Flight above 40,000ft

[Noise Unit]

Fact or Fiction?

On commercial flights, when an aircraft is being operated above 40,000ft at least one of the flight crew should be wearing an oxygen mask (with it turned on).

[av8boy]

US Regs:

14 CFR §91.211 Supplemental oxygen.


(a) General. No person may operate a civil aircraft of U.S. registry --

(1) At cabin pressure altitudes above 12,500 feet (MSL) up to and including 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen for that part of the flight at those altitudes that is of more than 30 minutes duration;

(2) At cabin pressure altitudes above 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen during the entire flight time at those altitudes; and

(3) At cabin pressure altitudes above 15,000 feet (MSL) unless each occupant of the aircraft is provided with 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.

Dave

[18-Wheeler]

It depends on the company as well.
In my old company we used to have the 35,000' rule, but it was removed for all altitudes.
No requirement after that at all.

[Bellerophon]

Noise Unit

Fiction, as far as UK registered aircraft are concerned.

There is a requirement for a suitable quick-donning mask to be readily available.

On my last aircraft type I spent many happy hours substantially above 40,000 ft and never once wore a mask.


Notso

I wonder if you missed part of av8boy's post?

...US Regs:..14 CFR §91.211…Supplemental oxygen…(a) General.

No person may operate a civil aircraft of U.S. registry...

Those particular regulations are not binding on UK registered aircraft, so you (and I) don't have to follow them.

Regards

Bellerophon