There are no specific provisions and conditions for such changes except in unforeseen circumstances, where, on the day, a Commander may use the provisions of Commander’s Discretion:
- to continue with an FDP which exceeds the maximum FDP that the crew will operate or reduces the minimum rest period, or
- to reduce the actual FDP and/or increase the rest period, in case of unforeseen circumstances which could lead to severe fatigue.
The operator may not plan or change an FDP at any time such that it exceeds the maximum applicable FDP.
FTL rules build upon the predictability of rosters so that crews can plan and achieve adequate rest (ORO.FTL.110 (a) and (g)). Operators are expected to plan sufficient capacity, at their operating bases, to deal with disruptions normally expected in daily operations using the specific FTL provisions (e.g. stand-by, reserve). Therefore, FDP changes after reporting should be an infrequent event as such changes can create roster instability and may generate fatigue. An aircrew member remains at all times under the responsibilities set out in CAT.GEN.MPA.100 (c)(5) to report unfit to fly, if s/he suspects fatigue which may endanger flight safety.
If changes to planned duties are to be made on the day of operation, all applicable limits apply: in particular the limits established pursuant to ORO.FTL. 205(b), (d), (e) or ORO.FTL.220. If a duty has not been planned with an operator’s extension under ORO.FTL. 205(d), it cannot be changed into a duty with such extension on the day of operation.
In addition, the operator must ensure that the impact on forward duties and days off, and importantly on cumulative limits, is accounted for.
EASA recommends that changes made on the day of operation to duties and FDP’s are monitored through appropriate performance indicators that operators use to demonstrate they fulfil all the required elements within ORO.FTL.110. The 33% exceedance threshold on the max FDP as set out in ORO.FTL.110 (j) may not always be adequate to capture negative trends.
EASA also recommends that appropriate performance indicators for FDP changes after reporting be part of the operator’s approved IFTSS to ensure that any resulting fatigue hazards are properly identified and mitigated.