Qantas 747 oxygen tank rupture
Qantas 747 oxygen tank rupture
(OP)
Any thoughts from the aero guys about the incident that happened last week?
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Qantas 747 oxygen tank rupture
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Qantas 747 oxygen tank ruptureQantas 747 oxygen tank rupture(OP)
Any thoughts from the aero guys about the incident that happened last week?
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RE: Qantas 747 oxygen tank rupture
RE: Qantas 747 oxygen tank rupture
RE: Qantas 747 oxygen tank rupture
Mike Halloran
Pembroke Pines, FL, USA
RE: Qantas 747 oxygen tank rupture
RE: Qantas 747 oxygen tank rupture
RE: Qantas 747 oxygen tank rupture
It will be interesting to see if the cylinder losing the regulator caused the hole or if the cylinder lost it as it hit something else departing the airplane. Rule #1 in these types of incidents is to never take what the media says as gospel.
RE: Qantas 747 oxygen tank rupture
but did a tank explode ? and more importantly, why ? these questions can only be answered by a detailed investigation.
question came to my mind ... why do we still use metal tanks ? wouldn't this be a good application for composites ?
RE: Qantas 747 oxygen tank rupture
RE: Qantas 747 oxygen tank rupture
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Nert
RE: Qantas 747 oxygen tank rupture
File is about 1 meg in size.
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Nert
RE: Qantas 747 oxygen tank rupture
B.E.
RE: Qantas 747 oxygen tank rupture
RE: Qantas 747 oxygen tank rupture
The O2 bottles are located in the forward cargo bay and each are equipped with a frangible rupture disc (among other components such as gauge and SOV).
The O2 system cylinders can be added or reduced depending on emergency descent profile for the route planned, saving weight.
O2 distribuion (free flowing, non free flowing and the capability to shut off O2 to areas where it is not needed) is per each customers requirement.
This system is very similar to previous 747's.
Hydrostatic requirements for high pressure cylinders is every 5 years hydro and internal inspection. I do not believe there is a fill/discharge cycle limit to these components.
It's very rare for a tank like this to rupture on its own if inspection intervals are being kept. Filling with other than O2 would most likely lead to an instant failure (explosion) and over filling would blow the disc. All the bottles are cascaded together, so the problem is in the one bottle that failed (assuming the SOV was open).
Mounting of the bottle, so that it was not secure and was damaged to the point of failure or a bottle that was dropped and had an inpending failure are the most likely reasons for failure...if the bottle failure is the sole excuse.
Something coming loose and damaging the bottle is another.
RE: Qantas 747 oxygen tank rupture
Que?
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Qantas 747 oxygen tank rupture
( It was Quantas )
found a link: http://www
google "oxygen cart nitrogen cart mix up"
RE: Qantas 747 oxygen tank rupture
RE: Qantas 747 oxygen tank rupture
I should have stated filling with anything that would cause the bottle to fail would most likely cause failure instantly (hydrocarbons). Oxygen is not too forgiving.
Inert gasses (like N2) would contaminate the system, but most likely not cause failure, as shown in the last two posts.
Another line of thought could be a faulty pressure transducer which is installed after the SOV but before the regulator. An electrical fault could cause an explosion. Didn't they find one of the valves in the passenger compartment?
RE: Qantas 747 oxygen tank rupture
See MIL-STD-1522A STANDARD GENERAL REQUIREMENTS FOR SAFE DESIGN AND OPERATION OF PRESSURIZED MISSILE AND SPACE SYSTEMS.
http://as
RE: Qantas 747 oxygen tank rupture
747-400-FTD-35-05001
originated 31-JAN-2005
last revised 09-JAN-2006
747-400 airplanes equipped with composite oxygen cylinders in the passenger oxygen systems that are installed in the ceiling area of the forward cargo compartment.
During production an interference condition was found between forward cargo compartment ceiling mounted passenger oxygen cylinders and the bottom of seat tracks above the cylinders. The interference condition has been checked for on some airplanes delivered with composite oxygen cylinders and some chafing damage has been reported.
This condition is the result of the larger diameter of the composite oxygen cylinders.
Boeing introduced composite oxygen cylinders for a weight savings.
Final corrective action will include replacement of PN B42365-1 composite cylinders with PN 801307-00 steel cylinders in forward cargo compartment ceiling areas and the addition of warning placards at the ceiling locations to prohibit installation of composite oxygen cylinders. A schedule for production and retrofit changes has been established. Production will be changed in-sequence to only steel cylinders in the ceiling area of the forward cargo compartment starting at LN 1375 (May 2006 delivery). Production has already been changed out-of-sequence in December 2004. Boeing released service letter 747-SL-35-022 on 1 April 2005 and released USG category service bulletin 747-35-2118 on 6 January 2006 for in-service airplanes.
RE: Qantas 747 oxygen tank rupture
B.E.
RE: Qantas 747 oxygen tank rupture
"....preliminary report now makes clear that discharge from the lower part of the bottle blew open the fuselage and propelled the main part of the bottle upward. The bottle burst through the main deck, making a hole 20 centimeters (8 in.) in diameter, then hit a door frame, a door handle and the overhead paneling before falling back out of the aircraft, leaving parts of the valve behind.
The implication is that, by a stroke of bad luck, the bottle had managed to escape through the two holes it had already made and then dropped into the sea—and is therefore unavailable for inspection."
RE: Qantas 747 oxygen tank rupture
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Nert
RE: Qantas 747 oxygen tank rupture
"....and is therefore unavailable for inspection." How convenient for 'them' and frustrating for 'us'.
Prost is right but standardisation is a good thing. The less confusion the better off - and safer, aviation will be.
RE: Qantas 747 oxygen tank rupture
It might be expensive to do so, but given GPS and a good estimate of the time of failure, it should be possible to find an oxygen bottle on the bottom of an ocean, because you don't have to drag the whole ocean.
Mike Halloran
Pembroke Pines, FL, USA
RE: Qantas 747 oxygen tank rupture
RE: Qantas 747 oxygen tank rupture
RE: Qantas 747 oxygen tank rupture
http://www.ntsb.gov/publictn/1992/AAR9202.htm
scroll down to par 4
RE: Qantas 747 oxygen tank rupture
RE: Qantas 747 oxygen tank rupture
The state of the art in minesweeping is classified (I'd guess). In fact, they may NOT want to go looking for this item, given that the success/failure of their search might reveal the limitations of their technology.
RE: Qantas 747 oxygen tank rupture
Sure, I'd like to go; it could be a grand adventure.
Mike Halloran
Pembroke Pines, FL, USA