I hope you thoroughly read Monday’s post on oxygen regulations, if not you could be in trouble answering this two question pop quiz to start of today’s blog. NO cheating!
1. When operating an aircraft at cabin pressure altitudes above 12,500 feet MSL up to and including 14,000 feet MSL, supplemental oxygen shall be used during
A—the entire flight time at those altitudes.
B—that flight time in excess of 10 minutes at those altitudes.
C—that flight time in excess of 30 minutes at those altitudes.
2. Unless each occupant is provided with supplemental oxygen, no person may operate a civil aircraft of U.S. registry above a maximum cabin pressure altitude of
A—12,500 feet MSL.
B—14,000 feet MSL.
C—15,000 feet MSL.
The correct answer to question 1 is C, No person may operate civil aircraft at cabin pressure altitudes above 12,500 feet MSL up to and including 14,000 feet MSL, unless the required minimum flight crew uses supplemental oxygen for that part of the flight at those altitudes that is more than 30 minutes duration.
The correct answer to question 2 is also C, No person may operate a civil aircraft at cabin pressure altitudes above 15,000 feet MSL unless each occupant is provided with supplemental oxygen.
You can find both of these answers outlined in 14 CFR §91.211, specifically section (a) as shown in the excerpt below.
§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.
One thing I like to point out when discussing regulatory requirements for the use of oxygen is that everybody’s physiology is a bit different. Based on an individuals physical condition and characteristics, oxygen deprivation may be felt at altitudes below those outlined in the regulations. With that said it is always a good idea to have oxygen available and in use when flying above 5,000′ MSL at night and 10,000′ MSL during the day.
If you want to learn more about the types of oxygen systems available to pilots check out section 7 of the Pilots Handbook of Aeronautical Knowledge (FAA-H-8083-25).
