How to enable Airline Mode for FAR 117 tracking

Airline Mode is the Part 121 path inside DaPilot. Toggling it on unlocks Flight Duty Period (FDP) entry, rest period logging, and a dashboard that shows your FAR 117 rolling windows updating as you log. This guide covers how to enable Airline Mode, what changes when you do, and what each tracked window means.

Why this matters

Part 121 pilots work under five rolling time limits and a series of FDP / rest constraints that compound across days. Tracking them by hand on a yellow legal pad in your kitbag works until it doesn't. Airline Mode shows you, at a glance, where each rolling window stands relative to its limit, with every value cited to the §117 paragraph it comes from.

DaPilot is an advisory tool. Your certificate holder's scheduling system is the system of record for duty assignments and what's required by 14 CFR. Airline Mode is a personal at-a-glance reference, not a replacement for that system.

What you need

DaPilot Pro. Airline Mode is a Pro feature.
About fifteen minutes to walk through the click-through and enter your most recent FDP and rest period for context.
A general familiarity with §117. If you've ever filled out an FRMS-related form or a duty trade form, you have enough.

Enable Airline Mode

1Open Settings → Airline Mode

The toggle lives under Settings → Pilot profile → Airline Mode. Tap to open.

2Read the click-through disclaimer

The first time you enable Airline Mode, DaPilot shows the full regulatory disclaimer in a modal. The text is the same as the one on the regulatory disclaimer page. Read it. Tap Accept.

Your acceptance is recorded server-side with a timestamp on your profile (airline_mode_accepted_at). If we materially change the calculation engine in a future release, the modal re-shows for a fresh acceptance.

3Enter your home base airport

DaPilot uses your home base for one specific calculation: the acclimation rule under §117.3. A pilot is acclimated to the local time at the home base unless they've been in a different time zone for at least 72 hours or have had a 36-hour rest in that zone (consult §117.3 for the precise definition).

Enter the four-letter ICAO of your home base (KORD for Chicago O'Hare, KDFW for Dallas-Fort Worth).

4(Optional) Backfill recent FDPs and rest

For the rolling-window math to be accurate from day one, DaPilot needs your recent history. The 100/672 window looks back 28 calendar days. The 28-day cumulative window looks back 28 days. The 7-day window looks back 7 days.

Tap Backfill and enter your most recent two weeks of FDPs and rest periods. You don't need to enter individual flights for this; the FDP report and release times plus the rest start and end times are enough for the rolling-window math.

If you skip the backfill, the rolling windows will show "insufficient history" until you've used DaPilot for a few weeks.

5Save and check the dashboard

Tap Save. The dashboard now has five new cards in a Part 117 section, plus a Flight Duty Period card with the most recent FDP. The cards look like:

§117.23(b)(1) Flight time, 672 hours: 61.4 / 100
§117.23(b)(2) Flight time, 365 days: 412 / 1,000
§117.23(c)(1) FDP, 168 hours: 47 / 60
§117.23(c)(2) FDP, 672 hours: 138 / 190
§117.25 Weekly rest: 30:00 / 30:00 since last 30+ hour rest
Acclimation: Acclimated to KORD (home base)

Tap any card to see the inputs feeding the value.

What gets tracked

The five rolling windows

Window	Limit	Source
Flight time in 672 hours (28 days)	100 hours	§117.23(b)(1)
Flight time in 365 days	1,000 hours	§117.23(b)(2)
Flight duty period in 168 hours (7 days)	60 hours	§117.23(c)(1)
Flight duty period in 672 hours (28 days)	190 hours	§117.23(c)(2)
Weekly mandatory rest	30 consecutive hours / 168 hours	§117.25

The cards show pressure as you approach the limit:

0 to 69%: Safe zone (muted teal). The card is unobtrusive.
70 to 89%: Pressure (amber). The card draws your eye.
90% and above: Heavy pressure (red). The card stands out at the top.

The colors are designed so a glance at the dashboard tells you whether you have any tight windows. They are not verdicts. The pilot is the decider.

Pre-FDP rest

Before each FDP, you need a minimum rest period. DaPilot reads your most recent rest period and compares it to the required rest based on your acclimation state and other factors. The card shows actual rest versus required.

Maximum FDP per Appendix B

When you start a new FDP, DaPilot looks up the maximum FDP from Appendix B based on the FDP report time (in your acclimated time zone) and the number of segments. The lookup result shows on the FDP card and updates if you change the report time or add segments.

If you cross time zones during an FDP, the acclimation flag stays where you set it. DaPilot does not auto-update acclimation; you mark yourself acclimated explicitly.

What does not get tracked in v1

Appendix C inflight-rest credit. The structure exists in the calculation engine, but the full implementation is in development. If your operation uses Appendix C augmented crew rest credit, log the FDP with the augmented flag and DaPilot uses the basic Appendix C cap; the more nuanced credit lookup is roadmap.
Reserve duty. §117.21 reserve duty rules are not modeled in v1.
Long-call vs short-call reserve. Same reason.

These are roadmap. If your operation depends heavily on reserve, drop us a note via the contact link in the footer and tell us how your reserve cycles work; that input shapes the order we ship.

How the dashboard updates

Every time you save an FDP or a rest period, DaPilot recomputes all five rolling windows from your full FDP/rest history. The math is:

Sum the flight time in the previous 672 hours (28-day cap, 100) and the previous 365 days (annual cap, 1,000), ending at the current time.
Sum FDP duration in the previous 168 hours (7-day cap, 60) and the previous 672 hours (28-day cap, 190).
Find the most recent 30+ consecutive-hour rest period within the previous 168 hours; if none, calculate cumulative rest needed.
For pre-FDP, look at the rest period preceding the most recent FDP and compare to the §117.X minimum based on acclimation.

Tap any card to see the FDP/rest periods feeding it. Pre-Airline-Mode flights (logged before you toggled it on) do not feed the windows; only Airline Mode FDPs and rest periods do.

Common pitfalls

Enabling Airline Mode without a backfill, then being confused when the rolling windows show 'insufficient history.' DaPilot needs at least the previous 14 days of FDP and rest data to render meaningful values.
Marking yourself acclimated to a destination too aggressively. The §117.3 acclimation rule has specific conditions; if you read 'I had 36 hours in this zone, so I'm acclimated,' make sure you actually had the 36 hours.
Logging a flight without the surrounding FDP. Airline Mode tracks duty, not just flight time. The FDP card needs report and release times to compute correctly. Without an FDP, the flight time still counts toward 100/672, but FDP windows show as missing.
Forgetting to log the rest period after an FDP. Rest periods are how the weekly rest and pre-FDP rest cards work. If you don't log them, DaPilot can't tell whether you've had 30 consecutive hours.
Treating the green/amber/red colors as verdicts. They are pressure indicators, not legality assertions. Verify against your ops manual before duty.

Tips from line pilots

Log the FDP at the end of the trip, not at the start. The release time is the only time that's hard to know in advance, and you'll have it when you walk to the parking lot.

If you fly a 4-day trip with overnight rest periods between each FDP, log each FDP and rest pair as a single entry per day. The dashboard rolls up correctly.

The acclimation flag is set once per trip. If you start in a new time zone and stay there 36+ hours, set it acclimated to the new zone in the FDP entry. The next FDP picks up the same acclimation.

If you're approaching 100 in 672 hours and need to know exactly which day to expect a window release, tap the §117.23(b)(1) card and look at the contributing flights. The oldest flight in the window is the one whose flight time will drop off first; subtract its flight time from 100 minus your current cumulative to see how much you'll have available after it expires.

Last updated April 27, 2026 · 9 min read