ToiletDuck

I can't imagine what would make that tank blow. I seen scuba tanks dropped 25ft and nothing.

KC10 FATboy

Defect in the bottle created while it was manufactured? Perhaps the contents inside were not 100% oxygen? Could a strong static discharge ignite the contents? Corrision?

Mason32

If pressure was too high, shouldn't the blow out valve have popped first? This will be interesting....

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Pozrategearup

Here's the report from the Aussie gov't. It's pretty detailed and has some interesting pics of the damage.

http://www.atsb.gov.au/publications/...053_Prelim.pdf

rickair7777

The usual problem in these cases is internal corrosion, probably due to water build up. A manufacturing defect is unlikely since the bottle was hydo-tested before entering service, and on a routine basis thereafter. It should have had routine borescope inspections too.

Static could not ignite the contents inside a metal bottle...no flow path for the current. Also (except for really exotic applications like spacecraft monopropellants), flammable mixtures are never stored in bottles...otherwise ignition at the output would likely flash back into the bottle

Oxygen itself is not flammable or explosive anyway. It would be almost unbelievable if a breathing oxygen bottle were accidentently filled with a flammable mixture...there is a higher standard of handling for breathing and medical O2.

If the cyclinder was composite, and not all-metal, it's possible that the composite wrap was damaged by a sharp impact or by corrosive fluids.

If the cyclinder was weakened significantly it's possible that the cyclinder failed at a pressure below the relief valve setting.

Another remote possibility is brittle fracture. Steel can crack spontaneously at cold temperatures. We design steel products to have a low or extremely low risk of BF (depending on the application), but it cannot be totally eliminated.

From an engineering perspective, this is very odd. Given the application (high mx standards, no salt water) the odds are against this event occoring. My guess would physically damaged composite wrap, but those bottles in the pictures look like aluminum from a distance.

FlyJSH

Improper filling could weaken it. Then tanks are filled too quickly, they can heat up too much too fast. That can make the metal more brittle (or so I was told way back when I worked the ramp).

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dudewannabe

Queensland And Northern Territory Air Service.

There is no U in "QANTAS" mate!

joepilot

If you are filling something with a gas by pumping it in with a compressor that will heat it up, but when you fill an O2 bottle from a higher pressure bottle, the O2 coming in will be expanding and cooling off.

For those who questioned the bottle construction, the Australian safety report says it was one piece steel. See the link in Posrates post, page 16.

Joe

thndr8

Actually it's the other way around. I don't know the physics behind it but as a former MX guy we used explosion proof cages to fill new crew O2 bottles. Believe me, they were warm after filling from 0 psi.

KC10 FATboy

The physics is (simplified) ... oxygen molecules are being squeezed together, running into one another. That creates friction which produces heat.