Follow-up – Southwest Engine Failure

Some days ago I posted information about a Southwest Airlines engine failure at Dallas. The FAA reported the Boeing 737 returned because of some vibration in the number 2 engine.

Apparently those information was wrong. Just a few days after posting I received a few comments of people who have been on this flight (#438). They stated it was no vibration, but a fatal engine failure.

Joe – Nov 21st, 2007 said:

This is not true. It was not during takeoff. There was alot of damage. There was no vidration. It doesnt say anything about an uncontained explosion at 25,000ft. I was sitting on that engine watching it happen with my own two eyes. The fan blades shot out towards the plane leaving holes on the engine cowlings and a huge hole on th other side.There was no vidration, but a huge explosion. That report is false and they should really clean it up! The blades could have easily penatrated the fusalage causing a crash, or went through and killed a passenger. (…) I have pictures and I will let people see them (…)

Jen – Nov 22nd, 2007 said:

I was on this flight also- We all thought we were going to die! We said our goodbyes. There was an explosion and holes in the right engine with something sharp still sticking out of the engine. The plane started shaking so bad. The flight attendant was crying and one was getting oxygen because she was hyperventilating. They were able to turn the flight around and land with no incident but not before the longest 20 minutes back to the ground and the plane being surrounded by firetrucks. A big chunk of the engine flew off and luckily it went away from the aircraft because if it came toward us, we wouldn’t be here. The chunk was on the outer side of the engine not seen from our view but could be seen while walking off the aircraft. There were smaller holes though in our view of the top of the engine. I saw the pilots taking photos when we made it to the ground so hopefully the FAA will do the right thing and investigate how this could happen.

-Update-
Bob D. – Dec 2nd, 2007 said:

To everyone interested in Flight 438… Sorry if my co-passengers made some inexcusable spelling errors… They are probably still traumatized. To the idiots that think it was no big deal for this event to occur… IF you had been on that flight – you would still be scraping the turd out of your pants… The incident started with a large “explosive” type impact to the entire plane – resulting in a massive shaking and vibration throughout the entire plane – that felt like every rivet was working loose. For a few seconds, I initially thought a bomb had gone off in the luggage…We then experienced severe vibrations for appx. 10 minutes.
If the explosion had directed shrapnel towards the plane – armor or not, I am glad it did not, asI am reasonably sure it would have pierced through, or propelled the armor as a secondary missile – like a knife through butter, through the fuselage.
The FAA’s report – a few days afterwards, was a one liner, and did not adequately address the scope and nature of what transpired. I am surprised that this incident was not covered in-depth, or more publicized. Do your homework, research, BEFORE you make any assumpions.
I can say the crew and pilot, and the pilot’s on-board, all did a professional job – under the circumstances. The Pilot, who landed on one engine, had made an announcement, “On the simulator, we prctice landing on one engine…” He did it real time, and made it happen! He refused $20.00 for drinks. One of the impressive pilots on travel informed me, that the simulator did not adequately cover the entire spectrum of mechanical events that occured… Lessons learned!
The only negative thing that happened was someone gave a legal speech before our take-off on the next plane out of Dallas… “Acts of nature…” blah blah etc. etc. Did not need to hear that!
We got a free drink on that flight! Awesome! (Next time I would like it during the incident) P.S. I said an prayer, immediately after the “explosion” and shaking…It and all the others must have been heard – say your prayers, and by the way…thank you LORD! and thank you for blessing the pilot with professionalism and skill, thank you for blessing the entire array of personnel who make flying safe! I would get on a plane anytime – all the passengers, and I did, on the next flight out of Dallas!!! Of course we flew Southwest!
To all you skeptics and engineer types who simply explain away the human element of the entire episode – Try a little humility… and a prayer.

I asked for submitting these photos to make them publicly available, unfortunately I didn’t get anything.
In the meantime – and that’s really great – some pictures somehow leaked to the internet.
The following photos were posted at the PPrune Forum.


Lately these pictures are even circulating among the Dallas tv stations, a WFAA news reporter told me.

Thanks to Jack for submitting the link.

Update
I just got further pictures from Joe, a passenger on this flight. Thanks Joe!
Southwest Airlines Engine Failure Southwest Airlines Engine Failure Southwest Airlines Engine Failure Southwest Airlines Engine Failure Southwest Airlines Engine Failure Southwest Airlines Engine Failure Southwest Airlines Engine Failure Southwest Airlines Engine Failure Southwest Airlines Engine Failure Southwest Airlines Engine Failure

For Preliminary NTSB Report visit:
Preliminary NTSB Report on Southwest Engine Failure Incident

100 thoughts on “Follow-up – Southwest Engine Failure”

  1. But the pictures seem to confirm. Sad that it sounds like they lied to cover their asses. If this is all true, instead of justifiably commending the skills of their pilot in getting everyone down safely and promising a complete investigation, they look completely untrustworthy.

  2. @kc: Sadly, most people can’t spell or use proper grammar in the first place. I work with a lot of copywriters, people who should know the English language and how to use it at an expert level, and I am constantly fixing simple mistakes that even pass the proof-readers as well!

  3. Let me explain it to you.

    When you take pictures, you do not ASK PERMISSION to publish them.

    That is what people do in mainland China. Not here in the US. In the US, we are a free country. You publish your pictures first, and let the FAA ask questions later. Not the other way around.

  4. You people are a bunch of nitpickers. *Forget* the spelling already; take a good look at the pictures, they’re what’s important!

    People almost died, and southwest lied, to coin a phrase. All I can say is hooray for cellphone cameras and quick-thinking average people.

  5. @KC

    Do you find comfort in pointing out others mistakes? A serious matter is being discussed and you can’t ‘hardly’ take the matter seriously due to their spelling and grammar usage? grow up…..

  6. I had a teacher in high school who worked for Boeing, designing the rotary blades for the engines. He says he left because he did not believe in making weapons. I think this story will sadden him.
    At least everyone got back on the ground alright. Just try to put yourself in that situation, you might not care about spelling vibration right after that either.

  7. So a engine fan came apart… big deal. Let’s review the facts here. An engine that spins large metal blades at thousands of revolutions per minute eventually came apart. The fan blades were contained by the engine structure and safely ejected from the now non-operative engine. When something like this happens the pilots will feel a vibration and then the engine failure warnings will start (including things like fail-safe engine fire warnings, etc.) Since you cannot even see the engines from the cockpit of a 737 the pilots would report the vibration and engine failure to ATC and begin emergency procedures. While one pilot was working on making sure the plane did not crash the other would be working the engine shutdown and fire suppression checklist. Frankly these guys have better things to do than calm down passengers (that is the flight attendants job and it sounds like they were the only ones to screw-up here.)

    There was no “cover up” and I am certain that if you dig through the FAA web site you will find the actual report that details both what the pilots thought was happening and the report from the ground that lists the actual damage.

    Get a grip people.

  8. I will make it short:

    Can’t damn a maintenance crew until you know a cause.

    Has anyone considered the possibility of some sort of debris (which seems unlikely but not impossible) entering the engine?

    It is even possible the crew followed absolute standards and received a substandard part.

    The only real issue is the lie by the airline regarding the incident. PR nightmare for them.

  9. 737’s are designed to fly on one engine. Yes, this isn’t an ideal way to fly a plane, but it is designed and engineered so that if there is a critical failure of one engine, the flight crew have the ability to control the plane and put it safely on the ground. This is called a redundant system and are designed into practically everything where complete failure can cost human lives. This event shows how important these systems are. Even if the second engine failed there is still another redundant system on board to allow the pilots to use the hydraulic powered flight controls. The people on that plane were not in significantly greater danger after the engine failed then when they first stepped onto the plane. People didn’t almost loose their lives; the engineering SAVED lives.

  10. Compared to other airlines out there Southwest has done an amazing job – not to mention, just like cars planes break down too. The pilots in this case did an awesome job at getting everyone back on the ground safely. An investigation will take place and I’m sure that whatever the findings are Southwest will step up to the plate to address them. The plane was a Boeing – could be something Boeing needs to address. I fly with Southwest and will continue to fly with them because among the other airlines, they are the best option.

  11. Not leaning either way, I do not understand how anyone can say whether Southwest is lying or these passengers are lying??? For those of you who say the pictures don’t lie, who said anyone was lying about the damage? Those pictures do not say word one that Southwest is lying. Those pictures show ground personnel and AFFR responding to an incident. As much as you say this proves Southwest is covering something up, I say it proves nothing. Who is to say this Joe and Jen are not making up their stories? I am sure they were scared but to say that because these two people gave their stories that it must be so is ludicrous. I say have each of the 133 passengers on board give the same account, without having talked to each other prior, and then we’ll talk.

  12. Sorry PENIX…but that’s not true. This problem could’ve been something the naked eye or even a magnifying glass could’ve seen. Let the facts play out and read what the NTSB, FAA, and GE/CFM inspectors have to say. There have been other uncontained engine failures that have resulted in deaths (UA 292, DL MD80 in PNS(?)) and others that haven’t (Mesa out of DEN and numerous Bizjets). Too many variables to come out and blatently say “poor maintenance” until the investigation is done.

  13. there is little risk of ejected fan blades penetrating into the fuselage. if you notice, there are no passenger windows in plane with the engine primary compressor. the manufacturer has armored plate here instead to prevent penetration. i believe they do the same thing on the inboard wall of the engine cowling – there are no pictures, but i’m curious if there are any holes through the in-board side of the engine. it is surprising the amount of system redundancies on modern air and spacecraft.

    we should all be impressed how this craft safely made it home.

  14. Clearly, this forum needs a dose of knowledgeable reality from someone with a bit of experience in this area. Let me help set the record straight. I apologize for the length, but this needs to be done!

    The pictures show what’s called an “uncontained turbine failure” or “uncontained compressor failure”. That means that some “rotary blades” (actually, turbine or compressor blades) fractured or disintegrated while the engine was rotating and were shot outward, with parts completely penetrating the engine cowling, the external, visible cover of the engine.

    (As an aside for Alex U., Boeing has never built jet engines or turbine or compressor blades, so either your HS teacher was mistaken or your memory of what he said is faulty.)

    Because jet engines rotate at incredibly high speeds (20,000 rpm is not uncommon) the engine cowling is designed to contain parts that come apart, as another commenter stated. Occasionally, as in this case, the dynamics of the engine failure resulted in a few small pieces completely exiting the engine cowling.

    Yes, passengers have been killed when high-speed metal debris penetrated the fuselage but, relative to the number of passengers flown in a year, your odds are better of winning the lottery. It is also highly unlikely the aircraft would have crashed due to debris penetrating the fuselage. Multiple redundant systems make this extremely rare. Again, you’re more likely to actually win playing PowerBall.

    One of the comments mentioned that “a big chunk of the engine flew off.” This is not uncommon either. The whole cowling around the outside of the engine is actually several pieces that have hinges and latches so they can be opened to perform maintenance on the engine.

    In an uncontained engine failure it’s possible for flying debris to destroy the latches and cause the cowling to pop open, and then the slipstream (the high velocity air passing over the airplane as it flies) will peel the cowling all the way off, just like the hood of a NASCAR racer does in a high-speed collision.

    I’d like to also set the record straight on this quote: “If an engine managed to explode in a fireball, it’s mostly likely going to take the whole plane out” Simply not true. An engine failure, even an explosive, uncontained high-speed turbine failure like this one, is extremely unlikely to “take the whole plane out”. The aircraft has two engines for exactly this reason — lose one, keep flying.

    There are numerous safety systems built into the design of the aircraft, the engines and the attachment point of the engine to the airplane (the pylon) that prevent this. Modern jet engines are some of the most reliable devices ever built, but they are mechanical systems and still occasionally fail, sometimes in spectacular fashion, but they almost never blow-up like a bomb and destroy an entire aircraft.

    To impugn SWA maintenance for this incident is also extremely premature. The investigation will probably find the root cause of the blade failure, but without any facts it’s irresponsible to say “it doesn’t speak well for Southwest’s maintenance crew.” Sometimes things just break, so let’s wait for the facts before casting judgment.

    As for the details of Southwest “lying” about what actually happened, you folks need to understand how aviation mishap reporting systems work. Most systems (including the one the USAF uses, with which I’m intimately familiar) include a data field for the phase of flight in which the mishap occurred.

    The FAA system may lump takeoff in with “departure”, the portion of the flight immediately after takeoff until the aircraft reaches cruise altitude. This is also a “preliminary report” — someone’s best guess what happened immediately after it happened, before an investigation is completed, before all the facts are in, and minor errors like the phase of flight, if it is an error, are not uncommon early on.

    The narrative from the report also says “on departure experienced a vibration in the number 2 engine” so the assumption that SWA is lying about when it happened is just silly. At worst it could be a clerical error, not some attempt to deceive. Does it really matter when the engine came apart? The note below this report also says “Source: FAA – Correctness not guaranteed, completeness not intended” — that’s “FAA” not “SWA”, so be careful when you start throwing around charges of “covering their asses…” [Alan].

    Commenter Joe also said “there was no vidration [sic]”, a reference to the report stating the aircraft “experienced a vibration in the number 2 engine.” Based on where Joe was sitting he may not have felt any, but up in the cockpit I’ll bet you the pilots felt some pretty hefty vibrations as the engine came apart.

    This has to do with the dynamics of structural vibration — bending modes, nodes, propagation, etc. — basically, there are points in the aircraft where the vibratory waves cancel each other out and can’t be felt or multiply so they are very noticeable. Where Joe sat he may not have felt any vibrations, but the pilots most likely did.

    Realize also that the pilots probably had numerous other indications of a problem, from gauges showing out-of-limit or fluctuating readings to warning lights and horns. Some aircraft even have indicators that precisely show engine vibrations though I doubt a modern 737 has these.

    So, bottom line, for the pilots to say there were “vibrations” isn’t a lie. There’s not an “engine exploded” light in the cockpit, and the safety report describes the indications the PILOTS had, not what the non-aviator passenger thinks they saw and felt.

    Lastly, if the flight attendants were crying and hyperventilating they need to be counseled for a lack of professional discipline. The aircraft had a fairly major problem but the cockpit crew were handling it in accordance with the flght manual and company procedures. Flight attendants are trained to remain calm so they can actually peform their duties, assist the pilots as necessary and take care of the passengers. If they were getting hysterical it sounds like there may have been a breakdown in discipline.

    One thing I would like to know from someone who was actually on the aircraft: Did the Captain or First Officer walk back into the cabin inflight and look at the engine to survey the damage?

    I hope this clears up many of the misconceptions and conjecture that this incident has generated. No, I’m not a pilot for SWA, though I think they are a very good airline. I am a USAF test pilot and have dozens of friends who fly for Southwest, and to the man they are some of the best, most professional aviators I’ve ever known.

    Kudos to the two guys who got this jet back on the ground safely despite the “fatal engine failure”, tearful goodbyes and hyperventilating stewardesses.

  15. RE: When you take pictures, you do not ASK PERMISSION to publish them.

    I’m with you on that, buddy. I did a double take there, too, but then went back and read the post. But you missed the point. The pilot took the photos. The original poster asked the pilot to submit them so he could publish them, but other photos showed up online first.

  16. Sorry Dude No Armor Plating on this aircraft. If the blades would have penetrated the other way it would have ripped a hole in the fuselage and there would have been massive decompression and the plane would have probably went down.

  17. No, the plane would not have gone down even in the event of a rather large hole in the plane.

    Airliners are amazingly redundant things, and the pilots have oxygen masks readily available for just such an emergency.

    take a look at a similar (albeit older) 737 that survived a BIT of hole at 24k ft and made a safe landing (albeit with a few fewer people on board)

    http://en.wikipedia.org/wiki/Aloha_Flight_243

    Also in the case of the PNS engine failure (a DL MD-88) the cause was shoddy work on the blades done by a contractor overseas (pakistan?)

  18. testpilot got this right. just about everyone else, wasting space here. incredible the amount of unhappy people out there nitpicking. important thing, nobody got hurt. now to see what caused the failure. for those not in the know, it is a mechanical device, which is prone to failure believe it or not. like testpilot said, this is an uncontained failure. lucky they went mostly away from the aircraft. i was an a & p tech. this is not a blame game thing. and truly, not a very big deal. that is why the shroud around the engine is made very sturdy, just in case. these things will happen.

  19. It is easy to explain why some people would feel vibrations and some wouldn’t.
    It’s the same reason people will feel turbulence and others won’t.

    The wings (with engines) act as a fulcrum in flight, much like the
    middle of a see-saw.

    People at the front and back of the plane will feel movement more acutely
    than people near the wings — just as you would sitting in the middle
    of a see-saw.

    Also, like ripples in a pond when you drop a stone, vibrations move outward,
    and are felt greater at the ends.

    Markus Diersbock

  20. Just to correct a couple of errors in the postings above:

    1) Boeing airliners are designed so that flight critical systems are not inline with the turbine blades. So, turbine blades flying out will not take out critical systems.

    2) Turbine blades penetrating the fuselage will not cause explosive decompression. The pressurized cabin will not fail like a balloon does when punctured, Boeing has spent a great deal of effort prevent this problem. You’ll probably hear a loud hissing sound and get a gradual decompression, and that’s it.

    3) Jet engines are highly stressed and full of energy. Thus, Boeing airliners are designed with the presumption that they will fail, so the plane must continue to fly safely. That’s why there are two engines, and why they are on pylons, and why critical flight controls are not in the way of engine failure, etc.

    4) This incident shows how well Boeing airliners are built, and the professionalism of the pilots. The airframe handled the mishap gracefully, continued to fly successfully, and the pilots did everything right and brought the airplane down safely with no injury or loss of life.

  21. Just one point to clarify on testpilot’s otherwise spot-on disection of this event. The 737NG (NG=next generation; that is, models 737-600, -700, -800, -900) have vibration indicators installed. You can bet that if the fan or compressor lost a blade, the vibration gage would have shown it. The engine may very well have kept running even with the damage sustained, in which case the pilots would reduce the power to the engine to reduce the vibration and shut it down if necessary.

  22. “Mark
    Nov 27th, 2007 at 5:22 pm
    Let me explain it to you.

    When you take pictures, you do not ASK PERMISSION to publish them.

    That is what people do in mainland China. Not here in the US. In the US, we are a free country. You publish your pictures first, and let the FAA ask questions later. Not the other way around.”

    Who cares? I would take pictures THEN publish them. Big deal! pfffttt

  23. From FAR 14 CFR Part 33.94 Blade containment and rotor unbalance tests. …it must be demonstrated by engine tests that the engine is capable of containing damage without catching fire and without failure of its mounting attachments when operated for at least 15 seconds…after each of the following events:
    (1) Failure of the most critical compressor or fan blade
    (2) Failure of the most critical turbine blade

    By this federal regulation, the engine performed properly. It contained the damage, did not catch fire and obviously remained mounted.

  24. Neither the captain or the first officer came back to check out the engine, the just so happened to be another pilot for southwest was traveling on the plane with us. He is the one that checked out the engine.

  25. Kudos to testpilot and Ex Boeing Engineer.

    People like jetguru are grossly ignorant about what the capabilities of an airliner are. Their prognostications about the plane “going down” are simply incorrect.

    For starters, the issues regarding the initial statement are simply incorrect. The statement linked is an FAA document stating only the basic event items. Plane departed, engine failed, plane returned. That is called an “incident report” and is simply a concise statement of what occured.To cast aspersions on Southwest for “trying to cover things up” is just plain stupid. In this litigious society, booger eating morons are regularly courted by shady attorneys who want to creat issues upon which to make money. This completely ignores the fact that the SWA crew did the right things and saved the day. I believe if you do some checking, SWA sends their engines off for repair/overhaul to FAA approved engine facilities. Blaming SWA simply flies in the face of reality.

    As for decompression, Boeing has over-engineered every plane since the 707. When the 707 was being tested, they shot scores of steel daggers through the hull of a fully pressurized 707 immersed in a huge pool to demonstrate the failsafe nature of the airframe structure (dual loadpaths, just like a WWII bomber). The 737 is nearly identical to the 707 airframe and, in fact, still flies with the 707 nose that first flew nearly 60 years ago. Look at a KC-135 tanker nose if you don’t believe me. Identical, except the radome.

    To the credit of those who stated the obvious, an airliner is comprised of over a million parts, many of them under extremely high pressure. The engines typify this stress and the fan hub/compressor core takes the brunt of this stress. For the record, the initial failure appears to have been a fan failure, not the turbine section. (Notice in one of the pictures the entire fan and spinner are gone.) The fan is like the propeller and pulls the plane through the air. A fan failure is often followed by a compressor/turbine hot section failure as parts from the fan section are ingested into the engine taking out compressor blades and turbine blades until the engine is either damaged partially or rendered completely inoperative. That is why every airliner comes with at least another engine. One breaks, you go land and get another jet.

    As for the flight attendant tears, please remember that they are people too. Some of them may have been on their first trip or first month of flying. Despite being air crew, they often have little understanding of airworthiness issues other than what they learn on the job over time. Their prime reason for being is to get your butt safely off the plane once it touches down. They have been well trained to do this and their training has been well documented time and again. In the seconds after an inflight event, the pilots are busy trying to ascertain what/where/why and trying to make sense of the instruments on the dash before them. To make matters worse, in a vibration event, often times it is very hard to read the instruments so drawing any quick conclusions is out of the question. The “prime directive” in aviation is “DO NOT ACT WITHOUT DELIBERATION BECAUSE IT MAY WORSEN YOUR SITUATION.” While these pilots were trying to figure out what was going on, the flight attendants were on their own, awaiting info from the cockpit. If the passengers demand attention for their fear of imminent peril, the same consideration must be offered to the inflight crewmembers. A badge doesn’t mean you are not human as well.

    The facts speak for themselves. An unintended and possibly unavoidable incident occurred inflight. The company trained crewmembers did their job and recovered the aircraft safely to the ground and all passemgers were safely deplaned. What other outcome is preferable to this outcome?

    Additional note: I believe this aircraft was a 300 model. Only the “Classic” 737’s have engine vibration indicators and in this type event, the severity of vibration on the failed engine may have pegged the opposing indicator. (The NG 737’s have no vibe indicators.)

    Engine failure in high-bypass turbo fans is incredibly rare when measured across the millions of hours jets fly each year. Uncontained engine failure is many magnitudes rarer yet. This track record is testimony to the safety and reliability offered by airline travel.

    The Internet is a wonderful place to get information. Unfortunately, in the absence of factual data, mob rule often occurs. Hopefully, the readers of this blog are now more educated as to the events that occurred.

  26. @JETGURU

    Airliner engines are most certainly “armoured” against potential blade failures. Should any blade in the engine fail and break off, the casing of the engine is specifically designed to safely contain the huge amount of energy released and prevent any debris from hitting the fuselage or wing.

    This video demonstrates blade-off testing for the A380’s engines.

    http://www.youtube.com/watch?v=j973645y5AA

  27. Thanks, Joe, I was just curious if the captain and FO had a trained eye look at the engine while they were up front running checklists and heading back to the airport. Did the pilot who was in the back relay his findings to the cockpit?

  28. “STEWARDESSES” Testpilot, c’mon. That is so last generation and UN-PC… And with regard to hyperventilating, we are trained that if there is suspected pressurization issues, take oxygen, immediately.

    Care to comment on the time of useful consciousness in rapid decompression, let me help you here… It would be as little as six seconds at altitude.

    She should have and seems that she did strap on the oxygen tank. In a situation such as this, better to error on the side of caution. I know that I would not want to be without oxygen in a rapid decompression, for if I was, all the passengers would have much more to worry about than grammar and spelling errors.

    Generally, your post was spot on and seemingly professionally sound, you just lost my vote with your careless use of the outdated word, “stewardess” and your uninformed assumption that the flight attendants would be fired.

    Typical after the fact, arm chair quarterbacking at its best.

  29. From someone studying for a 737 type rating:

    JetGuru is completely wrong when he speculates of all the ways the airplane would have broken apart, become uncontrollable, crashed, etc. I can’t imagine what his motivation is.

    Testpilot and the Ex-Boeing engineer have it completely correct. Let’s review the systems and design features in place to protect the passengers in the event of an engine problem.

    First – the airplane is designed to fly on one engine, maintain cabin pressurization with only one engine operating, and provide adequate electrical and hydraulic power with only one engine operating. There’s also an Auxiliary Power Unit (APU), a small jet engine in the back of the airplane that can be operated to provide additional electrical and bleed air energy. The worst case is that a fully loaded 737 might have to descend somewhat from it’s normal cruise altitude of 33000-41000 feet when operating on a single engine, but you can believe that for any domestic operation an engine failure calls for a descent and landing at the nearest suitable airport anyway.

    Second – There are no critical flight components in the ejection plane of the engine fan or compressor stages. This ensures that if a blade separates, and the energy is not fully contained within the kevlar belts lining the cowling and the cowling itself, that any penetration of the wing structure or fuselage (I believe the fuse does have some additional kevlar in it) will be minor and absorbable, and leave the airplane fully controllable. Additionally, the pylons the engine is mounted on are designed to protect the wing by failing first and separating the engine from the wing if sufficient stress is placed on them.

    Third – You may not be aware that an pressurized airplane is not actually completely sealed. Pressurized Air (called bleed air)from the engines is pumped into the aircraft after being cooled, and it flows out through an adjustable outflow valve in the fuselage. The pressurization comes from the difference in the amount of air pumped in (lots) and the amount of air allowed to exit through the outflow (less, but NOT zero). If the cabin were to spring a small leak (say the size of your fist), the outflow valve would simply close a bit to compensate, and it would be noisy by the hole, but pressure would probably still be adequate to not require supplemental oxygen. Only if structural maintenance were terribly deficient (as in the case of ?Aloha?) would there be a chance of significant skin loss and depressurization, and even in that case the airplane landed safely.

    Bottom line, an engine failure of this type is something the designers anticipated, designed for, TESTED their designs, and the FAA certified the design as being safe. You have a better chance of winning the lottery then you do of dying in a plane crash due to a design defect in the aircraft or engine. Most plane crashes are a result of pilot error (sad but true), or in rare cases terribly gross negligence on the part of the maintenance staff or ATC, or deliberate sabotage/terrorism.

  30. One of the spinner bolts is missing (or at least the bolt head is missing) and would have been injested (wacked by several fan blades). Damage that resulted from this spinner bolt impacting one or more fan blades may have eventually caused a crack that propogated until the blade failed which then caused this catastrophic, uncontained failure.

  31. This is an exceptionally rare failure (ignoring whatever the actual root cause) because of the amount of damage. Most of the time when the fan sustains heavy damage (even from a large bird strike for example) you usually don’t see this kind of damage. The fan blade containment is the engine outer fan case (not any of the cowls), but because of the amount of “shrapnel” in this case, some of it came out either in front of, or aft, of the fan blade containment section of the outer fan case. There is heavy fan case damage at 6 o’clock inline with the blade tips though. It was not designed to withstand quite this much, or kind of damage. The engine is certified to withstand a failure of one whole fan blade at Take-off Power and to be safely shutdown, mind you. Vibration monitoring is of no value in this case. The failure was I’m quite sure, instantaneous, very violent, recognized by the crew who would have immediately shutdown the engine. I had a look (a zoom) of another one of the fan photos and it sure does look like that one spinner attach bolt is completely gone.

  32. testpilot: According to a report filed by one of the F/As, there were 3 WN pilots that were flying non-rev on this flight and one of them called the cockpit from the interphone in the rear galley and informed the cockpit of what was going on with the engine. This same non-rev pilot entered the cockpit and was in the jump seat for the landing.

    testpilot2: This particular aircraft was a -300 – no dice on the vibration indicator unless they were available on the earlier models.

    It absolutely cracks me up to come in here and read all of these comments from people that know ABSOLUTELY NOTHING about aircraft! Thanks for providing me some entertainment this evening. (Obviously that wasn’t directed at the last few folks that have posted and actually know what they are taking about!)

    Matt
    My photos on Airliners.net: http://tinyurl.com/u4vro

  33. I just want to thank the Test pilots and the Boeing representative on here by clarifying all of the details of what a Boeing 737 really is all about….Guess thats why we fly them! And yes our pilots are very highly trained individuals and some of our pilots are even retired astronauts and even retired Air Force One pilots…yeah guess I’m bragging, but I am proud to work with some of the finest pilots out there….And for those of you who do not know, don’t know! So…until you know, you really have no room to talk.

    If I’m correct, our 300 and 500 series also have the vibration gauge. I think it’s located where the N1, N2, and the oil temp gauges are right directly in front of the throttles on the panel under the dash…Boeing am I correct? and for the civilians out there that thinks I’m a fool because I dont know where something is in the cockpit..it is because I work in Ground Operations, but possess a Private Pilots Certificate. Also…this armor plating you guys talk about..is really not what you think..its not metal…its Kevlar.. and theres alot of it in the engine where the blades turn. when you see a plane land and they engage the Thrust Reverser’s, you can see a green color inside the cowling….thats all Kevlar. There was a program on the Discovery Channel on a/c engines and they had an engine intentionally lose the blades and all you saw was the cowling bow up like a flexed bicep…it was really neat…Boeing or Test can you vouch?

  34. With the one missing spinner attach bolt, one has to wonder if some or all of the rest of them were ever torqued and could this be the cause of the spinner “departing” and wiping out the fan. It appears that at all or most of the remaining spinner bolts there is a broken remnant of the spinner attach flange still under the head of the bolt. Improperly torqued bolts could cause unequal loads being applied at the bolt hole locations of the flange leading to cracking and subsequent flange failure.

  35. To testpilot, testpilot2, ex boeing engineer, turbineheat, and a few of the others who obviously have a handle on the subject matter – good job. To testpilot: there were actually four company pilots in the back of the plane and, yes, they did report their findings to the cockpit through the intercom system as one would expect. To testpilot2: you are correct as to the presence of vibration indicators on the NGs. There are vibration gauges on the Classic fleet as well – the
    -300,400,500 series. The -200s we used to fly had no vibration gauges. To the others out there: don’t let your emotions get the best of you. Southwest is not trying to cover anything up. Together, the NTSB, FAA and Southwest will do a thorough investigation to determine what caused the failure and publish their findings when the investigation is complete. To the captain of the Southwest flight (who I know personally, but will not mention his name): Great job!

  36. Correction: In one of the pictures above you can see a portion of the fan assembly still attached. Initial pictures I saw (grainy cell phone shots) made the engine look like it was stator blades alone -minus fan.

    Additional note: Once the NTSB gets the incident, SWA CANNOT make any comments about the incident. The NTSB makes ALL statements about what did and didn’t happen. Their comments will come as the investigation continues. The holidays throw a wrench in the usual timing but, assuming they have a good idea and testing verifies the damage pattern, we should have some official report out in 60-90 days.

  37. “””evgen
    Nov 27th, 2007 at 6:55 pm
    So a engine fan came apart… big deal. Let’s review the facts here. An engine that spins large metal blades at thousands of revolutions per minute eventually came apart. The fan blades were contained by the engine structure and safely ejected from the now non-operative engine. When something like this happens the pilots will feel a vibration and then the engine failure warnings will start (including things like fail-safe engine fire warnings, etc.) Since you cannot even see the engines from the cockpit of a 737 the pilots would report the vibration and engine failure to ATC and begin emergency procedures. While one pilot was working on making sure the plane did not crash the other would be working the engine shutdown and fire suppression checklist. Frankly these guys have better things to do than calm down passengers (that is the flight attendants job and it sounds like they were the only ones to screw-up here.)

    There was no “cover up” and I am certain that if you dig through the FAA web site you will find the actual report that details both what the pilots thought was happening and the report from the ground that lists the actual damage.

    Get a grip people.”””

    Thank you, Evgen. I was hoping someone with a brain would post a reply. It is quite obvious that the F/A’s were the only ones who screwed up… the pilots safely got the plane on the ground as trained. Hopefully Herb will give them a fat Christmas Bonus.

    Southwest has one of the best MX crew in the world, but sometimes you just can’t tell when things like this will happen. When they do, you just have to count on a good Boeing airframe to get you down in one piece.

    Turbofans are a very complex (and beautifully engineered) piece of equipment, and are designed with saftey in mind. The reason none of the blades passed through the inner wall is because a layer of protective ‘armor’ (designed specifically for this purpose) is placed between the moving engine parts and the passenger cabin.

    I would certainly say it was not a birdstrike, as most commercial turbofans are required to ‘swallow’ a large bird in testing without a major failure.

  38. I think it would be unwise for a pilot to get out of the cockpit to check on an engine from the cabin. All indications and controls are in the cockpit. From n1 and n2 speeds it is possible to determine whether the engine is developing thrust. Abnormal engine vibration, fuel flow, or temperature can be indications of failure. Activated fire detection loops indicate fire while a detection loop failure in conjunction with other failures likely means something flew apart and/or is on fire. When an engine is out there may be no urgent need to secure it by closing fuel valves, bleed air lines, or hydraulics lines but something should be done in a timely manner due to competent decision making – either try to restart it or secure it and land. When the affected engine is secured the main focus should be to land, not look at the engine. What is the point of looking from the cabin when there are several separate systems telling you something is wrong. Furthermore, a decompression might follow a rotor burst since the pressure vessel may have been weakened critically due to impinging debris and leaving the cockpit means leaving the quick don O2. Both pilots are needed in the cockpit. One runs checklists and enlists the help of air traffic control, the other flies. Both pilots watch and listen to what the other is doing to detect errors. The Captain sets the pace and delegates. I know nothing about a 737 but I do have experience flying an Embraer 145 in passenger service. On my airplane it is impossible to see much of anything except the engine inlet from the cabin.

  39. About 5 of you know what your talking about. The crew did a supurb job. This was a very serious engine failure and it was handled textbook. Kudos to the SWA pilots and Flight Attendants!!!!

  40. 1. There is no way for a pilot in the 737 to determine that it was an “explosion” or “uncontained” engine failure. In this case it appears the vibration gauge for the engine went off scale high and the engine then failed. That is why the report references “vibration” and is in no way hiding anything.

    2. The pilots of this aircraft were fully busy flying the airplane on a single engine and did not need to leave the cockpit in flight to see the damage as (1) there was nothing they could do to fix it at that point and (2) they had SWA pilots in the cabin giving them reports about what they saw.

    3. Early FAA reports are nearly always a broad stroke description meant only to start the reporting process, you can be sure the final document will include full details of the failure and an accurate description of the event. This is IN no way a cover up of anything.

    4. Blaming this on SWA maintenance is extremely premature. Losing and engine blade is actually a very common event but it is true that having the blade come through the casing is rare. Why this all happened is yet to be determined.

  41. It is simply amazing the number of blithering idiots that come out and offer utterly stupid commentaries on subjects that are well above their stupid little heads. Except for the entertainment factor, they absolutely have zero credibility. Probably the same dummies that think the World Trade Center was a controlled explosion.

  42. So a engine fan came apart… big deal. Let’s review the facts here. An engine that spins large metal blades at thousands of revolutions per minute eventually came apart. The fan blades were contained by the engine structure and safely ejected from the now non-operative engine. When something like this happens the pilots will feel a vibration and then the engine failure warnings will start (including things like fail-safe engine fire warnings, etc.) Since you cannot even see the engines from the cockpit of a 737 the pilots would report the vibration and engine failure to ATC and begin emergency procedures. While one pilot was working on making sure the plane did not crash the other would be working the engine shutdown and fire suppression checklist. Frankly these guys have better things to do than calm down passengers (that is the flight attendants job and it sounds like they were the only ones to screw-up here.)

    There was no “cover up” and I am certain that if you dig through the FAA web site you will find the actual report that details both what the pilots thought was happening and the report from the ground that lists the actual damage.

    Get a grip people.
    ————————————————————————–
    Well said Evgen, well said

  43. Lets get one thing clear here……any kind of rotor failure including blade failure, wether it be fan, compressor or turbine does happen but it is “not common” and it is NOT normally inherent because of……the basic engine design, or the time or cycles on the engine. It is not just destined to happen. I worked for a company that had operated this engine and two other similar versions for 19 yrs. when I retired, and I can’t recall any fan/booster or compressor blade failures. Rotor/blade failure of any kind, even if it only initially causes an inflight shutdown is still a very expensive event for the company/owners/insurers and it always causes concern (initially for the passengers and crew of course) and then for the company, the aircraft manufacturer and particularly the engine manufacturer and the FAA. It can literally cost millions of dollars in engine repairs. This engine is worth about $6 mill. US, give or take. Don’t kid youself…….it is considered a very serious event. This one was worse being uncontained and it wasn’t just your basic fan blade failure by the look of it.

  44. GEEZ, I wish you people would read all of the posts before jumping down and putting in your two-cents worth. Only a few of you had something intelligent to say, particularly TestPilot and ExBoeingEngineer. Thanks for setting the record straight for us! The rest was just a bunch of mumbo jumbo eating up white space.

    And for the handful of you that followed with your redundant attempts at explaining what really happened, you were only successful in displaying your “Let me show you how smart I am” mentality.

    And to “Future 737 pilot”, what did you possibly think you could add to TestPilot’s very detailed and highly accurate synopsis? Considering that you’re only studying to become 737 rated you’re not exactly what we would consider a “qualified expert”. You sound like you’re going to be a know-it-all, but right now you’re J.A.F.O.

    Contrary to popular belief, people don’t read these posts for all the drama. But rather they usually end up here after googling for information to satisfy their questions about a particular incident or safety related information. So let’s try to keep it on point and cut out all the BS. (yes, mine included!)

    Thanks and be sure and let me know if I misspelled any words.

    -No trees were killed in the posting of this message. However, a great many electrons were inconvenienced.

  45. I spoke with maintenance manager tonight on my way from getting off of work here in DAL and he said that it WAS NOT a blade malfunction…so that has been ruled out. I asked him about the spinner coming off, he said that was another possibility. He said that they were about to send the engine out for rebuild, but the NTSB wanted to look into the engine further for more investigation work. I must also say that our MX team does an awesome job aswell as our pilots….guess the track record proves that.

  46. As a retired airline pilot with over 25,000 hours in the cockpit, let me assure you that professional pilots realize that engines do fail. That’s why you have more than one engine. No one was hurt in this incident and the pilots did a great job handling the problem. Grow up and move on to the next crisis!

  47. Actually “PlatinumRRMember”, whatever the hell that is, I thought “Future737Pilot” did add something to the conversation. Meanwhile yours didn’t! Who are you anyway? Great job to the SWA crew who did what they were supposed to do and to the engineers, mechanics and aircraft/engine assemblers that made it work like it was supposed to. And a great job to the people on this blog who actually know what they are talking about.

  48. With all due respect to testpilot and these other supposedly knowledgeable insiders, you’ve got this all wrong. Drawing upon vast amounts of experience as an air traveler, sky gazer, Oliver Stone movie watcher and web surfer, let me fill you in: This was a near-total disaster of biblical proportions caused by the gross negligence of the SWA mechanics and a million design defects by Boeing and IBM. First of all, understand that an engine is very, highly dangerous. ‘Nuff said. The fan blades which spin very, very fast — sometimes over one million rpms — are razor sharp with very jagged edges. People in Row 15 always go first, because that’s where the flying shrapnel coated with flammable jet fuel and the green stuff enters the fuselage on its way to blowing up the whole fuel system, which is next to the overhead oxygen tanks — which act like little bombs when they go off. Need I point out that the only SWA employee to post above didn’t even know where the switch/gauge thingy was located on the control panel!!! And the fact that the engine totally blew up in a massive explosion which almost consumed the whole jet should be a warning to all of us that, despite the PROPAGANDA about all those “successful” flight hours, Greyhound is the better option. Frankly, it was the bravery of those of us on the ground who willed the plane to stay together which led to the happy ending, and you alleged experts should stop posting your meaningless techno-babble lies — we can see right through you guys.

  49. I will explain a few things. I work for a competitive airline. The maintenance crew for SWA and many airlines are top notch. The planes go in for maintenance and looked at in great detail. They are even given a walk around by pilots before it takes off. There is no way to predict a loose nut, a flat tire, etc.
    When you drive your car, do you check the lug nuts or do a walk around for anything that might be wrong with the car….no, most people do not. So, do you blame the maker of the car or yourself when you get a flat tire or other damage happens?
    The stress of working for an airline is great for EVERYONE working in this industry. Thousands of lives are in our hands every day.
    There is no gross negligence, the worse that SWA did was try to minimize what happened. Get a life you pompous, know everthing asses!

  50. Those were some very entertaining comments in the first few posts. I’ve been in the aerospace industry for 14 years. From the pics, it looks like the spinner decided to exit the vehicle. I’d say it bounced around a couple times after coming loose and took some blades along with it and it finally exited through the engine cowl or at least what was left of the spinner. That part of the cowl in front of the N1 fan is not reinforced with kevlar(I believe). The sides of the engine cowl which are inline with the compressor blades and turbine blades are reinforced with kevlar to contain blade failures, as has been mentioned in previous posts. It could be a possible bird strike, a pretty descent size bird, but there is no evidence of a bird strike. I can’t wait to see the final NTSB report on this incident. Does anyone have the date or tail number to this aircraft? Thanks.

  51. While SouthWest should accurately report the incident, you have to look at how skilled the pilot was to be able to land such a disabled aircraft. This is the precise reason that planes have two engines….

  52. First, my hats off to the crew they did a great job and followed procedures just like they are trained to do.

    I am a Turbine Engine Mechanic and have been involved in several investigations in a small part of similar cases. I assure you the FAA (Federal Aviation Administration) will not lead the investigation, that will be the NTSB (National Transportation Safety Board)and they will find the cause and make recommendations to the FAA and possibly EASA (European Aviation Safety Agency).

    The Engine manufacturer CFM International (CFM, CFM56 and the CFM logo are all trademarks of CFM International, a 50/50 joint company of Snecma and General Electric) the Engine is a CFM56.

    I see much talk about being a uncontained failure. That is true to an extent, if you look at the pictures closely you will see the Fan Inlet Housing has sustained substantial damage without penetration, this is the area surrounding the Fan Blades, the FWD NAC is the area that has the penetration, FWD NAC are not normally part of the testing during certification runs for what they call Blade Out testing it could be supplied by Boeing or one of many Vendors.

    The larger issue is why, I would think some action will be taken very soon, NTSB will move quickly they always do and I am convinced they will do a great job, they really do care about the flying public.

  53. Lots of Brainless B.S. flying around this Blog. Are any of the stupid commenters Pilots? I sure hope not…

    If your teacher worked at Boeing and told you he had a hand in “designing the rotary blades for the engines” your teacher is a LIAR! The engines are bought from Prat & Whitney, General Electric or Rolls Royce. Boeing may specify what they would like in an engine (size, thrust, fuel burn, etc.) be they don’t design engines!

    “Massive Decompression” is called explosive decompression. This will trigger release of the cabin Oxygen masks. At an altitude of 25,000 feet you have 3-5 minutes of useful consciousness to don the mask. Common injuries in explosive decompression incidents include ruptured eardrums (painful but not fatal) Decompression Sickness (the bends, nitrogen bubbles forming in joints) and pulmonary edema (essentially bruising of the lungs from the inside resulting in the lungs filling with fluid).

    The time of useful consciousness quoted by “Male Flight Attendant” is accurate for adtitudes above 45,000 feet. Unfortunately, airliners simply don’t operate up that high, mostly because of the short time of useful consciousness. Some business jets can go that high, and some military planes can, but the benefit of operating that high (reduced fuel burn) is cancelled out by time and fuel spent climbing to that altitude.

    And c’mon, Male Flight Attendant, act like an adult snd stop whining about Un-P.C. We’ve all had more than a belly-full of the hypersensitivity masquerading as political correctness. Whatever happened to “Sticks and stones may break my bones but words will never hurt me”? Besides which, Steward and Stewardess are accurate and honorable titles with historical significance. I’m surprised your training didn’t include a simple definition of your title.

    We can partially blame Playboy magazine for giving Stewardess a negative connotation, by their frequent portrayal of Stewardesses as sex objects rather than the trained safety personelle they are. The rest of the blame falls squarely on the shoulders of the stewardesses who took full advantage of the sexual revolution and their travel benefeits to spread their lack of professionalism in a very high profile manner.

    A change of title doesn’t change the person…

    Referring to this incident as a “Fatal Engine Failure” is grossly incorrect, since no one died. It is correctly called a “catastrophic engine failure” since it was a worst-case scenario where parts separated with tremendous energy from the engine rather than gradually loosing power and simply quitting.

    Dave

  54. To everyone interested in Flight 438… Sorry if my co-passengers made some inexcusable spelling errors… They are probably still traumatized. To the idiots that think it was no big deal for this event to occur… IF you had been on that flight – you would still be scraping the turd out of your pants… The incident started with a large “explosive” type impact to the entire plane – resulting in a massive shaking and vibration throughout the entire plane – that felt like every rivet was working loose. For a few seconds, I initially thought a bomb had gone off in the luggage…We then experienced severe vibrations for appx. 10 minutes.
    If the explosion had directed shrapnel towards the plane – armor or not, I am glad it did not, asI am reasonably sure it would have pierced through, or propelled the armor as a secondary missile – like a knife through butter, through the fuselage.
    The FAA’s report – a few days afterwards, was a one liner, and did not adequately address the scope and nature of what transpired. I am surprised that this incident was not covered in-depth, or more publicized. Do your homework, research, BEFORE you make any assumpions.
    I can say the crew and pilot, and the pilot’s on-board, all did a professional job – under the circumstances. The Pilot, who landed on one engine, had made an announcement, “On the simulator, we prctice landing on one engine…” He did it real time, and made it happen! He refused $20.00 for drinks. One of the impressive pilots on travel informed me, that the simulator did not adequately cover the entire spectrum of mechanical events that occured… Lessons learned!
    The only negative thing that happened was someone gave a legal speech before our take-off on the next plane out of Dallas… “Acts of nature…” blah blah etc. etc. Did not need to hear that!
    We got a free drink on that flight! Awesome! (Next time I would like it during the incident) P.S. I said an prayer, immediately after the “explosion” and shaking…It and all the others must have been heard – say your prayers, and by the way…thank you LORD! and thank you for blessing the pilot with professionalism and skill, thank you for blessing the entire array of personnel who make flying safe! I would get on a plane anytime – all the passengers, and I did, on the next flight out of Dallas!!! Of course we flew Southwest!
    To all you skeptics and engineer types who simply explain away the human element of the entire episode – Try a little humility… and a prayer.

  55. Dave,

    Are you Miss Manners, masquerading as Dave? “hypersensitivity masquerading as political correctness”? It is you that blames Playboy magazine and acknowledge the negative connotation, at question. Who are you to scold me? Let me check…… Nobody.

    Testpilot was disrespectful to the cabin crew and obviously “stewardess” is an honorable title, in the past. Weather you like it or not, time does change and many words, terms and titles fall out of favor, weather you are dismissive about it or not.

    I would imagine in a decompression at altitude, you’d be screaming and clamoring for the oxygen mask, even if it is not at 45,000 feet.

    The fact remains and we are trained and the useful time of consciousness “theory”, as you’d have it, that I stated is accurate and I for one, would not want to rely on YOUR facts; I’m donning the mask.

    Now, raise your seat back and tray table to their full and upright and locked position and do something constructive with you life.

    The title Pompous Ass does not suit you well.

  56. I hope I never have Male Flight Attendant on my flight. The whole purpose of the FA is for safety and to keep the passengers calm. Rather his motto seems to be “When in danger, when in doubt, run in circles, scream and shout”. Just what the passengers want to see and hear. He’s more concerned over getting addressed as a stewardess. As far as theory regarding time of useful conscoousness at 25,000ft, it’s not theory once data has been collected. Sorry didn’t mean to confuse you with facts.

  57. After 35 years of flying (17 years at SWA), I must respond some of the negative comments about Southwest Aircraft Mx. In my professional opinion, these guys, are the best in the industry. They know what they are doing and they do it well. I thank them for my 17 safe flying years at SWA.

  58. I’ve been an aircrewman on military aircraft and any inflight incident is serious. I’ve also been on the test team of experimental aircraft and have had some close calls so any one who hasn’t been that close to a turbofan engine in selfdestruct mode should just put a cork in it and say thank God that the plane and passengers survived. If they hadn’t the FAA would have shut down all flights because at first glance it would have looked like a terrorist job. Since all survived they have eye witness accounts that can say otherwise. By the look of the engine and the reaction of the plane there may have been a massive shock wave which will cause an unrecoverable engine stall/surge. In any case those on board were lucky to land.

  59. I am exhausted after reading all this. There are a few pilots and mechanics that have gotten this information correct:
    -Testpilot
    -ExBoeing Engineer
    -PAUL
    -DGTCB
    -Aeronut
    -Captlucky
    Most everyone else are just very good imaginators. Which is ok as long as you end
    your input with… Just kidding – I don’t know. :o)

    My piece… Captlucky is right about SWA Mx. Unfortunately most of the industry
    is going to “outsourced” maintenance. Outsourced maintenance is a dangerous trend in our industry today. Experience and attention to detail does not have a price tag as far as I am concerned.

    Bravo Zulu to SWA Crew and Mx. teams for not only this safe landing but all the others before it.

    One more to GE/Pratt/Rolls for building dependable engines that hold up just as designed… as did this one.

  60. At US several years back we had an uncontained engine failure of a CF-6 GE Engine on A/C 654US a Boeing 767-200ER, it exploded on an engine run-up on the ground, thousands of pieces of sharpnel penatrated the fuselage, caused a massive fire of the engine and wing and the a/c was destroyed as it was beyond repair.

    If that happened in flight it would have been a disaster.

  61. SWAspirit1
    Nov 29th, 2007 at 7:43 am
    I spoke with maintenance manager tonight on my way from getting off of work here in DAL and he said that it WAS NOT a blade malfunction…so that has been ruled out. I asked him about the spinner coming off, he said that was another possibility. He said that they were about to send the engine out for rebuild, but the NTSB wanted to look into the engine further for more investigation work. I must also say that our MX team does an awesome job aswell as our pilots….guess the track record proves that.

    SWAspirit1 thanks for your post. I hope you are right about it not being the fan blades. I was the quality manger of one of the FAA certified repair stations that repaired some of these blades for Southwest. While I know the repairs are performed IAW the OEM repair manuals limits, with NO deviations, you always worry when you hear about incidents like this.

  62. The F/A’s were told by the DH’ing pilot that he thought the plane was losing pressure and to take the O2 from the masks’ that dropped above the jumpseat is what I read.

  63. Wow, I didn’t realize how scared people are about engine failures. Even if the blade had pierced the fuselage, decompression wouldn’t have happened and the plane would not have gone down. Someone may have gotten hurt though, true. But it was on take off for heavens sake. I have had it happen to me 2 times in 40 years of flying, both on takeoff where the most stress is placed on the engine. It’s not a big deal. I didn’t have flight attendants crying, people freaking out and thinking we are going to die. Both times, flight deck came on and told us that there was a problem with an engine, we are heading back to the airport, and there they have everything under control. Everyone seemed fine, we waited a little while, all got on another aircraft and went on to our destination.

  64. testpilot2: This particular aircraft was a -300 – no dice on the vibration indicator unless they were available on the earlier models.

    It absolutely cracks me up to come in here and read all of these comments from people that know ABSOLUTELY NOTHING about aircraft! Thanks for providing me some entertainment this evening.

    MattBNA thank you for adding to the entertainment factor. All 518 B-737’s at SWA have engine vibration meters. (194 -300’s, 25 -500’s, and 299 -700’s)

  65. my question is to you mister test pilot…If you were on an aircraft that suffered a malfunctiion in the engine,in any degree,that you deemed it necessary to shut it off…would you want your daughter or any beloved family member on board?

  66. Lemmee see here…

    An engine malfunctions (rare but, hey, it happens). The normal checklist response is to shut the engine down. Would I want my kid on that plane? Sure. Why not? She would learn a lot about how an aircraft works.

    Did you know an aircraft is not allowed to takeoff without being able to lose an engine at the worst possible time (on the runway prior to liftoff) and still fly safely around to a landing either at the departure aiport or another up to an hour away?

    Reality Reminder: An aircraft suffered a rare engine anomaly and flew back to the departure airport on one engine and landed, just like the training department trains the pilots to do. All passengers deplaned.

    What better outcome would anyone suggest?

  67. I have to comment that there are only a few that know what they are talking about here. Just because there was an uncontained failure, it does not imply negligence on the part of SWA. It is quite plausable that a manufacturing defect, FOD or other problems went undetected and caused the failure. There are technical limits to inspection techniques regardless of what people think. Kudos to the crew for bringing everyone home safely!!!

    I have been on planes that have experienced compressor stalls and the people onboard have thought the engine exploded. I have also witnessed people claiming that the Tip votices off the wingtip on humid days was caused by the pilot dumping fuel, and people claiming that the pilot had reversed the engines on approach!!!

    Please if you don’t know what your talking about, don’t pull a Rosie O’Donnel. The experts will conduct a thorough failure analysis, and will determine the cause of the failure. The layman would be quite amazed at the failure analysis process and what can be determined.

  68. Everyone should be aware that NTSB/FAA reports take time, sometimes years, to be published. I doubt it would take more than 6 months to a year in this case, but only a month after the incident is too soon to expect the report. This isn’t CSI, all the answers can’t come out in an hour. They’ll have a good look at the engine to see what they can learn about what happened, an “autopsy” if you will.

    Whoever posted about the spinner coming off I think is probably right about the cause of this failure. If any spinner bolts were missing or undertorqued (or even overtorqued), it could separate. I think the fan blade damage is pretty consistent with a fairly large object being bounced around on the fan section (think spoon in the garbage disposal). The large exit hole is consistent with the size of the spinner.

    Does this point to bad maintenance? Not necessarily. Not even probably.

    Here’s a scenario where no one is “to blame.” Most bolts on a plane are torqued to some specific value (say, 100 foot-pounds plus or minus a few). A calibrated torque wrench is used for this. This wrench is calibrated on some schedule dictated by whatever FAA-approved operating certificate the maintainers have. The wrenches are calibrated on a schedule because sometimes they drift out of calibration. So what happens when a wrench is out of calibration (perhaps badly), but was in calibration the last time it was checked and is used on the spinner? Well, undertorquing or overtorquing, both are bad.

    There are probably a lot of statistics that go in to determining a calibration schedule. Statistics that are gained from testing, operational data, and occasional incidents such as this one. Aviation is safe because data are collected (sometimes from incident and accident reports) and used to improve the process.

    The bottom line is that everyone lived and the plane can be used again (after a little maintenance and maybe a few new seat cushions). Despite the spectacular engine failure, the plane worked as advertised. The crew did its job. You can harp on the airline some for not being compassionate enough, but the rest of the aviation system did its job well.

    This probably isn’t very satisfying to the tin-foil hat crowd, but that’s reality sometimes.

  69. Well, I wasn’t expecting a final report, just a preliminary. On the NTSB site are several preliminaries for the month of November, just not the SWA incident. 🙁

  70. One comment (like any more are actually needed), however this issue was raised late and has a kneejerk quality about it….

    QUOTE: Unfortunately most of the industry is going to “outsourced” maintenance. Outsourced maintenance is a dangerous trend in our industry today. UNQUOTE

    This is a bad trend if the work is sent to shady shops in developing countries. – Really not a problem with US air carriers. The vast majority of airlines do not repair their own engines any longer. Truth be told, they are just not that good at it. In the case of this particular engine, Southwest does not have an engine shop. Their engines are serviced by General Electric (part owner of the CFM venture and therfore the Original Equipment Manufacturer). Call me crazy, but that does not sound too dangerous to me.

    To take it a step further, I have been to more aircraft and aircraft component repair facilities around the world than the vast majority of people who are reading this forum. All of them have good standards, but some are quite superior to any airline operated maintenance shop. Why? It is their core competency. An airline’s core compenency is the safe operation of aircraft. These shops are top notch facilities with highly trained maintenance professionals on the job.

    As a matter of fact, some of the third-party repair facilities I have had the opportunity to work with over the past 15 years are far better places to have aerospace equipment serviced than the operator (the airline) and, in some cases better than the OEM. I would argue that the outsourcing of maintenance (as long as it is properly overseen by the airline – and that is how it works in the US) actually CONTRIBUTES to safety – not the opposite.

  71. Before you start blaming Southwest or their maintenance you should check into the fact that this aircraft had just had maintenance done on it from another company. The company that did the maintenance was also subcontracted through a third company outside of Southwest. BOTH companies were approved and overseen by the FAA and not controlled by Southwest.

  72. Just came across this blog. I was also a passenger on this flight. I can confirm the truth of what the other passengers have said. Don’t know about the technical side of what happened but my gut told me the plane was going down. Thankfully my gut was wrong. I spoke with a uniformed SW pilot who was riding in the passenger section and sitting across the row from me who sprang into action as soon as the “explosion” occurred. After we landed, he told me it was extremely serious and that he had never experienced anything like it in his 22 years of flying. If he happens to read this, he needs to know the huge beneficial impact his calm demeanor had on the passengers. It was a pretty traumatic experience that really hits you a day or two later.

  73. I didn’t read all the entries, all I can tell you is that I worked for Southwest for over a decade & they work extra-hard to keep MANY things out of the media! Employees are often times the last to know, if ever… of any “incident” incurred. IMMEDIATLEY ANY INFO of that specific “incident” is gone! At one time (during he Kelleher era) the company was undeniably the best, as for now, it has declined drastically & will continue to. Southwest is no longer adored by its employees, for they have seen the companies true colors…as soon as the customers flying them see the REAL SOUTHWEST, they too will be disappointed!

  74. Ex Boeing Engineer wrote:

    3) Jet engines are highly stressed and full of energy. Thus, Boeing airliners are designed with the presumption that they will fail, so the plane must continue to fly safely. That’s why there are two engines, and why they are on pylons, and why critical flight controls are not in the way of engine failure, etc.

    http://beaudaniels.com/Infographic-pages/737-hydraulics.htm

    Not meaning to question your statements critically, bu this graphic shows 20 hydraulic lines penetrating the plane perpendicular to the aircraft centerline, defined by the compressor rotors.
    One could likewise imagine control systems cable, control linkages and electrical power distribution crossing that plane. Is there some metric for expected fuselage penetration, or am I missing the point on what’s considered critical flight controls?

  75. For starters…

    That pictorial is for the previous generation, the 200 model. I flew the aircraft in the Air Force and the lower wing skin adjacent to the engine is extra-heavy to act as “armor plating” should a turbine core disintegrate. In the 200, the engine is mounted to the wing spar (no engine pylon)with flight controls systems for the wings in the “hell hole” (wheel weel). In the extremely remote event that one or more items is damaged in the wheel well, the other functioning wing flight controls would suffice to recover the aircraft. I have never heard of a JT-8 disintegration that wasn’t contained (where the parts blow out the tail of the engine).

    The 300 engine sits far enough forward on the pylon to keep most of the wing and flight control plumbing still secure behind heavy wing skin. The fuselage skin at the wing carry-through section is also much thicker and stronger because it has to take the bending loads the wing provides to the fuselage. Forward and aft of the carry-through, the wing skin is standard thickness.

    This is the first uncontained failure I have seen in the CFM series. Even at that, fuselage penetration was minimal.

    Hope that helped.

    Ray

  76. The B737 classics also had a “dry bay” area of the fuel tank “above” the engine just in case an engine suffered an uncontained failure. Maybe someone knows if this is still the case with -300s and subsequent models. As it turned out the dry bay did not prevent the destruction of a B737-200 from an uncontained JT8D-9A failure in the 1980s. Just after starting the T/O roll one engine had an uncontained failure of the 13th stage compressor disk and a chunk of it penetrated the fuel tank (not in the dry bay area) and the subsequent fire from the leaking fuel burned the aircraft to destruction. Luckily everyone had time to safely evacuate the aircraft. I was working in the engine O/H shop of the airline that overhauled the engine under contract to the airline that suffered the loss, and the investigation into the failure and the liability aspects etc. went on for years. Uncontained failures like this one and the CFM56 one above are very rare but they do scare the hell out of anyone in the industry because it is almost impossible to guard against or prevent the serious consequences from all of them.

  77. The shroud surrounding the N1 fan did contain the blades. The area forward of the fan plane isn’t reinforced and that is what failed to contain what was probably fragments of the spinner.

    PS..where can I get one of those tin-foil hats? 🙂

  78. the fuselage is not armored at the fanblade plane of rotation. the window there is omited to make room for a riser duct that supplies cabin air located on the passenger service unit above your seat.