Holed Southwest Airlines flight makes emergency landing

[gimpy117]

Originally Posted by CCIP

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]

Originally Posted by 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.

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]

Originally Posted by gimpy117

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]

Originally Posted by gimpy117

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]

Originally Posted by Growler

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 - 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<<

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.