Confidential Human Factors
Incident Reporting Programme
The Charity
Aviation
Maritime
FC5347
Initial Report
Our company produces a great number of short-haul trips that necessitate a large shift in sleep patterns in a very short period of time, making it difficult to achieve sufficient rest. The trips inevitably involve reporting for an afternoon/evening duty on Day 1, followed by a clear Day 2, but with an extremely early report on Day 3. As an example (not from my personal roster), Day 1 could see a report time of 11:35am in the UK, and finishing after three sectors in a European night-stop destination at 10pm UK time, realistically not getting to bed at the hotel until around midnight. On Day 3, pick-up from the hotel is at 4.30am UK time (using the time to which oneās body clock is acclimatised), so realistically the alarm is going to go off at 3.45am. This day usually consists of three sectors again, as on Day 1. In order to achieve a proper nightās rest before this wake up on Day 3, I would usually try to go to bed at around 8pm on Day 2. However, given that my body clock has been set up to operate ālatesā, I find it incredibly difficult to switch to extreme āearliesā within the space of one day, and find Iām unable to get to sleep.
While I am aware of my responsibility to report unrested if I havenāt achieved sufficient rest, there isnāt a hard line between rested/unrested, and Iāve had to make a difficult judgement call on a number of occasions. I know that my performance has been negatively affected due to lack of sleep. I believe that while these trips are strictly legal as the minimum rest period is achieved, rosters should try to avoid transitions between early and late duties for this very reason. At our airline, trips constructed in this way are very common. I have five during this and next month. Additionally, our rostering system makes it very difficult to avoid these trips because they are very difficult to swap off (not least because they are so unpopular).
CAA Comment
The CAAās role in monitoring rosters is to ensure that roster patterns are legal and that any fatigue issues raised by the rostering practices are appropriately mitigated. Any systemic issues would be addressed with the operator concerned.
CHIRP Comment
The roster pattern described is similar to circumstances weāve seen before at CHIRP wherein an 18-30hr period between duties is troublesome because, although itās ālegalā and would appear on first sight to give plenty of time for rest, itās renown for being problematic due to the difficulty of fitting in 2 sleeps during the period. In the example given, if arriving at the destination and getting to bed at around midnight then that would imply a wake-up of around 8-10am or so on Day 2 depending on how tired the subject was. So itās not surprising that their body then finds it difficult to get to sleep again about 10-12hrs later as they prepare for Day 3ās wake-up. Having such duties rostered is sometimes unavoidable and is not ideal, but they should only be rostered occasionally rather than frequently rostering people for such duties. The rostering algorithms for dealing with fatiguing rosters differ from company to company but there should be a recognition that repeated rostering of such duties, although no doubt ālegalā, can be very debilitating. It may be that the other crew member in the cockpit might be on a different rostering cycle and can compensate for any lack of alertness on a one-off basis, but consecutive rosters with 18-30hr duty gaps will soon lead to chronic fatigue in those rostered in such a way.
We asked the company to comment on their policy for such 18-30hr duties on a one-off basis, and whether they had any processes in place to avoid repeated application to individualsā rosters so that cumulative effects could be avoided.Ā Unfortunately, we got no response, but the CAA have agreed to look into the concern as part of their oversight activities.
The CAA is also currently conducting a study into FTL/FDP assumptions in an effort to make them more coherent for UK purposes now that we are free from EASA oversight. One of the things they could usefully review within that is the frequency of people being rostered with 18-30hr periods so that more comprehensive guidance could be given to operators on how it is deployed, and how frequently.