Usage of 100% pressurized oxygen in helicopter
 

I recently took the seminar relating to the usage of 100% pressurized oxygen system in the helicopter.
There is a question in it, "Do the normal and abnormal procedures checklists for your aircraft include items related to the high-pressure 100% oxygen system?"

My company doesn't incorporate anything in our SOP so far and I'm wondering if there is someone who has the checklists which include items related to the high-pressure 100% oxygen system, please share the knowledge?

Thanks in advance

I deal with high pressure O2 through another hobby of mine, diving.
What do you want to know?

Is this medical oxygen for patients or crew oxygen for operations at altitude?

My company's normal and emergency checklist does not contain any reference to the medical oxygen system installed in our helicopters.

Difference between medical, aero and industrial oxygen is paper trail.
They are all filled from the same supplier tanks.

Yes, but different responses to an emergency if a medical bottle starts leaking, or the pilots' system goes berserk.

There is an urban myth about a fighter pilot whose moustache caught fire in his mask when the system got to 100% at altitude - he had been eating peanut butter for breakfast.

They may come for the same tank - but the installations in the aircraft are different as are the required crew actions and secondary effects in the event of an emergency or malfunction.

I used high pressure (2,000 psi) oxygen cylinders for high altitude sailplane flying for many years. I filled my own cylinders and maintained the system. High pressure oxygen is never delivered directly to flight crew. It is always regulated to a much lower pressure then passed to a mask or cannula by a manufacturer's proprietary regulator/delivery system.

I'd suggest you consult the manufacturer's documentation for the system that may be fitted to your aircraft. There are many different type of delivery systems.

The PRICE mnemonic checklist is generic and is probably useful for any system - https://www.faa.gov/pilots/safety/pi..._equipment.pdf

That is exactly that, a myth. Pure oxygen is not a problem under 10 bar of pressure. True, it helps with burning, but if it comes to that, you already have much bigger problems on your hand.
Like EXDAC already said, aero systems deliver oxygen at slightly above ambient level.
Unless it's explosive leak, oxy leak is not a problem in itself.

O2 is the common denominator but the where, how and why can change things. Cargo, Supplementary or MED.
Cargo is Hazmat as 1/ Compressed Gas and 2/ Oxydizer, installed isn't and portable supplementary under PVT isn't. MED has some exemptions. Pretty sure in all cases of installed under TD or STC whether supplementary, emergency or MED access to a manual shutoff accessible by the crew is required, apparently a flow limiter can be an also be an acceptable means but................?. That would bring up a line in certain EP's i.e. cabin fire with oxygen in use, oxygen leak large or small and also pre-flight/normal procedures? What does the RFM Supplement say for the STC? Just about anything will burn in the presence of oxygen and ignition can even occur by turning a valve on too quickly and cause adiabatic heating. Ever cut steel with Oxy Actylene cutting torch? If not find someone who will let you have a go.
Be aware that with an oxygen fed fire your Halon extinguisher will be slightly less than completely useless unless you can cut off the oxygen supply.
If you need an example of a cluster from a Swiss Cheese model read this.

Quite apart from that, surely the drop was given by the suggestion that the pilot had eaten penut butter for breakfast. No one does that, surely?

You must be unfamiliar with the American love of a PBJ. Been here over 40 years and never added J to PB with, or without, oxygen.

​​​​​​​I eat it quite often, and don't call me Shirley....

Try a grilled peanut butter sandwich…..just like making a grilled cheese except made using peanut butter.
Not recommended for regular consumption but a nice rare treat for a cold winter’s day.
Some hedonists add banana slices.

Yes, but the medical tanks/cylinders are handled differently during the filling process to ensure no contamination is present.

Thank you for that RVDT! Just so you know that "lessons learned" are put to use here, I'm traveling today to inspect a changed airplane breathing oxygen installation for approval (by STC) of its changed design tomorrow. Though upon considering the great information, I am confident that the design is already compliant as I found it to be 13 years ago when I first approved it, I will conduct my inspection, testing and design review with added wisdom having read that report!

This report is one small example of how an event which occurred in a helicopter was not really dependent upon the aircraft type, so the wisdom and lessons learned are applicable to any aircraft oxygen installation.

Thanks for that!

I notice that -- The Apollo 1 fire which killed three astronauts in 1967 occurred in an oxygen atmosphere at about 1 bar.

"After the hatches were sealed, the air in the cabin was replaced with pure oxygen at 16.7 psi (115 kPa), 2 psi (14 kPa) higher than atmospheric pressure"

Yes, the flight manual supplement of my helicopter medical kit includes items to normal and abnormal checklist. Those item mostly refer to closing the oxygen bottles before (normal or) emergency landing or in case of fire.

A fascinating report, RVDT. Thank you.

In my gliding career, one of the things that was drummed into all pilots, was to avoid using any tools with grease on them when manipulating oxygen connections.

In my club's hangar, the oxygen installation used to fill aircraft bottles has a dedicated wrench/spanner on a chain, that has never been used on anything except oxygen fittings.

There is a difference between a fire being sustained by an oxygen pressure of about 1 bar and a fire being caused by an oxygen pressure of about 1 bar.

If my recollection is correct the Apollo 1 fire was attributed to a spark caused by faulty capsule wiring.

If you turn off the oxygen before a normal landing your patient survival rate will be a tad low !!