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Sports => VTTW Message Board => Topic started by: PirateVOL on February 23, 2021, 12:25:04 EST



Title: OT Jeesh, wonder what caused the engine issue on the United/Denver flight?
Post by: PirateVOL on February 23, 2021, 12:25:04 EST
(https://theairlinewebsite.com/uploads/monthly_2021_02/152844002_10224369972578942_3558511734802398052_n.jpg.408c76b8aacee918be91e74583773472.jpg)


Title: Re: OT Jeesh, wonder what caused the engine issue on the United/Denver flight?
Post by: Tnphil on February 23, 2021, 01:18:15 EST
https://www.dailymail.co.uk/news/article-9282215/United-Airlines-flight-makes-emergency-landing-dropping-debris.html


Title: Re: OT Jeesh, wonder what caused the engine issue on the United/Denver flight?
Post by: Black Diamond Vol on February 23, 2021, 05:38:03 EST
FTR, it wasn't me. :inughout:


Title: Re: OT Jeesh, wonder what caused the engine issue on the United/Denver flight?
Post by: PirateVOL on February 23, 2021, 02:54:11 EST
https://www.dailymail.co.uk/news/article-9282215/United-Airlines-flight-makes-emergency-landing-dropping-debris.html
There is so much bullshizzle that is flat out WRONG in that article! :bird:
The engine did NOT "explode"
In point of fact, per the NTSB, the blade failure that started the incident is still in the engine, imbedded in the ring that was designed to stop it from exiting the engine (should be at Pratt to be analyzed - NTSB chairman indicated it had markings consistent from a fatigue failure)
The blade it struck did depart the engine (the aero effects could have resulted in that occurrence) and has been found and recovered
The damage to the cowls and panels most likely are due to the vibration from the engine minus 1.5 blades in the fan (you can see it in the video)
The fire is probably an oil fire and is outside where the fire bottles discharge (both were discharged - per NTSB)


Title: Re: OT Jeesh, wonder what caused the engine issue on the United/Denver flight?
Post by: PirateVOL on February 23, 2021, 04:00:56 EST
(https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/780x438/210222211840_02_boeing_aircraft_engine_failure_ntsb_exlarge_169_2d5c840ec413100ede43af9c05b91b3388a29caa.jpg)

You can see the blades are hollow core titanium alloy blades (~10% non titanium)


Title: Re: OT Jeesh, wonder what caused the engine issue on the United/Denver flight?
Post by: BanditVol on February 23, 2021, 04:42:54 EST
There is so much bullshizzle that is flat out WRONG in that article! :bird:
The engine did NOT "explode"
In point of fact, per the NTSB, the blade failure that started the incident is still in the engine, imbedded in the ring that was designed to stop it from exiting the engine (should be at Pratt to be analyzed - NTSB chairman indicated it had markings consistent from a fatigue failure)
The blade it struck did depart the engine (the aero effects could have resulted in that occurrence) and has been found and recovered
The damage to the cowls and panels most likely are due to the vibration from the engine minus 1.5 blades in the fan (you can see it in the video)
The fire is probably an oil fire and is outside where the fire bottles discharge (both were discharged - per NTSB)


What?  A communications major got something wrong about a technical or scientific story?  Say it isn't so!  That never happens!   :dielaughing:


Title: Re: OT Jeesh, wonder what caused the engine issue on the United/Denver flight?
Post by: Coupe De VOL on February 23, 2021, 05:32:54 EST
One little grain of sand striking the blade at just the right spot can cause such a failure.  However the resulting damage initially is just a teeny tiny microfracture that can grow and accelerate the so called metal fatigue.  Routine inspections are supposed to look for the tell tale signs of such things.  I had a really good prof for an aerospace materials & structures class BITD and he had been a NTSB type inspector in Europe.  He investigated a few jet engine failures.  Of course the engine tech today is probably a whole lot different than it was in his day.  He told us some great stories, like the possibility of cascade failure that those rings you mention protect against.  One blade fails and it can take out most of the engine blade array.  He also talked of a case, or cases?, where cascade failure occurred and blades had been thrown threw the cabin!  IIRC, there was a case of death involved.  Pretty cool stuff.  It could have all started with one little grain of sand - amazing to think about.  Really amazing when you consider today's safety records.


Title: Re: OT Jeesh, wonder what caused the engine issue on the United/Denver flight?
Post by: PirateVOL on February 23, 2021, 06:24:16 EST
What?  A communications major got something wrong about a technical or scientific story?  Say it isn't so!  That never happens!   :dielaughing:
There was a very similar incident with a Pratt engine on the 777 in 2018
The upshot is that Pratt had developed a thermal imaging system to detect issues in the hollow core surface and through 2 inspections failed to act on an anomaly in the blade
A result of that incident was an AD
The very first question to the NTSB chairman last night was if the engine was in compliance with the AD
Answer:  we don't know yet



Title: Re: OT Jeesh, wonder what caused the engine issue on the United/Denver flight?
Post by: 10EC on February 24, 2021, 07:05:08 EST
There was a very similar incident with a Pratt engine on the 777 in 2018
The upshot is that Pratt had developed a thermal imaging system to detect issues in the hollow core surface and through 2 inspections failed to act on an anomaly in the blade
A result of that incident was an AD
The very first question to the NTSB chairman last night was if the engine was in compliance with the AD
Answer:  we don't know yet



Wasn’t there an MD88 in Panama City or somewhere near the beach that that happened to on the ground.  I think it killed a woman.


Title: Re: OT Jeesh, wonder what caused the engine issue on the United/Denver flight?
Post by: PirateVOL on February 24, 2021, 07:13:06 EST
Wasn’t there an MD88 in Panama City or somewhere near the beach that that happened to on the ground.  I think it killed a woman.
Pensacola if I recall

Here it is:
https://en.wikipedia.org/wiki/Delta_Air_Lines_Flight_1288 (https://en.wikipedia.org/wiki/Delta_Air_Lines_Flight_1288)


Title: Re: OT Jeesh, wonder what caused the engine issue on the United/Denver flight?
Post by: Tnphil on February 24, 2021, 08:58:50 EST
Spent many hours as a final checker on the flight deck of a carrier....I never wrote "not that serious" in any maintenance logs....I let the maintenance chief do it. :biggrin:


Title: Re: OT Jeesh, wonder what caused the engine issue on the United/Denver flight?
Post by: BanditVol on March 01, 2021, 05:55:42 EST
One little grain of sand striking the blade at just the right spot can cause such a failure.  However the resulting damage initially is just a teeny tiny microfracture that can grow and accelerate the so called metal fatigue.  Routine inspections are supposed to look for the tell tale signs of such things.  I had a really good prof for an aerospace materials & structures class BITD and he had been a NTSB type inspector in Europe.  He investigated a few jet engine failures.  Of course the engine tech today is probably a whole lot different than it was in his day.  He told us some great stories, like the possibility of cascade failure that those rings you mention protect against.  One blade fails and it can take out most of the engine blade array.  He also talked of a case, or cases?, where cascade failure occurred and blades had been thrown threw the cabin!  IIRC, there was a case of death involved.  Pretty cool stuff.  It could have all started with one little grain of sand - amazing to think about.  Really amazing when you consider today's safety records.

Are you talking about Wilkerson?  Great prof.  I learned quite a bit from him.


Title: Re: OT Jeesh, wonder what caused the engine issue on the United/Denver flight?
Post by: PirateVOL on March 01, 2021, 06:05:46 EST
Spent many hours as a final checker on the flight deck of a carrier....I never wrote "not that serious" in any maintenance logs....I let the maintenance chief do it. :biggrin:
In the AF there is a thing called Exceptional Release.
It is where one signs in the aircraft forms to indicate the aircraft is safe to fly.
When I qualified for that the pucker factor increased exponentially.
The great thing is that every aircraft I signed the ER came back safely.
Now there were a couple of times the getting back safely was almost compromised by pilot shizzle but there you go.