Emergency Air Traffic Rules

FAR 91.139 — Emergency Air Traffic Rules

FAR 91.139 explains how the FAA uses NOTAMs to issue emergency air traffic rules, who can issue them, and pilot compliance requirements in designated airspace.

In Plain English

FAR 91.139 gives the FAA Administrator a way to respond quickly when an emergency condition threatens the air traffic control system's ability to keep operations safe and efficient. When that happens, the rule allows two things to occur:

The Administrator issues an immediately effective air traffic rule or regulation to address the emergency.
The Administrator or the Associate Administrator for Air Traffic publishes a NOTAM to notify pilots of the new rule.

Once a NOTAM has been issued under this section, no person may operate an aircraft (or other device covered by the rule) within the designated airspace except in accordance with the authorizations, terms, and conditions of that NOTAM.

These NOTAMs communicate information about flight operations, use of navigation facilities, and which airspace the emergency rules apply to.

Operationally, this is why a thorough NOTAM check during preflight matters — emergency rules issued under 91.139 can appear on short notice and carry the full force of regulation, even though they aren't printed in the FARs.

Regulation Text

14 CFR § 91.139

§ 91.139 Emergency air traffic rules. (a) This section prescribes a process for utilizing Notices to Airmen (NOTAMs) to advise of the issuance and operations under emergency air traffic rules and regulations and designates the official who is authorized to issue NOTAMs on behalf of the Administrator in certain matters under this section. (b) Whenever the Administrator determines that an emergency condition exists, or will exist, relating to the FAA's ability to operate the air traffic control system and during which normal flight operations under this chapter cannot be conducted consistent with the required levels of safety and efficiency— (1) The Administrator issues an immediately effective air traffic rule or regulation in response to that emergency condition; and (2) The Administrator or the Associate Administrator for Air Traffic may utilize the NOTAM system to provide notification of the issuance of the rule or regulation. (c) When a NOTAM has been issued under this section, no person may operate an aircraft, or other device governed by the regulation concerned, within the designated airspace except in accordance with the authorizations, terms, and conditions prescribed in the regulation covered by the NOTAM. Those NOTAMs communicate information concerning the rules and regulations that govern flight operations, the use of navigation facilities, and designation of that airspace in which the rules and regulations apply.

Oral Exam Questions a DPE Might Ask

Q1What is the purpose of FAR 91.139, and how does the FAA notify pilots of an emergency air traffic rule?

Per FAR 91.139, when the Administrator determines an emergency condition exists affecting the ATC system, an immediately effective air traffic rule may be issued, and the Administrator or the Associate Administrator for Air Traffic may use the NOTAM system to notify pilots.

Q2If a NOTAM has been issued under FAR 91.139 covering airspace on your route, may you operate through it?

Only if you comply with the authorizations, terms, and conditions prescribed in the regulation covered by that NOTAM. FAR 91.139(c) prohibits operation in the designated airspace under any other circumstances.

Q3Who is authorized to issue NOTAMs on behalf of the Administrator under FAR 91.139?

Under FAR 91.139(b)(2), the Administrator or the Associate Administrator for Air Traffic is authorized to use the NOTAM system to provide notification of the emergency air traffic rule or regulation.

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Related Sections in Part 91

§ 91.1

Part 91 Applicability