A crew member may report for duty within every applicable flight-time limitation and still arrive at base materially impaired by the journey taken to get there. The risk is easy to miss because commuting is usually treated as the individual’s private arrangement, outside the operator’s duty-time calculation. That distinction may be legally correct without being operationally sufficient. A long drive after a late arrival, an early-morning drive before report, or repeated travel between a remote home and the main base can reduce sleep opportunity and degrade attention before the first task begins. The issue is not the address itself; it is the interaction between travel, sleep, reporting time, route demand and the safety-critical work that follows.
Separate the FTL question from the fatigue question
Under EASA Part-ORO, including ORO.FTL where it applies, the operator must organise flight operations within the approved flight-time limitation scheme and manage fatigue as part of its operational controls. A crew member’s ordinary journey to or from work is not automatically converted into flight duty time merely because it is long. That does not prevent the journey from being a fatigue hazard under the operator’s approved safety management system.
This is the distinction that is often blurred during investigations. The question for FTL compliance is whether the rostered duty, rest and reporting arrangements comply with the applicable scheme. The question for SMS and fatigue risk management is whether the complete operating context creates a foreseeable reduction in alertness, including a demanding commute that the operator knows, or should reasonably know, is associated with a particular pattern of duties. Treating the second question as answered by the first leaves a gap in the risk assessment.
ICAO Annex 19 and the operator’s SMS framework require hazards to be identified, risks assessed and controls monitored. For operators under an authority’s national equivalent, the same principle normally appears in the approved management system requirements, although the detailed expectations vary. The operator should therefore be able to show not that it has prohibited long commutes, but that it has considered them, identified relevant exposure and defined what happens when the risk is not acceptable.
Use evidence about driving fatigue, not assumptions about mileage
Distance is a poor standalone proxy. Two crew members may live the same number of kilometres from base but face different fatigue exposure: one may use a motorway in daylight, while the other drives a congested route at 04:30 after restricted sleep. Scientific literature on driver fatigue, including simulator studies, on-road research and road-collision epidemiology, consistently associates sleep restriction, prolonged driving, circadian low points and monotonous conditions with poorer vigilance, slower responses and an increased tendency to lose concentration. The relevant hazard is often driving while sleepy, not simply driving for a long time.
Research resources used in fatigue work can help an operator structure this assessment. Peer-reviewed work in sleep and transport-safety journals, road-safety evidence reviews and validated subjective measures such as the Karolinska Sleepiness Scale provide a more defensible basis than an informal statement that a commute is “manageable”. These sources do not produce a universal safe distance for aviation staff. They support a risk assessment that asks how much sleep is likely to be obtained, when the journey occurs, how long it lasts, whether the route is monotonous or demanding, and whether the crew member must drive again after a late duty.
The operator should gather this information without turning the process into a surveillance exercise. A confidential fatigue survey can ask for typical one-way travel time, transport mode, departure and arrival windows, frequency of early or late duties, access to accommodation near base, and whether the person has ever curtailed a duty or reported unfit because of the journey. Rostering data can then be compared with reported fatigue, sick leave, fatigue reports, delayed starts and operational events. The purpose is to identify patterns, not to penalise people for living far from the airport.
Make the control measurable and auditable
Responsibility must be assigned at several levels. The accountable manager provides the resources and accepts the residual risk. The safety manager owns the hazard assessment and ensures that commute-related fatigue is integrated into the SMS rather than left in a separate welfare file. The flight operations or crew planning function tests proposed rosters against known exposure. Crew members remain responsible for presenting themselves fit for duty and for reporting fatigue or stopping a journey when they cannot safely continue. These responsibilities should be stated in the relevant manuals and training, not inferred from a general fitness-for-duty clause.
A practical assessment begins with a defined trigger. Examples include a report time during the biological night, a planned duty ending after a late arrival, a repeated sequence of early starts, a known one-way drive of several hours, or a crew member who must drive after positioning. The trigger should lead to a documented review, not an automatic conclusion that the roster is unsafe. Controls may include local accommodation, positioning the night before, adjusted reporting arrangements where operationally possible, a different duty sequence, transport, or a requirement to declare unfit without disciplinary pressure when safe travel cannot be assured.
Each control needs an owner and an effectiveness check. If accommodation is offered, record whether it was accepted, available and used for the relevant duty. If a roster change is made, retain the original and revised versions with the reason for the change. If a crew member reports fatigue, preserve the report, the assessment, the immediate decision, and any follow-up action. Personal details should be limited to what is necessary and handled under the operator’s data-protection arrangements. An inspector is more likely to ask for this chain of evidence than for a policy sentence saying that fatigue is taken seriously.
Software can operationalise the process by bringing roster times, declared travel information, fatigue reports, risk controls and review actions into one controlled record. It should not replace the safety judgement. A system may flag an early report following a late finish, but the nominated post holder still needs to confirm the applicable FTL position, consider the commute exposure and document why the chosen control is proportionate.
The assessment should also be reviewed after changes. A new main base, relocation of an operating crew, changes to public transport, seasonal traffic, or a revised roster pattern can alter the exposure without changing any published FTL limit. Trend reviews should look for repeated fatigue reports associated with particular report windows or routes, and for controls that are routinely offered but not practical. If the risk remains high, the correct response is to change the operating arrangement, not to redefine the commute as an individual failing.
The defensible position is therefore neither that commuting is always the operator’s responsibility nor that it is always irrelevant. Keep the legal FTL calculation clear, assess the driving and sleep risk separately within the SMS, and connect the assessment to real rosters and real decisions. Record the assumptions, the evidence, the person who accepted the risk and the result of the control. That is how a hidden exposure becomes a managed one.