The Federal Regulation That Decides When a Pilot Is Allowed to Be Tired

At 10:17 p.m. on February 12, 2009, Colgan Air Flight 3407 crashed into a house in Clarence Center, New York, on approach to Buffalo, killing all 49 people aboard and one person on the ground. Captain Marvin Renslow had commuted overnight from Florida and slept in the crew room at Newark before the flight. First Officer Rebecca Shaw had flown in on a red-eye cargo jump seat from Seattle, arriving with barely enough time to report for duty. Neither had gotten anything close to a full night’s sleep. The National Transportation Safety Board’s formal probable-cause finding centered on the captain’s response to a stall warning, not on fatigue directly, but the board’s investigation examined crew fatigue at length and issued safety recommendations on it, and the crash became the case that finally moved a rule that had been stalled for decades: the FAA’s flight-and-duty regulations for airline pilots hadn’t been meaningfully rewritten since the 1980s.

Congress passed the Airline Safety and Federal Aviation Administration Extension Act in 2010, directing the FAA to overhaul crew rest rules. The agency published the new regulation, 14 CFR Part 117, in January 2012, and airlines had until January 4, 2014 to comply. Part 117 is worth taking apart in detail, because it’s a rare thing: an entire industry’s wake-reliability problem solved not by asking individuals to be more disciplined, but by writing the discipline into federal law and making the airline, not the pilot, liable for violating it.

What Part 117 actually mandates

The rule has three parts that work together, and it’s worth being precise about each one, because civilian sleep advice tends to collapse them into one vague idea (“get enough rest”).

Minimum rest

Before a flight duty period, a pilot must be given at least 10 consecutive hours off duty, and that period must include an uninterrupted 8-hour sleep opportunity: not 8 hours of rest generally, but 8 hours in which sleep is actually possible, factoring in travel to the hotel, meals, and other physiological needs. If a pilot calculates that the 8-hour opportunity won’t materialize, they’re required to tell the airline before the duty period starts, and the airline is barred from assigning them to fly until a compliant rest period is provided. This isn’t advisory language. It’s an enforceable floor with the burden of proof on the operator.

Duty-period limits that shrink with the clock

This is the part of Part 117 most people have never heard of, and it’s the most interesting piece of engineering in the rule. The maximum flight duty period, meaning how long a pilot can legally be on duty and not just flying, isn’t a single number. It’s a table (Table B in the regulation) cross-referenced by two variables: the pilot’s scheduled start time, in time acclimated to their body clock, and how many flight segments they’re flying that day. A pilot starting a duty period at 7 a.m. with one or two legs can be on duty up to 14 hours. A pilot starting at 3 a.m. is capped at 9 hours, full stop, regardless of segment count. The logic: circadian alertness is worst in the pre-dawn hours, so the rule doesn’t let an airline schedule someone into that window and then also work them the longest possible day. The allowed workload contracts exactly where physiological risk expands.

Cumulative, rolling limits

A pilot can’t bank compliant single days and still accumulate a fatigue debt across a week or a month, because Part 117 also caps flight-duty hours across rolling windows: 60 duty hours in any 168 consecutive hours (a rolling 7 days), 190 in any 672 consecutive hours (a rolling 28 days), on top of flight-time caps of 100 hours per 28 days and 1,000 hours per year. There’s also a standalone weekly floor, at least 30 consecutive hours free of all duty within any 168-hour window, that exists independent of the daily rest rule, precisely so an airline can’t chain legally-compliant short rest periods back-to-back indefinitely.

Combined, these three parts mean an airline can’t game any single one of them without tripping another. A short daily rest period is legal, but only a limited number of times before the weekly and 28-day caps intervene.

Reserve duty doesn’t get a carve-out

Airlines need pilots on call, reserve crew who might not fly at all today but have to be ready to. It would be easy to treat reserve time as an exception: since the pilot might not fly, why apply the same limits? Part 117 doesn’t allow that gap. The moment a reserve pilot is actually assigned a flight, that assignment becomes a flight duty period subject to the same cumulative limits as any scheduled one, and the same 30-consecutive-hour weekly rest requirement applies to reserve pilots as to lined pilots. The rule treats “might be called” as a real cost against the fatigue budget, not a free option for the airline.

The part regulators trust least: self-report

Here’s the piece of Part 117, and its EU counterpart, that has no direct equivalent in most consumer discipline advice: a pilot who believes they won’t be adequately rested is required to say so, and saying so is explicitly not punishable. It sits alongside a broader fatigue-reporting provision that lets a crew member declare themselves unfit to fly due to fatigue, even on a schedule that is, on paper, fully compliant with the rule. The regulation’s authors clearly didn’t trust the hour tables alone to catch every case, so they built in a release valve that depends on the one person with direct information nobody else has: the pilot, in that particular body, on that particular morning.

A side note, since it cuts against how self-report is usually treated in accountability writing: self-reported compliance is normally the weakest possible signal, because a person motivated to look compliant will just claim they’re fine. Aviation’s fatigue self-report works because the incentives run the opposite direction. A pilot who calls in fatigued loses nothing, and a pilot who doesn’t and gets caught loses their certificate, so the honest report is also the cheap one. DontSnooze’s video-proof mechanic exists for the far more common case, where the incentives point the other way and “I’m up” needs to be checked rather than trusted.

When the table isn’t built for the route: FRMS

Table B assumes a normal two- or three-pilot cockpit on a domestic-length day. It wasn’t built for a 16-hour polar route with a relief crew sleeping in a bunk mid-flight, and airlines that fly those routes can’t just ignore the table: they have to prove an equivalent level of safety a different way. That’s what a Fatigue Risk Management System is: a data-driven alternative to the fixed hour limits, built from biomathematical fatigue models, incident data, and ongoing crew fatigue reports, submitted to the FAA (under Advisory Circular 120-103A) or EASA as an approved alternate method of compliance for a given operation. It’s the rule acknowledging its own table has edges, and requiring evidence instead of a waiver whenever an airline wants to operate past them.

Where the rule stops: the cargo carve-out

Part 117 is not universal, and the gap is instructive. When the FAA finalized the rule, all-cargo Part 121 carriers (FedEx, UPS, Atlas, and others) were excluded from the new rest requirements after industry lobbying, and they still operate under the older, less protective flight-and-duty rules that predate the Colgan Air reforms. Cargo pilots fly overnight far more often than passenger crews, which is precisely the window where the new rule’s protections would matter most. UPS pilots have been pushing to close the carve-out for years, citing the 2013 crash of UPS Flight 1354 near Birmingham, where the NTSB cited fatigue from circadian disruption among the contributing factors. A regulation is only as good as its scope, and Part 117’s scope has a hole in it that the people it doesn’t cover have been trying to get fixed for over a decade.

How the EU does the same problem differently

EASA’s version of this rule, Subpart FTL of the EU’s air operations regulation, solves the same problem by anchoring rest differently. Instead of a flat 10-hour rest floor, EASA pegs minimum rest to the length of the preceding duty period: rest must be at least as long as the duty that came before it, or 12 hours at home base and 10 hours away (with an 8-hour sleep opportunity), whichever is greater. Duty-time caps are similar in shape to the FAA’s (60 hours in 7 days, 110 in 14, 190 in 28), and flight time is capped at 900 hours a year rather than 1,000. The FAA’s fixed floor is simpler to check and enforce. EASA’s duty-proportional floor is harder to compute but responds better to an unusually long day. Neither is obviously superior; they’re two different answers to the same underlying question, which is whether a rest rule should be a constant or a function of what came before it.

What any of this teaches, apart from the numbers

None of the four hour figures above will transfer to a civilian’s life directly, since nobody’s employer is bound by Table B. But the underlying logic of the rule holds up as a template even stripped of the aviation numbers:

A rest floor that doesn’t bend to how busy the schedule looks is different in kind from “try to get more sleep.” Part 117 doesn’t ask airlines to prioritize rest; it makes insufficient rest illegal to schedule around, which removes the discretion entirely. The airline doesn’t get an opinion on whether 10 hours felt necessary that week. The equivalent move for a person isn’t a reminder app; it’s a rule you’ve made non-negotiable to yourself in advance, the way shift workers who don’t get to choose their hours still hold a fixed anchor wake time regardless of how the previous day went.

Allowed workload should shrink exactly where risk rises, not stay flat. Table B doesn’t treat every hour of the day as equally fair game for a long duty day; it deliberately restricts the pre-dawn window, because that’s where the body is worst equipped to compensate. Most personal schedules do the opposite: people protect their calendars during the day and let the first and last hours of it, the exact hours most vulnerable to being skipped or dragged out, go unprotected.

And a no-penalty way to flag your own unreliability, used before the failure rather than to explain it afterward, changes what people actually report. Part 117’s fatigue clause only works because reporting early costs the pilot nothing and staying silent risks everything. Compare that to how most people handle noticing, at 11 p.m., that tomorrow’s wake-up is already compromised: there’s rarely a way to say so in advance, only to apologize after the fact. Firefighters managing decades of forced middle-of-the-night waking develop something like this informally, station by station; airlines had to write it into federal law because a few thousand independent, informal versions weren’t consistent enough to bet fifty lives on.

The 10-hour number itself binds nobody outside a cockpit. What actually transfers is the decision underneath it: an entire industry concluded that wake-reliability was too important to leave to any individual’s judgment on a bad night, so it built a rule where the judgment call happens in daylight, on paper, before anyone’s tired. Aviation isn’t the only place that decision got engineered into a system instead of left to a person — nuclear control rooms, air traffic towers, ICUs, offshore rigs, and cargo ships each solved a version of the same problem through five mechanically different fixes, none of which look anything like Part 117 on paper despite starting from the same worry. College rowing solved a milder version informally, without a regulator involved — a coxswain’s account of why a boathouse runs on 4:45 AM wake-ups shows a team enforcing the same discipline through peer pressure and an empty seat instead of a duty-time rule.