D8.2.4.1. The maximum daily FDP may be extended by up to 1 hour not more than twice in any 7 consecutive days. In that case: D8.2.4.1.1. The minimum pre-flight and post-flight rest periods shall be increased by 2 hours; or D8.2.4.1.2. The post-flight rest period shall be increased by 4 hours.

Explanation: To avoid abuse D8.2.4 sets limits on extensions of the maximum daily FDP. According to D8.2.4, the FDP may be extended by up to 1 hour, but no more than twice in any 7 consecutive days, ensuring that such extensions remain occasional and cannot be used routinely. When these extensions are applied, the minimum pre and post-flight rest periods must be increased either by adding 2 hours to both pre and post-flight rest, or by adding 4 hours to post-flight rest alone so that the crew has sufficient recovery, which prevents casual or habitual use. Additional operational constraints include limits on the maximum number of sectors flown and restrictions related to WOCL (window of circadian low) encroachment, which guarantee that FDP extensions are applied only under safe and controlled conditions. Furthermore, D8.2.4.4 specifies that these extensions cannot be combined with other FDP extensions, such as those due to in-flight rest or split duty, preventing stacking and ensuring that extended FDPs are not used to regularly increase duty periods. Finally, D8.2.4.5 requires that the Flight Time Specification Scheme (FTSS) define all applicable limits in advance, which prohibits spontaneous or daily use of FDP extensions and ensures that all planning is conducted within the operator’s regulatory framework.

D8.2.6.9.1. The operator shall establish procedures, in the operations manual, for delayed reporting in the event of unforeseen circumstances, in accordance with the certification specifications applicable to the type of operation.

Explanation: Reporting time is the official time when the crew is considered on duty and their FDP clock starts running. Delayed reporting applies when unforeseen circumstances occur before the duty has actually started. Instead of making the crew show up at the originally planned report time and then just wait (which would eat into their FDP), the operator can push the reporting time forward. This way the FDP clock starts later, preserving crew duty hours for the actual operation. e.g. Planned reporting time: 01:00 → FDP max = 11:00 hrs → ends at 12:00 local. Unforeseen delay: aircraft arrives late, not ready until 04:00. If crew reported at 01:00, they’d be sitting around burning FDP until 04:00. With delayed reporting: operator shifts report time to 03:30 → FDP now starts 03:30 → runs until 14:30 instead of 12:00. This clause requires operators to establish procedures to avoid abuse (e.g. constantly moving report times to stretch FDP) and to ensure fatigue risk management is applied (crew can’t be told last minute after already commuting, etc.).

D8.2.6.1.1. the maximum daily FDP which results after applying points D8.2, D8.2.6 or para D14 may not be increased by more than 2 hours unless the flight crew has been augmented, in which case the maximum flight duty period may be increased by not more than 3 hours.

Explanation: D8.2 gives normal baseline FDP while D14 gives max FDP in unforseen circumstances before crew reports for duty. Establish the max duty from D8.2 or D14 and then extend it by 2 or 3 hours as explained above in D8.2.6.1.1.

D8.2.6.3.1. The exercise of Pilot In Command (PIC)’s discretion shall be considered exceptional and should be avoided at home base and/or company hubs where standby or reserve crew members should be available.

D8.1.1. Operator shall establish procedures specifying how the PIC shall, in case of special circumstances which could lead to severe fatigue, and after consultation with the crew members concerned, reduce the actual FDP and/or increase the rest period in order to eliminate any detrimental effect on flight safety.