New Part 91 and oxygen requirements
 

Do I read the new Part 91 legislation, due to come in on 2 December 2021, correctly regarding supplemental oxygen?

Rather than copy the proven US system, in Australia CASA has come up with a requirement that will add considerably to the cost. That is, they require the aircraft to be fitted with an oxygen system to fly above 10,000 feet, even though they have copied the FAA system in not requiring it to be used up to 12,500 feet.

Can anyone explain why there is such a requirement?

Flying above 10,000 feet quite often gets you above the inversion layer and means the flight is smooth and less fatiguing. It also means better fuel economy and a greater distance to glide if there is an engine failure in a single engine plane.

We have to have and use O2 above 10,000 now don't we? CAO20.4 refers. So what will change with the new Part 91 rules that isn't already covered under the existing legislation?

In the CASA plain English guide to Pt 91 it states oxygen requirements have been relaxed. It then states:

“Supplemental oxygen (MOS 26.43)
An aircraft operated at a pressure altitude above FL 125 must be fitted with supplemental oxygen equipment which can store and dispense the oxygen to crew members and passengers as set out in the following table.”

So as I read it, the new lower limit for oxygen is 12,500 ft. What’s your reference for the 10,000 ft limit?

You know the answer, Dick.

Australia's air is different.

Australia's pilots are too stupid to make their own decisions about when to use supplemental oxygen (whether above or below 10,000' AMSL up to 12,500' AMSL).

Australia's regulator 'harmonises' by making rules different to the world's biggest and best builder, operator and certifier of aircraft.

We should count ourselves lucky that supplemental oxygen hasn't been mandated for night flights over 6,000' AMSL.

Cloudee, the Part 91 MOS states:


Here is a link: https://www.legislation.gov.au/Detai...t#_Toc57289557

Soot looks like it’s true, you have to fit oxy equipment if you fly over 10,000 ft but don’t have to use it unless you go higher than 12,500 ft. Another CASA clanger?

Division 26.11 Oxygen equipment and oxygen supplies

26.43 Supplemental oxygen

(1) An aircraft operated at a pressure altitude above 10 000 ft (a relevant aircraft) must be fitted with supplemental oxygen equipment capable of storing and dispensing supplemental oxygen to crew members and passengers.

(2) A relevant aircraft must carry sufficient supplemental oxygen to meet the requirements set out in Table 26.43 (2).

(3) For a person mentioned in column 1 of an item in Table 26.43 (2), supplemental oxygen must be made available through an oxygen dispensing unit (a dispensing unit) in accordance with the supply requirements mentioned for the item in column 2.

(4) Each flight crew member must use the supplemental oxygen that is made available to each of them in accordance with the supply requirements mentioned in column 2 of item 1 of Table 26.43 (2).

Table 26.43 (2) – Supplemental oxygen requirements




Supplemental oxygen supply requirements

1

Flight crew member or cabin crew member

(a) For any period exceeding 30 minutes when the cabin pressure altitude is continuously at least FL 125 but less than FL 140, there must be supply for the entire period.

(b) For any period when the cabin pressure altitude is at least FL 140, there must be supply for the entire period.

(c) Without otherwise affecting paragraphs (a) and (b), when a pressurised aircraft is flown at an altitude of FL 250 or more (relevant flight), there must be at least 10 minutes supply even if the entire period of relevant flight is less than 10 minutes.

2

Passenger

(a) For any period when the cabin pressure altitude is at least FL 150, there must be supply for the entire period.

(b) Without otherwise affecting paragraph (a), when a pressurised aircraft is flown at an altitude of FL 250 or more (relevant flight), there must be at least 10 minutes supply after descending below FL 250 even if the entire period of relevant flight is less than 10 minutes.

Let’s hope it is simply an honest mistake and they will rectify it urgently.

What's the clanger here exactly? Seems prudent to me, anything over 10,000ft is definitely a good time to think about getting on oxygen, it's a little hard to do that if you don't have it. Above 12,500ft should definitely be on it just to be on the safe side. If you're getting above 10k then it wouldn't be unexpected to maybe even need an extra 1,000ft or so you weren't expecting to clear the weather and all of a sudden find yourself needing something you don't have.

It also isn't an onerous cost with purchasing a portable system and infact a company could have a handful of portables to cover a fleet and only carry when it looks like it'll be necessary?

Does a portable system meet the requirements?

Oxygen?
 

In a previous life as a flying spanner on Beverlys, I couldn’t figure out why I got so tired after pumping oil at about 10,000’. 🤭

108.26 is still relevant so far as I'm aware, it states: 4.3 Portable oxygen units may be used to meet the crew or passenger breathing requirements.

A Mountain High 02D2 kit with cylinder went for about 2k last I checked.

IxIX- I simply can’t believe your post is genuine!

Do you really believe there is no problem in CASA enforcing an oxygen fitment requirement for aircraft that fly between 10,000 and 12,500 even though there is no requirement to use oxygen?

Do you work for CASA? Have you ever owned or operated an aviation business? Or any business at all ?

Dick Smith can you stop being a smart arse when somebody says something different to you.

Actually, if what has been presented above is correct, it does seem logical. There are definite effects of lack of oxygen on some people above 10,000ft (some figure has to be chosen and 10,000 is as good as any). Rather than dictating you MUST wear the gear, it is sensible to have it there under 12,500ft (again another figure has to be chosen) in case its needed.

If I were a legislator I'd probably view that as a sensible concept. Like having a first aid kit available. Hope not to use it but it's there if you need.

Having a portable oxygen bottle on board in no way affects the viability of a business, particularly if the oxygen isn't even needed.

So maybe quit being a snide smartypants and accept others may actually have valid opinions.

So why not, then, mandate carriage and use of oxygen on night flights above 6,000'?

You know you can choose to carry and use oxygen on flights above 1'?

Oh really?

What about:

- Purchase of the equipment
- Maintenance of the equipment, purging etc
- Testing and certification
- Ops manual additions and approvals
- Training
- Refills (if used)
- Oxygen meters, portable or mounted. LAME work and approvals required for fixed units.
- Sanitisation of the units after use (even if not used in the current Covid climate)
- Reduced payload on aircraft

…. to name just a few.

A bit of history on the US regs first, in simple terms. Part 135 ops= above 10k for crew, part 91 ops 12.5k.
Why the difference? It was lobbied by a major group back in the early 70's for the 12,500' for P91 ops to be able to pop up and over mountain ranges in the west of the country. Not stay there all day. This was to save the impost of expensive gear on the private operator. Part 135 is not so accomodating.

Recently, during an FAA FAAST team webinar, FAA personnel and the CEO of AEROX did a great presentation explaining the history and the science behind when you should use it. For most people, even fit and healthy folks, there is a significant cognitive benefit above 8000' and they were recommending despite what the regs say, if you are flying above 8000' for an hour or more you really should be using supplemental O2. For flight at night, vision is greatly enhanced as well as cognitive ability and the recommendation was 5000' and above at night.

I can personally attest to the statements made in that webinar are true as that is exactly consistent with my own testing 10-11 years ago. Myself and most of my flying friends all have O2 systems now. It really is a cheap legal performance enhancing drug!

This link is the same material presented by the "Aerox Dude", this time however for the Cessna Pilots Assoc. It is a long watch but worth doing, especially some of the slides showing FAA data.
Search YouTube for "Complete Guide to Supplemental Oxygen Use for General Aviation "

Also consider the recent Hypoxia event where the pilot should have been using O2 the whole flight. ATSB have a good report on the Caravan that sailed over Brisbane and out to sea.
There are two major suppliers, AEROX and Mountain High. Both are represented in Australia and the Aerox dealer carries stock here.

Dick, I believe that while CASA should do in this instance leave the current rules in place, basically Part 135 style rules. What they mean or should mean is "fitted" includes a portable system such as Aerox or MH.
I assume you have a portable or built in system for your plane, and that you probably would/should be using it above 8000' anyway as the health benefits are well worth it, especially as we get older. What do you have if any, and how do you use it?

Squawk7700

Not sure what the business case is here, this is about Part 91. Anyone flying a lot, over longish legs and wanting the altitude, will not find the costs prohibitive.

As I posted above, myself and quite a few friends have adopted this gear as "normal" and the ongoing costs are trivial.

And for those looking for a fast track to the links I suggested previously from ATSB and the CPA try these.


and

https://www.atsb.gov.au/media/news-i...-mild-hypoxia/

It doesn’t pass the commonsense test.

I bet it was a simple error.

If such a requirement is necessary for safety for private operations why wouldn’t the FAA mandate fitment?

They have over ten times the number of aircraft that we have.

Competent pilots I know would not spend excessive time above 10,000 without oxygen but the US regs allow for good judgement.

Lets say you are a farmer living in the outback and visit the coast once a month or so. There will be times when going above 10,000 and getting above the inversion layer would be sensible. But. Hold on you can’t because you do not have an oxygen system fitted!

Now we're down to 5,000' for night ops, SWMBO?

Here's what the ATSB actually said about the 'recent Hypoxia event':I've spent many, many continuous hours cruising over 8,000' without supplemental oxygen without falling asleep or making dumb mistakes (or at least not more dumb mistakes than I usually make under 8,000').

The CEO of AEROX wouldn't have any commercial conflict?

2020 guidance from the FAA.