Close call for QANTAS 747.

[Night Owl]

I see there was an explosive decompression on a QANTAS 747 out of Hong Kong, that had to make an emergency landing at Manila.

http://www.theage.com.au/

What is very interesting is the fact that you can see items of luggage exposed. Why that is interesting is luggage is not just packed in the cargo hold loose. It is packed inside air cargo containers at the terminal, and then loaded as a container into the cargo hold of the jet.

As such, if there was a stuctural fault in the aircraft, and the pressure hull ruptured at the pictured location forward of the wing root, then HOW did the wall of the air cargo luggage container in the hold also rupture as well, right next to the same hole in the fuselage?

There is a disturbing answer. The air cargo container ruptured first, and the overpressure from that decompression damaged and then ruptured the external fuselage of the aircraft adjacent to the cargo container.

Now what would cause an air cargo luggage container to rupture in flight at around 30,000 feet? The answer is not unknown. It has happened before.

http://news.bbc.co.uk/2/hi/special_report/1998/12/98/lockerbie/235632.stm

The below graphics indicates that the QANTAS event has occured in a similar location on the airframe to that which destroyed flight PA103.

http://aviation-safety.net/photos/displayphoto.php?id=19881221-0&vnr=1&kind=G

What may have saved the QANTAS flight from the same fate as the PA103 Lockerbie flight is the fact that the rupture occured further back on the fuselage, and was contained by the extra structure of the wing / fuselage fairing, which has been lost as a result of the rupture.

The below video is of destructive tests conducted on a 747 and Lockheed Tristar. The forward fuselage tests is of the same amount of SEMTEX explosive that caused the downing of PA103, which was in the order of 250 grams, or a lump easily held in your hand. The test was also conducted under similar pressurised conditions as would have occured in flight.

The QANTAS event may have involved a lesser amount or lower grade of explosive, as SEMTEX is a high order high explosive. Improvised explosives such as ammonium nitrate and gunpowder are of a lower yield. It could have also been an incomplete detonation, or a partial missfire.

http://www.youtube.com/watch?v=arRJi3wHRnA

Where could an explosive device come from?

The plane had made a stop over at Hong Kong, and may have taken on board passangers, and luggage. As I understand it, when the depressurisation occured it was around 20 minutes in to its flight, and would have just finished its climb to 30,000.

In any event, if it was a terrorist attack by bomb, or just a structural failure (which are damn rare on well maintained 747's), the passengers on the QANTAS flight have been damn lucky.

[leon]

These things happen from time to time, and I think the media blow it out of proportion.

We all drive cars and things go wrong, and accidents occur, any thing mechanical can fail, so to aircraft, that is the risk we take when we leave our back door.

If we didn't realise the risk of moving from the couch, we may as well be dead.

This event with Quantas dose no disturb me, and I will fly, or drive again, thats life.

Leon

[madtuna]

yeah probably happens more than we know with some of the bodgey cut price airlines... but I'd still crap my dacks the moment the first bit of debris wizzed passed my head and the oxygen mask fell down

[casstony]

Very interesting observation Night Owl. I saw that on the news and thought it was a sign of poor maintenance, but a bomb makes more sense if you're correct about all the luggage going in containers prior to loading. I'll feel more comfortable flying if it was a bomb rather than Qantas just letting their planes fall apart. The airport security will get worse though - airports are one of my least favourite things to see.

[Jen]

:eyepop:
i think im gonna keep my two feet on the ground :P
:D

[glenc]

I suspect a bomb. Is that the plane that took the Pope back to Rome?

[jakob]

Geoff,
"What is very interesting is the fact that you can see items of luggage exposed. Why that is interesting is luggage is not just packed in the cargo hold loose. It is packed inside air cargo containers at the terminal, and then loaded as a container into the cargo hold of the jet."

I think bulky items get loaded loose. Reading the passangers observations, that the floor caved in, the air was going only one way, no explosion only a bang.

I think its corrosion, many rivets have broken. If the rivets were healthy, some would have stayed and torn the sheet.:rolleyes:

[TrevorW]

You know when you are asked to assume the position on a plane that you should start worrying, reason

"it's to kiss your ass goodbye"

:eyepop::rofl::rofl::rofl:

[GrahamL]

wow that nots a good look ..notice how its an almost perfect tear right around the panel ... I think its a bomb but not on the aircraft .. its been ticking away in the corner of the board room for a while now.

[Peter Ward]

And so the armchair expert theories comeforth.

Explosives? To be blunt....What a lot of bollocks.

Ockham's razor works in aviation as well as anywhere else.

The distinct lack of burn marks, frayed fabric and confettied T6 is pretty obvious.

Corrosion/metal fatigue. Plain and simple.

Plus a big well done to the operating crew :thumbsup:

[Kal]

I'm guessing the sudden dive is just the action taken by the pilots as a measure against the decompression in the plane? Still, it would be a harrowing and frightening experience as a passenger.

If I was on the plane I'd honestly not know wether to put my head between my knees and kiss my @$$ goodbye, or pull out a camera and record the ordeal so I can sell it to a news agency to make some easy $$$ :lol:

[Peter Ward]

Picked it in one. We are drilled on this procedure fairly regularly in the flight simulator. Rapid decompression from 29,000 (feet) while no doubt harrowing, is no where near as bad as say 39,000.

The difficult decision is "how quick do we descend?" (down to air the punters can breathe without an O2 mask).

I also use the word *descend*. Media hype of planes "dropping" 20,000 feet is just sensational rubbish. Only if the wings fall off will a plane *drop* (sadly, there is some very nasty footage out there of a water bomber doing just that)

Opposed to falling at 1g, the manoevure is very much a controlled affair.

Structural integrity of the airframe is invariably an unknown to the pilots after an event like this...but Boeing build them exceedingly well, and by virtue of the fact that despite a pretty large chunk of the aircraft is now sitting on the bottom of the south China sea, everyone walked away.

In short, the crew performed magnificently, and clearly earned their salary that day!

[Jen]

:lol::lol::lol::lol:

[casstony]

Peter, can you tell us anything regarding cutbacks on maintenance expenditure or inspection frequency? I assume management push the safety/reliability barriers in your industry the same as any other - pay a lot of attention to safety issues that don't cost anything to keep up appearances.

[Peter Ward]

I cannot comment on maintenance standards.

There has been a bit of tabloid coverage on this.

http://www.youtube.com/watch?v=pvlPBr3j2qs

But tabloids rarely get the facts correct (eg lasers)

That said, the overseeing body, CASA, is a weak, flaccid and ineffective standards authority IMHO.

[anthony.tony]

What do you think of Quantas's Flight record all up.Tony

[garyp]

Well done to the Qantas crew:thumbsup:.
I think it's structral rather than a bomb. Whatever it was the outcome could have been a lot worse. As they say any landing you can walk away from is a good one;)

[Kal]

Theres some more info on this coming out in the news today, including reports of oxygen masks not working. More bad news regarding Qantas Maintainence.





If oxygen cylinders ruptured, could this be why some passengers struggled with the oxygen masks?

link (http://www.news.com.au/story/0,23599,24084555-421,00.html)



I can definately understand now why you would want that rapid descent!

[Night Owl]

Well, I was right partially, something did blow up, but it looks like it was an oxygen cylinder. I wonder why?

My guess is it wasn't serviced / inspected properly. Doesn't happen? Read this little snippert....

http://www.theage.com.au/news/national/probe-after-qantas-pumps-wrong-gas-into-jets/2007/12/15/1197568332267.html

:eyepop:

[Peter Ward]

Maybe it just me, but, I have this problem with a press that also describes shining a beam of coherent light at an aircraft (albeit a dopey thing to do) as a laser "attack"

Had the thought not occurred to you, that the wing root fairing departing the aircraft would also rupture of the fuselage adjacent to the Oxy bottle rack and would likely damage the bottle(s) as it departed? True, the reverse order of events could have happened.

Either way, once the fuselage was ruptured, where also might the air that was in the (thin walled) baggage can, want to go?

plus, words like "explosion" and "blew-up" sound much more exciting , might even sell a paper or two.

Rather that take the tabloid press as gospel, I'll personally wait until I read the formal inquiry report/Boeing engineering directive.

[leon]

Not that I know the first thing about aircraft, and/or its manufacturing procedures, isn't it good to have a skilled pilot on board this forum who knows what he is talking about, with out the media crap.

Good one Peter.

Leon

[casstony]

I'm hoping for lots of media horror stories (go Today Tonight:thumbsup:) to clear some people out of that airport before I have to fly again. Gee I hate airports (and 747's).

[Peter Ward]

While some airports are wanting...( Heathrow...where the superlative ATC is in stark contrast to outstandingly mediocre ground handling, and Mac Bank's all-round Sydney basket-case come to mind) ....wash your mouth! :)

The B747-400 is one of the finest planes ever built!

[casstony]

Easy for you to say up front there with your recliners and taking turns at napping:P.

I'd be quite happy to have one parked on a block of land to live in (plenty of room for guests, slides for the kids, cupboard space for astro gear) but stuck back in the cattle truck for flights across the Pacific is torturous. We'll have to make one of our trips to a Buddhist monastery so I can learn to cope better.

[Peter Ward]

Yep, the auto-flight system handled the rapid decompression and diversion to Manila and still allowed the lads to enjoy a nap...but in the end there was too much noise from the inconsiderate hoi polloi in the cabin to sleep, and only enough time to enjoy one cup of earl grey before the gear had to be extended... down right inconvenient. :rofl:

[garyp]

Good idea. Usually the "real" truth comes out after months of investigating well after all the media hype has died down.




I agree peter. I don't know alot about 747s i particular but I know they have survived some rough treatment over the years.
In the 80s Air China had an incident where it went through some pretty impressive aerobatics with a load of passengers before landing. ( I think I have the facts roughly right. You may know better. I'm just thinking off the top of my head.)
The point is it stayed intact and everyone survived just as with the Qantas incident.

Cheers Gary:)