Don't let Qantas Airlines fill your tanks

[Gibby]

Sorry. That is the best title I could come up with. This is an interesting news story and I just thought I could see this happening in a dive shop someplace.

Nitrogen Used To Fill Aircraft Oxygen Systems

Airlines all over the world are being warned to check to make sure there’s 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 that’s 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 didn’t 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.

[tomhauburn]

I had a gas delivery man tell me about the same story about a maintenance crew at a hospital change the fittings. Only someone died because of it. I never saw it in the paper or anything but I figure he knew what he was talking about.
Tom



Sorry. That is the best title I could come up with. This is an interesting news story and I just thought I could see this happening in a dive shop someplace.

Nitrogen Used To Fill Aircraft Oxygen Systems

Airlines all over the world are being warned to check to make sure there’s 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 that’s 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 didn’t 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.

[Wizard]

If memory serves me right, they only use oxygen for the mask in emergencies. It's not used under normal circumstances, not in the cabin anyway. They compress the ambient air outside the plane to 6000 feet levels. Oxygen is the same percent all the way through the atmosphere, just less pressure.
Still scary though, if the had kept topping the tanks and really had an emergency, people would have died.

[JahJahwarrior]

*bell goes off as door opens*

"Welcome to the RedNeck Dive Shop, what can I do fer' ya'?"

"Can you top off the gas in these tanks sir?"

"Sure thing!"

*shop monkey carries tanks to back room.*

*shop monkey reappears*

"Hey, I fergot to ask. Did you want regular or the super stuff with the higher octane in them tanks? And you got the wrong valve on them, they won't match but I've got a locking Chevy and a standard Ford filler stem and cap I'll let you have for $15 a piece"

"By any chance, did you used to be a mechanic for Quantas?"

"Well now that you mention it, that's where I got my oxygen training, they just fired me last week"


I guess this is all the more reason to analyze your mix, and only fill at trusted shops if you can.

[curtschu]

If I remember correctly the Bottle O2 is for the flight Deck Crew, The masks that drop in an Emergency are a Catilist canister that reacts and makes o2. That is the thing the caught fire on the plane that crashed in the Everglades.

[Gibby]

If I remember correctly the Bottle O2 is for the flight Deck Crew, The masks that drop in an Emergency are a Catilist canister that reacts and makes o2. That is the thing the caught fire on the plane that crashed in the Everglades.

I thought they were part of the cargo.

[FW]

Curt is right, the O2 is for the crew, and at least one of them is required to be on it, so if the cabin pressure drops, they don't all blackout. Pretty scarey!

[sskasser]

I thought they were part of the cargo.

It sounds like the ones implicated in that crash actually were part of the cargo. http://www.cnn.com/US/9611/19/valujet.final/

[FW]

The canisters in the Everglades crash were old ones being returned, and were in the cargo. What Curt meant is they are the same type used in the passenger O2 masks, rather than compressed O2, like the crew uses.

[curtschu]

That is what I was saying Thanks Forrest. I was typing at work and trying to finish up quickly. SaberTech was returning out of date O2 Generators to Atlanta in the Cargo hold. They forgot to put safeties on the firing pins and something caused at lease one to cook off. Here's the tragic thing. That hold is designed to be airtight so if a fire starts it will use all the O2 and go out..... But this fire had it's own O2 source. They did not have smoke detectors or fire suppression so they did not know they had a fire until smoke was filling the cabin. Very sad but it forced airlines to install smoke detectors and fire suppression in cargo areas. That was ValueJet which is now AirTran. I wonder if there is a way we could adapt one of these O2 Generators for RB use?

[Gibby]

Funny you say that.
I was thinking the same thing.

[amtrosie]

That is what I was saying Thanks Forrest. I was typing at work and trying to finish up quickly. SaberTech was returning out of date O2 Generators to Atlanta in the Cargo hold. They forgot to put safeties on the firing pins and something caused at lease one to cook off. Here's the tragic thing. That hold is designed to be airtight so if a fire starts it will use all the O2 and go out..... But this fire had it's own O2 source. They did not have smoke detectors or fire suppression so they did not know they had a fire until smoke was filling the cabin. Very sad but it forced airlines to install smoke detectors and fire suppression in cargo areas. That was ValueJet which is now AirTran. I wonder if there is a way we could adapt one of these O2 Generators for RB use?



Wow!!!! I have to step in here and correct some facts and some clear up some miss-conceptions.

First let me say, I am an aircraft mechanic, and have been at it for almost 30 years. Second, I have worked for ValueJet/AirTran in the past.

Now, aircraft can have Oxygen supplied from bottles (usually PST 95's) for BOTH the flight crew as well as the passengers. The Oxygen available is for EMERGENCY SITUATIONS ONLY!! Flight crew goes on O2 only when their counterpart leaves the cockpit during the course of the flight, FOR ANY REASON (including potty break). The reason, is simply to be ready for an emergency, should it occur.

As I was saying, some aircraft have passenger O2 that is from bottles, Others do not. The aircraft that do not, have Oxygen generators for the passengers. These generators create O2 from a chemical reaction (the chemicals escape right now) when the pins are removed and allow the chemical reaction to occur. The result of this reaction is heat, to the tune of 400 F degrees. It was this reaction that occurred in the cargo compartment of the ValueJet DC-9 as it left Miami for Atlanta. What fueled that fire (you had heat and oxygen) were the RUBBER tires packed right next to the generators. One more thing about that. In those days cargo compartment were not air tight, nor did they have to be. Today, Federal Regulations require all seams in a cargo hold to be sealed with a heat resistant tape, allowing for the fire suppression units to be effective in suppressing any fire.
As for the O2 generators in the hold, Nobody FORGOT to put safety pins in the generators. The paper work reflected the securing of generators, they were just never done. The mechanics just never bothered to do it!! Those mechanics have been indicted for 109 counts of murder and 109 counts of manslaughter.

As for the Qantas thing, So the bottles didn't have 100% O2, the mix was never toxic, and would never have posed a danger to any one. The only ill affect would be that the pilots would not be able to clear up their hang-overs from the previous nights drinking. That is not to say that Qantas's mechanics did not screw up, just that this is not on the level of an issue were a diver needing this mix.

[Gibby]

That is not to say that Qantas's mechanics did not screw up, just that this is not on the level of an issue were a diver needing this mix.

Most people around here know what the reporters do to the facts. How many times do we read that a diver died because his oxygen bottles were dry. I think the real shocker to me is that they changed the fittings to match the bottles. Are not all O2 connections a left hand tread or is that just on welding bottles?

Thanks for the input. I didn't know the other guy is on O2 if one leaves the pit.

[mgersch]

Wow. I didn;t know that the O2 for emergencies was sometimes supplied by 02 generating chemical reactions. I wonder what the reaction is....

[curtschu]

Here is what I was talking about when I said airtight cargo hold.

The cargo compartment's fire suppression amounted to a no-air recycling environment, so a standard fire would have simply run out of air and burned itself out.

I guess it really is not airtight but the fire should run out of o2 and go out.

As for the saftey pins I was being nice

[amtrosie]

Most people around here know what the reporters do to the facts. I think the real shocker to me is that they changed the fittings to match the bottles. Are not all O2 connections a left hand tread or is that just on welding bottles?





What????? Reporters not reporting ALL the facts????? Say it ain't so!!!!!! Are not reporters nothing more than editorialists in waiting?


As for O2 fittings: Here in the USA there is no distinction between bottles and their fittings. Although there are several choices for valves that may lead to separate fittings. As for the Commonwealth and the EU, I'll not suppose to know their practices. I do know that on several British Airways and Virgin Atlantic 747's, the Airframe connection was a different thread with very different fittings. When I serviced their bottles, I had to service the bottles directly as opposed to servicing from the airframe connection.


While CurtShu will be nice in reference to those mechanics, I'll not mince words. Those guys were idiots!!! To charge them with murder is too nice. The irreparable damage they have done to my colleagues and our reputation as professionals will never be restored.