Flight time limitations: Pilots serving in more than one kind of flight crew

This regulation determines which flight time limitations apply when a pilot serves in different crew configurations within the same 30-day period (for example, switching between two-pilot crews and three-pilot crews).

The key factor is how much time you fly in two-pilot operations during those 30 days:

• More than 20 hours in two-pilot crews (or frequently switching between two-pilot and larger crews): You follow the standard two-pilot crew limits in §§121.503-121.509

• More than 20 hours in augmented crews (two pilots plus additional flight crewmember, or frequently switching to three-pilot crews): You follow §121.521 limits

• 20 hours or less in two-pilot crews within 30 days: You follow §121.523 limits

• Mixed assignments not covered above: Default to §121.523

This ensures pilots moving between different crew configurations have appropriate rest requirements based on their most demanding flying schedule.

*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.*