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View Full Version : No systemic problems with plane oxygen bottles


Dagger Dirk
17th Nov 2009, 13:39
The ATSB could not replicate the explosion.

http://www.abc.net.au/reslib/200808/r278684_1180283.jpg
The Australian Transport Safety Bureau (ATSB) says it has found no evidence of systemic safety problems with oxygen bottles like those involved in a Qantas incident last year.

An oxygen cylinder blew a hole in a Qantas jumbo jet on a flight from Hong Kong to Melbourne in July.

Flight QF30 was forced to land in Manila after an explosion blew a gaping hole in the side of the plane in front of the starboard wing.

A preliminary report confirmed that an exploding oxygen tank was responsible for the incident and that some oxygen masks failed.

Another interim report released today, says the ATSB have not been able to replicate the cylinder failure, using five oxygen cylinders obtained from the same manufacturing lot.

The original one was lost over the South China Sea.

The ATSB is continuing to conduct tests on the cylinders, examining them for mechanical and manufacturing flaws.

The ATSB's final report is expected some time next year.

Belgique
17th Nov 2009, 13:44
No-one's denying that it may have been one of the many oxygen bottles accidentally filled with Nitrogen by QANTAS more than a year earlier. Bottles were purged but never checked for residual moisture when replacing the nitrogenated oxygen with aviation quality Dry breathing oxygen.

Think "moisture in bottle plus pure oxygen" and what could then happen i.e. accelerated corrosion.

BrissySparkyCoit
17th Nov 2009, 14:17
Belgique, any chance you could provide a report or other evidence to back your comments about oxy bottles being filled with nitrogen?

Belgique
17th Nov 2009, 15:34
Link ONE (http://www.google.com.au/#hl=en&source=hp&q=oxygen+bottles+accidentally+filled+with+Nitrogen+by+QANTAS +&btnG=Google+Search&meta=&aq=f&oq=oxygen+bottles+accidentally+filled+with+Nitrogen+by+QANTA S+&fp=1&cad=b)

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LINK TWO (http://www.pprune.org/archive/index.php/t-304695.html)

and countless more.
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The time taken for accelerated corrosion in an all pure oxygen atmosphere equates well with the QF30 incident and the prior accidental nitrogenation of many airliners oxygen cylinders. The clincher is that aircraft refill nitrogen isn't dehumidified (like aviation's dry breathing oxygen is).

And they weren't all QANTAS airplanes either. QANTAS services many international airlines in transit. i.e. How many more corroding oxy bottles are out there ticking away?
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TheShadow
17th Nov 2009, 15:51
Probe after Qantas pumps wrong gas into jets
Matthew Benns
December 16, 2007

POTENTIALLY fatal gas being pumped into passenger jet emergency oxygen tanks in Australia has sparked a worldwide safety investigation.

The Australian Safety Transport Bureau confirmed yesterday that Qantas engineers accidentally put nitrogen into the emergency oxygen tanks of a Boeing 747 passenger jet at Melbourne Airport.

The Australian carrier immediately checked the oxygen supplies of more than 50 of its planes that had been serviced by the mislabelled nitrogen cart at the airport. But an aviation source said: "This could have affected hundreds of planes worldwide. Any international jet that passed through Melbourne and was serviced by Qantas could have had nitrogen pumped into its oxygen tanks."

Health experts warned that in an emergency the effects of nitrogen in the oxygen tanks could have potentially fatal results.

Dr Ian Millar, hyperbaric medicine unit director at The Alfred hospital, said: "If there was an emergency and the pilot took nitrogen instead of oxygen, instead of gaining control of the aircraft he would black out and it would be all over. It's a pretty serious mistake."

Nitrogen, which is non-flammable, is commonly used at airports to fill aircraft tyres. The aviation source said: "Qantas took delivery of the new nitrogen cart 10 months ago. It looked exactly like the old oxygen cart. When the attachments did not fit they went and took them off the old oxygen cart and started using it."

The mistake was eventually spotted by an aircraft engineer. "He was walking around the plane and asked what they were doing. When they said they were topping up the oxygen, he said, 'No you're not, that's a nitrogen cart'," said the source.

The incident was reported to the Civil Aviation Safety Bureau, which confirmed that an investigation detected nitrogen in the crew oxygen tanks on the Boeing 747-300. A bureau spokeswoman said it was a one-off incident.

But the aviation source said: "This has affected at least 175 planes and Qantas has had to tell any other airline that has been serviced in Melbourne to check out its oxygen supplies."

Air New Zealand was told about the problem six weeks ago. "As a result of receiving that letter we did take some precautionary measures," a spokeswoman said. "The oxygen tanks on a small number of planes were removed, checked, reserviced and refilled. No irregularities were found."

A spokeswoman for the Australian Transport Safety Bureau said: "Very clearly they (Qantas) needed to carry out a risk assessment because there was a chance that other aircraft were affected.

"They identified 21 that were at risk because they had had a reasonable amount of oxygen top-up, so there was a reasonable chance they had been contaminated. There were another 30 aircraft at minor risk because they have had minor top ups," said the spokeswoman. The planes were inspected and no positive results found.

She said the airline had turned the error into a learning exercise and informed engineers all over the world about the mistake. "They have talked to thousands of their engineers around Australia and overseas, informing them about this lesson that has been learnt," she said.

Qantas engineering executive general manager David Cox said: "We had a guy using a new rig and he inadvertently serviced the crew oxygen with nitrogen. He realised what he was doing and flagged it."

Mr Cox said that once the mistake had been realised, extensive safety checks were put in place to ensure no other aircraft had been contaminated and that it could never happen again.

"Every aircraft, including customer aircraft, that could have been touched with this rig has been checked," he said after confirming the rig had been in use at the airport for several months. Mr Cox said the airline had been completely open in informing all safety authorities, staff and other airlines about the mistake.


This story was found at: Probe after Qantas pumps wrong gas into jets - National - theage.com.au (http://www.theage.com.au/articles/2007/12/15/1197568332267.html)

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NITROGEN USED TO FILL AIRCRAFT OXYGEN SYSTEMS
Airlines all over the world are being warned to check to make sure thereís actually oxygen in their aircraft oxygen systems after an embarrassing mix-up by Qantas Airlines at Melbourne International Airport. For ten months, crews have been filling airliner oxygen systems from a nitrogen cart thatís supposed to be used to fill tires. The mistake went unnoticed until a couple of weeks ago when an observant aircraft engineer spotted service workers using the cart. "He was walking around the plane and asked what they were doing. When they said they were topping up the oxygen, he said, 'No you're not, that's a nitrogen cart,'" an unnamed source told The Age. As anyone who works with industrial gases knows, oxygen tanks have different fittings than other gases to prevent exactly this kind of mix-up. However, when the crews discovered the fittings on what they thought was their new oxygen cart didnít fit, they swapped them for the ones on the old cart they were retiring. Of course, Australian officials are looking into the error and Qantas has been busy notifying other airlines that use its services in Melbourne. Hundreds of aircraft may be affected.

Would've taken some lateral thinking to think through other than the immediate ramifications of this error.

OVERTALK
17th Nov 2009, 16:11
Hmm, interesting indeed:

a. Steel cylinders

b. Lost into the ocean during the explosion

c. Nowhere in the report (http://www.atsb.gov.au/publications/investigation_reports/2008/aair/ao-2008-053.aspx) is the word "corrosion" mentioned


QUE????

UNCTUOUS
21st Nov 2009, 03:05
Reported in this link (http://asj.nolan-law.com/2009/11/substantial-damage-from-burst-oxygen-bottle-led-to-emergency-landing/)

I'm wondering if the ATSB has addressed this possibility (or carried out trials to verify etc)
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Silverado
21st Nov 2009, 05:24
"And they weren't all QANTAS airplanes either. QANTAS services many international airlines in transit. i.e. How many more corroding oxy bottles are out there ticking away?"

One aircraft was serviced with nitrogen.

This from your link Belgique,

"The incident was reported to the Civil Aviation Safety Bureau, which confirmed that an investigation detected nitrogen in the crew oxygen tanks on the Boeing 747-300. A bureau spokeswoman said it was a one-off incident."

BigGun
21st Nov 2009, 06:46
was it confirmed there was a metal cylinder fitted to that position or a fiber based one.

Checkboard
21st Nov 2009, 13:50
Are they going to rename the aircraft "Apollo 13" ? ;)

"WHAT did you DO?"
"Nothing! I just stirred the tanks!" :}

mrdeux
21st Nov 2009, 21:45
The bottle was steel. It had been serviced only a few weeks prior to the incident, presumably corrosion would have been detected at that time...after all, it is the sort of thing they're looking for.

UNCTUOUS
22nd Nov 2009, 14:33
mrdeux said:
The bottle was steel. It had been serviced only a few weeks prior to the incident, presumably corrosion would have been detected at that time...after all, it is the sort of thing they're looking for.

AFAIK they don't remove valves and check for water/moisture/corrosion internally in DBO (dry breathing oxygen) bottles. Oxy cylinders are assumed to have 100% integrity internally. They're checked externally for damage.

BUT, how much humidity do you need in a 100% pressurized oxygen environment for corrosion to take-off?

RedTBar
22nd Nov 2009, 22:00
Maybe it was caused not by corrosion but by cosmic rays :E

They are apparently looking for them as a possible cause for the a330 incident off WA so why not this one.:oh:
ATSB probes 'cosmic rays' link to Qantas jet plunge - The West Australian (http://au.news.yahoo.com/thewest/a/-/newshome/6486629/atsb-probes-cosmic-rays-link-to-qantas-jet-plunge/)

The reality is that if they can't find the bottle(s) then how can they ever say what caused it with any certainty so I think this is one for the TV Mythbusters to do an episode on.
The results will be just as conclusive.

mrdeux
23rd Nov 2009, 03:53
My understanding is that they are chemically cleaned internally, and boroscoped.

blow.n.gasket
23rd Nov 2009, 13:16
What sort of stresses and potential crack propagation patterns could occur if an O2 cylinder was dropped say post hydrostatic test?

UNCTUOUS
26th Nov 2009, 10:14
MrDeux said:
My understanding is that they are chemically cleaned internally, and boroscoped.

That's not my understanding - nor is that the missing bottle was checked and tested in recent memory. Check the final report on that. If I'm wrong I'll go supra-unctuous..... and believe me, nobody wants to see that.
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QF94
26th Nov 2009, 14:06
Hmm, interesting indeed:

a. Steel cylinders

b. Lost into the ocean during the explosion

c. Nowhere in the report (http://www.atsb.gov.au/publications/investigation_reports/2008/aair/ao-2008-053.aspx) is the word "corrosion" mentioned



There is also the other possibility that the neoprene rubber between the retaining straps and bottles was either missing or worn very badly allowing chaffing of the retaining strap and the bottle. High vibrations, metal rubbing against metal, metal wearing thinner, then too thin to retain the 1600-1700psi pressurised oxygen = KABOOM!

During the mandatory inspection of all oxy bottles on QF's 744 aircraft after the event and many years after the FAA service bulletins to check for oxygen bottles, there were a few of the retaining straps that were found to have the neoprene rubber missing.

Nothing to do with filling nitrogen into oxygen cylinders.

Just a thought.

mrdeux
26th Nov 2009, 19:58
......nor is that the missing bottle was checked and tested in recent memory. Check the final report on that.You don't need to check the final report. They've already said that the bottle had recently been serviced, and had been installed in OJK about 5 weeks prior to the incident.

26 May 2008 Inspection and fifth hydrostatic testing Ė accepted
14 Jun 2008 Refitted to VH-OJK (right sidewall #4)From the interim report, page 26.

mrdeux
26th Nov 2009, 20:03
There is also the other possibility that the neoprene rubber between the retaining straps and bottles was either missing or worn very badly allowing chaffing of the retaining strap and the bottle. High vibrations, metal rubbing against metal, metal wearing thinner, then too thin to retain the 1600-1700psi pressurised oxygen = KABOOM!Yes, but there aren't any restraining straps in the area where the bottle failed. It's held at the bottom (in a cup like fitting) and at the top (by a strap). It's believed to have failed about 30% of the way up from the base....nowhere near any restraint.

KHZahorsky
19th Sep 2010, 19:57
I am the pilot of Mooney N228RM. We were on my 10th transatlantic flight from Sarasota (KSRQ), Florida to Kiel (EDHK) Germany. During our stop-over in Reykjavik (BIRK), Iceland, we needed fuel and oxygen as we are flying 20.000 to 25.000ft.
The flight service in Reykjavik advised us where the oxygen bottles were and that we had to handle the oxygen supply ourselves.
As I had watched the oxygen supply in the past, I felt secure to handle the process myself without any problems. I hooked the lines together and got properly connected to the Mooney oxygen inlet.
Finally I got my pressure gauge up to 1500 PSI.
So we had got oxygen and fuel and could could continue our flight inbound Kiel, Germany, around 09.44Z on Friday the 17th of September 2010.
Shortly after our take off, from runway 13, we were cleared to climb FL210. Passing through FL100 we activated our oxygen supply, monitoring the oxygen flow control and I put on the nasals while my copilot Steve put on the mask. After a while I felt some dizziness , but regarded this as a result of our previous long flight on oxygen using nasals on higher altitudes and thought, I also better have to use the oxygens mask instead of the nasals, so I switched to the mask as well.
As Steve told me later, it must have been 20 minutes after that, when we were at FL 210, that I did not respond to 2 calls from ATC and he then realized that I must be unconscious, while he also felt sick and had no feeling in his left leg anymore. So Steve assumed something must be wrong with the oxygen supply and he switched off the auto pilot and descended to FL100 immediately. After a short while I got conscious again and Steve explained to me what had happened.
I got out my oximeter that I had with me to measure oxygen saturation in the blood and we saw low levels of below 70%. An oxygen level of below 90% causes strong hypoxemia and we had gotten far below that and we were lucky that Steve was still able to react while I was already unconscious.
What had happened? Obviously the green bottle that I had been using for the oxygen supply in Reykjavik had not contained oxygen, instead it must have contained nitrogen! When I had gotten oxygen from flight service in Sarasota, the cylinders looked the same green as those in Reykjavik.

Searching the web, I found that this seems to be a general problem in Aviation, that oxygen bottles have different colors in different parts of the world and no big striking placard saying OXYGEN.
The other concern is: Never should flight service allow self-service of such a life-critical item be handled by someone not specially trained for that kind of service.
CONCLUSION: We were both lucky to be alive, since we would not have regained consciousness at FL210 if we both had become incapacitated. Aviation must have a professional secure level how oxygen should be handled!
Tracking of the flight ca be seen here:
POP3 GPS Tracking System (http://www.zahorsky.net/gps.php?action=showmap)

Pictures of one of my transatlantic flights can be seen here: SRQ-EDHK Trip N (http://www.zahorsky.net)

Jober.as.a.Sudge
19th Sep 2010, 21:21
A fascinating tale -well worthy a thread of it's own...

but what the L has it got to do with this discussion???