FAR 117 FDP Calculator
Maximum flight duty period and flight time under 14 CFR Part 117 Tables A & B — from report time and segments, computed exactly.
14 CFR 117 Tables A & B: max FDP depends on scheduled report time (acclimated) and number of flight segments; max flight time on report time. Unaugmented, acclimated values shown.
Tables A & B of 14 CFR 117 — acclimated, unaugmented crew. Augmentation, split duty, unforeseen-circumstances extensions and non-acclimated reductions (−30 min) modify these; the regulation and your ops manual govern.
With your numbers: Reporting at 700 for 3 segments: Table B allows a 13-hour FDP and Table A caps flight time at 9 hours (acclimated, unaugmented).
⚠️ Not for operational decisions. This is a record-keeping and planning aid only — not certified avionics, not a source of regulatory truth. Always verify against official sources (FAA) and your operator's approved documents before flying.
Free FAR 117 FDP calculator implementing Tables A and B exactly: report time and segments in, maximum flight duty period and flight time out — the lookup every 121 pilot does before every trip.
About FAR 117 FDP Calculator
Part 117 replaced one-size duty rules with fatigue science in table form: your maximum flight duty period depends on WHEN you report (circadian low reports get shorter FDPs) and HOW MANY segments you fly (each landing adds workload), while maximum flight time runs on report time alone. This calculator implements Tables A and B exactly as published for acclimated, unaugmented operations — the baseline every line pilot checks trips against. Worth keeping straight: FDP starts at report and ends at the last block-in (not duty end), flight time is block time, and the layers on top — augmentation (Table C), split duty rest, the 30-minute reduction when non-acclimated, and the commander's unforeseen-circumstances extension authority — modify the baseline per the rule's own terms. Crew schedulers compute this constantly; pilots verifying their own legality is exactly what the rule's joint-responsibility design expects.
How to use FAR 117 FDP Calculator
- 1Enter scheduled report time as local HHMM (e.g. 0645 → 645).
- 2Set the day's flight segments.
- 3Read max FDP and flight time; apply augmentation/acclimation modifiers per the rule.
Why use FAR 117 FDP Calculator?
- ✓Tables A & B implemented exactly as published
- ✓Report-time sensitivity: see WHY the 0500 show is a shorter day
- ✓Segment count handling — the workload variable pilots forget
- ✓Clear scope: acclimated/unaugmented baseline, modifiers flagged
- ✓Instant, free, browser-only
Frequently asked questions
What's the difference between FDP and flight time limits?+
FDP (Table B) runs from report time until the final flight's block-in — it bounds the whole working window including turns and ground time. Flight time (Table A) counts only block time — 9 hours for reports between 0500-1959, 8 otherwise. Both bind independently: a five-segment day can hit the FDP wall with flight-time margin remaining, and a two-segment transcon can do the opposite. Schedulers build to both; pilots verify both.
When can an FDP be extended past Table B?+
Two paths: scheduled extensions agreed before the day (up to 2 hours with specific consent and reporting structures, per 117.19's framework), and unforeseen circumstances after report — where the PIC and certificate holder share extension authority up to 2 hours (more for augmented), with mandatory FAA reporting past 30 minutes. The design point: extensions are exceptional, documented and bounded, not scheduling tools. Cumulative limits (117.23) still apply over everything.
What does 'acclimated' mean and what changes when you're not?+
Acclimated means your body clock is established in a theatre — initially home base, re-established after 72 hours in a new one (or 36 hours free of duty there). Non-acclimated crews get Table B's value MINUS 30 minutes, computed against the theatre where the FDP begins. It matters most on international patterns: the same 0800 report yields different legal days depending on your acclimation state, which is why the rule made it explicit instead of leaving it to fatigue.
Where is this data stored?+
Everything you enter is saved in your browser's local storage on your own device — nothing is uploaded to any server. Your records stay completely private, work offline, and load instantly. Use the CSV export regularly to keep an off-device backup copy.
Can I export these records for an audit?+
Yes — one click exports your complete duty computation as a CSV file that opens in Excel, Google Sheets or Numbers. The export preserves every column exactly as entered, so you can print it, attach it to paperwork, or hand it to an inspector, buyer or insurance underwriter as a supporting summary alongside your official records.
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