Holed Southwest Airlines flight makes emergency landing

[Gerald]

An airliner has made an emergency landing in the United States after a gaping hole in the roof caused a sudden drop in cabin pressure.

Southwest Airlines flight 182 from Phoenix to Sacramento put down safely at a military air base in Arizona.

Passengers heard a bang as the roof panel blew open in the cabin. "You can see completely outside," one woman told the Associated Press news agency.

http://www.bbc.co.uk/news/world-us-canada-12945453


Note: 2 April 2011 Last updated at 06:57 GMT

[CCIP]

2nd time relatively recently that a Southwest plane popped a hole in the upper fuselage. They do fly their fly their planes pretty hard - really fast turnarounds and a lot of cycles. Hopefully this isn't pointing to either a flaw in the 737-700, or Southwest's maintenance procedures...

[Gerald]

Luckily no one was hurt anyway

[Gargamel]

2nd time relatively recently that a Southwest plane popped a hole in the upper fuselage. They do fly their fly their planes pretty hard - really fast turnarounds and a lot of cycles. Hopefully this isn't pointing to either a flaw in the 737-700, or Southwest's maintenance procedures...


Doubt it's a flaw just due to the number of 737's flying....

[gimpy117]

It's probably from airframe age. Too many cycles on it, and poor or nonexistent inspections. There will probably be an investigation because this isn't the first time a 737 has lost a roof panel due to stress on the airframe from pressurization. It happened to Aloha Airlines in 1988. One flight attendant was blown from the aircraft.

http://www.tc.gc.ca/media/images/ca-publications/maintenance1_4.jpg

The FAA found that the aircraft was old, not well taken care of and not well inspected (there were actually visible cracks that were overlooked before the flight). They slapped a Huge Fine on Aloha and the company is currently no more. With the recent incident, it sounds like one of the 737's Safety measures Tripped, a "Controlled Area Breakaway Zone" designed to rupture before the rest of the structure did. Except on the Aloha plane it was so old that when this happened the rest went with it. The Southwest plane was lucky that this didn't happen.

[Gargamel]

Hmmmmm..... convertible model..... interesting..... :hmmm:


But I remember when that happened.

[Growler]

Rumor I've heard is that, aside from the inevitable grounding of their -300s for inspection, that SWA has been intending to phase out their operations of the -300's as the -800s come online.

Also, considering SWA's safety history against that of other airlines, and the quality of service I've had from them, I wouldn't hesitate any measurable amount of time to fly aboard their aircraft.

I expect that there will be lawsuits for emotional distress and lots of morning talk show circuit tours for many of the passengers, though.

[CCIP]

Rumor I've heard is that, aside from the inevitable grounding of their -300s for inspection, that SWA has been intending to phase out their operations of the -300's as the -800s come online.

Also, considering SWA's safety history against that of other airlines, and the quality of service I've had from them, I wouldn't hesitate any measurable amount of time to fly aboard their aircraft.

I expect that there will be lawsuits for emotional distress and lots of morning talk show circuit tours for many of the passengers, though.

Yup, that's what I'm seeing as well. I won't be surprised to see the 300s go though - I think even with the upgrades they got, they're still really getting to their age. Southwest definitely have a solid record, but boy do they fly their planes hard. So the -300s are definitely edging their airframe limits by now.

And yeah, I agree - none of this would make me hesitate to fly with them. All things considered, it seems like even with the failure, everything worked as designed - everyone's down safe and we're not looking at a 'convertible'.

[Platapus]

very glad no one was hurt. Even a small hole, at those speeds can make a very big hole.

[gimpy117]

And yeah, I agree - none of this would make me hesitate to fly with them. All things considered, it seems like even with the failure, everything worked as designed - everyone's down safe and we're not looking at a 'convertible'.


see I'm not so sure. Catastrophic failures like this should not happen Unless somebody is doing things carelessly or just wrong. The 737 has been flying long enough to know exactly how much those airframes can take. The fact that that 737 had its airframe blow up tells me that they are doing something wrong. Even more scary is that all the airframes have probably been flown the same way, and kept up the same way...so 737's of that age could all be effected by the same problem. Its been a known pattern, for example, then that engine separated from a DC-10 at o'hare in 1979 they found many other aircraft in the fleet had the same problems from poor maintainance. The FAA knows this could be a problem...and Southwest knows this too..thats why the fleet is grounded. I wouldn't be surprised in the least if more are found to be near failure.

[Growler]

Gimpy...

I'm not even sure where to start addressing that.

For starters: Aircraft are NOT duplicates of the ones that went off the assembly line before them. There are thousands of parts, and dozens of people involved in the assembly, quality checking, shakedown flights - there are literally thousands of ways for an aircraft to de-cert before ever leaving the yard the first time. every inspection after that has the same possibility.

Do you drive your car for 600 miles a day, every day, and not expect something to go wrong? Of course not, so you take preventative measures - new tires, oil changes, new wiper blades, replace headlights, etc. Does that mean you don't - occasionally - have problems with your car?

You can NEVER predict with 100% when a particular part will fail, especially when it's in constant interaction with other parts and the environment. The fact is, Southwest DOES push their airplanes hard - and to date, they have had very few serious incidents, and perhaps two fatalities involving their aircraft or actions of their aircraft. That's not two crashes - that's two individual people, and one of those was on the ground in Chicago when an SWA 737 overran the runway at Midway. So, with that record - if they're pushing their aircraft hard, their maintenance crews seem to have stepped up to meet those demands pretty well.

So now, they're taking ~80 aircraft out of service to re-check them, at considerable revenue loss to them, to make certain their remaining -300s are safe. Good for them, and good for us who fly them - it's not only sane business practice, but it's good PR, too.

You're making it sound like anyone under a 737 right about now is in danger of being pelted by aluminum rain, and the evidence just doesn't bear that out.

[gimpy117]

yes, Aircraft are different...but heres the thing:

there are rules and regulations for the upkeep of aircraft. There are also rules specific for the airframe. This isn't just a bad spark plug, or a tire that blew out...this as the airframe itself, a 5'x3' section...something that just shouldn't happen if an aircraft is properly maintained and is flown off of what the book tells you hours wise.

The wall street journal also reported that the aircraft was due to checked for structural damage as well...but fatigue like this should have been caught last time

EDIT: also, this happened 2 years ago to another Southwest plane... history seems to repeating itself.

[Growler]

yes, Aircraft are different...but heres the thing:

there are rules and regulations for the upkeep of aircraft. There are also rules specific for the airframe. This isn't just a bad spark plug, or a tire that blew out...this as the airframe itself, a 5'x3' section...something that just shouldn't happen if an aircraft is properly maintained and is flown off of what the book tells you hours wise.

The wall street journal also reported that the aircraft was due to checked for structural damage as well...but fatigue like this should have been caught last time

EDIT: also, this happened 2 years ago to another Southwest plane... history seems to repeating itself.

Seriously? History repeating itself off of two examples?

Of course there are rules and regs for maintaining aircraft - just like there are for automobiles, buses, trains... they all must meet minimum standards for safe operation - it's why in many states a car undergoes some form of inspection at the time of purchase, and in some cases, on some form of regular schedule after as well. And like any other "government mandate" the rules are no doubt applied more stringently by some than others, and the details that are important to some are not important to others - it's the human element of everything we do. Hell, the US changed enlisted submarine lookouts every thirty minutes just because of the human element - getting tired, bored, distracted - all contributed to missing things.

We need to be clear from the beginning that the cause of the incident has not yet been determined to be fatigue, and even if it is, we are talking about this individual case, not "history repeating itself." After all, there are hundreds of 737-300s in service today, and they're not falling apart - it's a well-made aircraft, but there are a LOT of things that factor into part failure - including the possibility of fatigue, but also including the factor that sometimes, things break. Metal flaws in the material, the rivets; a bad pressure seal... things break all the time. And sometimes in the same place. My car's passenger side headlight has burned out twice in the last three years. No one can find a wiring issue. So why have I replaced a part twice in three years that I hadn't had to replace in the seven years prior? Was that first headlight of ten years ago some sort of super-headlight with a big S on it? If so, then I must have its father on the left side, cause that one's still going strong after ten years.

Flight 812's aircraft's last major downtime inspection was March of 2010, from what I understand. Again, go back to my earlier statement: Drive your vehicle 600m a day for 365 days, with only a few hours of downtime for maintenance, and tell me if something doesn't require work. And that's in a car that doesn't experience the stresses of the pressurization/depressurization cycle a few times a day, or travel at some 300+ kph. Clearly, these aircraft are not falling out of the sky all around us, so somebody's doing something right somewhere.

SWA has downchecked their 300s that have not undergone skin replacement for inspection, at great financial loss to them both immediate and somewhat over a longer term, should passengers lose confidence in the airline. They've already been gigged once in the past by the FAA failure to comply with inspection protocol, a failure which the FAA allegedly colluded with.

Regardless, there is extraordinary danger in assigning blame to anyone at this stage of the game. Southwest MAY be culpable in this incident, or for factors leading to this incident. But the fact remains that they may not be, too.

The danger is in pseudo logic that leads us to somewhere, someone getting John Q. Lawmaker to step up and introduce some BS legislation earmarked onto some other equally stupid bill to "Engage the Aircraft Industry in Regulation, Monitoring, and Enforcement of Aircraft Skin Textures, Consistencies, Application, Exercise, Examination and Air Carriers Passenger Protection Act" or some equally stupid waste of taxpayer time and money trying to enforce a safety issue where there might not be one, and creating yet another layer of bureaucracy and paperwork and, purely by coincidence, higher flight fees. And THAT'S where history bloody repeats itself.

[gimpy117]

My car's passenger side headlight has burned out twice in the last three years.

don't touch the glass with your hand when you put it in. Im told oils from the skin mess with the bulb

also, all I'm saying is is that this isn't a normal occurance. Planes just don't rip open mid air. For an aircraft to fail like that isn't very common, and these things are designed with safeguards, and inspection intervals that are designed to occur before a problem like this happens. I don't get why you are defending SWA so much here. I don't want to assign blame to them...but I'm suspicious because they have put off airframe inspections before and had an accident very similar to this. After taking courses in aviation safety, and studying accidents therein You'd be surprised how many accidents have factors that occurred when the plane was being worked on in the shop. These Shops are often rushed, or pressured to skimp by the Management to save money....I would not be surprised this is the case.

Also, the plane flying so much has NOTHING to do with it and does not at all serve as an excuse. The more cycles and hours you fly, the more you need to work on the aircraft. Commercial carriers are required to fix their plane on an hour based system...when it reaches X number of flight time you need to look at it. There are also published Cycles for the airframe that will tell you when you need to look at the airframe. So no, I don't buy the whole "it's been used a lot" argument...because the System is DESIGNED to negate that issue.

[Betonov]

don't touch the glass with your hand when you put it in. Im told oils from the skin mess with the bulb

The oil from the skin starts to burn on the bulb glass casing, making a hot spot. The glass is under stress when some parts are hotter than others and starts to crack. So yes, dont touch the glass part with your hands

[Growler]

don't touch the glass with your hand when you put it in. Im told oils from the skin mess with the bulb

also, all I'm saying is is that this isn't a normal occurance. Planes just don't rip open mid air. For an aircraft to fail like that isn't very common, and these things are designed with safeguards, and inspection intervals that are designed to occur before a problem like this happens. I don't get why you are defending SWA so much here. I don't want to assign blame to them...but I'm suspicious because they have put off airframe inspections before and had an accident very similar to this. After taking courses in aviation safety, and studying accidents therein You'd be surprised how many accidents have factors that occurred when the plane was being worked on in the shop. These Shops are often rushed, or pressured to skimp by the Management to save money....I would not be surprised this is the case.

Also, the plane flying so much has NOTHING to do with it and does not at all serve as an excuse. The more cycles and hours you fly, the more you need to work on the aircraft. Commercial carriers are required to fix their plane on an hour based system...when it reaches X number of flight time you need to look at it. There are also published Cycles for the airframe that will tell you when you need to look at the airframe. So no, I don't buy the whole "it's been used a lot" argument...because the System is DESIGNED to negate that issue.

Yeah, I know about the bulb glass; I've done this before.

I'm not saying that the issue isn't Southwest's fault - there's clearly safety issues in their past; there are with every airline. What I am saying is there are factors involved beyond which an airline can address, even due to skimpy maintenance. They've not had a major casualty incident yet. There's a reason for that that argues competence on the part of their maintenance people - with all the ups and downs and miles they're putting on these airframes, it has to be more than luck that they've not had major issues and high body counts.

The NTSB has come forward with news that there are indications of existing fatigue in the aircraft metal, so that settles that issue. Now the question will be, "How long was it a noticeable condition, and why was it not noticed?" I suspect that someone's going to lose a job at the very least.

[gimpy117]

The NTSB has come forward with news that there are indications of existing fatigue in the aircraft metal, so that settles that issue. Now the question will be, "How long was it a noticeable condition, and why was it not noticed?" I suspect that someone's going to lose a job at the very least.

the thing is...aircraft don't just suddenly break very often...It takes a while for cracks to get so severe that a 5x3 section blows out of the aircraft. I'd like the believe that nobody screwed up...but i doubt it. Again, I bet the shops were rushed on pretty complex inspection..and sadly the guys who were told "get this done fast or you're fired" are gonna be fired to save company face.

[GoldenRivet]

you know i sat in one of the planes one time when they were doing a pressurization test.

Its amazing that you can actually hear all the crunching metal and popping aluminum - sounds similar to a submarine going deep - during this test.

fact is that this is happening every time the airplane climbs and descends, hundreds of times per week, tens of thousands of times per year for the 15 year lifespan of the airplane in question.

think of the paperclip. bend it a little back and forth, just a little. It will take time to break but it eventually will break.

these airliners are the same way.

sure there are inspections in place to locate cracks and prevent these sorts of failures, and maintenance did in fact find an alarming number of stress cracks in the airframe of this particular aircraft last year.

no matter how rigid and detail oriented your maintenance program may be - these sorts of incidents are not 100% preventable. all you can do is reduce the likelihood of them occurring, but you will never reduce that likelihood to ZERO.

look back at the dehavilland comet (http://www.rafmuseum.org.uk/milestones-of-flight/images/3comets.jpg) - there were a couple of them IIRC that developed a nasty habit of disintegrating mid flight. the culprit... the window corners had too much pressure buildup during pressurized flight.

the solution: change the windows to a more rounded shape.

the FAA - depending on its findings - may release an Airworthiness Directive on the 737 specifically - which will require periodic inspection of specific places for a specific type of stress fracture, or perhaps they will release some blanket requirement for closer airframe inspections and reduced intervals for aircraft that fly in excess of 1,000 hours per year (1,000 hours is only used as an example number) but at the moment, thats all i would expect to see come of this.

at the moment, the NTSB is of the opinion that nothing was missed on an inspection that should have otherwise been caught.

[Growler]

And, on a similar note: >>LINK (http://www.mercurynews.com/breaking-news/ci_17764666)<<

GR - thanks for that note; I'd not had a chance to complete review the NTSBs statement(s) before I had to duck out for awhile.

Gimpy - that "get this done fast or its your job" was what I was referring to earlier when I added that there's reason to suspect FAA collusion with SWA not meeting inspection standards.

[GoldenRivet]

And, on a similar note: >>LINK (http://www.mercurynews.com/breaking-news/ci_17764666)<<

probably an outflow valve stuck open or something like that

Gimpy - that "get this done fast or its your job" was what I was referring to earlier when I added that there's reason to suspect FAA collusion with SWA not meeting inspection standards.

Didnt southwest airlines' FAA liaison get in some deep kimchi over this a couple of years back?

here is a little history lesson for SWA http://www.faa.gov/news/press_releases/news_story.cfm?newsId=10179

we dont call them the low fare cattle car airline for nothing.

SWA is the wal mart of the airline industry IMHO

[Growler]

As to the SWA FAA liaison, I can't say - I haven't found any details on that story yet, but I've not been actively searching for the last few hours, so I can't honestly say I looked real hard.


we dont call them the low fare cattle car airline for nothing.

SWA is the wal mart of the airline industry IMHO

Perhaps, but by and large, their safety record is the best in the industry, and they do get the job done. And unlike the Wal-Mart kool-aid kids, the folks from SWA that I've dealt with always seemed to be pretty dialed in to doing their jobs.

Might just be my experience, but I've always gotten good service from them. I can't say the same for other airlines I've dealt with. In that regard, they're what Wal-Mart wishes it was.

[GoldenRivet]

by and large, their safety record is the best in the industry, and they do get the job done. And unlike the Wal-Mart kool-aid kids, the folks from SWA that I've dealt with always seemed to be pretty dialed in to doing their jobs.

Might just be my experience, but I've always gotten good service from them. I can't say the same for other airlines I've dealt with. In that regard, they're what Wal-Mart wishes it was.

I have had much the same experience, i just enjoy ribbing SWA whenever i can.

i dont remember the liaison story... perhaps im wording it wrong, maybe it was a manager or inspector or something.

i seem to recall there being a stink about corroboration in maintenance issues before

[Growler]

I have had much the same experience, i just enjoy ribbing SWA whenever i can.

i dont remember the liaison story... perhaps im wording it wrong, maybe it was a manager or inspector or something.

i seem to recall there being a stink about corroboration in maintenance issues before

Goes back to the 08 incident, IIRC. I've found a couple of different secondary sources that speak of doubt in the FAA's enforcement of SWA's maintenance failures, right around the time of the $10.5M fine, but that fine and the consequent settlement seems to draw all the attention away from the FAA question.

[sharkbit]

The FAA just issued an emergency Airworthiness Directive forthe 737-300, -400, and -500 models in conjunction with an alert Service Bulletin from Boeing to do an eddy current inspection on the joint that failed. It looks like it needs to be done within 5 days or 20 days, depending on the number of cycles.

http://www.amtonline.com/publication/article.jsp?siteSection=1&id=13191

I found it amazing how much time the SWA aircraft had:
Over 38000 landings and over 48000 hours. The highest time aircraft we have where I work is a Lear 35 with almost 14000 hours and over 10000 landings, built in 1978. Airlines fly the **** out of their airplanes.

For non-aviation people here, Airworthiness Directives (AD's) are issued when the FAA finds a condition that exists on aircraft that seriously affects the airworthiness of the aircraft and need to be addressed. They are law(an extension of the FAR's-Federal Aviation Regulations) and an aircraft owner/operator must comply with them.

Like any government item, normal AD's take months before being issued. They usually have to go thru a lengthy process before becoming effective. The FAA can issue an Emergency AD, such as this one, pretty quickly when needed though. They can bypass a lot of the normal process. Many emergency AD's will immediately ground an aircraft. This one at least gives operators a little time if they haven't already complied with the Boeing Service Bulletin.
Normal AD's give a certain length of time to comply with them.

All aircraft, engines, props, and aircraft appliances have AD's issued against them. Some serious, some not so serious. They are in no way a gauge on how safe a particular model is or isn't.

:)

[sharkbit]

Here's another article as well:
http://www.amtonline.com/publication/article.jsp?siteSection=1&id=13183

:)

[Growler]

Thanks for the links, Sharkbit - I had a feeling another AD was going to be issued on this one. IIRC, there was one several years ago for the skin of the -300s that required most of them to replace it with a different installation method.

All of this said, while the scene was undoubtedly bad, the rip-stop straps in the installation did their job - the airframe held together for the flight crew to put in on the ground. That, in some small way, is a victory.

[Gargamel]

All of this said, while the scene was undoubtedly bad, the rip-stop straps in the installation did their job - the airframe held together for the flight crew to put in on the ground. That, in some small way, is a victory.

Yes, when you start designing for controlled failures, rather than catastrophic ones, you can usually provide operators time to avert or at least recover before some really bad happens.

[Gerald]

PASSENGERS fainted when a 5-foot hole opened in the roof of a Southwest Airlines Boeing 737 flying from Phoenix to Sacramento last week. The most frightening moment may have been when, as one passenger said, “You could look out and see blue sky.”

It was an unusual episode in an industry with a strong safety record. But that record might be hard to sustain: on the very day that Southwest’s Flight 812 was diverted to Yuma, Ariz., for an emergency landing, the House of Representatives passed a bill likely to make it more difficult to detect and prevent midair ruptures, metal fatigue and other serious flight risks.

The bill would cut $4 billion from the Federal Aviation Administration’s $37 billion budget. Representative John L. Mica, a Florida Republican who is the chairman of the House Transportation Committee, says the bill would streamline F.A.A. programs and promised the bill would “not negatively impact aviation safety.”

Such streamlining would probably mean reduction of F.A.A. staff, including safety inspectors. As it is, the agency has been short-staffed for years. According to the Government Accountability Office, 1,100 inspectors oversaw 81 airlines, 5,200 repair stations, and 625,000 pilots in 2006. A $4 billion cut will necessarily reduce the work force further. And it’s hard to imagine this will not diminish safety.

http://www.nytimes.com/2011/04/10/opinion/10mcgee.html?hp


Note: Update Record, April 9, 2011