SWA1380 - diversion to KPHL after engine event

[Mk 1]

Originally Posted by Less Hair

Maybe the visual part of the mask donning demo should be changed?
FA's on a demo just put it close to their face but never show the mask sitting on the face like when actually using it. So people see and remember the distanced position and never realize they have to put it over nose and mouth as demanded in the vocal text.

This ^. Don't know if its a fear of germs or that they don't want to ruin their makeup but they are never shown on the face. However, the safety card will show how to use it - more fool those who don't read it.

[hoss183]

As pointed out, the mask does not have to be fully over both nose and mouth. Systems for providing oxygen to high alt flights in unpressurised a/c do include just nose clip tubes.
Any by the way just to be pedantic, there is as much oxygen at altitude as at sea level, its still 20.9%, what is different is the way the body absorbs it due to the partial pressure of the gas.
e.g

[Mk 1]

Originally Posted by Photonic

Agreed!



Yet to be verified, but here's the report in NYT:
https://www.nytimes.com/2018/04/17/u...pgtype=article


Maybe all of that was unnecessary, but it sounds like not just flight crew but pax were trying to help out. If true, that deserves some credit.

Yes it does and perhaps in due course we will hear about the heroic actions that occurred inside the cabin.

I was however railing against the pilots actions being described as heroic. The captain and first officer did a very competent job in the cockpit, no doubt about it - and the cherry on top was Tammy's concern for her passengers after landing. She could have left the evacuation to cabin staff and emergency crews - but she took her time to re-assure passengers etc, that's class.

[Carbon Bootprint]

Originally Posted by Rob Bamber

I've just rewatched it (season 1, episode 10). In their tests they couldn't get a crash test dummy to be sucked out of the plane, in any scenario.

However, they did blow out the window in a manner very similar to this one, and in the footage you can see how traumatic it would be for the passenger sitting next to it. Sucked out: no chance.

However unpleasant the thought, for the record, it has happened: National Airlines Flight 27.

One passenger, G.F. Gardner of Beaumont, Texas, was partially forced into the opening made by a failed cabin window, after it too was struck by engine fragments. He was temporarily retained in that position by his seatbelt. "Efforts to pull the passenger back into the airplane by another passenger were unsuccessful, and the occupant of seat 17H was forced entirely through the cabin window."

The unfortunate gentleman's remains weren't located for two years, and it took another year to positively identify them.

[wiggy]

Originally Posted by hoss183

Any by the way just to be pedantic, there is as much oxygen at altitude as at sea level, its still 20.9%, what is different is the way the body absorbs it due to the partial pressure of the gas.

there is as much oxygen at altitude as at sea level,

No there isn't.

Maybe it's a case of terminology but as understand it the partial pressure of oxygen (measured as a percentage) is the same at altitude as at sea level, but the actual amount of oxygen (as in molecules per unit volume/breath taken) is less at altitude.......

[ChicoG]

Originally Posted by DaveReidUK

Leaving aside the oxymoron inherent in that statement, the suggestion that

is simplistic in the extreme, being based on the assumption that if a blade is going to let go it will do so the first time N1 reaches a certain value and not on some subsequent occasion.

It's particularly irrelevant in this case, given that the NTSB is already reporting indications of metal fatigue at the blade root.

"Last year, the engine maker and the Federal Aviation Administration instructed airlines to make ultrasonic inspections of the fan blades of engines like those on the Southwest jet. The FAA said the move was prompted by a report of a fan blade failing and hurling debris. A Southwest spokeswoman said the engine that failed Tuesday was not covered by that directive, but the airline announced it would speed up ultrasonic inspections of fan blades of its CFM56-series engines anyway.".

https://www.newsday.com/news/new-yor...tim-1.18129205

[darobstacraw]

Can anyone comment on what it would take to detect the type of fatigue that would cause a blade failure like this?
If you pointed a high speed IR camera at the front of the engine(s), would you perhaps see a different heat signature from the root of the fan blades?
In this age of Internet of Things where data is being so heavily collected from everything (especially jet engines) what metric would give you fore-warning of a failure of a fan blade?

[ktcanuck]

Originally Posted by darobstacraw

Can anyone comment on what it would take to detect the type of fatigue that would cause a blade failure like this?
If you pointed a high speed IR camera at the front of the engine(s), would you perhaps see a different heat signature from the root of the fan blades?
In this age of Internet of Things where data is being so heavily collected from everything (especially jet engines) what metric would give you fore-warning of a failure of a fan blade?

Eddie current and dye static testing can detect cracks. Acoustic emission can detect crack growth (not very practical on a fan blade!).

[FIRESYSOK]

Eddy current testing, ultrasound

[alphasun]

I am not in aviation engineering, but have edited aircraft manuals. One report raised a question in my mind.
A passenger reported that there was a lot of vibration after the main disintegration impact. i.e as the pilot was reacting.
Could this mean that the engine hub was still rotating or would it be connected to rapid manoevering?

[OldnGrounded]

Metal Fatigue Testing

@darobstacraw:

There are a number of processes for detecting metal fatigue that is not visible to humans, including ultrasound, eddy current, radiography, etc. In cases like this (fan blades) some version of ultrasound testing is probably most-used.

I can't post links (I usually read here, not write), but the Aviation Pros website has a quick introduction.

[Lost in Saigon]

I assume the un-named male First Officer was the Pilot Flying during the descent and initial approach, while Captain Tammie Jo Shults ran the checklist and the radio. (except when the FO responded to ATC clearing SWA1380 direct to Philadelphia)

On final, when they switched to the tower frequency, Captain Shults took over flying while the First Officer worked the radio.
(after landing the Captain went on the radio again)



EDIT: This one is better than the one I originally linked to:

#WN1380 Southwest Engine Explodes in midair and a Window Breaks!

[FIRESYSOK]

Originally Posted by alphasun

I am not in aviation engineering, but have edited aircraft manuals. One report raised a question in my mind.
A passenger reported that there was a lot of vibration after the main disintegration impact. i.e as the pilot was reacting.
Could this mean that the engine hub was still rotating or would it be connected to rapid manoevering?

Alright let’s use some common sense here. 5,000 rpm disc weighing hundreds of pounds just became completely unbalanced. Even if the fadec commanded a shutdown automatically, nothing happens quickly. And the engine would likely continue to windmill. Significant damage to wing leading edge, nacelle, etc. What kind of maneuvers do you think the pilots put on that would cause airframe vibration? If anything some soeedbrake for the emer descent. This used to be a professional forum.

[Pilot DAR]

As pointed out, the mask does not have to be fully over both nose and mouth.

Correct. The mask should be worn to cover the nose and mouth, but if mis worn as shown, it's still going to get the oxygen to the wearer.

To complete the thinking on this, it helps to understand that your average adult will take about 12 one to two liter breaths per minute. Of those breaths, 21% or so will be oxygen, and the rest the other components of the air, most nitrogen. While the overhead oxygen generator is providing near pure oxygen to the mask, that need and may only be 1/5 of the volume of air which the wearer would naturally like to inhale. So, if they inhale the rest of the non (or very low concentration oxygen) "around" the mask, the objective of providing the oxygen has been met. To this end, close examination of the "dixie cup" oxygen mask will show that in addition to a rather poor face fit, it actually has a rubber flapper valve for both in flow, and outflow. So, if a panicked passenger is pressing the mask tight to their face, those valves can open to assure that an adequate volume of air is being breathed in, in addition to the required oxygen.

But, yes, it would be nice if the passengers actually comprehended the passenger briefing, and wore the mask as it is designed to be worn!

[pax2908]

Certification somehow requires to demonstrate that separation one fan blade be contained ... here it looks like it was not ... was wondering if the certification process requires only one such successful test instead of a statistically significant number of blade release tests and/or recurrent such tests? ($$$)

[gums]

No, Wiggy, the partial pressure is the problem as well as less total oxygen.

At my mountain cabin the pressure is about 75% of sea level and the total amount of "air" is also about 75%. Since I have COPD, I am intimately familiar with these things. Also wore a nose hose in jets for 20 years, so have been thru explosive decomp and flying unpressurized as high as 40,000 feet on positive pressure, pure oxygen.
+++++
The ATC transcript illustrates an outstanding degree of professionalism. Can't wait to see the CVR.

On my serious structural damage approach I was not as adamant about the serious part and both approach and tower didn't really give me the priority they gave SW1380. Lesson learned, and you don't have to scream at them, heh heh. On my profile and the linked interview/bio, you can see the damage of my plane and might be able to see/hear the video of the approach.

Gums...

[JW411]

I am reading elsewhere on Pprune that Captain Tammy Shults was one of the US Navy's first female F-18 pilots. Anyone who can reunite an F-18 with a pitching carrier deserves my respect at least. She did a good job and so did the rest of the crew.

[Highway1]

Originally Posted by pax2908

Certification somehow requires to demonstrate that separation one fan blade be contained ... here it looks like it was not ... was wondering if the certification process requires only one such successful test instead of a statistically significant number of blade release tests and/or recurrent such tests? ($$$)

You are making the assumption that the fan bade wasn't contained - no evidence to support that so far.

[Herod]

gums.

Right about the partial pressure. Perhaps another way to explain it to the uninitiated. (Aeromed lectures a long time ago.)

Call the pressure of air at sea level 100. Oxygen then has a partial pressure of 20, sufficient to force it into the bloodstream. At about 35,000' the pressure of the air in total is only now about 20. 100% oxygen from an economy (non-pressure) mask is still 20, so OK. Above this it drops with altitude, necessitating pressure breathing to get it back up again. As I understand it anyway.

[climber314]

Originally Posted by wiggy

No there isn't.

Maybe it's a case of terminology but as understand it the partial pressure of oxygen (measured as a percentage) is the same at altitude as at sea level, but the actual amount of oxygen (as in molecules per unit volume/breath taken) is less at altitude.......

"as in molecules per unit"

Correct!