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D L X
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 2:35 pm

gwrudolph wrote:
I think all parties are being conservative as a result of the MAX situation. All had egg on their face big time
i think all the parties are responding strongly because with air travel so low right now, this won’t hurt particularly much in comparison to times when fleet utilization is maximal.
 
Spetsnaz55
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 2:36 pm

B717fan wrote:
A new photo of the aircraft on the ground shows damage to the fuselage.
https://twitter.com/breakingavnews/stat ... 5947356161


This photo was posted yesterday.
 
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CALTECH
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 2:39 pm

Image
 
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CALTECH
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 2:39 pm

Image
 
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CALTECH
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 2:40 pm

Image
 
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CALTECH
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 2:40 pm

Image
 
smokeybandit
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 2:48 pm

B717fan wrote:
A new photo of the aircraft on the ground shows damage to the fuselage.
https://twitter.com/breakingavnews/stat ... 5947356161


Must have been from the cowling pieces, since the NTSB said the fan blade pieces were still contained in the engine.
 
SPREE34
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 2:50 pm

kearnet wrote:
Not to be melodramatic, but as it has now been essentially confirmed to be a blade-off uncontainable engine failure, is anyone else thinking about UA 232?


UA232 was a fan disk failure vs a single blade initiated event.
 
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CALTECH
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 3:00 pm

Wing To Body Fairing, it attaches to the wing and fuselage......

Image
Last edited by CALTECH on Mon Feb 22, 2021 3:13 pm, edited 1 time in total.
 
dtw2hyd
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 3:01 pm

B717fan wrote:
A new photo of the aircraft on the ground shows damage to the fuselage.
https://twitter.com/breakingavnews/stat ... 5947356161


That appears to be wingbox fairing damage not to the fuselage.
 
Spetsnaz55
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 3:03 pm

dtw2hyd wrote:
B717fan wrote:
A new photo of the aircraft on the ground shows damage to the fuselage.
https://twitter.com/breakingavnews/stat ... 5947356161


That appears to be wingbox fairing damage not to the fuselage.


A lot of posters here don't know the difference and that is all fuselage to them.
 
 
rj777
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 3:08 pm

B717fan wrote:
A new photo of the aircraft on the ground shows damage to the fuselage.
https://twitter.com/breakingavnews/stat ... 5947356161


How the heck were they able to get the gear down with that damage?
 
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CALTECH
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 3:23 pm

rj777 wrote:
B717fan wrote:
A new photo of the aircraft on the ground shows damage to the fuselage.
https://twitter.com/breakingavnews/stat ... 5947356161


How the heck were they able to get the gear down with that damage?


That damage is to WTB fairing, way forward of the wheel well.
 
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Revelation
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 3:29 pm

kearnet wrote:
Not to be melodramatic, but as it has now been essentially confirmed to be a blade-off uncontainable engine failure, is anyone else thinking about UA 232?

Not really.

UA328 is a fan blade off situation. There is a containment structure designed to handle single blade off events. Clearly this was two blades off and something escaped that containment, but it's not clear how much energy it had when it impacted that fairing, which is not a strong structure.

Regardless, IMO a grounding is justified. Time to take a good look at the entire fleet and make sure there is no undetected issue to be resolved.

UA232 was the failure of the fan disk itself. The chunk that fell off had many blades attached, so it had much more mass thus much more force (F = ma).

Image

Ref: https://en.wikipedia.org/wiki/United_Ai ... _component

That case resulted in extensive hydraulic damage largely due to the energy of the pieces and the concentration of the hydraulic runs:

Image

Ref: Ibid

The link addresses the shortcomings that were found in UA's inspection processes and McDD's design. Time will tell if any similar issues will be found. I would not jump to conclusions.

rj777 wrote:
B717fan wrote:
A new photo of the aircraft on the ground shows damage to the fuselage.
https://twitter.com/breakingavnews/stat ... 5947356161

How the heck were they able to get the gear down with that damage?

Seems it was the usual way, hydraulic actuators, right?

Maybe the damage was only skin deep.
 
B717fan
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 3:31 pm

I apologize for mistaking the wingroot for the fuselage.
 
Seat1D
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 3:49 pm

gwrudolph wrote:
I think all parties are being conservative as a result of the MAX situation. All had egg on their face big time


you bring up a good point. politics are ALWAYS at play. Makes you wonder if this happened in the middle of the summer with no pandemic, would the grounding have occurred. On top of that, lets say there was never an issue with the MAX, no pandemic and it in the middle of the super busy season, I{m not really sure the 777 PW fleet would have been grounded,.
 
WayexTDI
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 3:56 pm

jakubz wrote:
zippy wrote:
litz wrote:
The thing to remember is, there are several different variants of the PW 4000, among other differences are fan casing size (and, obviously, also fan *blade* size).

The 772 uses the -112 variant.


Yes, however the 747 that vomited engine bits all over the Netherlands was also PW 4000 powered.


Technically true, but that was a 94in PW4000. The B777 uses the 112in version. The 777's version is roughly 30% longer, and about 50% heavier. I suspect that while the engines are similar conceptually, there are plenty of differences to make them distinct models.

As a point of comparison, the lightest and heaviest RR Trent are the Trent 500 (11k lb) and Trent XWB (16k lb), which is a slightly smaller range. The fan blade sizes are also comparably spread.

(All states per Wikipedia)

If it's a manufacturing or design defect, the difference between the 2 engines (777 and 747) might be irrelevant if they are of similar design and/or manufacturing process.
We can only speculate now; investigations will tell us what happened.
 
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Aaron747
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 4:06 pm

CALTECH wrote:
https://www.youtube.com/watch?v=TMQPVe7YUwY&ab_channel=EntEduPinion


That's a helluva good shooting performance from a backyard civilian. Very helpful indeed.
 
FlyHossD
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 4:06 pm

CALTECH wrote:
Going to correct a post made by me earlier, the rumor or first scuttlebutt about UA328 was more opinion and speculation of a few folks more so than anything based on facts or actual knowledge. Even the blood all over the engine and or inlet might not have been based on a factual observation.
Still could be a birdstrike as a big bird can make a fan blade fail near the root of the blade. But this UA328 looks so much like the 2018 UA1175 incident which was a Fan Blade Failure near the root of the blade, so for me best to now wait till the facts come out about what happened. Everything has been locked and secured for the NTSB Investigation.


Comparing the photos of UA1175 three years ago and UA328 this weekend, there are some obvious visual similarities. Like others, I appreciate your information; please keep it coming.

And I'm jealous about your Ford Mustang. Some of my favorite conversations with mechanics were about cars and GA airplanes. IOW, those chats were not about work!
 
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litz
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 4:07 pm

The fact is, there's been no grounding (yet) of the PW4000 based 747s ...

Presumably if a systemic issue is found that's common, there will be.

Whatever they've found with the -112 variant PW 4000s certainly has regulators concerned enough.

It's pretty evident that current procedures are not finding defects ...
 
hivue
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 4:31 pm

Revelation wrote:
There is a containment structure designed to handle single blade off events. Clearly this was two blades off and something escaped that containment, but it's not clear how much energy it had when it impacted that fairing, which is not a strong structure.


Why do you assume it was a blade that caused the fairing damage and not nacelle/cowling debris? I haven't seen anything concrete to suggest that the blade and a half did anything but pass back into the engine.
 
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RyanairGuru
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 4:41 pm

litz wrote:
The fact is, there's been no grounding (yet) of the PW4000 based 747s ...

Presumably if a systemic issue is found that's common, there will be.

Whatever they've found with the -112 variant PW 4000s certainly has regulators concerned enough.

It's pretty evident that current procedures are not finding defects ...


If the FAA or other regulator decided to ground the PW4000-94 then - presumably - they would ground the PW 767s as well as 747s. That would hit United twice.
Last edited by RyanairGuru on Mon Feb 22, 2021 4:43 pm, edited 1 time in total.
 
889091
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 4:43 pm

CALTECH wrote:
Wing To Body Fairing, it attaches to the wing and fuselage......

Image


Is there an exit point? If not, can we safely assume that whatever punctured the fairing is still somewhere within the fairing? Was the centre fuel tank compromised? Looks like there is a wet patch underneath the hole, but it could just be melting snow.
 
Antarius
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 4:52 pm

Seat1D wrote:
gwrudolph wrote:
I think all parties are being conservative as a result of the MAX situation. All had egg on their face big time


you bring up a good point. politics are ALWAYS at play. Makes you wonder if this happened in the middle of the summer with no pandemic, would the grounding have occurred. On top of that, lets say there was never an issue with the MAX, no pandemic and it in the middle of the super busy season, I{m not really sure the 777 PW fleet would have been grounded,.


If there was no MAX issue, all that would mean is that the sloppiness would linger longer under the surface. The laissez faire oversight from the FAA would likely not have changed or been challenged until another incident happened.

This just says that some lessons were learned.
 
friendlyskies22
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 5:39 pm

I've wondered if an engine cam in commercial airliners would be of help in this type of incident. I realize the current monitoring info is of great help in deciding what to do next, but an engine cam in the fuselage somewhere around door 2 (777) may have helped the pilots in this incident, who may have not known there was an ongoing fire. Perhaps if they could have seen this, they may have chosen DEN runway 7 or 35 to get the aircraft landed sooner. I'm sure landing weight was also a factor however. I believe In the BA LAS incident, the crew apparently didn't know that #1 was on fire until a cockpit crew member went back and looked out a window.
 
OldB747Driver
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 5:51 pm

hivue wrote:
Why do you assume it was a blade that caused the fairing damage and not nacelle/cowling debris? I haven't seen anything concrete to suggest that the blade and a half did anything but pass back into the engine.

If the damage to the wing/body fairing was directly caused by the engine failure, physics and ballistics dictate that for a part to defy, say, 325 knots of wind force (the speed of UA328 at the time) oriented directly to the rear of the aircraft - and then travel roughly perpendicular to that force for any significant distance ( ~15 ft? ) requires a LOT of energy to do so.

Without diving into the math too deeply, suffice it to say that there is likely NO part of the cowling/nacelle or inlet/intake that can possess that kind of energy [the larger the size of a part, the exponentially larger the energy requirement]. Fan, compressor and turbine blades, on the other hand, possess that type of energy "no problem".

The FAA statement about the a blade imbedded in the containment shroud may not imply anything beyond that a portion of one of the two blades was retained in such a manner. Given that the shroud looks intact, it's reasonable to assume the other portion(s) of blade(s) traveled through the core which would then help to create the possibility that some more of those "high energy" turbine blades (downstream from the fan blades) were dislodged. The turbine blades do not have an engineered shroud to stop them because there is no reasonable way to do so (reasonable meaning weight/cost are considered).
 
kalvado
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 6:04 pm

friendlyskies22 wrote:
I've wondered if an engine cam in commercial airliners would be of help in this type of incident. I realize the current monitoring info is of great help in deciding what to do next, but an engine cam in the fuselage somewhere around door 2 (777) may have helped the pilots in this incident, who may have not known there was an ongoing fire. Perhaps if they could have seen this, they may have chosen DEN runway 7 or 35 to get the aircraft landed sooner. I'm sure landing weight was also a factor however. I believe In the BA LAS incident, the crew apparently didn't know that #1 was on fire until a cockpit crew member went back and looked out a window.

There are some people in the back - for example flight attendants who can talk to cockpit and comment on the situation.
It's not that knowing there is a fire would make things any different - engine jettison option wasn't available on this particular airframe, and they landed in ASAP fashion anyway.
 
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Revelation
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 6:07 pm

hivue wrote:
Revelation wrote:
There is a containment structure designed to handle single blade off events. Clearly this was two blades off and something escaped that containment, but it's not clear how much energy it had when it impacted that fairing, which is not a strong structure.

Why do you assume it was a blade that caused the fairing damage and not nacelle/cowling debris? I haven't seen anything concrete to suggest that the blade and a half did anything but pass back into the engine.

Fair enough. I looked at the shape of the impact and made an assumption that may prove to be false.

OldB747Driver wrote:
If the damage to the wing/body fairing was directly caused by the engine failure, physics and ballistics dictate that for a part to defy, say, 325 knots of wind force (the speed of UA328 at the time) oriented directly to the rear of the aircraft - and then travel roughly perpendicular to that force for any significant distance ( ~15 ft? ) requires a LOT of energy to do so.

Without diving into the math too deeply, suffice it to say that there is likely NO part of the cowling/nacelle or inlet/intake that can possess that kind of energy [the larger size a part, the exponentially larger the energy requirement]. Fan, compressor and turbine blades, on the other hand, possess that type of energy "no problem".

I also agree with this.

I'm looking forward to learning more about exactly what happened.
 
hivue
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 6:19 pm

OldB747Driver wrote:
Without diving into the math too deeply

Yes, I would assume cowl debris would be blown straight back from the engine under those circumstances. That's why in the case of WN1380 I was very surprised to see that fan cowl debris had impacted the fuselage at the row 14 window. The math involved may be a lot more complex than it at first appears.
 
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DIRECTFLT
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 6:25 pm

Remembering the fatality from an earlier engine failure, I would not chance sitting there filming from a seat near the engine. That seems to be just tempting fate.
 
pugman211
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 6:25 pm

I imagine the damage to the body fairing to be from the inlet cowel tbh.
 
catiii
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 6:47 pm

Any truth to the rumor that the manufacturer had coincidentally just put out last week guidance on fan blade inspection at a reduced interval as a result of the December 2020 JAL uncontained failure? As I recall they determined it was fatigue cracking in the fan blades:
https://www.youtube.com/watch?v=ac6CNlBMj0c

Also, I believe the fan blades are titanium correct? Not the super alloy aluminum being used in the GTFs?
Last edited by catiii on Mon Feb 22, 2021 6:49 pm, edited 1 time in total.
 
kalvado
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 6:48 pm

DIRECTFLT wrote:
Remembering the fatality from an earlier engine failure, I would not chance sitting there filming from a seat near the engine. That seems to be just tempting fate.

By the time you point the camera at the engine, whatever could happen already happened; fuel is cut off, high speed shrapnel - if any - flew away; and everyone onboard is in the same boat in terms of survival.
It may be a reasonable - I am not saying good! Just not a crazy - idea to choose your seat with engine failure in mind, especially in the turboprop, especially in Dash-8. Fuselage is already reinforced against blade impact in the hazard area, though.
 
DUSdude
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 6:49 pm

hivue wrote:
OldB747Driver wrote:
Without diving into the math too deeply

Yes, I would assume cowl debris would be blown straight back from the engine under those circumstances. That's why in the case of WN1380 I was very surprised to see that fan cowl debris had impacted the fuselage at the row 14 window. The math involved may be a lot more complex than it at first appears.


You have to take into account the aerodynamics of the piece involved. When a piece of cowl separates outward, the onrushing headwind may have unpredictable effects, as the piece in question can create all sorts of turbulence of its own. Combine that with the airflow coming off the leading edge of the wing and the forward fuselage and there are many ways in which a piece of cowling could head laterally for a sufficient enough time to strike the fuselage.

I'd still like to know what's behind that wing/fuselage fairing and what components behind that were impacted by whatever hit it.
 
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readytotaxi
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 6:56 pm

In the UK the CAA have ordered a temp banned on the engine type aircraft from their controlled airspace.
 
sgbroimp
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 6:59 pm

So to me the ETOPS question: Would this bird have made it halfway to HNL (or half way back to land) in this condition? If not, was this the one in ______ (fill in the number if you know it) flights that ETOPS theory was based on? Maybe silly me, but over water I like lots of engines.
 
gobears19
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 7:00 pm

Amp1 wrote:
This is a major problem for these engines. A fan blade failure can never be totally ruled out, so to get certification an engine has to demonstrate containment of high energy debris without the casing/intake/cowling separating from the engine. Clearly there is a fundamental problem with this containment system.


I would tend to agree, but I wouldn't limit it to just the PW containment system or the PW blades themselves. WN 1380/WN 3472 were both remarkably similar. It's evident that an inspection schedule for older engines has not been sufficiently designed to catch fatigued blades before they launch themselves into the engines. Furthermore, if a fatigued blade on an old engine is able to pass an inspection today, who is to say that tomorrow it won't fail an inspection with an additional cycle or two and thus be a ticking time bomb that no one knows about.

It would seem to me that replacing the entire fan after x cycles should be part of the maintenance schedule on new engines and aircraft, just like changing the tires after so many miles.
 
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Revelation
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 7:04 pm

A tweet I found interesting from @RWMann describes a certain pathology:

A repeating theme is fan blades appearing to migrate forward of containment ring at failure, which takes the lip out, and the rest of the nacelle is blown apart by the air stream, which causes damage to fuselage or flying surfaces. Engine certification test models need revision.

Ref: https://twitter.com/RWMann/status/1363852138682716160

Partially fits the description of the AF A380 that landed in Newfoundland, no?

In August 2019, the BEA announced that a part from the fan hub recovered from Greenland had been examined by the manufacturer Engine Alliance under BEA supervision. Metallurgical examination of the recovered titanium fan hub fragment identified a subsurface fatigue crack origin. The fracture was initiated in a microtextured area approximately in the middle of the slot bottom. Examination of the fracture was ongoing.

Ref: https://en.wikipedia.org/wiki/Air_France_Flight_66

Image

Ref: https://www.dailymail.co.uk/travel/trav ... blast.html
 
DUSdude
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 7:07 pm

gobears19 wrote:
Amp1 wrote:
This is a major problem for these engines. A fan blade failure can never be totally ruled out, so to get certification an engine has to demonstrate containment of high energy debris without the casing/intake/cowling separating from the engine. Clearly there is a fundamental problem with this containment system.


I would tend to agree, but I wouldn't limit it to just the PW containment system or the PW blades themselves. WN 1380/WN 3472 were both remarkably similar. It's evident that an inspection schedule for older engines has not been sufficiently designed to catch fatigued blades before they launch themselves into the engines. Furthermore, if a fatigued blade on an old engine is able to pass an inspection today, who is to say that tomorrow it won't fail an inspection with an additional cycle or two and thus be a ticking time bomb that no one knows about.

It would seem to me that replacing the entire fan after x cycles should be part of the maintenance schedule on new engines and aircraft, just like changing the tires after so many miles.


I believe that is already the case. Engine blades are life limited parts that need to be replaced after a certain number of cycles/hours precisely to avert metal fatigue. Question is whether that point in time has been calculated correctly for this engine type or whether certain use profiles merit earlier replacement (e.g. WN's short cycles and frequent climb to rather high altitudes - WN likes to cruise around FL40 with their -700s). .
 
OldB747Driver
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 7:13 pm

hivue wrote:
Yes, I would assume cowl debris would be blown straight back from the engine under those circumstances. That's why in the case of WN1380 I was very surprised to see that fan cowl debris had impacted the fuselage at the row 14 window. The math involved may be a lot more complex than it at first appears.

In light of the WN1380 evidence, certainly a valid point.

[@Revelation also good information]
Last edited by OldB747Driver on Mon Feb 22, 2021 7:17 pm, edited 1 time in total.
 
gobears19
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 7:16 pm

Spetsnaz55 wrote:
dtw2hyd wrote:
B717fan wrote:
A new photo of the aircraft on the ground shows damage to the fuselage.
https://twitter.com/breakingavnews/stat ... 5947356161


That appears to be wingbox fairing damage not to the fuselage.


A lot of posters here don't know the difference and that is all fuselage to them.


Is a damaged wingbox fairing materially less hazardous than a punctured fuselage?
 
StTim
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 7:22 pm

gobears19 wrote:
Spetsnaz55 wrote:
dtw2hyd wrote:

That appears to be wingbox fairing damage not to the fuselage.


A lot of posters here don't know the difference and that is all fuselage to them.


Is a damaged wingbox fairing materially less hazardous than a punctured fuselage?


Yes.

It isn't structural. To see if there was structural damage you would need to see underneath those panels.
 
kalvado
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 7:23 pm

gobears19 wrote:
Spetsnaz55 wrote:
dtw2hyd wrote:

That appears to be wingbox fairing damage not to the fuselage.


A lot of posters here don't know the difference and that is all fuselage to them.


Is a damaged wingbox fairing materially less hazardous than a punctured fuselage?

Yes, it is - fairing is aerodynamic structure, not part of a pressure vessel. It takes much less energy to damage fairing. The damage we see would contribute to drag and increase fuel burn, but is not a danger to the aircraft (hopefully) Basically people are saying, that whatever damaged fairing would hopefully cause little, if any, damage in case of impact to much stronger fuselage. We may have to wait for NTSB word on that, though.
 
catiii
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 7:42 pm

Revelation wrote:

Partially fits the description of the AF A380 that landed in Newfoundland, no?



Different engine, different manufacturer (although Pratt is part of the alliance), different airframe and the supposition here thus far is that the blade failed and not the hub although it is entirely too soon to tell.

If by "partially fits the description" you mean it was an engine failure, then yes.

Otherwise, no.
 
gobears19
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 7:42 pm

kalvado wrote:
gobears19 wrote:
Spetsnaz55 wrote:

A lot of posters here don't know the difference and that is all fuselage to them.


Is a damaged wingbox fairing materially less hazardous than a punctured fuselage?

Yes, it is - fairing is aerodynamic structure, not part of a pressure vessel. It takes much less energy to damage fairing. The damage we see would contribute to drag and increase fuel burn, but is not a danger to the aircraft (hopefully) Basically people are saying, that whatever damaged fairing would hopefully cause little, if any, damage in case of impact to much stronger fuselage. We may have to wait for NTSB word on that, though.


Makes sense. Maybe we'll know one day to what extent whatever busted the fairing also damaged other more significant parts.
 
jayunited
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 7:46 pm

gobears19 wrote:
Spetsnaz55 wrote:
dtw2hyd wrote:

That appears to be wingbox fairing damage not to the fuselage.


A lot of posters here don't know the difference and that is all fuselage to them.


Is a damaged wingbox fairing materially less hazardous than a punctured fuselage?


I'm no mechanic but from my time on the ramp at ORD I can tell you those are just panels they are removable and there is a sizable gap between the fairing and the fuselage.

Looking at the picture to the left of the hole in the wingbox fairing is where you will find the pneumatic air hook ups (used when doing an air start). Just behind the hole and again slightly to the left is where ramp hooks up one of the PC air hoses, the other hose is hooked up on the other side of the aircraft.

Also if my memory is correct there is a panel either forward of the landing gear bay doors or just after of the bay doors that maintenance uses to power the hydraulics when they are performing a gear swing test. Some other maintenance related items can be accessed by removing the wingbox fairing but I'm not exactly sure what they are.
 
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Revelation
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 7:50 pm

catiii wrote:

If by "partially fits the description" you mean it was an engine failure, then yes.

The common elements I was thinking of were "fan blades appearing to migrate forward of containment ring at failure, which takes the lip out, and the rest of the nacelle is blown apart by the air stream". As you say it's a different design, and probably a different failure mode (probably not hub failure or all the blades would have departed) but maybe we have blades migrating forward and taking the lip out and in the AF case some but not all of the nacelle ripped apart by the airstream.
 
catiii
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 7:56 pm

sgbroimp wrote:
So to me the ETOPS question: Would this bird have made it halfway to HNL (or half way back to land) in this condition? If not, was this the one in ______ (fill in the number if you know it) flights that ETOPS theory was based on? Maybe silly me, but over water I like lots of engines.


Well unfortunately for you practically every passenger airliner going over the water has two engines.

First, ETOPS isn't a "theory." It's a standard that requires approval. Second, it's not based on making it "halfway to HNL or halfway back to land." It's a 180 minute ETOPS to Hawaii. Third, "making it "halfway to HNL or halfway back to land" still results in the airplane being in the water so...not the outcome you're looking for. All the engines in the world won't help you at that point. You could have 30 engines and if you only make it halfway what's the point?
 
Western727
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Re: UA328 engine explosion at DEN

Mon Feb 22, 2021 7:59 pm

889091 wrote:
CALTECH wrote:
Wing To Body Fairing, it attaches to the wing and fuselage......

Image


Is there an exit point? If not, can we safely assume that whatever punctured the fairing is still somewhere within the fairing? Was the centre fuel tank compromised? Looks like there is a wet patch underneath the hole, but it could just be melting snow.


Wet patch is left of the centerline, so it appears to be melting snow or from some dripping from the port (left) side of the aircraft and therefore (based on the position of the camera to the aircraft) more aft than the penetrated wing root fairing.
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