Applicability

This regulation defines who must follow Part 117's flight and duty time limits. It primarily applies to flightcrew members and airlines operating passenger flights under Part 121 (scheduled airlines and commercial operators).

Part 117 covers you when:

• Flying passenger operations for a Part 121 certificate holder
• Operating under Part 91 (general aviation rules) on behalf of a Part 121 carrier, if any portion involves domestic, flag, or supplemental passenger operations
• Part 91 subpart K (fractional ownership) operations are specifically excluded

The key practical point: if you're a pilot flying passengers for an airline, Part 117's rest and duty limits apply to you, even if the specific flight operates under Part 91 rules. This ensures consistent fatigue management across airline operations.

Airlines may alternatively choose to conduct certain Part 121 operations under the older rest rules in sections 121.470, 121.480, or 121.500 instead of Part 117.

*This is a plain-English summary for study only. The official 14 CFR text on this page is controlling — always read the current regulation and consult a CFI.*