§ 91.173 ATC clearance and flight plan required
14 CFR Part 91 — Subpart B—Flight Rules
Official text — 14 CFR § 91.173
REGULATION — LEGALLY BINDINGNo person may operate an aircraft in controlled airspace under IFR unless that person has—
(a) Filed an IFR flight plan; and
(b) Received an appropriate ATC clearance.
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
The requirement, in controlled airspace under IFR, to file an IFR flight plan and receive an appropriate ATC clearance before operating.
Why it matters
It is short, absolute, and the starting point for every IFR operation in controlled airspace.
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.