§ 91.135 Operations in Class A airspace
14 CFR Part 91 — Subpart B—Flight Rules
Official text — 14 CFR § 91.135
REGULATION — LEGALLY BINDINGExcept as provided in paragraph (d) of this section, each person operating an aircraft in Class A airspace must conduct that operation under instrument flight rules (IFR) and in compliance with the following:
(a) Clearance. Operations may be conducted only under an ATC clearance received prior to entering the airspace.
(b) Communications. Unless otherwise authorized by ATC, each aircraft operating in Class A airspace must be equipped with a two-way radio capable of communicating with ATC on a frequency assigned by ATC. Each pilot must maintain two-way radio communications with ATC while operating in Class A airspace.
(c) Equipment requirements. Unless otherwise authorized by ATC, no person may operate an aircraft within Class A airspace unless that aircraft is equipped with the applicable equipment specified in § 91.215, and after January 1, 2020, § 91.225.
(d) ATC authorizations. An operator may deviate from any provision of this section under the provisions of an ATC authorization issued by the ATC facility having jurisdiction of the airspace concerned. In the case of an inoperative transponder, ATC may immediately approve an operation within a Class A airspace area allowing flight to continue, if desired, to the airport of ultimate destination, including any intermediate stops, or to proceed to a place where suitable repairs can be made, or both. Requests for deviation from any provision of this section must be submitted in writing, at least 4 days before the proposed operation. ATC may authorize a deviation on a continuing basis or for an individual flight.
Reproduced from the eCFR. Text as amended through 2026-07-31. Verify against the official source before relying on it operationally.
SkeyeMentor explanation
Educational — not an FAA sourceIn plain English
Operations in Class A airspace, including the requirement to operate under IFR and the equipment and clearance requirements.
Why it matters
It explains why VFR flight is not available at and above 18,000 feet MSL up to and including FL600.
Written and reviewed by the SkeyeMentor editorial team. This explanation is a study aid, not legal advice, and it is not part of the official text above. Verify current requirements through the official source before relying on them operationally.
Is this a regulation?
Yes — this is regulatory text and is legally binding.
Text published in the Code of Federal Regulations. Regulations are legally binding on pilots and operators.
Yes — this is the text of a Federal Aviation Regulation. It is legally binding. The explanation below it is SkeyeMentor educational content, not part of the regulation.