part 117 calculator: Max FDP & Rest Requirements

Part 117 Flight Duty Period Calculator

An essential tool for pilots to calculate maximum Flight Duty Period (FDP) and rest requirements according to FAA FAR Part 117 regulations.

FAA Part 117 Calculator

Scheduled Report Time (Local)

Enter the local time you are scheduled to report for duty. This is the primary factor for Table B limits.

Number of Flight Segments

Enter the total number of flights you are scheduled to operate during this duty period.

Acclimation Status

Select if you have been in the theater for 72+ hours or had 36+ consecutive hours free from duty.

Cumulative FDP in last 168 hours

Total flight duty period hours in the last 7 days. Limit is 60 hours.

Cumulative Flight Time in last 672 hours

Total flight (block) time in the last 28 days. Limit is 100 hours.

Maximum Allowable Flight Duty Period

–:–

Minimum Rest Required

10:00

Latest on Blocks Time

–:–

Duty Ends By

–:–

This part 117 calculator determines the maximum FDP based on FAA Part 117, Table B, which cross-references report time with the number of flight segments. The result is adjusted for acclimation status. Cumulative limits are checked against your inputs.

Visualizing Part 117 Limits

Cumulative Limits Overview

Comparison of your current cumulative hours versus the maximums allowed by the part 117 calculator.

FAA Part 117 – Table B (Unaugmented Operations)

Report Time (Local)	1-4 Segments	5 Segments	6 Segments	7+ Segments
00:00-04:59	9.0	9.0	9.0	9.0
05:00-05:59	11.0	10.5	10.0	9.0
06:00-06:59	12.0	11.5	11.0	10.0
07:00-11:59	13.0	12.5	12.0	11.0
12:00-16:59	12.0	11.5	11.0	10.0
17:00-21:59	11.0	10.5	10.0	9.0
22:00-23:59	9.0	9.0	9.0	9.0

Table B outlines the default maximum Flight Duty Period for unaugmented crews, which is a core component of this part 117 calculator.

What is a part 117 calculator?

A part 117 calculator is a specialized digital tool designed for pilots and airline schedulers to determine maximum legal flight duty periods (FDP), minimum rest requirements, and cumulative flight time limits as mandated by the Federal Aviation Administration (FAA) under 14 CFR Part 117. These regulations are designed to mitigate pilot fatigue, a known risk factor in aviation safety. The primary purpose of a part 117 calculator is to simplify the complex rules and tables within the regulation, providing quick and accurate answers to ensure compliance.

Pilots of all experience levels, from regional commuters to international long-haul captains, should use a part 117 calculator. It is also an indispensable resource for crew scheduling departments within airlines. A common misconception is that these rules are simple suggestions; in reality, they are strict legal limits, and violating them can result in significant penalties for both the pilot and the airline. This makes a reliable part 117 calculator a critical tool for daily operations.

{primary_keyword} Formula and Mathematical Explanation

The core logic of a part 117 calculator for unaugmented operations is based on FAA Part 117’s Table B. The calculation is a multi-step process that involves looking up a base value and then applying adjustments.

Determine Base FDP: The calculator first identifies the maximum FDP from Table B by cross-referencing the pilot’s scheduled report time (local) with the number of scheduled flight segments.
Apply Acclimation Adjustment: If a pilot is not “acclimated” (i.e., has not been in the theater for 72 hours or had 36 hours of rest), the maximum FDP derived from Table B is reduced by 30 minutes.
Check Cumulative Limits: The calculator then checks the user’s inputted cumulative flight duty hours and flight time hours against the regulatory maximums. An alert is shown if the current duty would exceed these limits.

Variables Table

Variable	Meaning	Unit	Typical Range
Scheduled Report Time	The local time a crewmember is required to report for duty.	HH:MM	00:00 – 23:59
Number of Segments	The number of individual flights in a duty period.	Integer	1 – 8+
Acclimation Status	Whether the crewmember is physiologically adapted to the current time zone.	Boolean	Yes / No
Max FDP	Maximum allowable Flight Duty Period.	Hours	9.0 – 13.0
Cumulative FDP (168h)	Total FDP hours in the preceding 7 days.	Hours	0 – 60
Cumulative Flight Time (672h)	Total block-to-block flight hours in the preceding 28 days.	Hours	0 – 100

Practical Examples (Real-World Use Cases)

Example 1: Early Morning Departure

Inputs: Report Time: 05:30, Segments: 4, Acclimated: Yes, Cumulative FDP (168h): 25, Cumulative Flight Time (672h): 50.
Calculation: The part 117 calculator looks at the 05:00-05:59 time block for 4 segments, which gives a base FDP of 11.0 hours. No acclimation penalty applies. Cumulative limits are well within range.
Outputs: Max FDP: 11.0 hours. Latest on Blocks: 16:30. Minimum Rest: 10 hours.

Example 2: Not Acclimated Evening Duty

Inputs: Report Time: 18:00, Segments: 2, Acclimated: No, Cumulative FDP (168h): 45, Cumulative Flight Time (672h): 85.
Calculation: The calculator finds the 17:00-21:59 block for 2 segments, yielding 11.0 hours. A 30-minute (0.5 hour) penalty is applied for not being acclimated.
Outputs: Max FDP: 10.5 hours. Latest on Blocks: 04:30 (next day). Minimum Rest: 10 hours.

How to Use This {primary_keyword} Calculator

Using this part 117 calculator is a straightforward process designed for efficiency.

Enter Report Time: Select your scheduled report time from the dropdown. This is the most crucial input for the calculation.
Input Flight Segments: Enter the number of flights you will be operating.
Set Acclimation Status: Choose ‘Yes’ or ‘No’ based on your recent duty and rest history.
Update Cumulative Hours: Enter your total FDP and flight hours for the rolling 168-hour and 672-hour periods, respectively. This allows the part 117 calculator to check for potential violations.
Review Results: The calculator instantly updates the ‘Maximum Allowable FDP’ and other key metrics. The ‘Latest on Blocks’ time tells you the absolute latest you can finish your final flight segment.

Key Factors That Affect {primary_keyword} Results

Time of Day: The primary driver of FDP limits. Duties infringing on the Window of Circadian Low (WOCL, 02:00-05:59) have significantly lower limits.
Number of Segments: More takeoffs and landings are considered more fatiguing, so FDP limits generally decrease as segments increase.
Acclimation: As shown in the calculator, being unacclimated imposes a 30-minute FDP penalty, a direct acknowledgment of the physiological stress of crossing time zones.
Split Duty: While not in this specific tool, using a split duty rest period can sometimes extend the FDP, but it comes with its own complex set of rules under §117.15.
Augmented Crew: Operations with additional pilots (3 or 4-pilot crews) have different, more generous FDP limits based on Table C, as in-flight rest is possible.
Cumulative Duty: Exceeding the 60-hour FDP in 168 hours or 190 hours in 672 hours is prohibited. This part 117 calculator helps you track this.

Frequently Asked Questions (FAQ)

What is the difference between Flight Duty Period (FDP) and Flight Time?: FDP starts when you report for duty and ends at block-in of the final flight. Flight Time (or block time) is the time from when the aircraft first moves for takeoff until it comes to a final stop at the gate. FDP is always longer than flight time.
Does deadhead transportation count towards my FDP?: Yes, time spent on deadhead transportation before a flight segment counts as part of your FDP. However, deadheading after your final flight segment does not.
What if I exceed the FDP calculated by the part 117 calculator due to unforeseen delays?: Part 117 allows for FDP extensions of up to 2 hours for unforeseen circumstances (e.g., weather, ATC delays) that occur after takeoff, with the consent of the pilot-in-command.
How often must I have a 30-hour rest period?: You must be given at least 30 consecutive hours free from all duty within the past 168 consecutive hours (7 days).
Does this part 117 calculator work for augmented crews?: No, this specific calculator is based on Table B for unaugmented (2-pilot) operations. Augmented crew limits are found in Table C of Part 117.
What is the minimum rest required before any duty?: You must have at least 10 consecutive hours of rest immediately before a flight duty period, which must include an opportunity for 8 hours of uninterrupted sleep.
Is this part 117 calculator an official FAA tool?: No, this is a guidance tool based on the regulations. Always refer to official company materials and the full text of 14 CFR Part 117 for final authority.
What are the cumulative flight time limits?: You cannot exceed 100 flight hours in any 672 consecutive hours or 1,000 flight hours in any 365-day period. This part 117 calculator helps monitor the 672-hour limit.

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