Southwest flight 1380 makes emergency landing in Philadelphia after engine failure

[Svnla]

Metal fatigue could be the cause for the engine failure - https://www.bloomberg.com/news/arti...west-jet-is-forced-to-land-with-engine-damage

 

[Atreus21]

Cool story about her in WP: https://www.washingtonpost.com/news...flight-and-broke-barriers-as-a-fighter-pilot/

One of the first female fighter pilots.

Cool as a cucumber the whole time. God bless this woman.

 

[Zorba]

For those interested, the FAA released an NPRM to inspect the fan blades on 8/25/2017, unfortantly it can take a long time to publish into a full rule and still has not been released as an AD. https://www.federalregister.gov/doc...ectives-cfm-international-sa-turbofan-engines

The NPRM is in response to Southwest flight 3472 on 8/27/2016, which appears to be very similar to this case. Here is the discussion section from that NPRM:

We received a report of a fan blade failure and inlet separation on a CFM56-7B engine that occurred during a revenue flight. This fan blade failure was contained by the engine case, but there was subsequent uncontained forward release of inlet cowl and other debris. The fracture in the blade initiated from the fan blade dovetail. The investigation, however, into the root cause of the fan blade failure is not complete. This condition, if not corrected, could result in fan blade failure, uncontained forward release of debris, damage to the engine, and damage to the airplane.

Just don't sit perpendicular to one of the engines and you should be relatively safe.

The damaged window was significantly aft of the engine, because the debris that hit the window was not high energy engine parts, but debris from the nose cowling that liberated from the engine nacelle. The fan blade itself appears to have been full contained as required/designed. High energy engine parts would've been much closer to radially outward from the engine and would've kept going through the fuselage.

The engine blew at 32500 feet and shattered the window. At that altitude its a miracle the plane didn't break up due to rapid decompression.

Great job by the pilots guiding it back to the ground and saving almost everyone.

The window only carries its own pressure loads, no other structural loads. The only loads from a decompression that could cause the airframe to come apart would be from trapped pressurized air. There are blow out panels all over the place to ensure no matter where the hole opens up, pressurized air can flow to it and will not be trapped. Loss of pressure reduces stress on the airframe, overall though, and there have been many rapid decompressions on 737s in the past with no secondary damage to the airframe.

The well know "depressurization cause the plane to explode" cases have their cause and effect backwards. The structure failed, which lead to decompression.

These engines spin at great speed and supposedly the cowling would stop projectiles from hitting the fuselage, it's far from foolproof it seems.

It appears that fan case fully contained the fan blade, but the stationary nose cowl came apart and liberated. Engines must prove containment of a full fan blade for engine certification, this is done at rotor red line speed, with an induced head wind similar to takeoff speeds. The inlet is part of that testing, however since this happened at altitude with an airspeed of a few hundred knots, the load on the inlet was probably higher than during the fan blade out test.

The NTSB has not released their report of the very similar incident on 8/27/2016, but they did release that the fan blade was contained, but the nose cowling failed. I am guessing they are still trying to figure out why the nose cowling failed because generally a final report for an engine event just takes about a year.

Hell, the pilot seems 10X as calm as the controllers on the ground. In any event, they were sorta lucky in that none of that flying shrapnel disabled any of the hydraulics and they had control throughout it seems.

The 737 has two fully independent hydraulic systems (and a standby system that isn't fully independent), either one is fully capable of controlling the aircraft and they did likely lose their left system (definitely lost the engine pump, if lines were damaged they probably lost the whole system, otherwise the smaller electric pump would provide some hydraulic power). But the 737 can also fly with no hydraulics, there are manual controls for the critical flight controls, and backups to unlock the gear and power the brakes.

Further, it is required for certification to do an analysis that shows no high energy engine component could take out any two redundant systems, i.e. two hydraulic systems, flight control cables, or electric buses. You do this analysis assuming everything within a cone is completely removed from the aircraft and you look at that cone in every angle around the engine. This is one reason the engines are in front of the wings and not under them.

It is also interesting to note, that the FAA does not considering killing one or two passengers catastrophic, as long as the aircraft can have "continued safe flight and landing." So you are allowed to kill people more often that you are allowed to lose an entire aircraft.

It's pretty rare so you're still more likely to die on the way to the airport than from the flight itself. There seem to be mixed reports so far on exactly what happened to the poor woman but I wonder if she was wearing her seatbelt or not. I always keep mine on due to the turbulence injuries and this so I'm curious to know if that would have mattered or not.

I'll be interested if she had her belt on, but I really doubt it would have helped much, it may have been what kept her from going all the way out. But the seat is very close to the window at that point and there could've been over a thousand pounds of force acting on her.

FYI, for those wondering about the masks, the standard oxygen generator can provide oxygen for only 12 minutes. Once an aircraft losses pressure, the flight crew will start an emergency descent to 10,000 feet, where people can breath normally. There are some routes over South America were mountains can prevent descent below 10,000 in 12 minutes and those aircraft have 20 minute generators. There are some other special cases out there, like over Greenland, planes could have to stay at 14,000 for 45 minutes, so you have to provide supplemental O2 for 10% of the passengers.

So by the time people had time to start doing the selfies, they may have been at a breathable altitude or just breathing through their mouths because air from generators smells bad.

 

[Doc Savage Fan]

The damaged window was significantly aft of the engine, because the debris that hit the window was not high energy engine parts, but debris from the nose cowling the liberated from the engine. The fan blade itself appears to have been full contained as required/designed. High energy engine parts would've been much closer to radially outward from the engine and would've kept going through the fuselage.

Excellent points! I just assumed it was thrown blade. Thanks for clarifying what actually happened.

 

[Zorba]

Excellent points! I just assumed it was thrown blade. Thanks for clarifying what actually happened.

Here is a picture that shows it, second window behind the "T":

 

[Doc Savage Fan]

^ Listen to Zorba. He knows what he's talking about.

 

[Hayabusa Rider]

Here's some footage from inside the cabin during the inflight emergency.

Here's an explanation of the problem.

Too soon, but I wondered as the page was loading if someone was going to link to Shatner in The Twilight Zone.

 

[Zorba]

I would like to add the pilots did do an excellent job. They train annually for engine out and for loss of pressure, but not for as a simultaneous failure. They have to don their masks very rapidly to prevent themselves from passing out, and their masks don't fall automatically. The pressure warning would've just been one of many warnings going off at the time, and it is very good they did not become fixated on the engine fire warnings and recognized the loss of pressure and donned their masks correctly.

If you look at their flight tract, they also picked the best airport for the diversion based on their altitude. They basically descended at a nearly constant rate all the way in and were on the ground in 20 minutes, at a city with good emergency services and trauma hospitals.

 

[Puffnstuff]

No doubt that having good pilots helped to mitigate this tragedy.

 

[Thebobo]

For those interested, the FAA released an NPRM to inspect the fan blades on 8/25/2017, unfortantly it can take a long time to publish into a full rule and still has not been released as an AD. https://www.federalregister.gov/doc...ectives-cfm-international-sa-turbofan-engines

The NPRM is in response to Southwest flight 3472 on 8/27/2016, which appears to be very similar to this case. Here is the discussion section from that NPRM:





The damaged window was significantly aft of the engine, because the debris that hit the window was not high energy engine parts, but debris from the nose cowling that liberated from the engine nacelle. The fan blade itself appears to have been full contained as required/designed. High energy engine parts would've been much closer to radially outward from the engine and would've kept going through the fuselage.



The window only carries its own pressure loads, no other structural loads. The only loads from a decompression that could cause the airframe to come apart would be from trapped pressurized air. There are blow out panels all over the place to ensure no matter where the hole opens up, pressurized air can flow to it and will not be trapped. Loss of pressure reduces stress on the airframe, overall though, and there have been many rapid decompressions on 737s in the past with no secondary damage to the airframe.

The well know "depressurization cause the plane to explode" cases have their cause and effect backwards. The structure failed, which lead to decompression.



It appears that fan case fully contained the fan blade, but the stationary nose cowl came apart and liberated. Engines must prove containment of a full fan blade for engine certification, this is done at rotor red line speed, with an induced head wind similar to takeoff speeds. The inlet is part of that testing, however since this happened at altitude with an airspeed of a few hundred knots, the load on the inlet was probably higher than during the fan blade out test.

The NTSB has not released their report of the very similar incident on 8/27/2016, but they did release that the fan blade was contained, but the nose cowling failed. I am guessing they are still trying to figure out why the nose cowling failed because generally a final report for an engine event just takes about a year.



The 737 has two fully independent hydraulic systems (and a standby system that isn't fully independent), either one is fully capable of controlling the aircraft and they did likely lose their left system (definitely lost the engine pump, if lines were damaged they probably lost the whole system, otherwise the smaller electric pump would provide some hydraulic power). But the 737 can also fly with no hydraulics, there are manual controls for the critical flight controls, and backups to unlock the gear and power the brakes.

Further, it is required for certification to do an analysis that shows no high energy engine component could take out any two redundant systems, i.e. two hydraulic systems, flight control cables, or electric buses. You do this analysis assuming everything within a cone is completely removed from the aircraft and you look at that cone in every angle around the engine. This is one reason the engines are in front of the wings and not under them.

It is also interesting to note, that the FAA does not considering killing one or two passengers catastrophic, as long as the aircraft can have "continued safe flight and landing." So you are allowed to kill people more often that you are allowed to lose an entire aircraft.



I'll be interested if she had her belt on, but I really doubt it would have helped much, it may have been what kept her from going all the way out. But the seat is very close to the window at that point and there could've been over a thousand pounds of force acting on her.

FYI, for those wondering about the masks, the standard oxygen generator can provide oxygen for only 12 minutes. Once an aircraft losses pressure, the flight crew will start an emergency descent to 10,000 feet, where people can breath normally. There are some routes over South America were mountains can prevent descent below 10,000 in 12 minutes and those aircraft have 20 minute generators. There are some other special cases out there, like over Greenland, planes could have to stay at 14,000 for 45 minutes, so you have to provide supplemental O2 for 10% of the passengers.

So by the time people had time to start doing the selfies, they may have been at a breathable altitude or just breathing through their mouths because air from generators smells bad.

Did you see just last week the episode on 60 minutes about FAA changing their rules on how they handle directives. Seems now the FAA just lets the airlines police themselves, it seems now.

https://www.cbsnews.com/news/allegiant-air-the-budget-airline-flying-under-the-radar/

 

[Linux23]

I would like to add the pilots did do an excellent job. They train annually for engine out and for loss of pressure, but not for as a simultaneous failure. They have to don their masks very rapidly to prevent themselves from passing out, and their masks don't fall automatically. The pressure warning would've just been one of many warnings going off at the time, and it is very good they did not become fixated on the engine fire warnings and recognized the loss of pressure and donned their masks correctly.

If you look at their flight tract, they also picked the best airport for the diversion based on their altitude. They basically descended at a nearly constant rate all the way in and were on the ground in 20 minutes, at a city with good emergency services and trauma hospitals.

Are you a pilot? Your posts are very informative.

 

[Stopsignhank]

"We are just going to stop here by the fire trucks. Thank you guys for the help"

How awesome is that??!!!! So cool to here how fantastic she was in this emergency.

 

[feralkid]

Excellent points! I just assumed it was thrown blade. Thanks for clarifying what actually happened.

Thanks for your previous post, which was direct from outofyouruninformedass.com Next time, maybe think before you post?

 

[Zorba]

Are you a pilot? Your posts are very informative.

I'm an aerospace engineer with quite a bit of direct experience.

 

[hal2kilo]

Thanks for your previous post, which was direct from outofyouruninformedass.com Next time, maybe think before you post?

Not in the habit of defending DSF but WTF.

 

[Doc Savage Fan]

Thanks for your previous post, which was direct from outofyouruninformedass.com Next time, maybe think before you post?

I actually know a little something about turbine failures (in an industrial environment) and incorrectly extrapolated to an airplane gas turbine engine. Why are you being such a complete dick?

 

[Zorba]

Did you see just last week the episode on 60 minutes about FAA changing their rules on how they handle directives. Seems now the FAA just lets the airlines police themselves, it seems now.

https://www.cbsnews.com/news/allegiant-air-the-budget-airline-flying-under-the-radar/

I didn't watch it, but just read most of the transcript. When I worked at an airline the FAA was very much up in our business and proposed fines a lot. I talked to the FAA at least once a week. But I haven't dealt with the FAA and that article makes it sound like things have changed, which I disagree with.

Even at the height of our adversal relationship with the FAA, though, the likelihood of being fined over one off failures was very low. In the case of the jammed controls, that would've resulted in a fine, though.

One huge problem now, though, is most airlines send heavy maintenance/modification work out of the US, and the FAA provides much less oversight, due to cost and logistics. They also almost always annouce they are coming, where in the US they'll just pop in all the time.

Even with all of the FAAs problems, aviation is still the most highly regulated industries with the most direct oversight. This is why it is by far the safest form of transportation.

 

[Puffnstuff]

Not in the habit of defending DSF but WTF.

Must be off his meds today as that isn't the only one like that.

 

[Darwin333]

The engine blew at 32500 feet and shattered the window. At that altitude its a miracle the plane didn't break up due to rapid decompression.

Great job by the pilots guiding it back to the ground and saving almost everyone.

Why would decompression cause the plane to break up?

 

[Svnla]

Can you get sucked out of an airplane? http://www.foxnews.com/travel/2018/04/17/can-get-sucked-out-airplane.html

 

[Puffnstuff]

Can you get sucked out of an airplane? http://www.foxnews.com/travel/2018/04/17/can-get-sucked-out-airplane.html

I remember in 1988 that another 737 had an inflight incident. Aloha flight 243 had an explosive decompression when the roof ripped off that expelled a flight attendant.

 

[BUTCH1]

For those interested, the FAA released an NPRM to inspect the fan blades on 8/25/2017, unfortantly it can take a long time to publish into a full rule and still has not been released as an AD. https://www.federalregister.gov/doc...ectives-cfm-international-sa-turbofan-engines

The NPRM is in response to Southwest flight 3472 on 8/27/2016, which appears to be very similar to this case. Here is the discussion section from that NPRM:





The damaged window was significantly aft of the engine, because the debris that hit the window was not high energy engine parts, but debris from the nose cowling that liberated from the engine nacelle. The fan blade itself appears to have been full contained as required/designed. High energy engine parts would've been much closer to radially outward from the engine and would've kept going through the fuselage.



The window only carries its own pressure loads, no other structural loads. The only loads from a decompression that could cause the airframe to come apart would be from trapped pressurized air. There are blow out panels all over the place to ensure no matter where the hole opens up, pressurized air can flow to it and will not be trapped. Loss of pressure reduces stress on the airframe, overall though, and there have been many rapid decompressions on 737s in the past with no secondary damage to the airframe.

The well know "depressurization cause the plane to explode" cases have their cause and effect backwards. The structure failed, which lead to decompression.



It appears that fan case fully contained the fan blade, but the stationary nose cowl came apart and liberated. Engines must prove containment of a full fan blade for engine certification, this is done at rotor red line speed, with an induced head wind similar to takeoff speeds. The inlet is part of that testing, however since this happened at altitude with an airspeed of a few hundred knots, the load on the inlet was probably higher than during the fan blade out test.

The NTSB has not released their report of the very similar incident on 8/27/2016, but they did release that the fan blade was contained, but the nose cowling failed. I am guessing they are still trying to figure out why the nose cowling failed because generally a final report for an engine event just takes about a year.



The 737 has two fully independent hydraulic systems (and a standby system that isn't fully independent), either one is fully capable of controlling the aircraft and they did likely lose their left system (definitely lost the engine pump, if lines were damaged they probably lost the whole system, otherwise the smaller electric pump would provide some hydraulic power). But the 737 can also fly with no hydraulics, there are manual controls for the critical flight controls, and backups to unlock the gear and power the brakes.

Further, it is required for certification to do an analysis that shows no high energy engine component could take out any two redundant systems, i.e. two hydraulic systems, flight control cables, or electric buses. You do this analysis assuming everything within a cone is completely removed from the aircraft and you look at that cone in every angle around the engine. This is one reason the engines are in front of the wings and not under them.

It is also interesting to note, that the FAA does not considering killing one or two passengers catastrophic, as long as the aircraft can have "continued safe flight and landing." So you are allowed to kill people more often that you are allowed to lose an entire aircraft.



I'll be interested if she had her belt on, but I really doubt it would have helped much, it may have been what kept her from going all the way out. But the seat is very close to the window at that point and there could've been over a thousand pounds of force acting on her.

FYI, for those wondering about the masks, the standard oxygen generator can provide oxygen for only 12 minutes. Once an aircraft losses pressure, the flight crew will start an emergency descent to 10,000 feet, where people can breath normally. There are some routes over South America were mountains can prevent descent below 10,000 in 12 minutes and those aircraft have 20 minute generators. There are some other special cases out there, like over Greenland, planes could have to stay at 14,000 for 45 minutes, so you have to provide supplemental O2 for 10% of the passengers.

So by the time people had time to start doing the selfies, they may have been at a breathable altitude or just breathing through their mouths because air from generators smells bad.

Interesting, maybe something was learned from the UA 232 DC-10 crash/landing, it's good that Boeing made the 737 that redundant although I'm not sure if that's possible on a heavy class aircraft. Yea, I noticed the window was far aft of where I expected to see it hit, although I did read the fuselage was penetrated as well, (they didn't give details of exactly where though). Have to LOL about those posting to Facebook "OMG! we're going down!", even a cursory knowledge of airplanes would know that after a decompression event the pilot(s) will get it down to where the air is breathable. That being said, still a fine job by that PIC, kept her cool so well considering the situation.

 

[Zorba]

Interesting, maybe something was learned from the UA 232 DC-10 crash/landing, it's good that Boeing made the 737 that redundant although I'm not sure if that's possible on a heavy class aircraft. Yea, I noticed the window was far aft of where I expected to see it hit, although I did read the fuselage was penetrated as well, (they didn't give details of exactly where though). Have to LOL about those posting to Facebook "OMG! we're going down!", even a cursory knowledge of airplanes would know that after a decompression event the pilot(s) will get it down to where the air is breathable. That being said, still a fine job by that PIC, kept her cool so well considering the situation.

Yeah, I believe a lot of the system separation analysis requirements came out of UA 232. The 737 is actually the largest aircraft that still has manual backups, all the larger aircraft have at least 3 fully independent and separated (or protected) hydraulic system, any one of which can safely fly the aircraft. Each system also has multiple pumps, etc. When you have to have a probability of catastrophic failure of less than 1 in 1 Billion per flight hour, it drives extreme redundancy.

 

[Puffnstuff]

Turns out that Jennifer Riordan was wearing her seatbelt when she was nearly sucked out the window. The Philadelphia medical examiner also states that she died of blunt force trauma to her head, neck and torso but doesn't elaborate any further.
https://www.cbsnews.com/news/southwest-flight-1380-jennifer-riordan-cause-of-death/

 

[Paratus]

Yeah, I believe a lot of the system separation analysis requirements came out of UA 232. The 737 is actually the largest aircraft that still has manual backups, all the larger aircraft have at least 3 fully independent and separated (or protected) hydraulic system, any one of which can safely fly the aircraft. Each system also has multiple pumps, etc. When you have to have a probability of catastrophic failure of less than 1 in 1 Billion per flight hour, it drives extreme redundancy.

Yes, counting to 3 is very important when talking fault tolerance and catastrophic failure mitigation. It’s also why two engine trans-oceanic passenger planes took awhile and were such a big deal. Without a 3rd or 4th engine the engine design has to be done to minimize risk as much as possible.