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ContinentalEWR
Posts: 5347
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 12:52 pm

The fan blades and metal fatigue are increasingly the focus of the investigation. While older airplanes are not inherently a risk issue, they can be with improper, incomplete maintenance routines. This plane was 26 years old. The 4th or 5th 777 to roll off the assembly line. These frames (222As at UA) were repurposed years ago into higher density, domestic trunk route rotations (hub to hub, mainland to Hawaii, principally). The incident does beg the question as to whether aircraft should have a shelf life and whether the cost of upgrading and meticulously maintaining older fleets is worth it vs. acquiring new aircraft, particularly now when the industry is in a tough squeeze.

Fan blades and metal fatigue are not new threats to commercial aviation safety. They've been an issue for decades. Plenty of incidents of the past, not limited to engines have highlighted this risk. Aloha Airlines, UA 811, to name a few.
 
United1
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 1:00 pm

crownvic wrote:
Did they remove the engine ringlet from that homeowners yard already? Is that it laying next to the engine on the ground in front of it? If so i'm shocked no one filmed its removal from the yard?


That’s it...by the engine in the UA hangar at DEN. I’m sure someone did film it’s removal. Knowing the YouTube algorithm if you search for cats in 7-10 years at 2am and you will find it. :)
 
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Polot
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 1:04 pm

ContinentalEWR wrote:
The fan blades and metal fatigue are increasingly the focus of the investigation. While older airplanes are not inherently a risk issue, they can be with improper, incomplete maintenance routines. This plane was 26 years old. The 4th or 5th 777 to roll off the assembly line. These frames (222As at UA) were repurposed years ago into higher density, domestic trunk route rotations (hub to hub, mainland to Hawaii, principally). The incident does beg the question as to whether aircraft should have a shelf life and whether the cost of upgrading and meticulously maintaining older fleets is worth it vs. acquiring new aircraft, particularly now when the industry is in a tough squeeze.

Fan blades and metal fatigue are not new threats to commercial aviation safety. They've been an issue for decades. Plenty of incidents of the past, not limited to engines have highlighted this risk. Aloha Airlines, UA 811, to name a few.

The airframe is 26 years old. That doesn’t mean the engine (the thing that failed, not the airframe) is 26 years old-those get swapped around and replaced all the time. I’m not sure if the age of the engine has been released yet-for all we know the engine could only be 10 years old.
 
joeblow10
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 1:45 pm

LAXLHR wrote:
joeblow10 wrote:
acavpics wrote:
Does it look like another Southwest 1380-style accident?
If so, then they are lucky as it could have resulted in injuries and even fatalities


WN1380 was an absolute freak accident - there have been a number of fan blade incidents before and since, and none have ever led to the exact separation needed of parts/debris to take out a single window.

That said - this certainly does appear to be a fan blade failure. And not the first for PW on these engines... me thinks suggested inspections are coming


I do recall a Delta Airlines MD88 or similar having an engine explosion, tearing through the fuselage killing two passengers.


Yes that was in PNS - bear in mind though that was also on an a/c where the engines are directly attached to areas with passengers. I’m not saying fatalities from fan blade events never happened - I’m saying the sequence of events required on WN1380 for the cowling itself to tear off, then strike one single window at just the right angle to cause a decompression event and fatality were and still are almost zero. It was simply a freak accident.
 
SUPER63DL
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 1:54 pm

smokeybandit wrote:

I believe if I were there, I would be looking Quickly for some type of shelter, perhaps under a vehicle. It looks like everyone in the video is just waiting for a piece of titanium fan blade to come down and Smack em!
 
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CALTECH
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 2:12 pm

WIederling wrote:
CALTECH wrote:
The grounding affects both 777-222s with PW4077s and 777-222ERs with PW4090-3.


i.e. all (both) PW4000 engine types with the 112" fan. ( and the same blades ?)


Yes.....

http://www.iasg.co.uk/pdfs/articles/eng ... Feb_06.pdf
 
rj777
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 2:16 pm

In those videos, it looks like the engine is about to fall off....... if it had...... would the plane have crashed or could they have made it?
 
dragon6172
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 2:25 pm

rj777 wrote:
In those videos, it looks like the engine is about to fall off....... if it had...... would the plane have crashed or could they have made it?

The real question is if an engine falls off AND they make it to landing does it count as both?? The engine crashed.... the airframe made it??
 
acavpics
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 2:31 pm

Is there a chance that these birds (like MANY others these days) may not return to service at all following the grounding? It popped into my mind, considering that these are the oldest 777's on the planet.
 
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Aaron747
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 2:39 pm

rj777 wrote:
In those videos, it looks like the engine is about to fall off....... if it had...... would the plane have crashed or could they have made it?


Not sure how you are able to judge the condition of the pylon assembly and attachment struts from that video - these are very robust structures that are designed to take a lot of wobble and vibration.

As for your question - it depends entirely on whether there is any serious damage to the wing. It is not unheard of for separations to cause serious accidents, but some have also been survivable, like this not so famous one:

https://www.ntsb.gov/investigations/Acc ... AR9306.pdf
 
Zeppi
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 2:40 pm

Aaron747 wrote:
Remember PAA 843?


Deary me, I never heard of this one, thank you for sharing. I think everyone needed a change of underwear after that. Some brilliant airmanship right there.
 
rj777
Posts: 1914
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 3:00 pm

Aaron747 wrote:
rj777 wrote:
In those videos, it looks like the engine is about to fall off....... if it had...... would the plane have crashed or could they have made it?


Not sure how you are able to judge the condition of the pylon assembly and attachment struts from that video - these are very robust structures that are designed to take a lot of wobble and vibration.

As for your question - it depends entirely on whether there is any serious damage to the wing. It is not unheard of for separations to cause serious accidents, but some have also been survivable, like this not so famous one:

https://www.ntsb.gov/investigations/Acc ... AR9306.pdf


The only thing with that is there were 3 other engines left on the plane, including one on that wing. the 777 only has 1 engine on each wing. Would we possibly be looking at a scenario like the AA DC-10 that crashed in Chicago?
 
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CALTECH
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 3:02 pm

Polot wrote:
ContinentalEWR wrote:
The fan blades and metal fatigue are increasingly the focus of the investigation. While older airplanes are not inherently a risk issue, they can be with improper, incomplete maintenance routines. This plane was 26 years old. The 4th or 5th 777 to roll off the assembly line. These frames (222As at UA) were repurposed years ago into higher density, domestic trunk route rotations (hub to hub, mainland to Hawaii, principally). The incident does beg the question as to whether aircraft should have a shelf life and whether the cost of upgrading and meticulously maintaining older fleets is worth it vs. acquiring new aircraft, particularly now when the industry is in a tough squeeze.

Fan blades and metal fatigue are not new threats to commercial aviation safety. They've been an issue for decades. Plenty of incidents of the past, not limited to engines have highlighted this risk. Aloha Airlines, UA 811, to name a few.

The airframe is 26 years old. That doesn’t mean the engine (the thing that failed, not the airframe) is 26 years old-those get swapped around and replaced all the time. I’m not sure if the age of the engine has been released yet-for all we know the engine could only be 10 years old.


Commercial airliners do have a 'shelf life'. It is based on Flight Cycles and Flight Hours that the manufacturer tests and sets.
Believe that engine was supposedly changed on that aircraft 3 years ago, more than likely came from a overhaul.
The cost of maintaining a older aircraft does rise maintenance wise, but the cheaper acquisition or lease payments can make it worth it.

https://www.federalregister.gov/documen ... an-engines
 
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Aaron747
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 3:11 pm

rj777 wrote:
Aaron747 wrote:
rj777 wrote:
In those videos, it looks like the engine is about to fall off....... if it had...... would the plane have crashed or could they have made it?


Not sure how you are able to judge the condition of the pylon assembly and attachment struts from that video - these are very robust structures that are designed to take a lot of wobble and vibration.

As for your question - it depends entirely on whether there is any serious damage to the wing. It is not unheard of for separations to cause serious accidents, but some have also been survivable, like this not so famous one:

https://www.ntsb.gov/investigations/Acc ... AR9306.pdf


The only thing with that is there were 3 other engines left on the plane, including one on that wing. the 777 only has 1 engine on each wing. Would we possibly be looking at a scenario like the AA DC-10 that crashed in Chicago?


Why are you so focused on number of engines? Also perhaps you should read up on AA in Chicago and think about what may or may not be different in that scenario from this UA incident.
 
catiii
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 3:12 pm

joeblow10 wrote:
LAXLHR wrote:
joeblow10 wrote:

WN1380 was an absolute freak accident - there have been a number of fan blade incidents before and since, and none have ever led to the exact separation needed of parts/debris to take out a single window.

That said - this certainly does appear to be a fan blade failure. And not the first for PW on these engines... me thinks suggested inspections are coming


I do recall a Delta Airlines MD88 or similar having an engine explosion, tearing through the fuselage killing two passengers.


Yes that was in PNS - bear in mind though that was also on an a/c where the engines are directly attached to areas with passengers. I’m not saying fatalities from fan blade events never happened - I’m saying the sequence of events required on WN1380 for the cowling itself to tear off, then strike one single window at just the right angle to cause a decompression event and fatality were and still are almost zero. It was simply a freak accident.


It was also almost 25 years ago...
 
musang
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 3:22 pm

OldB747Driver wrote:
musang wrote:
Continental DC-10, Socorro, NM, 1973.

That incident occurred after the crew did unauthorized (but at the time not prohibited :roll: ) pulling of CB's to analyze the autothrottle system:

"If you pull the N1 tach - will that autothrottle respond...?" - Flight Engineer to Captain of National 27, MIA-SFO, divert to ABQ, Nov 3, 1973

In depth work-up on the incident in "Air Disaster, Vol 1" by Macarthur Job if interested, probably a pdf of the NTSB report available as well...


I have that book, thanks for the reminder. The reason I mentioned the incident was someone mentioned not many window bursts due engine damage.
 
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Revelation
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 3:41 pm

N649DL wrote:
Right now, that's 24-28 UA 777s out of service. It sounds like the PW-based 777s are less reliable even compared to the existing UA 763 or 764. What will UA do if the pandemic subsides and needs additional metal and the PW-based frames keep this type of inconsistencies up? Use the Sh*tbox 739ER to HNL? Or pull PW 757s out of the desert? I doubt it at this point.

Seriously, what's the solution? They're likely going to be out for a while and that's a lot of aircraft to deal with regardless. It does seem like the PW 777s have been really run hard regardless of this incident (regardless of their interiors which are total crap as well.)

They probably aren't going to be out long enough to matter. Basically the blades will be inspected thoroughly then if they happen to find a meaningful failure rate then the grounding will be prolonged, but this hasn't been the case in the past because these things do get routinely inspected. After return to service the inspection interval will be shorter so they'll be out of service more often, and that will factor into fleet planning, but it won't significantly change the number of frames available, and the crap interiors will still be crap.

rj777 wrote:
The only thing with that is there were 3 other engines left on the plane, including one on that wing. the 777 only has 1 engine on each wing. Would we possibly be looking at a scenario like the AA DC-10 that crashed in Chicago?

https://en.wikipedia.org/wiki/American_ ... able_cause suggests very little overlap in these two incidents.

litz wrote:
And photos on the NTSB Flickr account

https://www.flickr.com/photos/ntsb/

Very interesting!

In particular:

ImageDEN 5 by National Transportation Safety Board, on Flickr

NTSB said the engine (technically) maintained containment. This means it wasn't a turbine or compressor blade that made it through the casing. If it was, I think we'd be seeing shrapnel damage. Instead we see one big hole without lots of little holes indicating hot high energy shrapnel from deep inside the engine.
Last edited by Revelation on Tue Feb 23, 2021 3:43 pm, edited 1 time in total.
 
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747classic
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 3:43 pm

CALTECH wrote:

Commercial airliners do have a 'shelf life'. It is based on Flight Cycles and Flight Hours that the manufacturer tests and sets.
Believe that engine was supposedly changed on that aircraft 3 years ago, more than likely came from a overhaul.
The cost of maintaining a older aircraft does rise maintenance wise, but the cheaper acquisition or lease payments can make it worth it.

https://www.federalregister.gov/documen ... an-engines



PW4000-112 engines (with 112 inch fan ), as installed at early built 777 aircraft, are not built new anymore for several years, the current active engines are all overhauled examples with new or overhauled time/ cycle limited parts. Full support still offered by P&W.
AFAIK the only PW4000 engine currently in production is the PW4062 for the KC-46A tanker, this is a PW4000-94 (with 94 inch fan ).
 
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Aaron747
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 3:56 pm

747classic wrote:
CALTECH wrote:

Commercial airliners do have a 'shelf life'. It is based on Flight Cycles and Flight Hours that the manufacturer tests and sets.
Believe that engine was supposedly changed on that aircraft 3 years ago, more than likely came from a overhaul.
The cost of maintaining a older aircraft does rise maintenance wise, but the cheaper acquisition or lease payments can make it worth it.

https://www.federalregister.gov/documen ... an-engines



PW4000-112 engines (with 112 inch fan ), as installed at early built 777 aircraft, are not built new anymore for several years, the current active engines are all overhauled examples with new or overhauled time/ cycle limited parts. Full support still offered by P&W.
AFAIK the only PW4000 engine currently in production is the PW4062 for the KC-46A tanker, this is a PW4000-94 (with 94 inch fan ).


IIRC, ANA took delivery of a handful of -281ERs for domestic use in 2013. Those would probably have the last new build 4000-112s.
 
hivue
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 4:03 pm

Aaron747 wrote:
Not sure how you are able to judge the condition of the pylon assembly and attachment struts from that video - these are very robust structures that are designed to take a lot of wobble and vibration.


I believe the pylon engine mounts are designed to shear before the engine vibrations get severe enough to compromise the wing structure.
 
2175301
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 4:09 pm

From a practical standpoint; this may result in a limit of the total number of hours or cycles that these specific fan blades can have. It will be much cheaper to replace the fan blades every X years than replace the aircraft.

I'm making the assumption that the fan blades were correctly inspected after the 2018 AD. NDE technology always has limits on what it can see - and the failure area just might be in an area where we just don't yet have the technology to see what is going on in a cost effective manner, yet.
 
jeffrey0032j
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 4:12 pm

Aaron747 wrote:
747classic wrote:
CALTECH wrote:

Commercial airliners do have a 'shelf life'. It is based on Flight Cycles and Flight Hours that the manufacturer tests and sets.
Believe that engine was supposedly changed on that aircraft 3 years ago, more than likely came from a overhaul.
The cost of maintaining a older aircraft does rise maintenance wise, but the cheaper acquisition or lease payments can make it worth it.

https://www.federalregister.gov/documen ... an-engines



PW4000-112 engines (with 112 inch fan ), as installed at early built 777 aircraft, are not built new anymore for several years, the current active engines are all overhauled examples with new or overhauled time/ cycle limited parts. Full support still offered by P&W.
AFAIK the only PW4000 engine currently in production is the PW4062 for the KC-46A tanker, this is a PW4000-94 (with 94 inch fan ).


IIRC, ANA took delivery of a handful of -281ERs for domestic use in 2013. Those would probably have the last new build 4000-112s.

The last PW 772ER (and also the last 772ER) went to Asiana. HL8284 LN1117.
 
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Aaron747
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 4:24 pm

jeffrey0032j wrote:
Aaron747 wrote:
747classic wrote:


PW4000-112 engines (with 112 inch fan ), as installed at early built 777 aircraft, are not built new anymore for several years, the current active engines are all overhauled examples with new or overhauled time/ cycle limited parts. Full support still offered by P&W.
AFAIK the only PW4000 engine currently in production is the PW4062 for the KC-46A tanker, this is a PW4000-94 (with 94 inch fan ).


IIRC, ANA took delivery of a handful of -281ERs for domestic use in 2013. Those would probably have the last new build 4000-112s.

The last PW 772ER (and also the last 772ER) went to Asiana. HL8284 LN1117.


By golly you’re right - also in 2013.
 
slider
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 4:43 pm

WIederling wrote:
ordbosewr wrote:
Noshow wrote:
Did they recently change any maintenance procedure or similar?


or is it just the number of hours (aka just getting old)? all good questions to ask and ones that i am sure the NTSB will ask.


The basic idea in this area is to adequately have checks and maintenance arranged such that deterioration is detected before things come apart.
This seems to have not worked here?


Well, that's the big question. NTSB will closely look into the engine shops at UA that do this. When were these blades last boroscoped? When were components replaced? Condition of blades and service history and mx records for ALL said PW blades and engine parts....and so on...

Until we get to facts, it's all just speculation.
 
01pewterz28
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 5:06 pm

rj777 wrote:
In those videos, it looks like the engine is about to fall off....... if it had...... would the plane have crashed or could they have made it?


Aircraft are designed so that in the event of a catastrophic engine failure and the engine is vibrating in such a manner it will shear off the bolts and fall away (below the wing) thus preventing any damage to the wing and or hydraulic lines.

Several aircraft have lost an engine in flight and landed without incident a 747 out of Anchorage lost its # 1 engine and upon landing and inspection the engine was missing.
 
StTim
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 5:18 pm

I am of two minds with the communication. Yes it was a little stressed, which showed, but it was a high workload situation and with high terrain ahead they did need a turn quite quickly so the communication was necessary. But whilst it was a little unclear it did not affect the outcome.

I am constantly amazed at the professionalism of the people that work under this pressure. The air traffic controller her. The air traffic controller and Sully on the miracle on the Hudson, The air traffic controllers and the BA pilot of the 777 that crashed just short of runway 27L at Heathrow.
 
smokeybandit
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 5:45 pm

Revelation wrote:
In particular:

ImageDEN 5 by National Transportation Safety Board, on Flickr

NTSB said the engine (technically) maintained containment. This means it wasn't a turbine or compressor blade that made it through the casing. If it was, I think we'd be seeing shrapnel damage. Instead we see one big hole without lots of little holes indicating hot high energy shrapnel from deep inside the engine.


Could that damage simply be from the cowling ring flying off? There's somewhat of a circular pattern to the damage.
 
gobears19
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 5:54 pm

WIederling wrote:
ordbosewr wrote:
Noshow wrote:
Did they recently change any maintenance procedure or similar?


or is it just the number of hours (aka just getting old)? all good questions to ask and ones that i am sure the NTSB will ask.


The basic idea in this area is to adequately have checks and maintenance arranged such that deterioration is detected before things come apart.
This seems to have not worked here?


It seems to not work more often than we should be comfortable with. In the last 4 years in the US alone, we've had two 737 NG and two 777 blade off incidents all resulting in potential catastrophic events, including 1 death and potentially hundreds with PTSD. All 4 aircraft were aged with tens of thousands of cycles, and hundreds if not thousands of similar aircraft take to the skies everyday.

In the absence of data detailing how many events have been avoided due to more rigorous examination schedules, it concerns me that these exams aren't appearing to serve their purpose.
 
catiii
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 5:56 pm

Aaron747 wrote:
CaptainHaresh wrote:
CriticalPoint wrote:

What a disgusting post.

Of course they did the inspections. Blades can crack for a lot of reasons.

Communication was sloppy? You don’t fly airplanes do you? Did you hear the fire bells going off In the back ground? Their EICAS was lit like a Christmas tree with both cautions and fire bells going off. Need to monitor the aircraft, get the nose down, and get a quick plan. You think that maybe there were a lot of distractions???

It doesn’t matter what direction you turn a jet doesn’t care.

How are you going to keep the fire retardant in the engine without a cowling???? :roll:

The crew doesn’t fail to pull a fire handle when the fire bell goes off every three seconds. Also really hard to complete an ECL without firing the bottles.

Get a clue and ask questions before you decide to lambast a crew that did a phenomenal job and an airline that prides its self on safety.

Signed United 787 Captain (retired)

Excellent job boys!


I wouldn't sign myself a United 787 Captain writing such science fiction.

You can and should turn into a failed engine of a B777, when that engine just exploded, is hanging by a tread and you don't know the extent of the damages to the wing. You are 5000ft AGL with sufficient speed, you barely need any bank given thrust asymetry, and you avoid having that big heavy engine dangling up there in a stronger bank fighting assymetry.

The communication was inefficient.
They sounded like they were trying to chase 10 rabbits at the same time.
It's a high stress situation, but that's when you need to be efficient.
English isn't their second language, you would expect them to be much smoother in their own language.

Shouldn't fire extinguishing systems account for missing cowlings?
If not, why have them at all?


What in the world did I just read...?


Something written by someone who a) is not an airline pilot, b) has no idea on 777 systems, c) continues to show they have no idea what they're talking about, and d) is simply a troll.

"Captain..."

yeah, right.
 
CaptainHaresh
Posts: 58
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 6:04 pm

StTim wrote:
I am of two minds with the communication. Yes it was a little stressed, which showed, but it was a high workload situation and with high terrain ahead they did need a turn quite quickly so the communication was necessary. But whilst it was a little unclear it did not affect the outcome.

I am constantly amazed at the professionalism of the people that work under this pressure. The air traffic controller her. The air traffic controller and Sully on the miracle on the Hudson, The air traffic controllers and the BA pilot of the 777 that crashed just short of runway 27L at Heathrow.


Talking about the communications in this incident, I also thought back to US1549 and just listened to the recordings.
That is professionalism at its finest, efficient, concise.
Sully truly is a good pilot.

The UA328 pilot on the radio said his callsign wrong 2 times before the engine failed...and when it failed he was all over the radio instead of on his checklist.
I expect pilots paid 300K a year to show a little more focus than that, I'm certainly not going to applaud for not screwing up a very manageable situation.
Last edited by CaptainHaresh on Tue Feb 23, 2021 6:07 pm, edited 1 time in total.
 
Sancho99504
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 6:07 pm

gobears19 wrote:
WIederling wrote:
ordbosewr wrote:

or is it just the number of hours (aka just getting old)? all good questions to ask and ones that i am sure the NTSB will ask.


The basic idea in this area is to adequately have checks and maintenance arranged such that deterioration is detected before things come apart.
This seems to have not worked here?


It seems to not work more often than we should be comfortable with. In the last 4 years in the US alone, we've had two 737 NG and two 777 blade off incidents all resulting in potential catastrophic events, including 1 death and potentially hundreds with PTSD. All 4 aircraft were aged with tens of thousands of cycles, and hundreds if not thousands of similar aircraft take to the skies everyday.

In the absence of data detailing how many events have been avoided due to more rigorous examination schedules, it concerns me that these exams aren't appearing to serve their purpose.

That's hard to say that they're not serving their purpose. When you think about it on a grand scale, there are over 3,000 CFM56-7 engines in operation. 2 out of over 3,000.
What may need to happen, similar to other fatigue issues that were found on aircraft fleets later in their lives, is that the inspection interval needs to be decreased. Instead of inspection every 3,000 hours, make it 2,000 hours.(not sure what the inspection interval is, so just throwing numbers out there)
 
mm320cap
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 6:08 pm

CaptainHaresh wrote:
StTim wrote:
I am of two minds with the communication. Yes it was a little stressed, which showed, but it was a high workload situation and with high terrain ahead they did need a turn quite quickly so the communication was necessary. But whilst it was a little unclear it did not affect the outcome.

I am constantly amazed at the professionalism of the people that work under this pressure. The air traffic controller her. The air traffic controller and Sully on the miracle on the Hudson, The air traffic controllers and the BA pilot of the 777 that crashed just short of runway 27L at Heathrow.


Talking about the communications in this incident, I also thought back to US1549 and just listened to the recordings.
That is professionalism at its finest, efficient, concise.
Sully truly is a good pilot.

The UA328 pilot on the radio said his callsign wrong 2 times before the engine failed...and when it failed he was all over the radio instead of on his checklist.
I expect pilots paid 300K a year to show a little more focus than that, I'm certainly not going to applaud for not screwing up a very manageable situation.


Are you an airline pilot? What’s your profession “Captain”?
 
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Revelation
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Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 7:08 pm

mm320cap wrote:
This crew did an excellent job in exceptionally difficult circumstances.

:checkmark:

It's absurd to nitpick. This crew did an excellent job, period, full stop.
 
Okcflyer
Posts: 910
Joined: Sat May 23, 2015 11:10 pm

Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 7:26 pm

This was a 772 (non-ER) model. Max thrust is ~ 77klbs. The engines on it should be ER spec later models capable of ~92klbs thrust, derated down to the 77klbs required for the early frame model.

Fan speed (rpm), and thereby thrust, for this 77A application is slower than if the same engine was installed on a 77E.

RPM largely determines the tensile loading of the blades. Brittle fatigue fracture occurs in metal subject to tensile stress.

As the engine was "not at it's limits" in this case, I'm a bit surprised that this failure on a 77A (non-ER) frame, rather than on one of the 77E with full engine rating available.

- Does P&W increase the life expectancy of the fan blades in the lower thrust rated models? Fatigue failure is a function of stress (load) and load cycles, and increasing life is reasonable to do so. Did their models overestimate the life remaining? If so, why?
- Maybe there is a dynamic load issue, likely from a resonance case, that increases the stress (load) and/or increases the number of cycles? These tend to be pretty easy to test and measure for, so it seems highly unlikely to find such a situation this late in product maturity level.
- Material composition issue?
- Record keeping issue?
 
User avatar
N1011
Posts: 17
Joined: Sun Dec 25, 2016 2:22 pm

Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 7:40 pm

Revelation wrote:
mm320cap wrote:
This crew did an excellent job in exceptionally difficult circumstances.

:checkmark:

It's absurd to nitpick. This crew did an excellent job, period, full stop.


100% accurate, I am sure he is no captain at all........

Plane was landed safely over gross landing weight, no injures, you post is clearly meant to be flame bait....

Hats off to the crew on this.
 
WayexTDI
Posts: 2963
Joined: Fri Sep 21, 2018 4:38 pm

Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 7:42 pm

Sancho99504 wrote:
gobears19 wrote:
WIederling wrote:

The basic idea in this area is to adequately have checks and maintenance arranged such that deterioration is detected before things come apart.
This seems to have not worked here?


It seems to not work more often than we should be comfortable with. In the last 4 years in the US alone, we've had two 737 NG and two 777 blade off incidents all resulting in potential catastrophic events, including 1 death and potentially hundreds with PTSD. All 4 aircraft were aged with tens of thousands of cycles, and hundreds if not thousands of similar aircraft take to the skies everyday.

In the absence of data detailing how many events have been avoided due to more rigorous examination schedules, it concerns me that these exams aren't appearing to serve their purpose.

That's hard to say that they're not serving their purpose. When you think about it on a grand scale, there are over 3,000 CFM56-7 engines in operation. 2 out of over 3,000.
What may need to happen, similar to other fatigue issues that were found on aircraft fleets later in their lives, is that the inspection interval needs to be decreased. Instead of inspection every 3,000 hours, make it 2,000 hours.(not sure what the inspection interval is, so just throwing numbers out there)

I don't think you should look at those numbers for the effectiveness of the inspections.

2 engines, out of 14,000+ CFM56-7Bs produced (2 per each 737NG), had blade failures.
But how many defective blades were ever found thanks to inspection? If the answer is 0, then the inspection is not effective.
I doubt that's the case, I'm sure most defective blades are found during inspection, and not during catastrophic failures; but you need to look at the percentage that might have failed detection (and that were later revealed during ejection).
 
B6twufa
Posts: 10
Joined: Tue Dec 15, 2020 3:35 pm

Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 7:49 pm

CaptainHaresh wrote:
StTim wrote:
I am of two minds with the communication. Yes it was a little stressed, which showed, but it was a high workload situation and with high terrain ahead they did need a turn quite quickly so the communication was necessary. But whilst it was a little unclear it did not affect the outcome.

I am constantly amazed at the professionalism of the people that work under this pressure. The air traffic controller her. The air traffic controller and Sully on the miracle on the Hudson, The air traffic controllers and the BA pilot of the 777 that crashed just short of runway 27L at Heathrow.


Talking about the communications in this incident, I also thought back to US1549 and just listened to the recordings.
That is professionalism at its finest, efficient, concise.
Sully truly is a good pilot.

The UA328 pilot on the radio said his callsign wrong 2 times before the engine failed...and when it failed he was all over the radio instead of on his checklist.
I expect pilots paid 300K a year to show a little more focus than that, I'm certainly not going to applaud for not screwing up a very manageable situation.


Aren't you that flywithgarrett guy getting crucified online for doing that infamous YouTube video criticizing the crew?
 
Okcflyer
Posts: 910
Joined: Sat May 23, 2015 11:10 pm

Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 7:51 pm

This is a very good read. P&W had a problem with their inspection process historically.

http://aerossurance.com/safety-manageme ... w4077-fbo/

P&W developed the TAI inspection process in about 2005 to be able to inspect the interior surfaces of the hollow core PW4000 fan blade. The records for the TAI inspection in July 2015 as well as an earlier TAI accomplished in March 2010 revealed a thermal indication in the same location as where the LCF crack occurred. The records for the fractured fan blade’s July 2015 TAI inspection was annotated ‘paint’ that, according to the inspector, was consistent with him accepting the indication because he thought it was an issue with the paint.
 
FlyHossD
Posts: 2280
Joined: Mon Nov 02, 2009 3:45 pm

Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 8:07 pm

mm320cap wrote:
...So you always want to turn into the exploded engine, eh “Captain”? What if the drag is sufficient to induce a rolling moment that you exasperated by banking into it and can no longer recover from? I would have gone left too to ensure that I wasn’t going to get into a roll rate that I couldn’t get out of.

You’re just plain ignorant with regard to the halon fire bottle system. Clearly, it was ripped off the airplane with the cowl. You “have them at all” because the vast vast majority of engine fires don’t have an exploded cowl. Talk to Pratt if you have an issue, not the pilots.

Your trolling is ridiculous. This crew did an excellent job in exceptionally difficult circumstances. There’s always one hero on these boards. *eyeroll*. It’s like a guy that chooses Tom Brady in his fantasy league and therefore thinks he knows how to throw a football or marry a supermodel.


Well said MM320Cap. Thank you.

If this person is actually an airline pilot, I’d like to know where, so I can avoid that carrier.
 
IADCA
Posts: 2558
Joined: Mon Feb 26, 2007 12:24 am

Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 8:36 pm

CaptainHaresh wrote:
StTim wrote:
I am of two minds with the communication. Yes it was a little stressed, which showed, but it was a high workload situation and with high terrain ahead they did need a turn quite quickly so the communication was necessary. But whilst it was a little unclear it did not affect the outcome.

I am constantly amazed at the professionalism of the people that work under this pressure. The air traffic controller her. The air traffic controller and Sully on the miracle on the Hudson, The air traffic controllers and the BA pilot of the 777 that crashed just short of runway 27L at Heathrow.


Talking about the communications in this incident, I also thought back to US1549 and just listened to the recordings.
That is professionalism at its finest, efficient, concise.
Sully truly is a good pilot.

The UA328 pilot on the radio said his callsign wrong 2 times before the engine failed...and when it failed he was all over the radio instead of on his checklist.
I expect pilots paid 300K a year to show a little more focus than that, I'm certainly not going to applaud for not screwing up a very manageable situation.


Just to be clear, you're criticizing these guys for communicating with ATC while managing a serious emergency in busy airspace (including an uncontained engine failure on a heavy pointing directly into ~13000 foot mountains, necessitating an immediate turn while raining metal on a populated area) and you're...applauding Sullenberger's crew for doing pretty much the same thing, just because they speak a bit more clearly?
 
catiii
Posts: 3976
Joined: Mon Mar 31, 2008 1:18 am

Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 8:43 pm

CaptainHaresh wrote:
StTim wrote:
I am of two minds with the communication. Yes it was a little stressed, which showed, but it was a high workload situation and with high terrain ahead they did need a turn quite quickly so the communication was necessary. But whilst it was a little unclear it did not affect the outcome.

I am constantly amazed at the professionalism of the people that work under this pressure. The air traffic controller her. The air traffic controller and Sully on the miracle on the Hudson, The air traffic controllers and the BA pilot of the 777 that crashed just short of runway 27L at Heathrow.


Talking about the communications in this incident, I also thought back to US1549 and just listened to the recordings.
That is professionalism at its finest, efficient, concise.
Sully truly is a good pilot.

The UA328 pilot on the radio said his callsign wrong 2 times before the engine failed...and when it failed he was all over the radio instead of on his checklist.
I expect pilots paid 300K a year to show a little more focus than that, I'm certainly not going to applaud for not screwing up a very manageable situation.


Direct question: what was the "very manageable" situation? Also which is it? They screwed up? Or they managed it?
 
User avatar
airportugal310
Posts: 3771
Joined: Sun Apr 11, 2004 12:49 pm

Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 9:06 pm

B6twufa wrote:
CaptainHaresh wrote:
StTim wrote:
I am of two minds with the communication. Yes it was a little stressed, which showed, but it was a high workload situation and with high terrain ahead they did need a turn quite quickly so the communication was necessary. But whilst it was a little unclear it did not affect the outcome.

I am constantly amazed at the professionalism of the people that work under this pressure. The air traffic controller her. The air traffic controller and Sully on the miracle on the Hudson, The air traffic controllers and the BA pilot of the 777 that crashed just short of runway 27L at Heathrow.


Talking about the communications in this incident, I also thought back to US1549 and just listened to the recordings.
That is professionalism at its finest, efficient, concise.
Sully truly is a good pilot.

The UA328 pilot on the radio said his callsign wrong 2 times before the engine failed...and when it failed he was all over the radio instead of on his checklist.
I expect pilots paid 300K a year to show a little more focus than that, I'm certainly not going to applaud for not screwing up a very manageable situation.


Aren't you that flywithgarrett guy getting crucified online for doing that infamous YouTube video criticizing the crew?


Probably is!! This guy and that Garrett idiot deserve everything they get...
 
ethernal
Posts: 504
Joined: Mon May 06, 2019 12:09 pm

Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 9:24 pm

Sancho99504 wrote:
gobears19 wrote:
WIederling wrote:

The basic idea in this area is to adequately have checks and maintenance arranged such that deterioration is detected before things come apart.
This seems to have not worked here?


It seems to not work more often than we should be comfortable with. In the last 4 years in the US alone, we've had two 737 NG and two 777 blade off incidents all resulting in potential catastrophic events, including 1 death and potentially hundreds with PTSD. All 4 aircraft were aged with tens of thousands of cycles, and hundreds if not thousands of similar aircraft take to the skies everyday.

In the absence of data detailing how many events have been avoided due to more rigorous examination schedules, it concerns me that these exams aren't appearing to serve their purpose.

That's hard to say that they're not serving their purpose. When you think about it on a grand scale, there are over 3,000 CFM56-7 engines in operation. 2 out of over 3,000.
What may need to happen, similar to other fatigue issues that were found on aircraft fleets later in their lives, is that the inspection interval needs to be decreased. Instead of inspection every 3,000 hours, make it 2,000 hours.(not sure what the inspection interval is, so just throwing numbers out there)


Yes.. I am not trying to dismiss the failure (every incident is an opportunity to improve - and every incident could end worse) but if you reframe the "oh my gosh, we've had 4 blade off incidents and someone has died" to "it appears we have blade off incidents at a rate of 1 in 16 million flights and an apparent fatality rate of 1 fatality per 4 billion passengers" it puts things into context. Of course, any one of these incidents (especially the truly uncontained ones) could have been more catastrophic, so I am not trying to dismiss them.

As with any opportunity, investigators will figure out what happened and provide recommendations to (hopefully) be implemented. And we'll get incrementally safer. As we always do.

And, unfortunately, the only way to completely prevent these types of events would both extreme expense and likely require a cessation of progression of engine technology (to prevent new, previously undiscovered failure modes from arising). So, we will likely still - on very rare occasion - suffer through these events. The question is "are we improving on a per flight and per flight hour basis" or not. If the answer is "no", we probably need to find a broader root cause (are we pushing materials science to such a limit that is putting too many lives at risk?). But my hypothesis is that the answer is "yes" - we continue to improve.

The difference is that (1) COVID aside, more planes are flying every day meaning more chances for incidents and (2) everyone having a smart phone and being able to film things (both in the air, and in this case, on the ground). It makes the events much more "real" and memorable. A video of a flaming jet turbine is much more memorable than "A plane had a major engine failure and had to make an emergency landing."
 
User avatar
Blimpie
Posts: 318
Joined: Fri Mar 21, 2014 3:48 pm

Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 10:14 pm

mm320cap wrote:
CaptainHaresh wrote:
StTim wrote:
I am of two minds with the communication. Yes it was a little stressed, which showed, but it was a high workload situation and with high terrain ahead they did need a turn quite quickly so the communication was necessary. But whilst it was a little unclear it did not affect the outcome.

I am constantly amazed at the professionalism of the people that work under this pressure. The air traffic controller her. The air traffic controller and Sully on the miracle on the Hudson, The air traffic controllers and the BA pilot of the 777 that crashed just short of runway 27L at Heathrow.


Talking about the communications in this incident, I also thought back to US1549 and just listened to the recordings.
That is professionalism at its finest, efficient, concise.
Sully truly is a good pilot.

The UA328 pilot on the radio said his callsign wrong 2 times before the engine failed...and when it failed he was all over the radio instead of on his checklist.
I expect pilots paid 300K a year to show a little more focus than that, I'm certainly not going to applaud for not screwing up a very manageable situation.


Are you an airline pilot? What’s your profession “Captain”?


Upthread, he stated he flies for UA B787

I will leave it at that, and am staying out of it.
 
hivue
Posts: 2183
Joined: Tue Feb 26, 2013 2:26 am

Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 10:25 pm

slider wrote:
When were these blades last boroscoped?


Why would anyone borescope a fan blade?
 
GalaxyFlyer
Posts: 9178
Joined: Fri Jan 01, 2016 4:44 am

Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 10:29 pm

hivue wrote:
slider wrote:
When were these blades last boroscoped?


Why would anyone borescope a fan blade?


Because they heard a fancy word without knowing what a horoscope does and what it’s used for, so they thought it was cool.
 
ethernal
Posts: 504
Joined: Mon May 06, 2019 12:09 pm

Re: UA328 engine explosion at DEN

Tue Feb 23, 2021 10:50 pm

GalaxyFlyer wrote:
hivue wrote:
slider wrote:
When were these blades last boroscoped?


Why would anyone borescope a fan blade?


Because they heard a fancy word without knowing what a horoscope does and what it’s used for, so they thought it was cool.


Horoscope a blade? "Ahh, yes, this blade is a Cancer... based on the celestial bodies, it's going to have a really topsy-turvy, spinning, turbulent month.. we may need to remove it in case the stress gets to it!" ;)
 
Spetsnaz55
Posts: 352
Joined: Wed Feb 20, 2019 2:38 am

Re: UA328 engine explosion at DEN

Wed Feb 24, 2021 12:09 am

Can some more Captains or Pilots chime in on which way to turn with a failed engine?
 
User avatar
Aaron747
Posts: 17813
Joined: Thu Aug 07, 2003 2:07 am

Re: UA328 engine explosion at DEN

Wed Feb 24, 2021 12:14 am

Spetsnaz55 wrote:
Can some more Captains or Pilots chime in on which way to turn with a failed engine?


Are you referring to light twins or transport category jets? If it’s the latter, that has already been answered.
 
catiii
Posts: 3976
Joined: Mon Mar 31, 2008 1:18 am

Re: UA328 engine explosion at DEN

Wed Feb 24, 2021 12:53 am

Aaron747 wrote:
Spetsnaz55 wrote:
Can some more Captains or Pilots chime in on which way to turn with a failed engine?


Are you referring to light twins or transport category jets? If it’s the latter, that has already been answered.


And not by the “Captain.”

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