Staying Sharp Under Pressure: What Fatigue Changes Before You Notice
Fatigue can affect performance before you recognize how much it has changed. Here is what the research shows, why your duty clock and your time awake are different clocks, and 4 moves to make before your next flight.
The United Aerial Firefighting Association conference runs October 27 through 29 in Boise, and I’m speaking there in a session called “Staying Sharp Under Pressure.” Preparing it meant reading what the research says about fatigue and performance. Most of that research comes from laboratories and ground crews, and every pilot who has flown on a short night can use it.
The Numbers That Started This
Aerial firefighting has gotten safer by one measure. A 2015 CDC report found the historical fatality rate fell from 8.0 per 100,000 Forest Service-reported flight hours in 2000 to 2006 to 4.7 in 2007 to 2013. That is deaths per flight hour, so it does not line up with accident-rate figures, and the Forest Service’s FY2023 safety summary adds a caution: “While the 30-year accident rate is still trending down, the 10-year rate is trending up.”
The CDC review counted 78 deaths in 41 fatal events. Loss of control, failure to maintain clearance, and weight and balance together account for 19 of the 41 events (46 percent) and 39 of the 78 deaths (50 percent); each category raises questions about aircraft control, clearance, configuration, and decisions made in demanding operations, but the review does not establish fatigue as a cause. The rest of this post is about how fatigue could change what a crew does on a day like the ones fire season produces: An early show, rising workload, and pressure to finish the job.
What Fatigue Changes First
A review of sleep research in wildland firefighters (Vincent et al., 2018) reports that in self-paced simulated wildfire work, 4 hours of sleep restriction did not adversely affect physical task performance compared with 8 hours. The restricted firefighters were less physically active, mostly through more passive rest breaks. Cognitive performance after 4 hours of sleep declined more than after 8 hours, and firefighters were unreliable at perceiving that decline.
Those were firefighters, not pilots, so what follows is an inference: A pilot can have steady hands and a flawed plan at the same time. A cognitive deficit could show up in a flight like this:
- Accepting an approach you would have rejected after a full night of sleep
- Skipping a briefing item because the briefing felt finished
- Pressing on past a trigger point you set on the ground
Why You Cannot Feel It Happening
Van Dongen and colleagues (2003) compared chronic sleep restriction with total sleep deprivation in 48 healthy adults aged 21 to 38. Restricting sleep to 6 or 4 hours a night for 14 days caused cumulative, dose-dependent declines in performance, and the losses from 6 hours or less per night were comparable to up to 2 nights of total sleep deprivation. Self-rated sleepiness rose sharply after the first restricted day and then changed little; it did not clearly separate the 6-hour group from the 4-hour group. The participants appeared largely unaware their deficits were growing.
Lapses in alertness rose almost linearly with time awake beyond about 15.84 hours, across every condition in the study. That is a statistical relationship in laboratory alertness testing, not an aviation fitness-to-fly rule.
How tired you feel is not a reading of how well you are performing.
You May Arrive Already Behind
In a study of Ontario wildland firefighters (McGillis et al., 2017, as summarized in the Vincent review), ground crews averaged 4.8 hours of sleep on initial attack days. They averaged 6.2 hours on both project fire days and base days. Morning reaction time was also reduced on initial attack days compared with base days. These are ground-crew figures; no study I found measured sleep in aerial firefighting pilots.
In one laboratory study (Belenky et al., 2003), volunteers limited to 5 or 7 hours in bed for 7 days settled at a reduced level of performance. After 3 recovery nights with 8 hours in bed, their response speed on a reaction-time test had not recovered.
Where the Clock Starts
Duty and flight-time limits depend on the rules that apply to your operation. Time awake is a separate consideration: It counts from the moment you wake up.
Take an alarm at 0430, a 0700 report, and a duty day that ends at 2100. You have been awake 16.5 hours at 2100, before the drive home, and you pass 17 hours at 2130. In Williamson and Feyer’s laboratory work (2000), after 17 to 19 hours awake, performance on some tests was equal to or worse than at a blood alcohol concentration of 0.05%. Individual results vary, and these were laboratory tests, not flight operations. Whether that duty day is legal depends on your operation and your regulations; the research above is about the other clock.
What a Pilot Can Do: 4 Moves
Write your wake time at the top of the flight plan, then the clock time you will hit 16 hours awake. Use that time as a prompt to review your plan, not as a safe-to-fly cutoff: Sleep obtained, time of day, workload, and your operation’s fatigue-management procedures all matter, and a flight that ends before hour 16 is not safe for that reason alone. If your planned landing is after that line, decide now, with a clear head, what you will change; short sleep, time of day, and workload can matter well before hour 16. Sixteen is drawn from laboratory data and is not a regulation, so adjust it to your own history.
Because feeling tired is unreliable, ask a crewmate, CFI, dispatcher, or friend to ask you 3 questions before departure: When did you wake up, how much did you sleep the last 3 nights, and what time do you land? The NTSB identified monitoring or challenging errors in 31 of the 37 accidents it reviewed (NTSB/SS-94/01). That finding concerns monitoring, not fatigue, and reinforces the value of an outside check: A second person does not depend on how you feel.
Treat fatigue, workload, and pressure as 3 loads on the same pilot; this is a working rule, not a research finding. When 2 are already high, change the third before you leave: Simplify the plan, add fuel or time, or delay.
“I’m at hour 16” is a usable sentence in an aircraft. It only works as good airmanship if the culture allows it, which makes it a question for chief pilots and flight school leaders, and it starts with someone senior saying it first.
If you use slow breathing to settle before a busy phase of flight, treat it as only that; it does not change how long you have been awake.
What the Evidence Cannot Tell Us Yet
As of this writing, I could not find a published study of mental health, burnout, or help-seeking in aerial firefighting pilots, a human-factors coding study of aerial firefighting accidents, or quantified data on fatigue as a contributing factor in those mishaps. The sleep findings above come from laboratory work and ground crews; they point to a risk without measuring it in pilots.
It takes 2 minutes and works for a lesson, a ferry flight, or a trip. Treat the 16-hour time as a prompt to review your plan, not as a safe-to-fly cutoff.
- Write your wake time at the top of your plan.
- Next to it, write the clock time you will have been awake 16 hours.
- If your planned landing falls after that time, decide before you start the engine what you will change: Swap a leg, add a stop, bring in a second pilot or CFI, or delay.
The research and historical figures discussed here are drawn from the sources below.
- Butler CR, O’Connor MB, Lincoln JM. Aviation-Related Wildland Firefighter Fatalities, United States, 2000 to 2013. MMWR 2015;64(29)
- USDA Forest Service. Annual Aviation Safety Summary, Fiscal Year 2023
- Vincent GE, et al. Sleep in wildland firefighters: What do we know and why does it matter? Int J Wildland Fire 2018;27(2)
- McGillis Z, et al. Sleep Quantity and Quality of Ontario Wildland Firefighters Across a Low-Hazard Fire Season. J Occup Environ Med 2017;59(12)
- Van Dongen HPA, et al. The cumulative cost of additional wakefulness. Sleep 2003;26(2)
- Belenky G, et al. Patterns of performance degradation and restoration during sleep restriction and subsequent recovery. J Sleep Res 2003;12
- Williamson AM, Feyer AM. Moderate sleep deprivation produces impairments in cognitive and motor performance equivalent to legally prescribed levels of alcohol intoxication. Occup Environ Med 2000;57(10)
- NTSB. A Review of Flightcrew-Involved, Major Accidents of U.S. Air Carriers, 1978 through 1990 (NTSB/SS-94/01)
- United Aerial Firefighting Association: 2026 Annual Conference
Coaching supports planning and decision-making under pressure; it is not treatment for sleep problems. If short nights persist despite good scheduling, that is a question for your clinician.
Start with the free, confidential Career Pilot Mental Fitness Check to see where you stand. If you want to work on it, 1:1 coaching covers stress, decision-making, and performance at any stage of your flying, not only before a checkride.
Take the Mental Fitness Check → Explore 1:1 Coaching →Early lessons and long teaching days stack up. Coaching for CFIs covers burnout, difficult student dynamics, and the pressure of building hours while teaching.
Book CFI Coaching →Workshops that give your pilots, students, and CFIs a shared, practical way to talk about performing under pressure.
See Workshops →- “I’ve Come This Far”: Why Turning Around Is the Hardest ManeuverMove 1 gives you a line to set on the ground; this post covers setting a turn-back trigger before you fly and acting on it under pressure.
- Three Go-Arounds and a Refused Diversion: Three Ways to Keep Making Decisions Under PressureHow stress narrows attention, and a way to keep making decisions when the plan stops working.
