O2 Charging

[spannerhead]

If the crew O2 contents are low do you replace the bottle, recharge it in situ or remove the bottle and then recharge it?
I've worked at european airports where you can't get hold of O2 airside even though some A/C have recharge adapters built in to the fuselage.

[spanners]

If the botle is low, it should be replaced. This is something to do with the fact that condensation may have occurred in the bottle creating undesirable bits.
I read somewhere that under JARs you are not supposed to charge O2 in situ anyway but that big players have exemptions. comments?


[This message has been edited by spanners (edited 17 March 2001).]

[redtail]

Delta set a 727 on fire in Denver during the 1980's servicing the O2 with the service panel on the aircraft, which led stateside operators to require bottle removal for servicing. Probably the service panel was ok to use, provided one was checking bottle temperature while servicing.

[Gnd_Chk_Satis]

I'd rather use a purpose designed remote fill point....as either struggling in-and-out with an oxy bottle or getting a line inside to the bottle always seems to be rushed and eventually threads get damaged and contamination is a bigger concern.

Remote filling with a dedicated oxy team is the safest way to go.

[Clever Bloke]

Charging O2 in situ is fine as long as it's in the MM and basic safety measures sre followed, no refuelling, no people on board and tools are clean/grease free.
Most remote fill points have a pressure regulator that shuts off if too much pressure is pushed in.

However I do feel a dedicated team is the way to go. At least they will have a set of tools only used for O2.

[spannersatcx]

How many 1hr transits do you do when there is no refuel in progress, no people onboard, and how many people have grease free tools!

We are not allowed to charge on a/c, so have to change the bottle.

Should have dedicated O2 tools available, i.e never been used for anything else.

[Clever Bloke]

In the UK in situ o2 charging is currently allowed.
If the correct procedure cannot be followed, don't do the job!!
Use the MEL or ground the aircraft.

[Penn Doff]

At VS the oxygen servicing is carried out by the avionics guy's (+ gals), although as Spannersatcx points out it can be a pain in the ar*e on a short t/r, try explaining to the crew that you can not board pax due oxy servicing!!
On the subject of UK vs US rules the RAF TriStars could have bottled oxy charged in situ on the ex BA aircraft but on the ex Pan Am the bottle had to be removed.

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"please report further"

[This message has been edited by Penn Doff (edited 18 March 2001).]

[Lu Zuckerman]

Here is a little story dealing with charging of an Oxygen cylinder or, was it a Nitrogen cylinder. Back in the late fifties an Air Force tech was in process of charging the oleo-pneumatic landing gear struts on an F-86 when the pressure in the bottle dropped below minimum pressure. The bottle he was using to contain the Nitrogen was in reality an Oxygen bottle that had been repainted Grey with a black stripe. The bottle was metal stamped near the neck “For Oxygen Service Only”. Oxygen cylinders as you may know have left hand threads so in order to use it for Nitrogen service the technician had to cobble several fittings together to attach to the bottle and still use a conventional threaded flex tube to connect to the Schrader valve on the strut. He filled out the paper work and took the bottle to tech supply for refilling with Nitrogen.

Although the paper work requested Nitrogen the technician at tech supply saw the stamping on the bottle that said for Oxygen service only. Despite the fact the bottle was painted grey with a black stripe he removed the original threaded fittings and replaced them with left hand thread fittings and filled the bottle with Oxygen. The bottle was delivered back to the maintenance hanger with the original cobbled fittings installed.

The technician went to an F-86 and began to service the nose strut when it blew up in his face killing him and starting a fire that consumed about ten F-86s in the hanger.

Who made the first mistake?


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The Cat

[WideBodiedEng]

If there is a procedure and you have the correct equipment it is perfectly safe.
Nice and s...l...o...w does it. But the same applies to filling N2 systems. I've refilled from about 300 psi and done top ups. Just use the head - one of the correct tools!!

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The Stamp is mightier than the Toolbox!!