Civil Aircraft Airworthiness

Section 91.7 is the airworthiness anchor rule for Part 91 operations. It requires that no person may operate a civil aircraft unless it is in an airworthy condition, and it assigns the determination of airworthiness specifically to the pilot in command.

Definition of "airworthy": While § 91.7 doesn't define the term, the FAA has long held airworthiness to mean: (1) the aircraft conforms to its type design (or properly altered configuration); AND (2) the aircraft is in condition for safe operation. Both elements are required. An aircraft with a current annual but a known unsafe condition is not airworthy. An aircraft in perfect mechanical condition but with an expired inspection is also not airworthy under FAA enforcement interpretation.

The PIC determination (paragraph b): The PIC is responsible for determining whether the aircraft is in condition for safe flight. This is a preflight obligation that doesn't get delegated — not to the mechanic who signed the logs, not to the line crew, not to the operator. The PIC walks the aircraft, checks the documents, and decides go/no-go.

Discontinuance in flight (paragraph b): The PIC must discontinue the flight when unairworthy mechanical, electrical, or structural conditions occur. "Discontinue" here means the flight must end as soon as it can be safely concluded — not necessarily an immediate emergency landing, but the operation cannot continue as planned. The PIC selects the safest course consistent with the condition.

Interaction with the MEL (§ 91.213): If the aircraft has an approved Minimum Equipment List, certain equipment may be inoperative under the conditions specified in the MEL and the aircraft remains airworthy. Without an MEL, § 91.213(d) provides a kinds-of-operations equipment list framework for small piston aircraft. Either way, § 91.7 still applies — the PIC must determine airworthiness.

Reference: AC 43-9 (Maintenance Records) and FAA-H-8083-30 (AMT General Handbook) Chapter 12 cover the airworthiness framework. The FAA Chief Counsel's 2009 "Coleal" letter is a foundational interpretation on what "airworthy" means and how § 91.7 applies in enforcement.