Qantas Depressurisation

[Raymond Rowe]

Originally Posted by Paul McFarlane

Just wanna ask what may seem a silly question..

How do they go about repairing the aircraft? Do they send a team from Oz over to Manila and rent a hanger for a while?

Just curious...

Paul M

Word has it that the Boeing Crash crew will be doing the repairs.

[Rhys Xanthis]

Originally Posted by Raymond Rowe

Word has it that the Boeing Crash crew will be doing the repairs.

I'd be surprised if otherwise.

I read a comment from someone about the issue.

"Blame Qantas for something which has never happened before – or do we look at Qantas, one of the world's leading airlines, as being the real cause of a day or two which most Aussies would prefer to forget?"

which they replied with:

"Blame Qantas for a measurable and objective increase in adverse maintenance related incidents."

I thought it was an interesting reply...anyone care to comment? I personally believe Qantas has pretty high maintenance standards and i would probably never have any reservations about stepping foot onto a Qantas jet ever in my life (however, the future hasn't happened yet...).

[Rhys Xanthis]

Hopefully this reassures the general flying public...

really the last thing QF needs right now is a mass exodus of passengers who refuse to fly blaming "safety standards"...

[Will T]

The discussion re Brenden's intellectual property has been moved to its own thread in 'Technical Discussion', to keep this one on topic.

[damien b]

Originally Posted by Brenden S

Oxygen installation on OJK


Oxygen distribution system to passengers


There is no check valve on the cylinders so if one was to leak/rupture all of the oxygen would be vented.

Here is the station diagram and also a photo of the fwd caro.





I hope this explains everything for everyone.

Q for you Brendan. I happen to train Avionic AME's and my understanding of aircraft oxygen systems is that the flight crew and passenger systems are isolated from each other to prevent cross contamination and also the scenerio that you metion in loosing presure from one system, thus taking out the entire aircraft supply. Are the flight crew and pax systems sepreate, or as you mention are they combined together? Curious.

[Steve B.]

Brenden,

Aren't those 4 large green containers potable water tanks? Certainly don't look like oxygen tanks.

Regards
Steve.

[Philip Argy]

See Brenden's clarification yesterday, Steve:
http://yssyforum.net/board/showpost....&postcount=107

[Montague S]

interesting new report from 9msn..

http://news.ninemsn.com.au/article.aspx?id=605382

Will or AJ able to expand on this?

The cockpit voice recorder of the Qantas jumbo jet forced to make an emergency landing in the Philippines did not capture the explosion that tore a hole in its fuselage, an investigator says.

It is a setback for Australia's Air Transport Safety Bureau, whose team is combing the Boeing 747 plane to pinpoint the cause of the blast - thought to have been caused by an oxygen bottle, lead investigator Neville Blyth said.

He told reporters in Manila that the voice recorder, which records crew conversations, radio traffic and cockpit sounds, had been downloaded by the ATSB's specialists in Canberra.

"Unfortunately, the standard two-hour recording which works on an endless-loop principle did not contain the depressurisation event.

"The cockpit voice recording commenced after the descent and diversion to Manila, so the event itself appears to have been overwritten."

Experts from the ATSB had hoped to analyse

acoustic data from the recording to help in the investigation, he said.

"There's a surprisingly large amount of information that could be obtained from acoustic spectrum analysis, if indeed we had a recording of the event."

It would also have helped investigators determine whether the flight crew handled the emergency well, Blyth added.

Experts are also examining the separate flight data recorder that logged 25 hours of flight data, and results could come within a few days, Blyth said.

He said it now appeared very likely that the rupture had been caused by an exploding oxygen cylinder, one in a row of six that is used for emergencies.

"The explanation regarding the loss of the cylinder is the most probable," he said.

Investigators have found the valve and handle from the missing cylinder but the bottle itself remains unaccounted for.

Blyth said the hole "is immediately adjacent" to where the cylinders were located.

The Qantas jet was flying from Hong Kong to

Melbourne last Friday when the explosion led to a sudden loss of air pressure in the cabin.

The plane, which had originated in London and was carrying 365 passengers and crew, plunged 6,000 metres (20,000 feet) before stabilising, then made an emergency landing in Manila.

Blyth and other officials say they are unaware of any previous cases in which an oxygen tank caused an airline accident. Qantas has ordered all oxygen tanks on its fleet of 747-400s to be inspected.

Qantas suffered another safety scare on Monday when a landing gear door failed to close, prompting a flight to return to Adelaide shortly after takeoff.

The airline insisted the plane was never in danger, but passengers already jittery over the Philippines incident described panic inside the Melbourne-bound plane after the pilot announced the problem.

[Brenden S]

Crew and Pax systems are totally separate, however they are installed in the same area. I showed the picture of the fwd cargo hold as It was the best I could to. The frames to the left is where the oxy cylinders are.

[Philip Argy]

I have seen a number of ATSB Reports that note that the CVR was left running after a major incident and therefore wiped out all record of the incident they were investigating, but usually this relates to post landing where I gather the protocol is to turn off the CVR to preserve the previous two hours rather than capture ground staff chatter.

If more than 2 hours elapses between incident and shutdown of the a/c post landing, I don't see how the incident can be preserved with existing CVR processes. It shouldn't be hard these days to increase the capacity of a CVR, or to make provision for CVR history to be copied manually to other onboard storage media after any major incident so that, short of loss of a/c, more than 2 hours of CV is available.