Legal Interpretations
Rawlings 2013
Summary
The Question
Is the five-second requirement for donning a quick-donning oxygen mask measured from within reach of the mask or from the flight crewmember's duty station?
Background
An individual asked how the five-second quick-donning standard for flight crew oxygen masks applies under the certification rule in 14 CFR 25.1447(c)(2) and the operating rule in 14 CFR 121.333(c)(2).
The FAA’s Interpretation
Neither alone: the five seconds are measured from within immediate reach while the crewmember is at the duty station. 14 CFR 25.1447(c)(2) requires the mask to be immediately available when seated at the station and donnable with one hand within five seconds, and 14 CFR 121.333(c)(2) is similar. The requirement cannot extend from the duty station; it is measured at it.
- Requester
- Rawlings
- Issued
- May 7, 2013
- Subjects
- Air Carrier & Commercial Operations · Aircraft & Parts Certification
Regulations Cited
Page 1
U.S. Department
of Transportation
Federal Aviation
Administration
M>:f - 7 2013
Rick Rawlings
Dear Mr. Rawlings,
Office of the Chief Counsel 800 Independence Ave., S.W.
Washington. D.C. 20591
This letter responds to your request for a legal interpretation regarding the use of oxygen masks by flight crewmembers. You specifically ask whether the five second requirement for quick-donning of the oxygen mask is measured from within reach or from the duty station. As explained below, the five second requirement is measured from within immediate reach while at a flight duty station.
Certification and Operating Requirements
14 C.F.R. § 25.1447(c)(2) provides the certification standards for quick-donning oxygen masks:
(c) If certification for operation above 25,000 feet is requested, there must be oxygen dispensing equipment meeting the following requirements:
Each flight crewmember on flight deck duty must be provided with a quick-donning type oxygen dispensing unit connected to an oxygen supply terminal. This dispensing unit must be immediately available to the flight crewmember when seated at his station, and installed so that it:
(i) Can he placed on the face from its ready position, properly secured, sealed and supplying oxygen upon demand, with 011e hand, within five seco11ds and without disturbing eyeglasses or causing delay in proceeding with emergency duties (emphasis added) ...
With regards to operating requirements, §121.333(c)(2) provides similar requirements in pertinent part:
(c)(2) When operating at flight altitudes above flight level 250, one pilot at the controls of the airplane shall at all times wear and use an oxygen mask secured, sealed, and supplying oxygen, in accordance with the following:
The one pilot need not wear and use a n oxygen mask at or below the following flight levels if each flight crewmember on flight deck duty has a quick-donning
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type of oxygen mask that the certificate holder has shown can be placed on the face from its ready position, properly secured, sealed, and supplying oxygen upon demand, with one hand and withinjive seconds (emphasis added). The language of both sections is specific and clear. Each flight crewmember on flight deck duty, when operating above flight level 250, must have an oxygen mask within immediate reach while at his or her duty station. Also, the pilot at the controls of the airplane must at all times wear and use an oxygen mask, unless each flight crewmember has a quick-donning type of oxygen mask that can be placed on the face with one hand within five seconds. By contrast, consider§ 25.1447(b), which details the certification of operations up to 25,000 feet, and uses the words "within easy reach" instead of "immediately available." This indicates a clear intent that, for operations above flight level 250, a different standard is necessary.
Thus, the two parts of your question cannot be separated. It is not an either/or situation. The five second requirement for donning an oxygen mask is measured from a pilot's immediate reach while at his or her duty station. The certification and operating regulations require both conditions. As a result, the five second requirement cannot extend from the duty station, it can only be measured at the duty station. We appreciate your patience and trust that the above responds to your concerns. In addition, FAA Policy ANM-03-111-07 dated February 14, 2011, provides acceptable test methods that can be used to show compliance with the quick donning requirements in § 25.1447(c)(2). If you need further assistance, please contact my staff at (202) 267- 3073. This letter has been prepared by Robert H. Frenzel, Manager, Operations Law Branch, Office of the Chief Counsel and coordinated with the Air Transportation and Aircraft Maintenance Divisions of Flight Standards Service. ar . Bury
Acting Assistant Chief unset for International
Law, Legislation and Regulations, AGC-200
Regulations Referenced
Snapshot retrieved August 6, 2026.