Air Crash Thread: Boeing MAX and Other Problems

[Dennisch]

Today in the Netherlandsland:

A 747-400F bombarded Meersen with several of its turbine blades. It took off from Maastricht-Aachen Airport, heading for New York.

 

[TenEightyOne]

Would have been a decent load of fuel, but not particularly close to it's range limit.

Indeed - I wasn't curious that it might be too heavy to take off, it's that it didn't appear to dump fuel before returning to KDEN.

EDIT: Here's the ATC of the mayday call (with an unsurprisingly pre-occupied pilot), unfortunately there's not enough to hear the conversation about souls-and-fuel, and dumping plans. From the pilot's tone of voice my guess would be that the plane was being landed immediately and that was that.

A 747-400F bombarded Meersen with several of its turbine blades. It took off from Maastricht-Aachen Airport, heading for New York.

That looks a proper mess, incredible that nobody was hit by debris in either incident (EDIT: minor injuries to woman and child on ground - thanks for correcting me @Dennisch). And some of those blades would have been travelling pretty bloody quickly.

 

[Dennisch]

That looks a proper mess, incredible that nobody was hit by debris in either incident. And some of those blades would have been travelling pretty bloody quickly.

A woman and child were injured but nothing serious.

 

[McLaren]

The fact both trips were scheduled to travel over water makes it a relief the issues were able to be resolved quickly into the flights.

 

[Keef]

Super fun day in aviation as I study for my multi rating.

 

[Barra333]

EDIT: Here's the ATC of the mayday call (with an unsurprisingly pre-occupied pilot), unfortunately there's not enough to hear the conversation about souls-and-fuel, and dumping plans. From the pilot's tone of voice my guess would be that the plane was being landed immediately and that was that.

He sounded reassuringly calm through that though. I've read a bunch of air disaster summaries on reddit and it is crazy how often a survivable incident becomes deadly thanks to crew not following procedure or panicing.

 

[Danoff]

A United Airlines Boeing 777 (Flight 328 ) leaving Denver for Honolulu has suffered an failure of the engine nacelle (blades are seemingly intact, if wobbly), fortunately with no injuries on the aircraft or on the ground. BBC.



View attachment 992977

Looks like the failure was during the latter stages of the take-off run or just as the aircraft began to climb, the crew were able to make straight back around to land. Makes me wonder what the fuel weight was - Denver to Honolulu would be quite the tankful.

View attachment 992978

Just glad it didn't hit my house. I saw the cops out taping it off yesterday.

 

[Eunos_Cosmo]

What exactly happened here? Looks like the turbine is still spinning.

 

[Keef]

What exactly happened here? Looks like the turbine is still spinning.

Some sort of failure blew the cowling apart. From the video we can't really tell where that failure was but it seems like the fan is intact. We also don't know when exactly this video was taken but we can hear from the audio that the passengers seem calm so I imagine it was at least a couple minutes after the failure. What we do know is that by this time the pilot have shut down the engine and its fuel - the fan is windmilling because the plane is flying at over 200kts and we see the flame die out slowly as residual fuel is burned off. Well I suppose we also know that the flame isn't supposed to be wear it is, it should be contained inside the combustion chamber, but we still don't know why it's leaking out. There could've been a compressor blade failure but the framerate of the video makes it hard to tell.

A 747-400F bombarded Meersen with several of its turbine blades. It took off from Maastricht-Aachen Airport, heading for New York.

I'm curious why this plane ended up holding instead of immediately being vectored for the approach like the 777 was. In a four engine plan an engine failure is fairly benign but it still exposes the wing to further damage so as soon as that mayday call comes in, other planes should be broken off their approaches and sent elsewhere and this one should be brought in. Maybe the pilots chose to hold to configure the plane since they were so close to the landing airport. Does that timeline suggest the plane was in the air for an hour? That's ridiculous. Also, if it were headed to NYC then why did it take off and get vectored east? What a weird choice.

Edit: Stumbled on this site (I have no idea what site this is) while looking for departure procedures which I can't find. But I did find that apparently airplanes require a startup clearance at this airport? Is this typical in Europe?

1.2.1 Start-up permission
Pilots of aircraft must have obtained start-up permission from ATC before starting their engines. A request for start-up shall be made to Beek Delivery after all preparations for departure have been made (doors closed etc.) and shall include:

• aircraft identification (e.g. TRA2345).
• position (e.g. opposite tower).
• ATIS information (e.g. information "J").
• flight rules (e.g. IFR).
• destination (e.g. Malaga).
• request start-up (request start-up).

Due to the short flying time to the FIR boundary, pilots of aircraft departing direction Belgium and Germany may request start-up permission before all preparations have been made, indicating the time at which they will be ready to start engines: "...... destination ..... ready to start engines at ......".

Permission for start-up will be issued as soon as possible after the request has been made to Beek Delivery. The pilot shall be able to comply with the start-up and taxi permission, since ATC planning of outbound traffic (involving en route clearance and co-ordination with adjacent ATC units) is based on the start-up time. Any delay in start-up or taxiing shall be immediately reported to ATC. In case of indefinite delay the probable duration of the delay will be given.

What in tarnation? They expect me to sit there for several minutes running my avionics off the battery while they coordinate my taxi and flight plan? That's insane. In the US we don't start doing anything flight related until the engine is running and the avionics are on, we've heard the weather, and we've called for our clearance. Pilot requests are issued on our time, not ATC's. The exception is IFR clearances which have void times but that time limit is usually 10 minutes which is plenty of time for pilots to get settled and taxi when ready. In fact, "request taxi when ready" is a common phrase. The idea that almost anything is "shall-comply" as this is written is ridiculous, and the idea of reporting the probably duration of an indefinite delay makes no sense. What a weird set of procedures.

Edit: Found the 21 departure at the bottom of the page. As you plebs can see, the departure begins with a left turn toward EH319 and then a right turn to LNO VOR, after which the clearance or plan is flown.

Edit: In fact I can probably tell you where the failure happened based on that departure compared to the flight track. You can see they flew way past the right turn they should've made so I imagine the failure happened shortly after the left turn, forcing them to declare the emergency at which point they just continued straight until they sorted it out. And now the reason for the hold occurs to me as they probably had to both calculate their landing weight/distance for that runway and burn some fuel to meet it.

 

[TenEightyOne]

All 777s of this type have been grounded. In the US this affects United Airlines, the only other operators are in Japan and South Korea. BBC.

Some sort of failure blew the cowling apart. From the video we can't really tell where that failure was but it seems like the fan is intact. We also don't know when exactly this video was taken but we can hear from the audio that the passengers seem calm so I imagine it was at least a couple minutes after the failure. What we do know is that by this time the pilot have shut down the engine and its fuel - the fan is windmilling because the plane is flying at over 200kts and we see the flame die out slowly as residual fuel is burned off. Well I suppose we also know that the flame isn't supposed to be wear it is, it should be contained inside the combustion chamber, but we still don't know why it's leaking out. There could've been a compressor blade failure but the framerate of the video makes it hard to tell.

Memory One is surely "switch the ****ing fuel off", I think this is oil lines that have been exposed.

I'm curious why this plane ended up holding instead of immediately being vectored for the approach like the 777 was. In a four engine plan an engine failure is fairly benign but it still exposes the wing to further damage so as soon as that mayday call comes in, other planes should be broken off their approaches and sent elsewhere and this one should be brought in. Maybe the pilots chose to hold to configure the plane since they were so close to the landing airport. Does that timeline suggest the plane was in the air for an hour? That's ridiculous. Also, if it were headed to NYC then why did it take off and get vectored east? What a weird choice.

There are a couple of differences with the 777 incident. It seems 777 the pilots did make an overweight landing without dumping fuel, which is why I was querying it's highly expeditious return. With the 747 it has Liege to the east, a heavy transport hub for FedEx and the like, it has 747 facilities and a much longer runway, and they could have had the opportunity to dump.

startup clearance at this airport? Is this typical in Europe?

We're a lot more densely packed, it's usually a noise abatement procedure.

what in tarnation? They expect me to sit there for several minutes running my avionics off the battery while they coordinate my taxi and flight plan? That's insane. In the US we don't start doing anything flight related until the engine is running and the avionics are on, we've heard the weather, and we've called for our clearance. Pilot requests are issued on our time, not ATC's. The exception is IFR clearances which have void times but that time limit is usually 10 minutes which is plenty of time for pilots to get settled and taxi when ready. In fact, "request taxi when ready" is a common phrase. The idea that almost anything is "shall-comply" as this is written is ridiculous, and the idea of reporting the probably duration of an indefinite delay makes no sense. What a weird set of procedures.

I think you'd start the APU though. If you weren't able to do that, or had no GPU, you'd request engine-start permission earlier. Some major internationals (like EGCC) don't even allow reverse thrust on landing, it's a constant struggle between airports and local populations over noise. Realistically the engine start is factored into commercial operation plans so there aren't any delays from that, but if you miss your slot to get out of the gate... you're stuck at the gate.

I've never flown in the USA except on VATSIM (ruthlessly realistic) but I can tell you that in Europe, until you open the throttles on the runway the Tower is king. And for some time after, if you really irritate them.

EDIT: 747 requested Liege specifically for overweight landing and enroute dump of 40 tons: ATC.

 

[Liquid]

777 is the Dreamliner, isn't it? Was a bit of a white elephant during its development, I seem to recall.

 

[Dotini]

777 is the Dreamliner, isn't it? Was a bit of a white elephant during its development, I seem to recall.

I was on the 777 "Triple Seven" program from its inception through first few years of production. IMHO it was the best airplane program Boeing has ever had during my career, I think the plane you are thinking about is the 787 Dreamliner. That was a program with many flaws and woes.

 

[Liquid]

Ah, okay my mistake.

 

[Dotini]

Ah, okay my mistake.

The 777 from the beginning was designed around two different, competing engines, the Pratt & Whitney and the Rolls-Royce. I believe United Airlines has immediately grounded its entire fleet of 777's with the Pratt & Whitney engine.

Edited to correct significant errors.

 

[TenEightyOne]

777 is the Dreamliner, isn't it? Was a bit of a white elephant during its development, I seem to recall.

I think, along with the 747, the 777 is one of the best planes made. The 787 is the Dreamliner, it has a common type rating with the 777, i.e. pilots of one type are automatically rated for the other, in theory. It had some issues with its onboard batteries early on but overall it's been a success, particularly given that it only sips fuel and therefore has an astonishing potential for economy. The industry needed a plane like that to be built, the question is whether or not Boeing regret being the people to do it.

The 777 from the beginning was designed around two different, completing engines, the GE and the Rolls-Royce. I believe United Airlines has immediately grounded its entire fleet of 777's with the Rolls-Royce engine.

This is a very early one, from the first order run of United 777s (number 5?), it has Pratt & Whitney 4000s, the 'hollow blade' engine. It's planes with this PW unit that have been grounded for blade inspections, United are the only US operator.

Which brings me to the cause - earlier it looked like just the nacelles had blown away but it seems this was indeed an uncontained blade failure. Not good.

EDIT: And there it is. Or partly isn't.

 

[Keef]

Ah nice, it blasted right through the kevlar and into the fuselage, gotta love it.

 

[Dotini]

Ah nice, it blasted right through the kevlar and into the fuselage, gotta love it.

Judging solely from that one photo, it appears that the composite wing-to-body fairing was pierced. This is not to say it didn't continue on into the aluminum fuselage, although I don't think it did.

At the time, the diameter of the engine powering the 777 was the largest ever made. Uniquely, P&W went with a hollow fan blade, which seems not to have been the best idea. 777's made with that engine (and its bespoke strut) will likely face grounding and possibly extremely if not prohibitively costly redesign.

 

[Danoff]

777's made with that engine (and its bespoke strut) will likely face grounding and possibly extremely if not prohibitively costly redesign.

I wonder what's up though. Because the 777 is one of the only planes that is certified with an ETOPS 330 rating (the only? no it looks like 787 is too, looks like since that article Airbus has at least one as well). It makes you wonder whether we're looking at a fluke, or something was wrong with that analysis.

 

[TenEightyOne]

I wonder what's up though. Because the 777 is one of the only planes (the only? no it looks like 787 is too) that is certified with an ETOPS 330 rating. It makes you wonder whether we're looking at a fluke, or something was wrong with that analysis.

We can't be sure its ETOPS capability was compromised as it didn't have to cover that range as an emergency, but there's nothing to suggest it couldn't have completed that flight on that engine. This is definitely a P&W problem rather than a general 777 problem, and its still the plane I'd most choose to fly as a passenger. The bulk of US aircraft are GE and RR fitted, as @Dotini alluded too, those conventionally-bladed engines have far fewer problems iirc.

 

[Barra333]

I wonder what's up though. Because the 777 is one of the only planes that is certified with an ETOPS 330 rating (the only? no it looks like 787 is too, looks like since that article Airbus has at least one as well). It makes you wonder whether we're looking at a fluke, or something was wrong with that analysis.

There would only be a couple of routes that require 180+ anyway. Crossing the South Pacific and South Atlantic mainly. Even Australia-US might be OK for alternates within 180min (Syd-New Calendonia-Fiji-Hawaii-LA). Fiji-Hawaii might be a stretch. There is nothing between NZ/South America or Perth/South Africa worth considering. Even flights over the north pole would likely be OK, thanks to Russian military bases. not ideal but work in a pinch. I've spoken to a B777 captain who didn't like Toronto-Seoul because none of the emergency alternates were very appealing (snow, Russian military, North Korea)

 

[Danoff]

We can't be sure its ETOPS capability was compromised as it didn't have to cover that range as an emergency, but there's nothing to suggest it couldn't have completed that flight on that engine. This is definitely a P&W problem rather than a general 777 problem, and its still the plane I'd most choose to fly as a passenger. The bulk of US aircraft are GE and RR fitted, as @Dotini alluded too, those conventionally-bladed engines have far fewer problems iirc.

My understanding is that the ETOPS rating is based on the frequency of engine failures. Of course that doesn't mean that engine failures won't ever happen. So this event might be completely anticipated by the statistics used to certify the plane for use with that rating. But... why would you ground the P&W fitted 777s if that were the case? Is this Boeing just jumping so that they don't repeat the MAX problem? Or is it because they think there's something unexpected in the particular way this failed? @Dotini seemed to imply that he thought there was an inherent problem with the design.


This article suggests that 3 P&W4000 engine failures have occurred "in recent years" (no idea what that means). But it also says that there are 24 such planes being grounded. Only 24 planes operating (albeit in a major downturn for the industry), but 3 failures in recent years? I mean, they only had (until the other day) roughly 48 of those engines in service at all. That's not a lot of engines to spread 3 failures across.

Luckily it seems like worst case scenario the P&W4000 gets swapped out with one of the other engines.

 

[Keef]

Is this Boeing just jumping so that they don't repeat the MAX problem? Or is it because they think there's something unexpected in the particular way this failed?

Yes and yes. They learned that it's better to make the conscious decision to ground and inspect them before the FAA does it. They'll have to do at least a visual inspection of these engines and probably x-ray the fan blades for signs of fatigue. My previous company got some planes grounded by the FAA and it was kind of a ****-show especially for us pilots. I was actually one of a group who happened to be in the hangar just in time to get a talking to by a FSDO inspector along with our boss. Needless to say, that fiasco basically destroyed all our pilots' confidence in operations.

 

[Danoff]

Yes and yes. They learned that it's better to make the conscious decision to ground and inspect them before the FAA does it. They'll have to do at least a visual inspection of these engines and probably x-ray the fan blades for signs of fatigue.

Yea it sounded like fan blade inspection was going to need to be increased. Maybe this failure can be predicted with a reduced inspection interval. Only someone with access to more data about the 3 failures "in recent years" could answer that question. If the denver flight had just been inspected, it wouldn't bode well.

 

[TenEightyOne]

is it because they think there's something unexpected in the particular way this failed? @Dotini seemed to imply that he thought there was an inherent problem with the design.

The opposite would be an expected failure, so naturally it was (literally speaking) unexpected, only Boeing/P&W/United know if they feel this engine had an inspection recently enough that this failure is particularly worrisome. And it seems to be.

Looking at the video and then the picture of the nacelle lip I'm not sure that the blade left through the engine side, I think the broken piece cut the nacelle lip and then (inevitably) the whole cowling was smashed open by the airflow (see video at top of this page, then the nacelle pic below), but either way it's still a Very Bad Thing. I think this is the third blade failure (if that's what it turns out to be) on a PW-40xx engine, one occured on a United sister plane of the same batch, also bound for Honolulu, and another on a Japanese aircraft. Iirc the Japanese investigation found poor inspection practices at P&W, but I need to look that up.

On the whole it remains a very safe engine but (as @Dotini mentions) they may need to rethink the hollow blade design (or the strut design in order to retro-spec GE/RR engines) if they feel the failure rate is significantly higher than others. We still don't know what caused this but it's so early on the rollout that foreign objects can't be discounted at this point... but we'll know more after the metallurgical bods do their stuff.

EDIT: tree'd by you and @Keef as I thumped out my slow reply!

 

[Danoff]

The opposite would be an expected failure, so naturally it was (literally speaking) unexpected, only Boeing/P&W/United know if they feel this engine had an inspection recently enough that this failure is particularly worrisome. And it seems to be.

Looking at the video and then the picture of the nacelle lip I'm not sure that the blade left through the engine side, I think the broken piece cut the nacelle lip and then (inevitably) the whole cowling was smashed open by the airflow (see video at top of this page, then the nacelle pic below), but either way it's still a Very Bad Thing. I think this is the third blade failure (if that's what it turns out to be) on a PW-40xx engine, one occured on a United sister plane of the same batch, also bound for Honolulu, and another on a Japanese aircraft. Iirc the Japanese investigation found poor inspection practices at P&W, but I need to look that up.

On the whole it remains a very safe engine but (as @Dotini mentions) they may need to rethink the hollow blade design (or the strut design in order to retro-spec GE/RR engines) if they feel the failure rate is significantly higher than others. We still don't know what caused this but it's so early on the rollout that foreign objects can't be discounted at this point... but we'll know more after the metallurgical bods do their stuff.

EDIT: tree'd by you and @Keef as I thumped out my slow reply!

Yea that wasn't the most graceful failure (though honestly... how graceful can it really get given that huge pieces of spinning metal are aimed at the fuselage). I didn't really mean that the failure itself was unexpected, but rather that the manner of failure was unexpected somehow given a failure.

 

[Dotini]

Luckily it seems like worst case scenario the P&W4000 gets swapped out with one of the other engines.

it would really be great if they could indeed just swap it out for, say, the newer GE engine. But if my guess is right, the swapping out of a P&W for GE engine, strut, controls, etc., may involve considerable redesign and certification hoops to jump through.

 

[Danoff]

it would really be great if they could indeed just swap it out for, say, the newer GE engine. But if my guess is right, the swapping out of a P&W for GE engine, strut, controls, etc., may involve considerable redesign and certification hoops to jump through.

Isn't that basically what the aviation industry does constantly for like... everything? Swap, retrofit, re-certify, re-engineer, bandaid, inspect, polish?

"We need to come up with a fix for the wing damage from when the food truck smashed into the plane... let's get that engineered, retrofitted, re-certified, and back in the air"

 

[Eunos_Cosmo]

I think, along with the 747, the 777 is one of the best planes made. The 787 is the Dreamliner, it has a common type rating with the 777, i.e. pilots of one type are automatically rated for the other, in theory. It had some issues with its onboard batteries early on but overall it's been a success, particularly given that it only sips fuel and therefore has an astonishing potential for economy. The industry needed a plane like that to be built, the question is whether or not Boeing regret being the people to do it.



This is a very early one, from the first order run of United 777s (number 5?), it has Pratt & Whitney 4000s, the 'hollow blade' engine. It's planes with this PW unit that have been grounded for blade inspections, United are the only US operator.

Which brings me to the cause - earlier it looked like just the nacelles had blown away but it seems this was indeed an uncontained blade failure. Not good.

EDIT: And there it is. Or partly isn't.

View attachment 993432

Am I seeing things or did the fan blade fail at mid-length? That seems weird! I would think it would fail where it connects. Axial tension failures must be the rarest type!

 

[TenEightyOne]

Am I seeing things or did the fan blade fail at mid-length? That seems weird! I would think it would fail where it connects. Axial tension failures must be the rarest type!

Is it because it's hollow? I have no idea, not a metallurgisticalator at all.

 

[Danoff]

Am I seeing things or did the fan blade fail at mid-length? That seems weird! I would think it would fail where it connects. Axial tension failures must be the rarest type!

I wonder if that's not the blade that failed. That could be damage from debris. Some of the results of the failure often get projected forward and sucked back in to the engine (the blade next to it looks like it's missing).