Why Interviewers Probe FAR 117 Knowledge
FAR 117 replaced the old Part 121 rest rules in 2014, and it remains one of the most tested regulatory areas in airline interviews. Chief pilots want to know you can apply fatigue rules in real-world scenarios — not just recite numbers. Expect scenario-based questions, not pure memorization.
The regulation applies to all Part 121 passenger operations. Understanding the distinction between flight time, flight duty period (FDP), and rest period is foundational. Interviewers at legacy carriers and regionals alike use FAR 117 questions to screen for CRM judgment and fatigue awareness, not just compliance.
Core Concepts You Must Own
Flight Duty Period vs. Flight Time
The FDP begins when you report for duty and ends when aircraft engines are shut down after the final flight. Flight time runs engine start to engine shutdown for each leg. Know both because the limits are separate and both can be the constraining factor on any given pairing.
Cumulative Limits
- 100 flight hours in any 672 consecutive hours (28 days)
- 1,000 flight hours in any 365 consecutive calendar days
- 60 flight hours in any 168 consecutive hours (7 days)
Interviewers often frame these as "you're on day 6 of a 7-day pairing" scenarios. Know which limit is likely to be the binding constraint and how to check it.
Minimum Rest and Table B
The baseline pre-duty rest is 10 consecutive hours, of which the carrier must provide an 8-hour sleep opportunity. FDP maximums come from Table B, which cross-references your scheduled report time (local) and number of flight segments. If your report time falls within the Window of Circadian Low (WOCL, 0200–0559 local), your maximum FDP is reduced. If your rest location differs more than two time zones from your home domicile, you use that location's local time for WOCL calculations — a detail that trips up many candidates.
"You report at 0400 local for a 3-leg day. What is your maximum FDP, and does the WOCL affect you?"
A strong answer walks through the logic: report time falls in the WOCL (0200–0559), so you reference the WOCL column in Table B. For 3 segments, the maximum FDP is 11.5 hours. Then acknowledge you'd also verify cumulative hours and any augmentation provisions.
Augmented Crew Operations
With a second qualified pilot, carriers can extend the FDP up to 13 hours if a rest facility meeting specific criteria is provided. 14 hours is available with two additional pilots. Know that the rest facility classification (Class 1, 2, or 3) affects the calculation — Class 1 is a flat bed, Class 3 is a seat. Interviewers at wide-body operators frequently probe this area.
High-Frequency Interview Questions
- What is the minimum rest requirement before beginning an FDP?
- A crew member declares fatigue before a turn. What are your responsibilities as captain?
- You're two time zones east of domicile. Which time zone governs your WOCL calculation?
- Can the airline or dispatcher extend your FDP beyond Table B limits? Under what authority?
- Explain the difference between a short-call reserve FDP start and a long-call reserve FDP start.
- How does a deadhead affect your FDP clock?
The fatigue declaration question is particularly revealing. The correct answer establishes that a pilot declaring fatigue cannot be pressured, the airline must remove them from the pairing, and there are whistleblower protections under 49 U.S.C. § 42121.
State the regulation, apply the numbers, then show judgment: "Under 117.5, my FDP started at report. With 4 segments and a 0600 report — outside the WOCL — Table B gives me 13 hours. We're currently at hour 11 with one leg remaining. We have margin, but I'd note cumulative hours and confirm the crew is fit for duty."
How to Prepare Effectively
Memorize Table B until it's automatic — print it and work through representative scenarios. Practice applying it with varying report times and segment counts until the WOCL question feels routine. Then layer in augmented ops, short-call reserve windows, and the deadhead provisions.
For carrier-specific nuances, review how individual airlines have implemented FAR 117 in their collective bargaining agreements and ops specs — some carriers have more restrictive contractual limits that take precedence over the regulatory floor.
Pilots preparing for interviews at United or Delta report FAR 117 appearing in both technical oral and CRM sections. Practicing answers aloud — working through the logic at interview pace — is where most candidates find gaps. The AI Voice Coach on Vectors to Hired scores your spoken answers on FAR 117 scenarios on a 1–5 rubric, with specific feedback on whether you're demonstrating regulatory command or just approximate knowledge. The platform's 12,800+ questions include recent gouge from pilots who've been through the chair in the last 90 days.
Know the regulation cold. Show the judgment behind it. That combination is what separates candidates in a technical oral.