible FOD damage, yet it was not.
I think an internal mechanical problem with the Norwegian engine is very likely.

[vs69]

I believe RR were only granted access to the engine yesterday but initial word I am getting is intermediate turbine blade failure through sulphidation. Be an interesting boroscope to say the least!

[atakacs]

Not a metallurgist by any means but I thought that sulfidation was actually a desired process?

[vs69]

Good insight here
https://www.rolls-royce.com/products-and-services/civil-aerospace/airlines/trent-1000-updates-hub.aspx#/

I'm no metallurgist either I just try to keep em turning and burning...

[atakacs]

Thanks for the link. I had no idea that the issues were so severe. It really sounds like RR have stretched the limits too far.

It would be really interesting to know if that donk was an upgraded one...

[ManaAdaSystem]

Thanks for the link. I had no idea that the issues were so severe. It really sounds like RR have stretched the limits too far.

It would be really interesting to know if that donk was an upgraded one...



Indeed, and if this failure is in the same area as the not upgraded ones.
If there is a tick mark in both those boxes, should this aircraft be flying?

[Sailvi767]

Indeed, and if this failure is in the same area as the not upgraded ones.
If there is a tick mark in both those boxes, should this aircraft be flying?

I suspect if this was a upgraded engine and the failure mode is the same you will see the same hour restrictions imposed on the upgraded engines as the non upgraded version. This will have a enormous impact on 787 operators using RR engines.

[lomapaseo]

I suspect if this was a upgraded engine and the failure mode is the same you will see the same hour restrictions imposed on the upgraded engines as the non upgraded version. This will have a enormous impact on 787 operators using RR engines.

Premature conclusion. Even if it was the same failure mode, one needs to establish if the upgrade improved the reliability or expected time-between-failures and thus made it unlikely that a dual engine failure were to occur in the lifetime of the B787 RR fleet.

Nobody should expect perfections (no failures) but of course the corrective action were expected to significantly lower the risk of no duals

[Sailvi767]

Premature conclusion. Even if it was the same failure mode, one needs to establish if the upgrade improved the reliability or expected time-between-failures and thus made it unlikely that a dual engine failure were to occur in the lifetime of the B787 RR fleet.

Nobody should expect perfections (no failures) but of course the corrective action were expected to significantly lower the risk of no duals

Post 737max debacle I don’t think it’s premature. I could actually see a reduction in hours for both versions if the failure is the same. Time on the failed engine will of course be a consideration.

[atakacs]

Well let's put it that way: this one could have staggering implications for RR, Boeing and operators.

[tdracer]

A sense of perspective is sorely lacking in most of these comments. Metal out the tailpipe is obviously not good, but it happens - more often than you might think (you usually don't hear about it because the bits don't land on anybody) - it's still considered to be a relatively benign shutdown (uncontained high energy metal coming out the side is a different story).
There are roughly 400 Trent powered 787s currently in commercial operation - that pencils out to somewhere around a quarter million Trent 1000 operating hours per month. If they're averaging one or two shutdowns/month, that's still a pretty respectable shutdown rate (certainly good enough for 180 ETOPS). If it's more like 4 or 5/month - then it's a serious problem on an ETOPS aircraft. I no longer have access to the Trent shutdown rate information - but I seriously doubt anyone else here does either. What I do know is that the regulators and operators have all that information and are keep close track to determine what, if any, further steps are required to insure fleet safety.
There is a tendency on this form to treat every engine failure as the end of the world (especially the unusual ones). It's not - engines fail. It's an inescapable fact just like death and taxes. It's the rate and severity of the failures that you need to pay attention to.

[ManaAdaSystem]

A sense of perspective is sorely lacking in most of these comments. Metal out the tailpipe is obviously not good, but it happens - more often than you might think (you usually don't hear about it because the bits don't land on anybody) - it's still considered to be a relatively benign shutdown (uncontained high energy metal coming out the side is a different story).
There are roughly 400 Trent powered 787s currently in commercial operation - that pencils out to somewhere around a quarter million Trent 1000 operating hours per month. If they're averaging one or two shutdowns/month, that's still a pretty respectable shutdown rate (certainly good enough for 180 ETOPS). If it's more like 4 or 5/month - then it's a serious problem on an ETOPS aircraft. I no longer have access to the Trent shutdown rate information - but I seriously doubt anyone else here does either. What I do know is that the regulators and operators have all that information and are keep close track to determine what, if any, further steps are required to insure fleet safety.
There is a tendency on this form to treat every engine failure as the end of the world (especially the unusual ones). It's not - engines fail. It's an inescapable fact just like death and taxes. It's the rate and severity of the failures that you need to pay attention to.

Or the possibility of two of them having benign shutdown at the same time.
If a program that puts all 787 aircraft on the ground in order to modify away an engine problem, and that problem continues, that is a cause for concern.
Time will tell.

[tdracer]

Or the possibility of two of them having benign shutdown at the same time.

Mana, that's tracked by the shutdown rate. There has always been the possibility that two engines on a twin could shutdown at the same time (or more precisely, on the same flight). For ETOPS, the focus has been to eliminate 'common cause' shutdowns (e.g. maintenance errors or fuel contamination), and manage the rate of independent 'random' shutdowns. There are ETOPS regulations that govern the allowable shutdown rate relative to the max ETOPS time make the probability of a dual engine shutdown acceptably small.
You're focused on one shutdown - with a large fleet of aircraft and engines, one shutdown is not that meaningful - it's the overall rates that you should be paying attention two.

[ManaAdaSystem]

Mana, that's tracked by the shutdown rate. There has always been the possibility that two engines on a twin could shutdown at the same time (or more precisely, on the same flight). For ETOPS, the focus has been to eliminate 'common cause' shutdowns (e.g. maintenance errors or fuel contamination), and manage the rate of independent 'random' shutdowns. There are ETOPS regulations that govern the allowable shutdown rate relative to the max ETOPS time make the probability of a dual engine shutdown acceptably small.
You're focused on one shutdown - with a large fleet of aircraft and engines, one shutdown is not that meaningful - it's the overall rates that you should be paying attention two.

I see your point, and no, one engine failure is nornally not an issue. Unless there is another one.
And it happens in a part of the engine where it’s not supposed to happen because it has been modified.
The first Max crash was not a cause for concern either.

[BluSdUp]

ManAdaSystem
There were a few of us that are able to see the big picture that was plenty concerned with the Max after the first accident.
But lack of info and fact made us relax a bit.

Lets compare the Max with the Rudder Hardover in the 737 and now You have something similar, but still not the same.

Tdracer
In hear what You say, but i for one will not book a 787RR trip any time soon.
Not had much luck lately!
And I generally do not like statistics and certainly not when I am up front, hence very happy with my old 737-800 cfm, Thank you very much.

Now
Lets reverse the statistics : 400 frames with less then perfect engines, You have to agree!
250 000 hrs per month,
The next one out of London bound for LA,,,,,,!
Two scenarios from and old sim Instructor: RH engine is going to fail completely and the remaining is gone after say 3 minutes.
1 After V1 , we dont want that, no con fields!
2 Over Greenland stepping up from say FL 340 to FL 360! bad for ca 290 people!
( Adding 3rd option: RH blows before V1 , RTO all good, and we find LH had issues)

We can go into details until the Cow come home, but I am good at the Big Picture, and we are forewarned!
Nothing against B or RR. and You could call me an uninformed scaremonger, and I can live with that.
The problem is to a certain degree that we as Pilots and DH Pax are told to trust the Manufacturers and NCAAs, and the timing of that is unfortunately not good for RR and B, on this specific Frame/Engine combination.

As opposed to the Max there is a perfectly safe option on the 787RR namely the other Engine manufacturer, Eh?!
Anyway
Heading south for a week on duty, lets hope we are more informed on both the 787RR and the Max and that it all ends good.
Wish You all a safe week.
Regards
Cpt B

[back to Boeing]

Having had long conversations with those in the know. It’s not as simple as “the other engine was a better option”. GE had many many similar problems as RR but GE was better tooled up for spares and engine overhauls.

Yes Rolls bears most of the responsibility however a lot of it was driven by Boeing. They insisted on a cut off date where no further modifications to the design could be made (read in to that testing) They had a deadline that was driven by timelines of worldwide production. If Rolls had had more time to test the engine (rather than the design being completely finalised on day x) then the issue will have become more apparent sooner (and before so many engines were in commercial use).

Lets not forget that the 787 has had many teething problems. The RR engine issue is by far and away completely the worst, but remember the batteries catching fire? Yes Rolls made mistakes (serious mistakes that they also made in the spey engine) such as not coating the entire blade including the fir tree. But some of those errors were driven by a very demanding customer.

[etudiant]

Mana, that's tracked by the shutdown rate. There has always been the possibility that two engines on a twin could shutdown at the same time (or more precisely, on the same flight). For ETOPS, the focus has been to eliminate 'common cause' shutdowns (e.g. maintenance errors or fuel contamination), and manage the rate of independent 'random' shutdowns. There are ETOPS regulations that govern the allowable shutdown rate relative to the max ETOPS time make the probability of a dual engine shutdown acceptably small.
You're focused on one shutdown - with a large fleet of aircraft and engines, one shutdown is not that meaningful - it's the overall rates that you should be paying attention two.

All that notwithstanding, it would be very damaging if there were a related dual engine failure on an ETOPS flight. The record of problems not fully resolved would not play well in the current environment.

[Meester proach]

All that notwithstanding, it would be very damaging if there were a related dual engine failure on an ETOPS flight. The record of problems not fully resolved would not play well in the current environment.

Quote of the day....very damaging.....and rather silent I’d imagine .

[EDML]

LOT almost had a dual engine failure on a 788 last year (LO-6506 Cancun Warsaw on Mar 23rd 2018). Lost one engine SW of Bermuda, decided to divert to KJFK instead of KMIA due to operational reasons (passenger visa). 2nd engine surged during the diversion. After landing at KJFK both engines had to be changed.
LOT internally clarified the definition of „nearest suitable airport“ afterwards.

[Meester proach]

LOT almost had a dual engine failure on a 788 last year (LO-6506 Cancun Warsaw on Mar 23rd 2018). Lost one engine SW of Bermuda, decided to divert to KJFK instead of KMIA due to operational reasons (passenger visa). 2nd engine surged during the diversion. After landing at KJFK both engines had to be changed.
LOT internally clarified the definition of „nearest suitable airport“ afterwards.
yes, passenger visa would be a lame ass reason to fly longer on one engine .

[Sailvi767]

LOT almost had a dual engine failure on a 788 last year (LO-6506 Cancun Warsaw on Mar 23rd 2018). Lost one engine SW of Bermuda, decided to divert to KJFK instead of KMIA due to operational reasons (passenger visa). 2nd engine surged during the diversion. After landing at KJFK both engines had to be changed.
LOT internally clarified the definition of „nearest suitable airport“ afterwards.

I would have thought Bermuda would be a better option than either JFK or MIA. Nice place to be stuck for a few days also!

[BDAttitude]

LOT almost had a dual engine failure on a 788 last year (LO-6506 Cancun Warsaw on Mar 23rd 2018). Lost one engine SW of Bermuda, decided to divert to KJFK instead of KMIA due to operational reasons (passenger visa). 2nd engine surged during the diversion. After landing at KJFK both engines had to be changed.
LOT internally clarified the definition of „nearest suitable airport“ afterwards.
What's in Miami different than in NY with regard to visas?

[EDML]

They had another 788 there that would have performed a scheduled flight JFK WAW. They cancelled that flight and transferred the pax on the Cancun flight airside to the other 788.
The pax on the JFK flight where rebooked. Being already in the US they had visas.
Operationally clever - safety wise very questionable.

[BDAttitude]

They had another 788 there that would have performed a scheduled flight JFK WAW. They cancelled that flight and transferred the pax on the Cancun flight airside to the other 788.
The pax on the JFK flight where rebooked. Being already in the US they had visas.
Operationally clever - safety wise very questionable.
Indeed, thanks!

[EDML]

I would have thought Bermuda would be a better option than either JFK or MIA. Nice place to be stuck for a few days also!


They where 440NM SW of Bermuda. - More or less halfway between MIA and BDA. Miami would have been the better place to change the engine(s).

Anyway, JFK surely wasn’t the nearest suitable airport.

[golfyankeesierra]

Interesting quote, supposedly in a letter by the LOT Safety Pilot, according to
AVHerald reporting on the LOT B787 incident (https://avherald.com/h?article=4b69e455&opt=0)
From RR bulletins it is clear that the shut down of one engine dramatically increases the likelihood of the other engine failing.

And another quote from the letter:
As we all know while analyzing our case with the engine shut down on our flight from Cancun to Warsaw we were very close to serious trouble. The "good" engine has experienced 3 seconds of "ENGINE SURGE" which could have led to its shut down.

The acronym ETOPS Engines Turning Or People Swimming, long used tongue in cheek, almost became reality��

[EDML]

The acronym ETOPS Engines Turning Or People Swimming, long used tongue in cheek, almost became reality��

Yes, that one was very close to a disaster. A week or two later the FAA and EASA restricted ETOPS for certain versions of the Trent 1000.

[Porrohman]

An ANA 787 had a double engine shutdown on landing in January this year. The engines would not restart and the aircraft had to be towed from the runway. It was suspected to have been caused by a software issue triggered by the manner in which reverse was engaged but was still being investigated last I heard. With FADEC, shouldn't the engines be protected from inappropriate inputs?

[BleedingOn]

An ANA 787 had a double engine shutdown on landing in January this year. The engines would not restart and the aircraft had to be towed from the runway. It was suspected to have been caused by a software issue triggered by the manner in which reverse was engaged but was still being investigated last I heard. With FADEC, shouldn't the engines be protected from inappropriate inputs?


That is a different issue than being discussed. In the ANA case, the engines shutdown because of a software fault, not because they were damaged in any way

[SMT Member]

That is a different issue than being discussed. In the ANA case, the engines shutdown because of a software fault, not because they were damaged in any way


I'll venture the proposition, that when you're halfway across the pacific it doesn't really matter whether it's mechanical, electronic or software - the end result will be equally wet.

[EDML]

I'll venture the proposition, that when you're halfway across the pacific it doesn't really matter whether it's mechanical, electronic or software - the end result will be equally wet.

This issue will never happen in flight. It is connected to a protection system (TCMA) that will disable the engines when high forward thrust settings are selected instead of reverse. This system is only active on the ground and when selecting reverse thrust.

[etudiant]

This issue will never happen in flight. It is connected to a protection system (TCMA) that will disable the engines when high forward thrust settings are selected instead of reverse. This system is only active on the ground and when selecting reverse thrust.

Does that not introduce a serious software dependency risk on top of any mechanical engine issues?

[Turbine D]

Not a metallurgist by any means but I thought that sulfidation was actually a desired process?
No, it's exactly the opposite, sulfidation is bad, nasty stuff. Unlike oxidation in aluminum that provides a protective coating and longer life, sulfidation in superalloys shortens life causing premature cracking and component failure. Protective coatings have been devised to guard against sulfidation, but there are other factors that contribute to premature sulfidation failures in turbine blades and vanes. Here is a photo of sufidation attack on a superalloy where a crack has developed. Add stress and cycles to the equation and the component will crack and fail prematurely...


https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/1600x2000/ymht_a_1392414_f0005_oc_1a5a02701370a24853f19409a56c5205564c 0ade.jpeg

[Dave Therhino]

This issue will never happen in flight. It is connected to a protection system (TCMA) that will disable the engines when high forward thrust settings are selected instead of reverse. This system is only active on the ground and when selecting reverse thrust.

That feature is only active when on the ground, but it is not limited to reverse thrust.

[Dave Therhino]

Yes, that one was very close to a disaster. A week or two later the FAA and EASA restricted ETOPS for certain versions of the Trent 1000.


The ETOPS restrictions had already been in work for some time before that event happened, and were not driven by that event. The biggest concern about that flight was the crew's decision not to divert to the nearest suitable airport.

[hans brinker]

This issue will never happen in flight. It is connected to a protection system (TCMA) that will disable the engines when high forward thrust settings are selected instead of reverse. This system is only active on the ground and when selecting reverse thrust.


Just like MCAS is only active at high AOA.






Until the AOA sensor is kaput.
So what happens when the WOW or RA or whatever single source B likes to use for critical systems breaks.......

[ManaAdaSystem]

The ETOPS restrictions had already been in work for some time before that event happened, and were not driven by that event. The biggest concern about that flight was the crew's decision not to divert to the nearest suitable airport.

The crew’s decision made the situation worse, but the biggest concern was one engine failing and the other engine nearly failing.

[tdracer]

Just like MCAS is only active at high AOA.
So what happens when the WOW or RA or whatever single source B likes to use for critical systems breaks.......

TCMA uses multiple air/ground sources to determine 'on-ground'. Default is air. It's resident in the FADEC software and DAL A s/w (which MCAS wasn't).
I'm not familiar with the specifics of the 787 TCMA, but on the 747-8 TCMA uses three radio altimeter and two WOW signals. At least three signals must indicate ground, with at least one each from the Radio Altimiter and WOW.

[ManaAdaSystem]

«It will never happen in the air»

Engines will never go into reverse in the air either. Yet it did. All by itself.

[Dave Therhino]

The crew’s decision made the situation worse, but the biggest concern was one engine failing and the other engine nearly failing.

Well, yes, but I was referring to how the folks making the ETOPS AD decisions were viewing that event at the time in the context of everthing else going on with the 787 Trent at the time. That event was not what drove the ETOPS restrictions.

[tdracer]

«It will never happen in the air»

Engines will never go into reverse in the air either. Yet it did. All by itself.

Considering that I was personally responsible for certifying TCMA on the 747-8, the constant sarcasm/criticism is getting pretty close to being personal.
Hans has already crossed that line...:mad:

[hans brinker]

Considering that I was personally responsible for certifying TCMA on the 747-8, the constant sarcasm/criticism is getting pretty close to being personal.
Hans has already crossed that line...:mad:

TCMA uses multiple air/ground sources to determine 'on-ground'. Default is air. It's resident in the FADEC software and DAL A s/w (which MCAS wasn't).
I'm not familiar with the specifics of the 787 TCMA, but on the 747-8 TCMA uses three radio altimeter and two WOW signals. At least three signals must indicate ground, with at least one each from the Radio Altimiter and WOW.


So, was definitely not trying to get personal, your input on these forums is very much appreciated by me.
It definitely sounds like B took the right approach with the amount of inputs to prevent problems here.
I was just pointing out that there have been a few times were B could have done better, specifically on the 737. The THY crash in AMS happened because the pilots were asleep AND because the AT only looked at one RA input. B could have taken the hint, and not have changed from the original MCAS on the KC-46 that used both AOAs to use only one AOA on the 737. Getting a stick-shaker on one side because that side has a failed AOA??? Maybe I should not have commented on this specific issue, but B has had a thrust reverser deploy in the air, with a subsequent design change, and it looks like it might have to do some work on MCAS for the 737. I am on the A320, and there is a LOT of things I wish were done the Boeing way*), but having a vote between 3 systems for most things is a plus.


*):
-side-sticks not interconnected
-throttles not moving
-VNAV not arming
-can't update descend profile after TOD
-will disregard restrictions on the arrival because it "thinks" it's on the approach
-ASO

[EDML]

The ETOPS restrictions had already been in work for some time before that event happened, and were not driven by that event. The biggest concern about that flight was the crew's decision not to divert to the nearest suitable airport.

Well, at least EASA AD 2018-0086 mentions that incident and was issued April 2018 (incident was on March 23rd). It requires depairing certain Trent 1000 versions. At the same time the FAA released AD 2018-08-03 imposing ETOPS limitations.

[Fursty Ferret]

can't update descend profile after TOD

Re-entering the temperature or QNH in the approach page will force a recalculation.

[etudiant]

TCMA uses multiple air/ground sources to determine 'on-ground'. Default is air. It's resident in the FADEC software and DAL A s/w (which MCAS wasn't).
I'm not familiar with the specifics of the 787 TCMA, but on the 747-8 TCMA uses three radio altimeter and two WOW signals. At least three signals must indicate ground, with at least one each from the Radio Altimiter and WOW.

That is serious software verification.
So while it would be interesting to understand the details of the 787 runway shutdown, we can at least be pretty confident that it does not translate to an in flight probability.

[hans brinker]

Re-entering the temperature or QNH in the approach page will force a recalculation.

And so will changing from config 3 to full and back, and numerous other hacks. So if the system is capable of recalculating why not make it available directly without having to re-enter data?

Why can't I update my descent speed without re-cruising??

[ManaAdaSystem]

Considering that I was personally responsible for certifying TCMA on the 747-8, the constant sarcasm/criticism is getting pretty close to being personal.
Hans has already crossed that line...:mad:

Nothing personal, I have just been in this industry long enough to take «it will never happen» with a big pinch of salt.
Murphy is a friend most senior pilots are very familiar with.

[etudiant]

Nothing personal, I have just been in this industry long enough to take «it will never happen» with a big pinch of salt.
Murphy is a friend most senior pilots are very familiar with.

Agree that anything may happen, but in fairness, the safeguards Tdracer enumerates for TCMA seem adequate to push the failure probability below that of both engines falling off.

[tdracer]

So, was definitely not trying to get personal, your input on these forums is very much appreciated by me.
It definitely sounds like B took the right approach with the amount of inputs to prevent problems here.
OK, fair enough (I was in a bit of a bad mood last night anyway - had to take the dog in for surgery yesterday and I was rather stressed about the whole thing).
But you need to keep in mind that the redundancy is always connected to the perceived system criticality. The autothrottle was always intended as an aid - not a flight critical system - and there are a number of single failures that can adversely affect the Autothrottle functionality. That's why pilots need to be trained that they need to monitor the system and not just assume it'll do the right thing (and shame on any training program that does not emphasize that fact). Just a few examples, pre-FADEC, is was not particularly uncommon for high downstream cable loads to overwhelm the clutch and cause one throttle to not move (or not move as much) - and even with FADEC, if someone drops something like a pencil down in the throttle quadrant, it can restrict a throttle. On the 747, 757, and 767, the autothrottle drive is a single worm gear - if that gear fails the autothrottle can't move the throttles. As a propulsion guy, we never assumed the autothrottle would always work properly - it made our job harder but we designed for it. The pilots needed to be trained for it as well (I was told that the 787 A/T was designed as a flight critical DAL A system - a first for Boeing Commercial, but I don't know details).

I was just pointing out that there have been a few times were B could have done better, specifically on the 737. The THY crash in AMS happened because the pilots were asleep AND because the AT only looked at one RA input. B could have taken the hint, and not have changed from the original MCAS on the KC-46 that used both AOAs to use only one AOA on the 737.
All the issues with MCAS trace back to one simple mistake - MCAS was not determined to be a flight critical system. While this appears incredibly dumb with 20-20 hindsight, it was assumed that an MCAS malfunction was no worse than major and it was designed as a DAL C system. Using a single input for a DAL C system is very normal and acceptable. It's only after people died that it was realized MCAS was flight critical and needed to be designed as such with appropriate levels of redundancy.

[oliver2002]

Well, Lauda 4 operated by a 763 also had a thrust reverser deploy in 1991 and Boeing claimed it was possible to recover from it.
Only Niki Lauda offering to test such a situation himself bought about an admission.

https://en.m.wikipedia.org/wiki/Lauda_Air_Flight_004

[tdracer]

Well, Lauda 4 operated by a 763 also had a thrust reverser deploy in 1991 and Boeing claimed it was possible to recover from it.
Only Niki Lauda offering to test such a situation himself bought about an admission.

https://en.m.wikipedia.org/wiki/Lauda_Air_Flight_004

Wiki is far from an authority. I was personally involved in the investigation, and early on it was believed to be recoverable. Boeing did test an in-flight deployment during the original 767 certification flight testing - and it was controllable (at ~200 knots and the engine at idle). Early on, Niki did try it in the simulator and agreed it should have been controllable - however what was programed in the simulator didn't accurately represent 'real world' when a reverser deployed at Mach 0.78/23k/max climb power.
It took months of investigation and wind tunnel testing to understand why it wasn't controllable - after which Boeing added the third lock. I was part of the wind tunnel testing of what a hi-bypass wing mounted engine could do if it deployed in-flight with the engine at high power. I'll always remember the aero S&C guy during the testing - he was rather arrogant and before we'd started he was positive that it was controllable - even volunteered to go on a flight test to test the exact Lauda scenario. But after we started testing and he examined the data, he started getting real quiet, and by the time we finished up he wouldn't talk to most of us. Last test we did was a flow visualization using hundreds of yarn tufts. It was frightening to witness - with the engine at power, the reverser efflux basically blanked out most of the upper surface of the wing on that side. The wing would have dropped like a rock.
What's not commonly known is that when the FAA/JAA went to Airbus and wanted them to add a third lock, Airbus refused, claiming that it could never happen with their system. Until it did. They very nearly had their own Lauda - they were fortunate that the reverser re-stowed and the pilot was barely able to regain control and save it.

[atakacs]

What's not commonly known is that when the FAA/JAA went to Airbus and wanted them to add a third lock, Airbus refused, claiming that it could never happen with their system. Until it did. They very nearly had their own Lauda - they were fortunate that the reverser re-stowed and the pilot was barely able to regain control and save it.

Maybe a dumb question but to what incident do you make reference ?

[DaveReidUK]

Maybe a dumb question but to what incident do you make reference ?

Korean A300, November 1998.

[Fursty Ferret]

I was told that the 787 A/T was designed as a flight critical DAL A system

Makes sense. But if that worm gear strips, the associated autothrottle fails, which I find astonishing. Likewise the very peculiar decision to have the automation drive switches and levers, instead of having it drive surfaces / commands directly and reflect that afterwards.

(ie, in an RTO the speed brake level is commanded to full up, which demands full speed brake. If that lever or motor fails, the speed brakes don’t deploy. In this case, why not drive the surface directly and have the lever reflect the surface deployment? Likewise the engine start switches, which leave one in a very entertaining scenario if the release solenoid fails after engine start and the switch jams on. This is an aircraft designed in the 21st century, FFS. Don’t get me started on the FLCH trap).

IMHO having flown both Airbus and Boeing types, pilots are very much an “afterthought” in the Boeing design. The controls might not be back-driven in an Airbus, but the aircraft tells you far more about what it’s thinking than any Boeing.

[BobbyHowie]

https://www.flightglobal.com/news/articles/serious-norwegian-787-trent-failure-traced-to-blade-460649/