12 August 2026

Find the Base Unaugmented Flight-Duty Limit for Any Start Time and Segment Count

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Priya Ellison 12 August 2026

FAR 117 Table B is the federal lookup table for finding the base maximum scheduled flight-duty period, or FDP, for an unaugmented operation. It uses two inputs: the flightcrew member’s scheduled FDP start in applicable acclimated time and the number of scheduled flight segments.

Select the correct start-time row, select the segment-count column, and read the intersecting cell. The result will be between 9 and 14 hours. That result is only the base Table B maximum—not a complete determination that an assignment complies with Part 117.

What FAR 117 Table B covers—and what it does not

Table B to 14 CFR Part 117 is titled “Flight Duty Period: Unaugmented Operations.” Under § 117.13, a certificate holder may not assign—and a flightcrew member may not accept—an unaugmented operation whose scheduled FDP exceeds the applicable Table B maximum, except as otherwise provided by Part 117. The current Part 117 text contains § 117.13, the applicable definitions, and the related limitations.

This page has one limited purpose: finding the base Table B maximum from:

The scheduled FDP start expressed in the flightcrew member’s applicable acclimated time.
The applicable number of scheduled flight segments.
The cell where the selected time row and segment column intersect.

Table B applies to unaugmented operations. An operation using an augmented flightcrew requires analysis under Table C and the associated augmented-operation provisions; Table B is not a substitute.

A Table B result does not establish by itself that an assignment is legal or operationally acceptable. Depending on the facts, the evaluation may also require consideration of:

Whether Part 117 applies to the operation and assignment.
The flightcrew member’s acclimation status.
Table A flight-time limitations.
Table C for augmented operations.
Reserve availability period restrictions.
Cumulative FDP and flight-time limitations.
Rest requirements.
Split-duty provisions.
FDP extensions.
Assignment changes and other operational facts.
More restrictive certificate-holder procedures or collective-bargaining terms.

This article does not decide whether Part 117 applies to a particular operator, flightcrew member, flight, or assignment. It also does not determine whether or when a flightcrew member has become acclimated or reacclimated.

Informational-only notice: This is a lookup reference, not operational, legal, or scheduling authorization. Do not use this table or any standalone calculator as the sole basis for an operational decision. Verify the live regulation, follow the certificate holder’s approved manuals and procedures, and seek qualified aviation-regulatory guidance when applicability or interpretation is uncertain.

The complete FAR 117 Table B

The matrix below gives the maximum FDP, in hours, for lineholders in unaugmented operations. Select the row using the scheduled FDP start in applicable acclimated time, then select the column using the number of scheduled flight segments.

On a narrow screen, scroll horizontally while keeping the selected start-time row in view.

Scheduled FDP start in acclimated time	1 segment	2 segments	3 segments	4 segments	5 segments	6 segments	7+ segments
0000–0359	9 hours	9 hours	9 hours	9 hours	9 hours	9 hours	9 hours
0400–0459	10 hours	10 hours	10 hours	10 hours	9 hours	9 hours	9 hours
0500–0559	12 hours	12 hours	12 hours	12 hours	11.5 hours	11 hours	10.5 hours
0600–0659	13 hours	13 hours	12 hours	12 hours	11.5 hours	11 hours	10.5 hours
0700–1159	14 hours	14 hours	13 hours	13 hours	12.5 hours	12 hours	11.5 hours
1200–1259	13 hours	13 hours	13 hours	13 hours	12.5 hours	12 hours	11.5 hours
1300–1659	12 hours	12 hours	12 hours	12 hours	11.5 hours	11 hours	10.5 hours
1700–2159	12 hours	12 hours	11 hours	11 hours	10 hours	9 hours	9 hours
2200–2259	11 hours	11 hours	10 hours	10 hours	9 hours	9 hours	9 hours
2300–2359	10 hours	10 hours	10 hours	9 hours	9 hours	9 hours	9 hours

Source note — last checked August 13, 2026: Every cell above was checked against the eCFR reproduction of Table B, which displayed Title 14 as current through August 11, 2026.

Table B’s base limits range from 9 to 14 hours. The 7+ column does not impose a universal 9-hour limit. For example, seven or more segments produce an 11.5-hour maximum for a 0700–1159 start, a 10.5-hour maximum for a 1300–1659 start, and a 9-hour maximum in several other bands.

Always read the actual intersecting cell. Do not replace the table with a generalized rule based only on a high segment count or an early or late report time.

How to read Table B in three steps

A reliable lookup requires two correct inputs. If the acclimated start time or segment count is wrong, an otherwise accurate table reading will still produce the wrong answer.

Step 1: Establish the scheduled FDP start in applicable acclimated time

Begin with the scheduled start of the FDP expressed in the flightcrew member’s applicable acclimated time. Do not automatically use the departure airport’s local wall-clock time merely because that time appears on an itinerary or schedule display.

Acclimation can become fact-dependent during travel across time zones. This article does not determine whether a flightcrew member is acclimated, has remained acclimated, or has reacclimated. Apply the complete regulatory definition and the actual assignment history rather than a shortcut based solely on present location.

Once the applicable acclimated time has been established, place the scheduled start in one of these bands:

0000–0359
0400–0459
0500–0559
0600–0659
0700–1159
1200–1259
1300–1659
1700–2159
2200–2259
2300–2359

Step 2: Determine the applicable number of scheduled flight segments

Count the scheduled flight segments applicable to the Table B lookup. Use the 7+ column for seven or more scheduled segments.

Do not count every itinerary line as a flight segment. Ground events, transportation entries, administrative items, and other duty events are not necessarily Table B flight segments. Deadhead transportation receives specific treatment, discussed below.

If the assignment contains six applicable scheduled flight segments, use the “6” column. If it contains seven, eight, or more, use “7+.” Do not extrapolate beyond the table.

Step 3: Cross-reference the row and column

Move across the selected start-time row until it meets the selected segment-count column. The intersecting value is the base maximum scheduled FDP under Table B, expressed in hours.

For example, a 0730 acclimated start belongs in the 0700–1159 row. With five scheduled flight segments, the “5” column produces a base maximum of 12.5 hours.

Exact boundaries matter:

0459 is in the 0400–0459 row; 0500 is in the 0500–0559 row.
1159 is in the 0700–1159 row; 1200 is in the 1200–1259 row.
2159 is in the 1700–2159 row; 2200 is in the 2200–2259 row.
2259 is in the 2200–2259 row; 2300 is in the 2300–2359 row.

A one-minute change can alter the result. For one segment, a 0459 start produces a 10-hour value, while a 0500 start produces a 12-hour value. For four segments, a 2259 start produces 10 hours, while a 2300 start produces 9 hours. These boundaries and values appear in the Cornell Legal Information Institute reproduction of Table B.

For an auditable lookup, record:

The scheduled FDP start.
The acclimated time used and how it was established.
The scheduled segment count.
The selected row and column.
The Table B version or verification date.
The resulting base maximum.

That record can help distinguish a simple table-entry error from a disagreement about acclimation, segment counting, reserve status, or another Part 117 issue.

Label the output accurately: base Table B maximum for an unaugmented operation. Avoid calling it the “legal duty limit” without qualification.

Worked Table B examples

The following examples all use the same method: identify the acclimated start-time row, identify the scheduled segment column, and read the intersecting value.

Example	Input	Selected row	Column	Cell value
1	0730 start; 2 segments	0700–1159	2	14 hours
2	0730 start; 7+ segments	0700–1159	7+	11.5 hours
3	0530 start; 5 segments	0500–0559	5	11.5 hours
4	0630 start; 4 segments	0600–0659	4	12 hours
5	1230 start; 6 segments	1200–1259	6	12 hours
6	1500 start; 7+ segments	1300–1659	7+	10.5 hours
7	1800 start; 5 segments	1700–2159	5	10 hours
8	2230 start; 3 segments	2200–2259	3	10 hours
9	2330 start; 4 segments	2300–2359	4	9 hours

These example values are direct applications of the complete federal matrix and may be cross-checked against the Table B reproduction cited above.

Changing only the segment count: Examples 1 and 2 use the same 0730 start. Increasing the segment category from two to seven or more reduces the Table B maximum from 14 hours to 11.5 hours.

Changing only the start-time band: Examples 2 and 6 both use the 7+ category. Moving the start from 0730 to 1500 changes the applicable row and reduces the value from 11.5 hours to 10.5 hours.

Comparing adjacent late-night bands: At 2230, three segments produce 10 hours. At 2330, three segments would still produce 10 hours, but four segments produce 9 hours. A time-band change does not affect every segment column in the same way.

Every example produces only a base Table B maximum. Before treating an assignment as compliant, check applicability, flight-time limits, reserve status, cumulative totals, rest, extensions, assignment-specific facts, and any more restrictive carrier or contractual requirements.

Counting flight segments and handling deadhead transportation

The Table B column is based on the applicable number of scheduled flight segments, not the total number of movements, entries, or duty events shown on an itinerary.

Deadhead transportation is important because its treatment is not necessarily intuitive. Under Part 117’s definition, deadhead transportation is duty rather than rest, but it does not count as a flight segment when determining the maximum FDP under Table B. The Part 117 definitions state this distinction directly.

Consider a bounded example:

A flightcrew member reports for a deadhead movement.
The deadhead precedes two worked flight segments.
The deadhead can add duty time.
It does not change the Table B segment count from two to three.

The lookup therefore uses the applicable column for the two worked flight segments. The additional duty time can still matter because the scheduled assignment must remain within the applicable FDP constraints.

This example should not be expanded into a universal rule about precisely when every FDP starts or ends. Those determinations depend on the regulatory definitions and the facts of the assignment.

Likewise, this article does not prescribe one universal segment-count rule for:

Diversions.
Added or removed flights.
Reassignments after report.
Aircraft changes.
Irregular operations.
Airport standby with no flying initially scheduled.

When the scheduled segment count changes or an edge case arises, consult the current regulation, applicable FAA interpretations, and the certificate holder’s approved procedures before selecting a Table B column.

Table B versus Table A, Table C, and other Part 117 limits

Table B limits the scheduled flight-duty period for an unaugmented operation. It does not establish the maximum flight time that may occur within that FDP.

Table A addresses maximum flight-time limits for unaugmented operations. When both apply, the flight-time and FDP limits operate concurrently: satisfying Table B does not authorize flight time beyond Table A, and remaining within Table A does not authorize an FDP beyond Table B.

For an augmented-flightcrew operation, use Table C and the associated augmented-operation provisions. The applicable table depends on the operation, not on which table provides the more favorable number.

Part 117 also includes rolling cumulative constraints:

60 FDP hours in 168 consecutive hours.
190 FDP hours in 672 consecutive hours.
100 flight hours in 672 consecutive hours.
1,000 flight hours in 365 consecutive calendar days.

These limits measure different quantities over different windows; flight time and FDP are not interchangeable totals. The ALPA Part 117 reference lists the flight-time and FDP cumulative categories separately.

Rest requirements and other Part 117 provisions must also be checked. A Table B value may be one applicable cap without being the controlling restriction for the complete assignment.

A practical screening sequence is:

Confirm applicability. Determine whether Part 117 applies to the operation, assignment, and flightcrew member.
Identify the crew configuration. Determine whether the operation is unaugmented or augmented.
Check flight time and FDP. For an unaugmented operation, check Table A and Table B. For an augmented operation, evaluate Table C and its related provisions.
Check reserve restrictions. If reserve is involved, calculate the applicable RAP and FDP limits.
Check cumulative limits. Review both FDP and flight-time totals over their respective windows.
Check rest and related provisions. Include any applicable split-duty or extension rules.
Check more restrictive requirements. Apply certificate-holder procedures and contractual restrictions that are more conservative than the federal maximum.

Among concurrently applicable quantified caps, the earliest permissible endpoint will ordinarily control the scheduling screen. That principle does not resolve questions about applicability, acclimation, exceptions, assignment changes, or regulatory interpretation.

How Table B interacts with short-call reserve

An FDP assigned during short-call reserve cannot be evaluated solely by starting a Table B clock at the beginning of the FDP. The reserve availability period, or RAP, creates additional constraints measured from the RAP start.

For an unaugmented operation, the combined RAP and FDP may not exceed the lesser of:

The applicable Table B maximum plus four hours, measured from the RAP start; or
16 hours, measured from the RAP start.

The assigned FDP must also remain within the Table B maximum selected from the FDP’s own start time and scheduled segment count. A short-call RAP may not exceed 14 hours. The reserve-status reference reproduces the combined RAP-and-FDP rule and illustrates the competing clocks.

Use three separate checks:

Table B from the FDP start: Select the Table B value using the assigned FDP start in applicable acclimated time and the scheduled segment count.
Table B plus four hours from the RAP start: Select the applicable Table B amount for the RAP-based test, add four hours, and measure the combined period from the RAP start.
The 16-hour cap from the RAP start: The FDP must end no later than 16 hours after the RAP began.

The scheduled FDP must end within all applicable constraints.

Consider a RAP beginning at 0600 and a two-segment FDP beginning at 1200:

FDP-start Table B check: A 1200 start with two segments produces a 13-hour maximum, reaching 0100.
Table B-plus-four check: The applicable 13-hour amount plus four hours gives 17 hours from the 0600 RAP start, reaching 2300.
16-hour RAP cap: Sixteen hours from 0600 reaches 2200.

The earliest endpoint is 2200. Because the FDP begins at 1200, the RAP-based cap leaves 10 hours for the assigned FDP even though Table B alone permits 13 hours from the FDP start.

A second illustration shows why the RAP-based and FDP-based Table B entries should be evaluated separately. Assume an 1100 RAP start, a 1500 FDP start, and five scheduled segments:

At 1100, the five-segment Table B value is 12.5 hours; adding four gives 16.5 hours from the RAP start.
The separate 16-hour cap therefore produces a 0300 endpoint.
At 1500, the five-segment Table B value is 11.5 hours, producing a 0230 endpoint.

In that illustration, the FDP-start Table B limit ends first at 0230. The fact that one example is controlled by the 16-hour RAP cap does not mean the same clock controls every reserve assignment.

Airport standby and long-call reserve have distinct classifications and requirements. They should not be treated as interchangeable with short-call reserve or resolved solely through the short-call formula.

Neither illustration is a complete legality assessment. Acclimation, rest, cumulative limits, extensions, the exact assignment, and other applicable provisions can change the operational conclusion.

When a Table B limit may be extended

A Table B extension is not automatic or routine extra duty time. The existence of extension authority does not permit a certificate holder or pilot to add time merely because a planned assignment exceeds the table.

For unforeseen operational circumstances arising before takeoff, the pilot in command and certificate holder may extend the applicable Table B or Table C maximum by up to two hours. A pre-takeoff extension cannot cause the flightcrew member to exceed the cumulative FDP limits in § 117.23(c). An extension longer than 30 minutes may occur only once before the rest period described in § 117.25(b). Section 117.19 states these pre-takeoff conditions.

A certificate holder must report a qualifying pre-takeoff extension that exceeds the applicable Table B or Table C maximum by more than 30 minutes to the Administrator within 10 days. If the circumstances were within the certificate holder’s control, the report must identify corrective actions, and those actions must be implemented within 30 days of the extended FDP.

Different authority applies when unforeseen operational circumstances arise after takeoff. In that situation, the FDP may be extended as necessary to land safely at the next destination or an appropriate alternate. The after-takeoff provision has its own frequency and reporting rules and differs materially from the pre-takeoff restriction concerning cumulative FDP limits. It is not open-ended authority to continue ordinary operations beyond the planned maximum.

Whether an event qualifies as an unforeseen operational circumstance depends on the regulatory definition and the actual facts. Avoid informal lists claiming that an event always qualifies. Consult the current text of § 117.19 and the certificate holder’s approved procedures.

Which source to trust when online Table B charts disagree

Use separate hierarchies for two different questions.

To determine the current federal text and its interpretation:

Check the live eCFR and applicable official publications.
Review official FAA rules, interpretations, and guidance.
Use reputable legal reproductions as a cross-check.
Treat commercial training articles, application documentation, screenshots, forums, and undated charts as secondary aids only.

To determine operational or contractual requirements:

Follow the certificate holder’s current approved manuals and procedures.
Apply any more restrictive collective-bargaining terms.
Use current company scheduling and compliance systems as directed, while remaining alert to input or configuration errors.

A carrier manual may be operationally controlling or more restrictive without being a higher source for establishing what the federal Table B itself says. Federal-source verification and carrier-procedure compliance answer related but distinct questions.

The eCFR describes itself as authoritative but unofficial and states that it is not the official legal edition of the CFR. At the last check for this article, the eCFR displayed Title 14 as current through August 11, 2026, stated that Title 14 was last amended July 31, 2026, and reported no change to the Table B content after January 3, 2017.

That history is useful, but it does not justify relying indefinitely on a saved table. Verify every cell against the live eCFR before publication, training use, schedule-system configuration, or an operational decision. Update the visible “last checked” date whenever the page receives a material review.

Official FAA materials can also help with issues beyond the matrix. The FAA’s March 5, 2013 clarification rule addressed subjects including unaugmented FDP start-time and segment-count adjustments, augmented operations, reserve, extensions, cumulative limits, and rest. The rule was published as 78 FR 14166.

Unofficial charts can contain transcription errors, shifted segment thresholds, improperly combined rows, or stale information. Do not treat two conflicting tables as equally authoritative merely because both are professionally formatted.

Software requires the same scrutiny. An application may reproduce every Table B cell correctly yet produce the wrong operational output because of an incorrect acclimation assumption, stale schedule data, unsupported reserve logic, or incomplete handling of reassignment, split duty, or augmented operations.

The repeatable lookup rule is straightforward: establish the applicable acclimated start-time band, count the scheduled flight segments correctly, and read the intersecting Table B cell. Label the answer as the base unaugmented FDP maximum.

Before relying on it, verify the live regulation and check applicability, Table A flight-time limits, reserve constraints, cumulative limits, rest, extensions, augmented or split-duty provisions, and any more restrictive carrier or contractual requirements.

Does a deadhead count as a flight segment under FAR 117 Table B?

No. Deadhead transportation is duty rather than rest, but it does not count as a flight segment when selecting the Table B column. A deadhead before worked flying can therefore add duty time without adding a Table B segment.

That answer does not establish precisely when every FDP begins or ends; apply the regulatory definitions and the facts of the assignment.

What is the difference between Table A and Table B in Part 117?

Table A limits flight time for unaugmented operations. Table B limits the scheduled flight-duty period for unaugmented operations according to scheduled start in acclimated time and scheduled segment count.

Both can apply to the same assignment. Compliance with Table B does not override a more restrictive Table A flight-time limit, and compliance with Table A does not authorize an FDP beyond Table B.

Can a FAR 117 Table B limit be extended by two hours?

Potentially, but not automatically.

Before takeoff, qualifying unforeseen operational circumstances may permit the pilot in command and certificate holder to extend a Table B or Table C maximum by up to two hours, subject to the pre-takeoff cumulative-limit, frequency, reporting, corrective-action, and rest provisions.

After takeoff, a separate rule permits an extension as necessary to land safely at the next destination or an appropriate alternate. The after-takeoff authority should not be treated as identical to the pre-takeoff rule.

How does Table B apply to an FDP assigned during short-call reserve?

Run three checks:

Apply Table B from the assigned FDP start.
Apply the Table B-plus-four combined limit from the RAP start.
Apply the separate 16-hour cap from the RAP start.

The FDP must be scheduled to end within every applicable constraint. For a 0600 RAP start and a two-segment FDP beginning at 1200, Table B permits 13 hours from the FDP start, but the 16-hour RAP cap requires the FDP to end by 2200. That leaves 10 hours from the 1200 FDP start.

Is the eCFR version of FAR 117 Table B the official legal edition?

No. The eCFR describes itself as authoritative but unofficial and states that it is not the official legal edition of the CFR.

It remains the most useful live federal regulatory reference for checking the current table. For operational or legal reliance, verify the current eCFR, applicable official publications and FAA materials, and the certificate holder’s approved guidance.