Qantas investigated after filling crew oxygen tanks with nitrogen!

[Danny]

"Probe after Qantas pumps wrong gas into jets (The Age)" (http://www.theage.com.au/news/national/probe-after-qantas-pumps-wrong-gas-into-jets/2007/12/15/1197568332267.html?page=fullpage#contentSwap1)

[Nige321]

From Avweb (http://www.avweb.com/eletter/archives/avflash/1016-full.html#196776)

[hetfield]

Are the connectors the same?

Can't believe.:ugh:

[perkin]

The connectors are different, but according to the article on Avweb (linked previously) the crew changed the connectors, apparently without thinking about it, from the nitrogen type to the oxygen type when they discovered the connectors on their new 'cart' didnt fit...how idiotic can you get?! :ugh:

[The Flying Pram]

It's unbelievable (and rather frightening) to think that with all the Quality assurance systems and paperwork trails involved in aviation that something as potentially life threatening could happen. Perhaps the contractors involved though that since nitrogen is the main component in air, then it would do the same job as oxygen? Err maybe not....

[fox niner]

That surely must be (unintentional) gross negligence. It certainly is more criminal than speeding, through a red light, with your headlights off.

But...Does this mean that the tyres are filled with oxygen? That could be "nice" as well.

[lomapaseo]

Let's get off the blame game and criminality discussions and into the training compentence (are these guys certified?) and quality assurance arena.

How often are these systems used? How long could this problem have existed?

[WHBM]

.... with all the Quality assurance systems and paperwork trails involved in aviation that something as potentially life threatening could happen....
Anyone who has ever worked with Quality Assurance, ISO-9000, and all that stuff will be only too aware that, alas, it does little in terms of avoiding blunders (which are generally prevented by commonsense anyway) and a great deal towards keeping paperpushers in jobs.

[Desperate]

Aviation's excellent safety record has only been achieved because people are willing to admit their mistakes without fear of the Police knocking on their door.

As soon as you introduce phrases such as 'criminal negligence' for what passes as human error - or even human stupidity - our industry will move backwards. It's why we have ASRs, MORs and safety bulletins - to learn from others' mistakes and to publicise our own errors without fear of prosecution.

The system seems to have worked in this case. Introduce prosecution and you introduce cover-up and conspiracy.

[barit1]

It's happened before (http://archives.cnn.com/2000/US/12/14/nursinghome.deaths.ap/index.html)

[Say again s l o w l y]

Whilst this is a pretty massive blunder, the point about having a "no blame" culture is a very valid one.

Having said that though, what sort of dumbass would change the connectors over without checking?

Luckily this incident didin't lead to any further problems or disasters, but if it had someone would definately be getting their collar felt.

[Beeline]

Oxygen fittings on Boeing Aircraft are left-handed threads, whilst Airbus use right-hand threads, the aircraft carries an adapter to fit the oxygen rigs! Murphy proof??

A sign to employers to ensure that staff need to be adequately trained and strictly from Aircraft recognised backgrounds for the degradation of this standard is becoming more common place. :ugh:

[glhcarl]

Beeline,

Nothing can be made "Murphy Proof" only "Murphy Resistant".

[cwatters]

As I understand it if you breath pure nitrogen you might not notice untill too late. No CO2 in your lungs so it doesn't feel like you are suffocating.

[Check Airman]

I agree that talk of criminal charges should be silenced. I'm a firm believer in the no-blame culture. Everyone makes mistakes. Bravo Zulu to Qantas for alerting other carriers and openly admitting it, so that lives can be spared and perhaps more importantly, a lesson is learned.

Perhaps the contractors involved though that since nitrogen is the main component in air, then it would do the same job as oxygen?

Flying Pram, funny comment, but it could well be true. I met a guy a few weeks ago that didn't know CO2 was toxic if the room is filled with it. How does the saying go, a little knowledge is a dangerous thing????

Does this mean that the tires are filled with oxygen? That could be "nice" as well.

:D;)

[moggiee]

I recall reading a similar story about a Hunter pilot in the RAF suffering hypoxia - so he switched from airmix to 100% but he was getting 100% Nitrogen and it just made the problem worse.

He just had enough wits left to descend below 10,000' and remove his mask to breath ambient air.

[R J Kinloch]

Opposite thing happened in the RNZAF in the 70's.
A4 Skyhawk Gun Nitrogen Accumulator filled with Oxygen.
Resulting fire nearly cost the aircraft.
Cause: Nitrogen Bottles all black, Oxygen Bottles black with a blue green top?
Battered oxy bottles had most of the blue green paint missing.
Cure: Stores not to accept gas bottles unless colour coding paint in pristine condition.

[old,not bold]

Perhaps the contractors involved though that since nitrogen is the main component in air, Did I miss those parts of the linked reports that said the error was made by contractors rather than permanent QF staff?


A sign to employers to ensure that staff need to be adequately trained and strictly from Aircraft recognised backgrounds for the degradation of this standard is becoming more common place.You would think that such checks are standard, mandatory even. You would be wrong, in maintenance organisations in pretty much every part of the world, including EU and USA, with a few, very few, notable exceptions.

[Intruder]

As I understand it if you breath pure nitrogen you might not notice untill too late. No CO2 in your lungs so it doesn't feel like you are suffocating.
OTOH, a "top off" of the O2 with N2 would likely cause NO problems...

First, free air is 70%+ nitrogen; nitrogen is not inherently poisonous.

Second, even at altitude we can breathe easily with less than 100% O2. Only in extreme cases and/or for prolonged periods at high altitude would the effects of an N2 mixture be noticeable.

As an example, say a system that is normally at 1200 psi goes below the 900 psi minimum, and needs to be topped off. Now it is about 25% N2 and 75% O2. There is over 3 times as much O2 in the mix than in free air, so the user would get a sea-level partial pressure of O2 to above 20,000' cabin altitude (using the guide that 18,000' ~~ half standard atmospheric pressure), and a breathable mixture above that.

So, while it IS a gross error on the part of the people who did it, it is NOT necessarily an immediately critical problem unless they were filling EMPTY O2 systems -- not just "topping off" as described in the article.

[Beeline]

I do belive in some countries Gaseous crew o2 recharging is not permitted, the whole bottle assy is replaced and refilled, does anybody know if and where this is practiced??

[Hand Shandy]

If it is`nt in the maintenance manual the bottles are replaced , the last 2 companies i`ve worked for operate on this policy , and that was for 737s and a320 series .

[BEagle]

moggiee, are you sure it was the pilot of a Hunter?

I recall a serious incident in the Hunter simulator many years ago, when the 'breathing air' had been refilled with nitrogen. The instructor thought that the student was being a bit dull, until he failed to respond to simulated radio calls. They opened the canopy and found him close to death....

Since then I never, ever connected my oxygen mask in any simulator!

Slightly less serious was the occasion, early in the days of Anglo-French aircraft, when some bonehead tried to dismantle a helicopter jack marked 'Gonflé à l'azote...' Just as he was undoing the last part of the thread, there was a bang and the jack parted company from the cylinder at a somewhat rapid pace...

Fortunately, no-one was injured. The Franglais label meant 'charged with nitrogen' - which it undoubtedly proved to have been!

[moggiee]

moggiee, are you sure it was the pilot of a Hunter?
99.99% certain that it was a Hunter - I read it in "Air Clues", so it must be true!

[ChristiaanJ]

It is so damn difficult to make anything foolproof.... because fools are so damn ingenious ....

[barit1]

Every time we Murphy-proof some aspect of our lives, we merely succeed in raising a new-and-improved generation of Murphies! :}

(I think there's an echo in here - or maybe I've said this before...)

[toolowtoofast]

The filling/placing of nitrogen in the place of oxygen is a problem in many critical industries. There was recently an incident at a local (large) hospital where the delivery AND maintenance staff colluded with each other to replace the theatre oxygen with nitrogen - they discussed thread types at length and STILL changed the bottles over - we're talking about a DOZEN bottles here. Not good for the person being operated on.....

I beleive the tap threads are different, but the fittings that are often ingeniously fitted to the top of bottles is open to interpretation

[Brian Abraham]

Nothing can be made "Murphy Proof" only "Murphy Resistant".
It is so damn difficult to make anything foolproof.... because fools are so damn ingenious

It takes the average idiot five seconds to find a work around on a idiot proof piece of gear.

[cwatters]

Intruder

> Second, even at altitude we can breathe easily with less than 100% O2.

Ah yes I forgot it would be mixed. Perhaps a good job the mixing isn't automatic using an O2 sensor - might have detected the incorrect 02 level and tried to correct it by turning the percentage, which wouldnt have worked with a tank of Nitrogen.

[Ancient Mariner]

My company supplies equipment worldwide that requires Nitrogen filling before commissioning. This means that we will also have to include adapters to fit the 11 different connection standards that exist. Standards, what standards?
Per

[mcdhu]

Uk airline - when the crew o2 gets low, the whole bottle is replaced although it is physically possible to 'top-up'.

Downside is that if there are no spares, you might see a Level 1 Add to say that the ac is fit for only 2 pilots on the FD because the O2 is below that required for 3.

Cheers,
mcdhu

[Tankengine]

I suppose nobody has thought of writing OXYGEN or NITROGEN in f$£$£%&
big letters down the bottle!!??:ugh:


On the subject of thread standardisation US and European aviation oxy bottles have differing threads too!:mad:

[groundfloor]

Common sense not very common any more, Are we not training a bunch of paper punching robots?? Always nice to bump into techs who question everything that looks or feels remotely wrong. Especially in these days of software....:)

[Arado]

"The filling/placing of nitrogen in the place of oxygen is a problem in many critical industries" (TOOFASTTOOLOW)

Too right there. I recall a contractor working inside a storage tank, using an air-powered angle grinder. Instead of the compressed air supply, plugged the hose into a nitrogen line, and gassed himself; and nearly did for 2 would be rescuers,too.
remember having heated argument with H&S bod because the fittings were also the same as on the respirator feed points!

[Fizix]

I know I am stepping out of my preferred domain of Fizix and into Chemistry, but why not also include the internationally accepted chemical symbols O2 (subscripted 2) or N on each container instead of any words in English - different names for Oxygen in different languages. That way, any "trained " re-filler should be able to tell the difference immediately. Forget colour codes, because I certainly don't know the colour for oxygen when it comes in gas bottles.

[tristar 500]

I do belive in some countries Gaseous crew o2 recharging is not permitted, the whole bottle assy is replaced and refilled, does anybody know if and where this is practiced??

I think you will find this happens in several countries, but mainly any N reg A/C

Tristar 500

[lomapaseo]

Sorry, but I'm back again making one last try to get a question or two answered:)

1) Were the guys who supposedly dicked around with the O2/nitrogen bottles licensed?

2) How often per 1000 flights are these bottles actually used in flight?

3) How long (months) has this contamination likely existed?

[Captain Calamity]

Some thoughts as a technical diver, rather than a pilot.

Breathing the wrong gas has killed plenty of divers. Cylinder markings, colour, labels etc don't make any difference.

At the end of the day you need to know what you are breathing, that you have enough of it to get you to safety, and that the regulator and mask will deliver it when needed.

The only way you can be sure of this is to analyse the gas (few seconds work with very cheap oxygen analyser), check the cylinder pressure, and breathe the system to confirm it is working. Repeat *every* dive.

The same simple and quick checks would certainly work in the cockpit, and the atmosphere at crusing level is no more compatible with life than 50 metres of sea water.

CC

[old-timer]

Confirm that ti is indeed standard practice for many organisations to re-charge the cylinders off the a/c, thi type of incident occured in a uk mro a few years ago resulting in revised practices

keep safe folks - & REMEMBER - DO NOT USE ANY OIL OR GREASE ON OXYGEN CONNECTORS


OXYGEN for breathing :-)

NITROGEN for tyres :-)

if either are the other way around = :-((

[L-38]

In a similar incident many years ago, someone had mistakenly serviced our charter B-727's CSD's (constant speed drive generator) with skydrol during an itinerant fuelstop. An in-flight loss of all generators was the result.

[Wiley]

Lifted from my post on the Dunnunda thread on the same topic:Since the mistake was found before the proverbial hole in Dr Reason's last slice of cheese lined up with some hapless crew suffering a decompression or a cabin fire, I suppose we should be grateful that the original mistake was getting a nitrogen cart confused with an oxygen cart and not the other way around. Had it been the other way around, there could have been a major explosion had some unfortunate LAME tried working on the cart with a greasy spanner - or, as someone has mentioned already, if someone had tried using oxygen to fill an undercarriage oleo.

[Brian Abraham]

Are we not training a bunch of paper punching robots?? Always nice to bump into techs who question everything that looks or feels remotely wrong

In God we trust - everything else we check.

[John Farley]

Although I am not aware of any military or civil operator that screens potential pilots for their reaction to reduced oxygen levels there are definite piloting advantages to being abnormal in this context. The classic response of most people to reduced blood oxygen levels is euphoria. But some actually feel unwell and sweat when you turn off their oxygen. I always counted myself lucky to be one such. So did Andy Jones (later Mr Hawk).

In the early 70’s Andy was doing a performance climb on an export Hunter at Dunsfold. That aircraft had a cabin altitude of about 22,000ft when the aircraft was at 45,000ft (a low level of pressurisation by today’s standards I know - but that is how it was then) By 30,000ft he felt unwell so checked all his oxygen indications. All fine, flow and pressure. By 40 he felt rotten and decided he was ill. He checked the oxygen system again but no problems showed up. He decided he needed to land ASAP before whatever was wrong with him got worse. He remembered putting the aircraft into a rapid descent but the next thing he recalled was waking up to find himself supersonic and going through 10k very quickly. He sorted things out and landed. When we checked his oxygen cylinders they had been filled with air. Now that is what I call a gotcha. When he had selected 100% oxygen and emergency flow it blew out nicely all round his mask so everything about the system seemed normal. In those circumstances what is a guy to think? Just imagine if he had tent-pegged. Would they have ever dug deep enough to find the bottles? Probably not and it would have been put down to just another unexplained pilot problem.

[TowerDog]

Well, if they are going to fill up the oxygen bottles with the wrong gas, use Nitrous oxide, also called Laughing Gas: The crew will have a good time and it won't kill 'em. :cool:

[moggiee]

BEagle - see John Farley's post - I was 89% right (89% being the amount of Nitrogen in the "Oxygen" bottle).

[Scylla]

I recall tale from a pal working on Tristar heavy maintenance in the UK. They asked a work experience guy to fill the nitrogen accumulators for the hydraulics and, you guessed it, he went to stores and managed to connect the O2 via an improbable number of connectors to the N2 accumulator.

Legend has it that when the Big Boss noticed what was happening, he broke into a run for the first time in his life. (Away - if you're wondering)
:bored:

[Aeroshell48]

cwatters, to answer your question, I regularly use nitrogen in my job in the petrochemical industry, and there have been many cases of people being asphyxiated by this very hazardous gas. It doesn't kill by poisoning, but by lack of oxygen. Apparently there is no warning whatsoever, just instant blackout and death!! This is my first reply and I'd like to say how much I enjoy reading this fascinating and educational forum.

[skol]

I used to work for a pacific airline in the '70's that was equipped with HS748s. Some moron filled the water methanol tanks with kerosene. Since the kero apparently floated on the water meth, once it was used up kerosene was injected into the cold section. Torque gauges went off the clock, lucky to avoid a double engine failure.

[Beausoleil]

Yep, you can fence off the control board and remove the fuses before you work in the shredder, but every now and then some guy will hop over the fence and put new fuses in when he gets back from his tea break.

[Dysonsphere]

Yep, you can fence off the control board and remove the fuses before you work in the shredder, but every now and then some guy will hop over the fence and put new fuses in when he gets back from his tea break.


He He did something similiar was trying to make a circuit live so we replaced all empty fuse holders and turned on everything, 10 mins later angry tech turn saying we nearly killed him, pointed out the lack of a warning placard saying he was working on circuit. (not avation related i know but the same procdures apply)

[Red Top Comanche]

Maybe I missed something but why doesn't the rig have a big huge sign saying NITROGEN or OXYGEN as appropriate.

As a QA guy I have long been in favour of making things simple. Put a sign on something that says "OPEN THIS AND DIE" tends to catch peoples attention.

[Joetom]

This thread has gone a bit cold, anyone got any news about Oxygen systems ???

[411A]

This thread has gone a bit cold, anyone got any news about Oxygen systems ???

Yeah.
On the L1011, the FD crew oxygen bottle is replaced when servicing is necessary, not filled in situe.
It is also green in color, and clearly marked aviators breathing oxygen...hard to miss.:}

[bArt2]

Although I am not aware of any military or civil operator that screens potential pilots for their reaction to reduced oxygen levels

During my training in the Air Force we had several visits to the decompression chamber to practice this, the first time was during medical screening in the Belgian Air Force. I've had some more visits during my training in the USAF where we even did a rapid decompression exercise.

We noticed that not one of us was immune to hypoxia :}

Expanding gas in the intestins did his work too. :O

Bart

[Metro man]

Well, if they are going to fill up the oxygen bottles with the wrong gas, use Nitrous oxide, also called Laughing Gas: The crew will have a good time and it won't kill 'em.

I had the pleasure of spending a few hours on this gas while having my teeth crowned. Basically I found it gave me a new insight in problem solving, I was able to do some very good thinking while under it. Unfortunately you couldn't care less what is happening to you, had the dentist pulled my teeth out instead I would not have objected.

Some people with access to Nitrous Oxide get addicted to it, and I can understand why. :E

[Tankengine]

A question for the experts would "does a nitrogen filled bottle have more chance of exploding tan an oxy one??":eek:
[I doubt it]

[ExSp33db1rd]

Post #27 Yes, but I still need to find a passing 5 yr. old to operate the child-proof cigarette lighter that I use to light the barbie !! ( Can't buy non-child proof ones now.

[cwatters]

I was reading elsewhere that moisture can dramatically accelerate corrosion in an oxygen bottle and implying that you have to be careful following use of incorrect gas that might contain moisture. Do aircraft system have special equipment or proceedures to remove moisture or was it necessary to remove all the bottles for specialist cleaning following this incident?

[tristar 500]

411A says nYeah.
On the L1011, the FD crew oxygen bottle is replaced when servicing is necessary, not filled in situe.
It is also green in color, and clearly marked aviators breathing oxygen...hard to miss.:}

Not strictly true, Tristars on the British Register were fitted with a recharging facility. The charging point was in the fwd freight hold and featured a left hand thread connector.

There were some (not British reg) around that had a right hand thread and we needed an adaptor to allow our Oxygen rigs to be connected.

tristar 500

[Joetom]

http://www.hse.gov.uk/pubns/hse8.pdf
.
A little info on Oxy systems, light reading matter.

[FlexibleResponse]

This sort of maintenance-induced incident has happened before and unfortunately, WILL happen again.

The Aviation community's major defence against this sort of incident occurring has been to tightly control and supervise the training, licensing and supervision of aircraft trade apprentices, AMEs and LAMEs.

Unfortunately, all this corporate history of training and safety checks is being currently undone by the management staff of the so-called low cost carriers by their employment of the cheapest engineers and pilots and out-sourcing that money can buy.

Now mainline carrier managers in their struggle to contain costs and to compete with the low cost carriers have also resorted to the same tactics.

Out-sourcing of maintenance activities is seen to be the way to cheaper costs because the sub-contractors employ semi-skilled low-cost workers off the street and the employing carrier thinks it can can duck and shirk the responsibility for the work undertaken.

However, an airline cannot outsource the responsibility for the airworthiness of their fleet of aircraft. That responsibility always remains with the holder of the AOC. Many airline CEOs would not understand the meaning or significance of this concept.

To wit, just look at the woeful response of a CEO at an airline that has just suffered a major structural damage and decompression. If is obvious to even non-aviation observers that said CEO is totally out of his depth and hasn't got the faintest clue as to what the operational side of the airline is confronted with. Said CEO is already saying that the airline has done nothing wrong, in advance of the investigation. He says that if Oxy cylinders explode through the side of his aircraft, then that is not his company's fault!

The concept of the low cost carrier has finally turned us down the path of a sad decade of airline disasters.

[Wader2]

A question for the experts would "does a nitrogen filled bottle have more chance of exploding tan an oxy one??":eek:
[I doubt it]

No, nitrogen is inert.

It used to be the case that aircraft pneumatics were charged with high pressure air. The presence of oxygen allowed dieselling to take place. I believe this was what led to the replacement of air charging with nitrogen charging.

I am told the Hawk uses 6000 psi but at one time Malaysia had no very high pressure nitrogen facilites and used air instead. Not recommended.

There was also a comment earlier in the thread that an nitrogen mix in an oxygen system would not be catastrophic. Well given the recent Quantas depressurisation even a partial mix could have been fatal as at a cabin altitude in excess of 33000 ft the requirement is for 100% oxygen.

Given that the aircraft descended at 5000 feet per minute, had it been at 39000 feet the crew would have suffered from oxygen starvation for over a minute until at 33000 feet. Indeed immediately below 33000 feet they would be expecting an O2 mix near 100%, if the mix was 75% then their starvation might have lasted another 30 seconds of more.

[ARINC]

Did you hear the apocryphal one about the FJ mate eating his sandwiches whilst on 100% and them subsequently blowing up in his face... a little less butter next time dear...:\

[IO540]

Is that really true? O2 can ignite grease etc but only at a high pressure; not at the 15psi or so which is the max you would have in this case. The similar often repeated story about igniting lipstick is equally unlikely.

[Wader2]

I was reading elsewhere that moisture can dramatically accelerate corrosion in an oxygen bottle and implying that you have to be careful following use of incorrect gas that might contain moisture. Do aircraft system have special equipment or proceedures to remove moisture or was it necessary to remove all the bottles for specialist cleaning following this incident?

A steel bottle yes. Remember 'rust' is ferrous oxide usually forming in moist air with only 21% oxygen content. Remove the nitrogen and you will hasten the oxidisation process.

I would not be sure that aircraft oxygen bottles were made of steel which is a different can on worms. We used to use Aluminium walk-around bottles. The fixed bottles were also aluminium but wire bound for strength. Modern bottles will undoubtedly be made of lightweight materials and I think it was suggested that they may be of composite, and therefore non-rusting or oxidising material. The valve assembly would be possible aluminium or brass.

This website has some interesting information on oxygen bottles:

Aviation Maintenance Magazine :: Houston, It's the Same Old Problem (http://www.aviationtoday.com/am/categories/military/496.html)

Contaminants in oxygen systems are potential fire or explosion hazards. When a gas is compressed, it releases energy in the form of heat. When the gas is compressed quickly inside a closed system such as a container or piping, temperatures inside the system can rise sharply. In an oxygen system, this rise in temperature can be high enough to cause explosive ignition of contaminants such as oil, grease, solvents and materials such as dust, lint, metal chips and many organic materials.

Oxygen flowing at high speed through valves and piping systems can also propel contaminants with such force that friction or impact between particles can raise their temperature to the ignition point. The ignition of these particles may be enough to cause heavier metal sections to ignite and cause a major accident.

Most oxygen regulators are made of brass or aluminum. Aluminum and its alloys are more likely to ignite than brass. In standard tests, aluminum can burn vigorously at pressures as low as 25 pounds per square inch (psi),

A cylinder that has been fully depleted may allow the ingress of moisture and/or contaminants so oxygen cylinders should be maintained at a positive pressure at all times. Theoretically, any pressure differential is sufficient to prevent contamination, but cylinders that have been depleted to zero PSI must be internally inspected and purged.