Duty Time

Duty time (or flight duty period) is the period during which a flight crew member is required by an operator to be on duty for any purpose, including flight time, ground duties, positioning flights, administrative tasks, and standby at the airport. Duty time limitations are strictly regulated to manage fatigue and ensure flight safety.

Regulations vary by authority but typically include:

• Maximum daily duty period: Usually 10-14 hours depending on start time, number of sectors, and time zone crossings
• Maximum flight time: 8-10 hours per duty period for two-pilot crews; extended with augmented crews
• Minimum rest period: Typically 10-12 hours between duty periods, including an opportunity for 8 hours of uninterrupted sleep
• Weekly/monthly/annual limits: Cumulative caps on total flight hours and duty hours

The FAA (14 CFR Part 117) and EASA (ORO.FTL) have different specific rules, but both are based on fatigue science research. Airlines must also have a Fatigue Risk Management System (FRMS) to identify and mitigate fatigue-related risks beyond what prescriptive rules cover.