Definition
A federal regulation that prohibits a pilot from acting as pilot in command, or in any other capacity as a required flight crewmember, while that pilot knows or has reason to know of any medical condition that would make them unable to meet the requirements for the medical certificate necessary for the flight, or while taking medication or receiving treatment for a medical condition that results in the pilot being unable to meet those requirements.
Plain English
A rule that says you must not fly if you know — or have good reason to suspect — that something is wrong with your health, or that a medication or treatment you are using, would stop you from passing the medical exam required for the flight you are about to make.
Context Anchor
Seen in discussions of pilot medical fitness, medications, drugs, illness, and the preflight decision about whether you are safe and legal to fly today.
Derivation
‘14 CFR’ refers to Title 14 of the Code of Federal Regulations, which covers Aeronautics and Space. ‘Part 61’ contains the rules for certification of pilots, flight instructors, and ground instructors. ‘Section 61.53’ is the specific subsection dealing with prohibition on operations during medical deficiency. Knowing the address helps a pilot find the rule quickly when needed.
Why Pilots Care
A pilot who flies while knowingly medically deficient risks certificate action, enforcement, and endangering flight safety.
Grounding Statement
Before a flight, this rule is the legal backstop behind the question: “Am I medically safe to fly today?”
Intuition Check
Do not read this as just a recommendation from a handbook. 14 CFR part 61 section 61.53 is a federal rule, and it applies when your medical condition, medication, or treatment affects your ability to fly safely or meet the required medical standard.
Example Sentence 1
After starting a new prescription medication, the pilot grounded herself under 14 CFR part 61 section 61.53 until she confirmed with an aviation medical examiner that it was safe to fly.
Example Sentence 2
Before the checkride the applicant reviewed 14 CFR part 61 section 61.53 to confirm no recent illness or medication would prevent acting as pilot in command.