Rostering and Duty Periods

The CHIRP Comments below refer to a number of reports about rostering and duty periods.

In a similar manner to the reporting of absence management and use of discretion, reports that CHIRP receives about rostering and duty periods necessarily contain route and personal information that mean we are unable to approach companies directly about specifics due to the fact that reporters would be easily identifiable.  Our only recourse is to engage with companies where possible with aggregated information from a number of reports, and to ask the CAA for their perspective on a company’s operations. Post-COVID resourcing pressures have resulted in a number of changes to rostering practices wherein it is clear to CHIRP that some companies are approaching FTL maximums much more frequently than hitherto. CHIRP’s view on FTL maxima has consistently been that they should be approached only infrequently and in a managed manner – as with any system, running resources at the red line for prolonged periods is a sure way of increasing risks that should not be contemplated without considerable caution; the response of ‘it’s legal’ is not a mature way of managing fatigue and FTLs.

Although we cannot claim any specific successes ourselves in resolving these issues, CHIRP regularly engages with the CAA and they have conducted specific oversight activities based at least partially on our inputs in association with their own intelligence about what is going on. There have been changes made to some rostering practices as a result, but we continue to engage about other aspects of rostering that appear to be ‘legal’ in pure FTL terms but not sensible from a Human Factors perspective as far as we are concerned. Part of CHIRP’s concerns lie within the sometimes black-and-white outcomes and temptations to rely on the certitudes of ‘sleep science’. There has to be some structured and systematic basis for constructing rosters but, whereas concepts such as WOCL and circadian rhythms provide a good basis for understanding the background factors affecting sleep, we’re not yet convinced that ‘sleep science’ is robustly able to deal with the multiple idiosyncrasies of individual people, circumstances or route structures to predict specific outcomes.

Example comments received by CHIRP are:

“Pre-covid as a pilot I rarely felt the need to nap whilst at the controls. Now I feel it’s a necessity to do it on every night sector to minimise micro-napping and falling asleep at the controls at critical stages of flight.”

“No matter what studies these so proclaimed sleep specialists and scientists claim to have done and what monitoring devices they use in their studies, they have not done the job first hand. And if they have, it has not been for a prolonged period of months, or years. Yet airlines seem to think it’s ok to roster to the limits. There is a complete lack of understanding. They are called Flight Time Limitations. They are not called Flight Time Targets.”

“Fatiguing flight outbound. More time spent in the aircraft than resting down route. When I arrived at the hotel I needed to rest for a few hours as already exhausted. This then impacts quality of sleep before 5am body clock wakeup for return sector.”

“High levels of fatigue experienced in cruise needing attempts at multiple periods of controlled recovery rest. Too fatigued on landing to travel away from the airport without a proper full rest so booked hotel, at my own expense, as a self-imposed fatigue mitigation.”

“Fatigue is clearly an issue at [Airline], but the company discourage fatigue forms, penalise absence and crewing are clearly manipulating rest periods/duty times to make things legal. There is definitely a safety issue here. Last night I had to get the First Officer to fly both sectors because I was so drunk on tiredness.”

It’s vital that crews continue to submit fatigue reports when appropriate, even if they suspect they are not being sufficiently acted upon, so that actual data can be used to modify theoretical scientific assumptions. Thankfully, many companies are receptive to such reports as they evolve their rosters, and the development of associated fatigue risk management regimes hinges on an understanding gained from these about the stresses and rest opportunities pertaining to each duty and individual. Regulations for rostering/scheduling are many and complex, not least in respect of FTL requirements. Overarching requirements for operators to “…allocate duty patterns which avoid practices that cause a serious disruption of an established sleep/work pattern, such as alternating day/night duties” are stated within ORO.FTL.110(e) Operator responsibilities, whilst the associated AMC1 ORO.FTL.110 Operator responsibilities defines the underpinning scheduling requirements that state:


(a) Scheduling has an important impact on a crew member’s ability to sleep and to maintain a proper level of alertness. When developing a workable roster, the operator should strike a fair balance between the commercial needs and the capacity of individual crew members to work effectively. Rosters should be developed in such a way that they distribute the amount of work evenly among those that are involved.

(b) Schedules should allow for flights to be completed within the maximum permitted flight duty period and flight rosters should take into account the time needed for pre-flight duties, taxiing, the flight- and turnaround times. Other factors to be considered when planning duty periods should include:

(1) the allocation of work patterns which avoid undesirable practices such as alternating day/night duties, alternating eastward-westward or westward-eastward time zone transitions, positioning of crew members so that a serious disruption of established sleep/work patterns occurs;

(2) scheduling sufficient rest periods especially after long flights crossing many time zones; and

(3) preparation of duty rosters sufficiently in advance with planning of recurrent extended recovery rest periods and notification of the crew members well in advance to plan adequate pre-duty rest.

Alternating day/night duties, alternating eastward-westward or westward-eastward time zone transitions and the scheduling of sufficient rest periods especially after long flights crossing many time zones get specific mentions in ORO.FTL.110, but there are many more other factors that affect the quality of in-flight rest and the ability to sleep both down route and when home. Humans are not machines that can be turned off at the flick of a switch, the ability to fall asleep is something that varies from individual to individual, and even for a specific individual depending on the context of their duties, pressures and stresses, personal circumstances and activity profile in the hours immediately prior to attempting to fall asleep. In our discussions with the CAA, they have indicated that they also recognise the limitations of some of the current fatigue management regulations. Now that UK is no longer tied to EU requirements, and subject to resources being allocated, they have a medium-term aspiration to look again at the fatigue regulations inherited from EASA and to tailor the UK FTL//FRMS document set to reflect better our specific perspectives and circumstances.