Southwest oopsie - ‘woman partially sucked out of window’

Fearless Tower said:
How does a single fan blade (which based on the latest NTSB photos appears to be the case with SWA 1380) cause that kind of catastrophic damage?
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I'm no jet engine mechanic, but I do understand the concepts behind them. Just from my uneducated eye, it seems to me that there's a tremendous pressure build up (possibly due to a compressor stage failure) that somehow allows the gases to backflow through the fan or low pressure compressor side and thus cause a miniature explosion. The pics I've seen don't look like a fan/compressor blade failure. They're more reminiscent of damage from a blast or a high pressure failure as the shrouding and the protective honeycomb (kevlar/carbon fiber?) shielding inside the nacelle is literally torn/ripped to shreds. Seems to me a fan blade failure would more contained and more "cleaner" (damage wise) if you will. I used to be in the destructive testing business (oil field BOPs, pumps, tubular goods, etc) and when the components fail (usually from fatigued metal) they're not clean breaks. They're usually all jagged/deformed with no defined pattern. The pics of those jet engines just reminded me of some of the stuff I blew up when I was in the oil patch. :cool:
 
midwestpa24 said:
From an pure statistical standpoint, Part 121 aviation has the safest record per passenger seat mile. Part 91 private and 135 charter operations have a higher incident rate per seat mile.
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Oh I'm not arguing that point at all... simply thinking there may have been a very ironic discussion previously, considering the profession of the person that died.
 
PaulS said:
I believe they were performing ultrasonic tests on the blades after the last incident.
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They were. Having been part of similar inspections on F-15/F-16 Engines, it’s not the easiest thing to do in the field.

My observation had more to do with the hullabaloo over Allegiant and the 60 Minutes “investigation” and the inevitable “we have to do something!” mentality of Congress. Technically, I would be comfortable with just periodic untrasound given what I think I know but political pressure could result in more useless design changes like a bigger/longer containment ring. Predicting where a failed blade will go is a total crap shoot.

Cheers
 
azblackbird said:
I'm no jet engine mechanic, but I do understand the concepts behind them. Just from my uneducated eye, it seems to me that there's a tremendous pressure build up (possibly due to a compressor stage failure) that somehow allows the gases to backflow through the fan or low pressure compressor side and thus cause a miniature explosion. The pics I've seen don't look like a fan/compressor blade failure. They're more reminiscent of damage from a blast or a high pressure failure as the shrouding and the protective honeycomb (kevlar/carbon fiber?) shielding inside the nacelle is literally torn/ripped to shreds. Seems to me a fan blade failure would more contained and more "cleaner" (damage wise) if you will. I used to be in the destructive testing business (oil field BOPs, pumps, tubular goods, etc) and when the components fail (usually from fatigued metal) they're not clean breaks. They're usually all jagged/deformed with no defined pattern. The pics of those jet engines just reminded me of some of the stuff I blew up when I was in the oil patch. :cool:
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Definitely a blade failed and maybe more.

What you’re describing is an engine stall or surge. Almost impossible to cause that kind of damage. Happens a lot and other than a precautionary shutdown, usually not a really big deal but can scare the s*** out of you. Ask me how I know. If the cause of the stall/surge was a failed part like FOD breaking a blade, the damage starts with the failure and that can be much more serious.

Cheers
 
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X3 Skier said:
They were. Having been part of similar inspections on F-15/F-16 Engines, it’s not the easiest thing to do in the field.

My observation had more to do with the hullabaloo over Allegiant and the 60 Minutes “investigation” and the inevitable “we have to do something!” mentality of Congress. Technically, I would be comfortable with just periodic untrasound given what I think I know but political pressure could result in more useless design changes like a bigger/longer containment ring. Predicting where a failed blade will go is a total crap shoot.

Cheers
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I think they need to be a little more aggressive, like a one time full inspection of each one of these engines to be completed over a reasonable amount of time. If it involves disassembling the rotor then so be it. This type of action happens more often than I think we might suspect, only it's generally before a disaster happens. Hopefully they can link this to a series of blades rather than an inherent design flaw.
 
PaulS said:
I think they need to be a little more aggressive, like a one time full inspection of each one of these engines to be completed over a reasonable amount of time. If it involves disassembling the rotor then so be it. This type of action happens more often than I think we might suspect, only it's generally before a disaster happens. Hopefully they can link this to a series of blades rather than an inherent design flaw.
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do you realize how many of those engines are fielded and operational?....I'm told thousands with tons of flight hours....and we have how many failures?

One of the most popular jet engines in the world, the CFM56-7B can be found on more than 6,700 aircraft.
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Checkout_my_Six said:
do you realize how many of those engines are fielded and operational?....I'm told thousands with tons of flight hours....and we have how many failures?
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One too many is going to be the correct answer. Of course we don’t know what exactly failed or even whether the fan blade departure was the cause or a result of the failure.

But go inspect something by all means...
 
Checkout_my_Six said:
do you realize how many of those engines are fielded and operational?....I'm told thousands with tons of flight hours....and we have how many failures?
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Didn't we have a nearly identical uncontained failure on another Southwest jet last year?

If both were in the same place and were from fatigue, its probably not a coincidence.
 
Clark1961 said:
One too many is going to be the correct answer. Of course we don’t know what exactly failed or even whether the fan blade departure was the cause or a result of the failure.

But go inspect something by all means...
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depends....on the cost analysis. google CFM56-7B....there are others and a Lesson's Learned case study too.
 
The inlet cowl has very little in it and I can't believe that a single blade caused teh e
Fearless Tower said:
How does a single fan blade (which based on the latest NTSB photos appears to be the case with SWA 1380) cause that kind of catastrophic damage?
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I agree. The inlet cowl has very little in it and I can't believe that a single blade destroyed the cowl. How does a blade move forward and shred the entire inlet cowl? It strike me like Kennedy's magic bullet. If anyone claims that it happened, I need to understand the positioning and trajectory to understand how it can happen. All the rest of the of the debris flew backwards and didn't even hit the plane for several rows of seating.

The other idea I've heard proposed is something with the deice system, which takes air from the exhaust system. An over pressurization here could have caused the cowl to explode and come from together. This seems more reasonable, but I don't know the systems well enough to state that it's what I think.
 
dell30rb said:
Didn't we have a nearly identical uncontained failure on another Southwest jet last year?

If both were in the same place and were from fatigue, its probably not a coincidence.
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Yes, aug 2016 over the Gulf of Mexico. The damage is nearly identical and it was also a SWA plane. There are pictures higher in the thread.
 
just heard the whole transmission... Kudos to the captain .. she is dead calm..... man she got some balls
 
Clark1961 said:
One too many is going to be the correct answer. Of course we don’t know what exactly failed or even whether the fan blade departure was the cause or a result of the failure.

But go inspect something by all means...
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“One too many” is a non answer. Zero is only possible if every airplane in the world is grounded and then somebody will pull the gear handle and collapse the gear on something or somebody.

Cheers
 
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WannFly said:
just heard the whole transmission... Kudos to the captain .. she is dead calm..... man she got some balls
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I hope she doesn't. Have balls that is!

But, yes, she was cool, calm, and collected. Being up front and receiving messages from the flight attendants in the cabin is difficult because pilots can't leave the cockpit, so they're not exactly sure what is going on. She and her FO did well, and ATC, especially the last controller in the video above, were excellent also. The Capt even went beyond after landing and talked to all the passengers after they landed.

Well done Capt and crew, to include the FAs. And ATC! They all did what they were trained for and did it well.
 
bflynn said:
The inlet cowl has very little in it and I can't believe that a single blade caused teh e


I agree. The inlet cowl has very little in it and I can't believe that a single blade destroyed the cowl. How does a blade move forward and shred the entire inlet cowl? It strike me like Kennedy's magic bullet. If anyone claims that it happened, I need to understand the positioning and trajectory to understand how it can happen. All the rest of the of the debris flew backwards and didn't even hit the plane for several rows of seating.

The other idea I've heard proposed is something with the deice system, which takes air from the exhaust system. An over pressurization here could have caused the cowl to explode and come from together. This seems more reasonable, but I don't know the systems well enough to state that it's what I think.
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The blade didn’t total the cowl. Damage from the blade probably opened the cowl skin to the airflow and the 450kt or so airstream did the real damage. Predicting where a failed blade will go before it departs the airframe is about as simple as predicting the lotto winning numbers:D

Cheers
 
PaulS said:
Agreed, but being sucked out the window certainly makes the situation much worse. It will be interesting to see if she had her belt on. Even if she hadn't been wearing her belt though, this is in no way her fault, may she RIP.
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Doen’t matter. Even if she had her belt on and tight, you’d probably need to be in a 5 point harness snugged down to keep from moving under 8.6 PSID. That automobile seatbelt isn’t going to keep you in your seat if the window next to you goes at FL380.
 
WannFly said:
just heard the whole transmission... Kudos to the captain .. she is dead calm..... man she got some balls
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Night carrier landing on a pitching deck in weather in an F-18 with min fuel and no ACLS gives one some ability to handle a little thing like an in-flight engine failure:cool:.

Add my kudos to the entire crew.

Cheers
 
Checkout_my_Six said:
do you realize how many of those engines are fielded and operational?....I'm told thousands with tons of flight hours....and we have how many failures?
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Clark1961 said:
One too many is going to be the correct answer. Of course we don’t know what exactly failed or even whether the fan blade departure was the cause or a result of the failure.

But go inspect something by all means...
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You guys don't seem to understand, this is never supposed to happen. If a blade fails, the engine is designed to keep that blade contained, which essentially means it is not supposed cause the outside of the engine to breach. This particular model of engine has had two of these failures within a few years, something is wrong. If they can't trace it to a particular part or maintenance practice, then f it, pull them apart and inspect them. Bravado is absolutely f'ng stupid in this situation. Err to caution is warranted before it happens again.
 
X3 Skier said:
“One too many” is a non answer. Zero is only possible if every airplane in the world is grounded and then somebody will pull the gear handle and collapse the gear on something or somebody.

Cheers
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Actually ‘one too many’ is a real world answer. Ask any insurance company.
 
Is a fan blade missing by the man's elbow in this photo?


180417204557-02-ntsb-southwest-exlarge-169.jpg


Edit, it must be the missing No. 13 blade that's being mentioned in this excerpt from flightglobal.com

An NTSB 'Go Team' dispatched to Philadelphia focused on the missing Number 13 fan blade in the left engine, which had separated at the point where the blade attaches to the hub.

“Our preliminary examination of this was that there was evidence of metal fatigue where the blade separated,” says NTSB chairman Robert Sumwalt.

The fan blade failure marks the second such event in a CFM56-7B installed on a Boeing 737-700 since August 2016. In that incident, the NTSB blamed metal fatigue for a similar fan blade separation in a separate Southwest Airlines 737-700. In 2017, the US Federal Aviation Administration issued an airworthiness directive in response to that incident, mandating ultrasonic inspection procedures for certain CFM56 engines.

It was not yet known if the engine onboard flight 1380 on 17 April was subject to the inspections called for under the airworthiness directive, Sumwalt says.​
 
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X3 Skier said:
The blade didn’t total the cowl. Damage from the blade probably opened the cowl skin to the airflow and the 450kt or so airstream did the real damage. Predicting where a failed blade will go before it departs the airframe is about as simple as predicting the lotto winning numbers:D
Cheers
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There are videos out there on containment tests where a charge is used to separate a blade. This makes me wonder if blade detachment is necessarily so clean. Terrible tragedy for that woman and her family.
 
Clark1961 said:
Actually ‘one too many’ is a real world answer. Ask any insurance company.
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If zero were possible, nobody would need insurance:D. Just wondering what you think is an acceptable number of these kinds of failures so that one more is one too many. IIRC, the number we used in the USAF was around 1 in-flight shutdown from all causes per 100000 flight hours at 1000000 flight hours total operation.

Cheers
 
X3 Skier said:
What you’re describing is an engine stall or surge
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More like a reverse stall that allows pressure to build up forward of the low speed compressor and fan. Combine that with the inlet pressure and you have the makings of a mini explosion... enough to blow apart anything forward of the fan itself. Can a tossed blade be the precursor? Sure it could, especially if it makes it way back to the high speed compressor and stalls it out. Just my theory. :dunno:
 
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azblackbird said:
More like a reverse stall that allows pressure to build up forward of the low speed compressor and fan. Combine that with the inlet pressure and you have the makings of a mini explosion... enough to blow apart anything forward of the fan itself. Can a tossed blade be the precursor? Sure it could, especially if it makes it way back to the high speed compressor and stalls it out. Just my theory. :dunno:
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Not to belabor the point, but that’s exactly what happens in a stall/surge. Because it can happen for many reasons, misrigging varible geometry, damage, excessive clearances, wear, etc. and is considered inevitable, the inlet is designed with considerable margin to withstand a stall at max power at max total inlet pressure.

Cheers
 
X3 Skier said:
Not to belabor the point, but that’s exactly what happens in a stall/surge. Because it can happen for many reasons, misrigging varible geometry, damage, excessive clearances, wear, etc. and is considered inevitable, the inlet is designed with considerable margin to withstand a stall at max power at max total inlet pressure.
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So what the heck is causing that much damage? Looks to me like too much pressure is building up somewhere and causing a failure. Almost as if somebody tossed a grenade into the inlet.
 
azblackbird said:
So what the heck is causing that much damage? Looks to me like too much pressure is building up somewhere and causing a failure. Almost as if somebody tossed a grenade into the inlet.
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As I posted earlier, I think the blade ripped open the skin of the inlet and the 450kt+ Wind did the rest.

Cheers
 
AWACSEng said:
Doesn't really matter in a loss of cabin pressure at high altitude, they aren't pressure masks, just a breeze flowing across your face. Once lower, yeah they might help some...
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The oxygen flow increases the oxygen partial-pressure to reduce the effects of hypoxia during the emergency descent.
 
PaulS said:
You guys don't seem to understand, this is never supposed to happen. If a blade fails, the engine is designed to keep that blade contained, which essentially means it is not supposed cause the outside of the engine to breach. This particular model of engine has had two of these failures within a few years, something is wrong. If they can't trace it to a particular part or maintenance practice, then f it, pull them apart and inspect them. Bravado is absolutely f'ng stupid in this situation. Err to caution is warranted before it happens again.
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What is not known.....did the blade fail first or was it a secondary or tertiary failure.....but, it's early yet.
 
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X3 Skier said:
As I posted earlier, I think the blade ripped open the skin of the inlet and the 450kt+ Wind did the rest.
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You're probably right. Just googled fan blade failures and most all look like the SW pics. Some are worse than others. I guess it just all depends on how they come apart.
 
Sluggo63 said:
Doen’t matter. Even if she had her belt on and tight, you’d probably need to be in a 5 point harness snugged down to keep from moving under 8.6 PSID. That automobile seatbelt isn’t going to keep you in your seat if the window next to you goes at FL380.
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Maybe not the window, but if your 737 suddenly becomes a convertible, you'll be OK.
 

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mryan75 said:
Boy, glad you guys find this so funny! The woman friggin' died. Stay classy!
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Well to be clear, it wasn't reported that she had passed away when I posted that, nor did it give much of any extent of injuries sustained. Ever heard of gallows humor? ie., making light of something in a troubling time.

No, I do not find this funny in the least.
 
X3 Skier said:
If zero were possible, nobody would need insurance:D. Just wondering what you think is an acceptable number of these kinds of failures so that one more is one too many. IIRC, the number we used in the USAF was around 1 in-flight shutdown from all causes per 100000 flight hours at 1000000 flight hours total operation.

Cheers
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Same plane, same engine, same carrier and (allowing the assumption) same cause in 2 years is different than none of those things being true and happening 20 years apart.
 
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