Microsleeps on Approach: Fatigue Risk and Roster Pressure
A 38-year-old first officer on a short-haul jet reports two episodes of nodding off in the cruise and one microsleep during an approach briefing over the past month. He has had five consecutive early starts with 04:30 report times, 9-hour duty days, and eight landings per day. He sleeps 4–5 hours per night, has a 3-month-old infant, and uses about 400 mg of caffeine daily. He denies snoring, witnessed apneas, and restless legs. He is otherwise healthy and has no medication. His next roster has four more early starts. The safety manager asks whether he can finish the roster, what fatigue assessment is needed, and what mitigations are appropriate.
1. What is the immediate safety decision?
Read the worked answer
He should be removed from flying duty now and not finish the roster. A microsleep during an approach briefing is a red flag for severe sleepiness and impaired attention during a high-workload phase; cruise nodding off is also operationally significant. The decision should be made without punishment and under a just-culture framework so that fatigue reports are not suppressed. Arrange transport home and ensure he is not driving while dangerously sleepy. Notify the aeromedical examiner and the fatigue risk management program. The immediate question is not whether he “can push through” but whether he is safe for the next flight. A medical evaluation should occur before any return, and the roster should be covered by another crew member. The safety manager should also preserve relevant duty, sleep, and caffeine data for review, because the event may reflect both an individual medical issue and a systemic roster problem.
2. How should acute versus chronic fatigue and contributing causes be assessed?
Read the worked answer
Use a structured assessment rather than a single question about tiredness. Obtain a sleep and duty diary for at least two weeks, actigraphy if available, caffeine and alcohol timing, and a fatigue scale. Screen for obstructive sleep apnea with a validated tool plus questions about snoring, witnessed apneas, and morning headaches, even though he denies them. Assess circadian disruption from repeated 04:30 starts, cumulative sleep debt, recovery sleep, and whether the roster provides adequate rest. Screen for depression, anxiety, substance use, and medication effects. Review the previous month’s duty times and landings for a systemic pattern. The key reasoning is that this first officer has both acute sleep restriction and a chronic roster pattern, so removing one flight is not enough. If OSA or another medical cause is suspected, refer for objective testing before return; if the cause is primarily roster-driven, the fatigue risk management program must act.
3. What mitigations and program changes are appropriate?
Read the worked answer
Individual mitigations include protected sleep opportunity before duty, strategic caffeine use early rather than late, hydration, and sleep hygiene support for a parent of an infant. If he returns, consider a period of reduced early starts, no consecutive ultra-early reports, and no high-workload pairing until reviewed. In-flight controlled rest may be used only under approved procedures and with both crew members coordinating; it is not a substitute for pre-flight fitness. The operator should review the five-early-start pattern and the 9-hour duty with eight landings for fatigue risk, adjust rostering, and ensure adequate recovery between blocks. Fatigue training should include reporting pathways and the difference between acute sleepiness and chronic sleep debt. Medical follow-up should confirm resolution and screen for OSA. Program-level indicators such as fatigue reports and microsleep events should be audited. The final judgement is that this is both a personal fitness issue and a system warning.