Donning O2 mask in cruise?

[n_sabardin]

Can anyone tell me what the rule is under IASA for oxygen mask donning requirement if one of the pilots has to leave the flight deck while in cruise? Under FAA, I believe that the remaining pilot has to be on O2 if cruising above FL250. What is it in Europe?

[Juan Tugoh]

It has to do with the type of O2 masks fitted. If they are of the "quick don" type then there is no requirement for the remaining pilot to be on O2 in your scenario.

[Escape Path]

It has to do with the type of O2 masks fitted. If they are of the "quick don" type then there is no requirement for the remaining pilot to be on O2 in your scenario.

I remember something like one pilot on O2 if the other one leaves the cockpit above 300 or 320; memory fails me at the time. I don't remember anything about FL250 other than the max altitude for an airplane without O2 masks for pax.

EDIT: I found something on the Colombian regulations (which are very similar, almost identical, to the FARs)

RAC 4.18.9.2. Cabina Presurizada (Pressurized Cabin)
D) A alturas superiores a 250 uno de los pilotos debe usar máscara de oxígeno
asegurada y sellada suministrando oxígeno todo el tiempo a no ser que la aeronave esté provista de máscaras de tipo «instalación rápida» que pueda ser colocada y asegurada con una sola mano en cinco segundos y que suministre oxígeno según demanda.

"At altitudes greater than FL250, one of the pilots must wear the oxygen mask and it must be providing oxygen at all times unless the aircraft is equipped with quick donning masks"

But I still recall one of my friends who flies a 767 saying that he still needed to wear the mask at FL3XX if the Captain left the cockpit.

[galaxy flyer]

In FAA land, if above FL 410, one pilot has to be wearing a mask at all times. Yes, above FL 250, if one pilot leaves the cockpit, the other has to wear a mask, regardless of the type installed.

Since, on SAFA checks, I have heard that the inspector has checked the O2 levels on N-registered planes for signs of O2 use when the cruising level was clearly above 410, what is the EU-OPS regulation, in it's entirety?

GF

[FullWings]

In FAA land, if above FL 410, one pilot has to be wearing a mask at all times. Yes, above FL 250, if one pilot leaves the cockpit, the other has to wear a mask, regardless of the type installed.
Didn't know that. Does anyone actually do it? On our ships, the Eros masks are great but we're told re-stowing is an engineering function...

Since, on SAFA checks, I have heard that the inspector has checked the O2 levels on N-registered planes for signs of O2 use when the cruising level was clearly above 410, what is the EU-OPS regulation, in it's entirety?
Had a quick search through EU-OPS for "oxygen" and couldn't find any reference to 40K+ flight. Only requirements for O2 over 10K and quick-don over 25K.

[galaxy flyer]

Thanks, Full Wings. That's the rub, the SAFA inspector asks why there is a full O2 system! Our plane does have a slightly more comfortable "cruise" mask, but 8 hours is too much. Don't know wh the rule persists, either.

GF

[Feather #3]

For several years, we went through the other guy wearing a mask when one had to leave the seat.

Then [ahh...the GOD's!] we had a Scott Sierra guy up front one night across the Pacific when we did this. He was horrified. The masks aren't easy to restow [see comment above] and were only designed to be removed from the box in emergency or for maintenance [annual?]

This feedback saw a change in the rules for O2 use >F250 as long as the masks are of a quick donning type.

G'day ;)

[galaxy flyer]

Feather #3

Could you post a reference to the CASA reg, please? I'd love to pursue it with the FAA

GF

[FullWings]

All of our longhaul fleets (767, 777, 747) have the capability to cruise over 40,000' but we don't have anything in our manuals about special procedures >40K. EU-OPS compliant.

I'm more worried about the high-energy photons and bits of relativistic matter that bombard the aircraft when you're up in the gods like that...

[draglift]

Taken from my flying manual. (In normal operation the aircraft has a max cruise FL of 430.)

Loss of Crew Oxygen

Flight Level / Oxygen
---------------------------
Below FL 250 /Not required
FL 250 - FL 350 / Portable oxygen to hand (both pilots)
FL 350 - FL 400 / HP to wear oxygen mask

Flight above FL400 not permitted.

[hptaccv]

...if cruising above FL410 and only one Pilot at the controls O2 Mask needs to be donned... dunno if it's actually an EU-OPS Requirement, but that's the what the book says...

[Capn Bloggs]

Galaxy Flyer:

http://casa.gov.au/wcmswr/_assets/main/download/orders/cao20/2004.pdf

Section 8.4 and 8.5. :ok:

[2992]

§ 91.211 Supplemental oxygen.

(b) Pressurized cabin aircraft. (1) No person may operate a civil aircraft of U.S. registry with a pressurized cabin-

(i) At flight altitudes above flight level 250 unless at least a 10-minute supply of supplemental oxygen, in addition to any oxygen required to satisfy paragraph (a) of this section, is available for each occupant of the aircraft for use in the event that a descent is necessitated by loss of cabin pressurization; and

(ii) At flight altitudes above flight level 350 unless one pilot at the controls of the airplane is wearing and using an oxygen mask that is secured and sealed and that either supplies oxygen at all times or automatically supplies oxygen whenever the cabin pressure altitude of the airplane exceeds 14,000 feet (MSL), except that the one pilot need not wear and use an oxygen mask while at or below flight level 410 if there are two pilots at the controls and each pilot has a quick-donning type of oxygen mask that can be placed on the face with one hand from the ready position within 5 seconds, supplying oxygen and properly secured and sealed.

(2) Notwithstanding paragraph (b)(1)(ii) of this section, if for any reason at any time it is necessary for one pilot to leave the controls of the aircraft when operating at flight altitudes above flight level 350, the remaining pilot at the controls shall put on and use an oxygen mask until the other pilot has returned to that crewmember's station.

[galaxy flyer]

Thanks, Cap'n Bloggs, a vast improvement over the FAA rule, the GLEX doesn't spend much time above FL450.

GF

[FullWings]

Fascinating!

To go back to a previous question, does anyone actually abide by this regulation? I've been frequently flying in US airspace for a decade or two and have never heard *anyone* wearing an oxygen mask (you can tell, you know!). Especially as the vast majority of jet traffic is FL350 or above... There must be many a time where one of the pilots has nipped back to the loo and the other needs to make a radio call?

[BizJetJock]

The response to ignorant SAFA inspectors is that when the cabin altitude is below 10k the masks won't supply any oxygen even when worn. they just let air in from the cabin.
This is of course with the switch in "NORM" - obviously if there is smoke that is not much use which is one of the reasons why the switch should be in "100%" when the mask is stowed.

[canadansk]

In UAE GCAA it is when flying above FL430.

[DeltaGolf]

here in Chile we have the same regulation, above FL350 if one pilot leaves the station the other one has to wear the mask and breathe Pure magic O2.

I can speak for myself and the Captains I fly with, we follow the procedure, you never know what can happen.. and like you said, we 90% of the time are above FL350...

they could be really close to you (thats why called Quick donning) but in a loss of presurization that high, don't have many time to think about it..


and flying the last leg of the day at 6-7am, a little bit of pure O2 is not bad for wake up :D

[HS125]

Whilst I think the reasoning behind the legislation is clear, I don't regard it as very sensible at all.

In the event of a decompression gasses are going to try and escape from the body as well as the cabin itself, restricting any orifice likely to assist this (e.g the nose and mouth with an oxygen mask) is therefore probably a very bad idea indeed - If you really want to rupture all of your internal organs then why not stick a cork in your backside at the same time as donning the mask?

[Capn Bloggs]

I was never under the impression that, when wearing the mask because I was the only one of the Flight Deck, I had to use 100%. Obviously, if a depressurisation occurs, the oxygen percentage will be increased as cabin altitude increases because the masks are diluter-demand.

I was under the impression that the rule exists because of the increased difficulty of performing an emergency descent single-pilot whilst getting your mask on.

[lederhosen]

Fact is some are required to wear the masks, some are not. The benefit of wearing the mask is clear. I think the disadvantages are also pretty obvious.

Our masks, at least so we are told are not designed to be continuously taken out. Given three hour sectors and a cruising level almost always above 350 our masks would probably be used several thousand times a year.

Maybe practice makes perfect but I tend to believe restowing properly is a maintenance activity. Having them work when you need them could be argued to be more important than the five seconds you save in the emergency descent by not having to don the mask in the explosive decompression scenario.

The only actual case where this might have been a factor if I remember correctly was the Payne Stewart Learjet in the US where presumably the regulation applied, but for whatever reason did not help. How do people who apply the rule deal with restowing?