Q&A

Plain-language answers to the questions pilots actually ask about the fatigue rules. Each one cites the CARs sections and Advisory Circular 700-047 it relies on.

• What does 'acclimatized' mean, and why does it change my maximum FDP? Acclimatized means your body clock is aligned with local time. If you're not acclimatized to where your FDP begins, you determine the FDP start time using the local time at the location where you're still acclimatized — which can change your maximum FDP.
• How do split flight duty periods work, and how much extra FDP does a break buy? A break of at least 60 consecutive minutes in suitable accommodation during an FDP can increase the maximum FDP under 700.28. To calculate the increase, subtract 45 minutes from the time spent in suitable accommodation, then credit 100% of the remaining time if the break is provided between 00:00 and 05:59 acclimatized time, or 50% if it is provided between 06:00 and 23:59.
• What counts as a disruptive schedule, and what extra rest does it need? When your hours of work switch between early duty and late or night duty, you need the normal 700.40 rest PLUS one local night's rest — unless you're more than four hours off the time zone you're acclimatized to.
• For an unforeseen operational circumstance, who has the authority to extend a flight duty period? The pilot-in-command. The operator may provide guidance, but the decision to extend or reduce an FDP because of an unforeseen operational circumstance rests with the PIC, after consulting all crew members on their level of fatigue.
• What is "continuous duty", and do the hours I sit at an outstation count as rest? "Continuous duty" isn't a CARs term — it's the pattern of reporting in the evening, waiting hours at an outstation, then flying back in the morning. The wait is flight duty period time, not rest. Only a qualifying split-duty break in suitable accommodation counts.
• I'm too fatigued for my assigned duty but could do a shorter one. What do the rules say? The CARs are silent on partial fitness — but AC 700-047 says it would be reasonable for the operator to reassign you to a duty you are fit for. What the CARs do require is that you tell the operator you're not fit for the assigned duty.