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Summary of CrewPairings, Inc. 

Economic Analysis of 

Flightcrew Member Duty and Rest 

Requirements Rulemaking

September 2012
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 1

Table of Contents

INTRODUCTION ..................................................................................................................................................... 3

BACKGROUND...............................................................................................................................................................3

OBJECTIVES ..................................................................................................................................................................4

CREWPAIRINGS BACKGROUND .........................................................................................................................................5

CREWPAIRINGS METHODOLOGY.......................................................................................................................................5

CASES..........................................................................................................................................................................7

OVERVIEW OF RESULTS ...................................................................................................................................................8

UNCERTAINTIES .............................................................................................................................................................8

CASE A: MAINLINE PASSENGER NARROW-BODY....................................................................................................9

SUMMARY....................................................................................................................................................................9

DETAILED RESULTS.........................................................................................................................................................9

Buffers..................................................................................................................................................................9

Pairings...............................................................................................................................................................10

Bid Lines .............................................................................................................................................................11

Results................................................................................................................................................................11

CASE B: MAINLINE PASSENGER NARROW-BODY.................................................................................................. 14

SUMMARY..................................................................................................................................................................14

DETAILED RESULTS.......................................................................................................................................................14

Buffers................................................................................................................................................................14

Pairings...............................................................................................................................................................15

Bid Lines .............................................................................................................................................................16

Results................................................................................................................................................................17

CASE C: MAINLINE PASSENGER WIDE-BODY ........................................................................................................ 19

SUMMARY..................................................................................................................................................................19

DETAILED RESULTS.......................................................................................................................................................19

Buffers................................................................................................................................................................19

Pairings...............................................................................................................................................................20

Bid Lines .............................................................................................................................................................21

Results................................................................................................................................................................22

CASE D: MAINLINE PASSENGER WIDE-BODY........................................................................................................ 25

SUMMARY..................................................................................................................................................................25

DETAILED RESULTS.......................................................................................................................................................25

Buffers................................................................................................................................................................25

Pairings...............................................................................................................................................................26

Bid Lines .............................................................................................................................................................27

Results................................................................................................................................................................28

CASE E: REGIONAL PASSENGER............................................................................................................................ 30

SUMMARY..................................................................................................................................................................30

DETAILED RESULTS.......................................................................................................................................................30

Buffers................................................................................................................................................................30

Pairings...............................................................................................................................................................31

Bid Lines .............................................................................................................................................................32
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Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 2

Results................................................................................................................................................................32

CASE F: REGIONAL PASSENGER............................................................................................................................ 35

SUMMARY..................................................................................................................................................................35

DETAILED RESULTS.......................................................................................................................................................35

Buffers................................................................................................................................................................35

Pairings...............................................................................................................................................................36

Bid Lines .............................................................................................................................................................37

Results................................................................................................................................................................37

CASE G: ALL-CARGO NARROW-BODY ................................................................................................................... 40

SUMMARY..................................................................................................................................................................40

DETAILED RESULTS.......................................................................................................................................................40

Buffers................................................................................................................................................................41

Pairings...............................................................................................................................................................41

Bid Lines .............................................................................................................................................................42

Results................................................................................................................................................................43

CASE H: ALL-CARGO WIDE-BODY ......................................................................................................................... 45

SUMMARY..................................................................................................................................................................45

DETAILED RESULTS.......................................................................................................................................................45

Buffers................................................................................................................................................................46

Pairings...............................................................................................................................................................47

Bid Lines .............................................................................................................................................................49

Results................................................................................................................................................................50

CASE I: SUPPLEMENTAL WIDE-BODY.................................................................................................................... 52

SUMMARY..................................................................................................................................................................52

DETAILED RESULTS.......................................................................................................................................................52

Buffers................................................................................................................................................................53

Pairings...............................................................................................................................................................54

Bid Lines .............................................................................................................................................................55

Results................................................................................................................................................................56

APPENDIX 1: PAY VARIABLES............................................................................................................................... 58
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Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 3

Introduction

BACKGROUND

The Flightcrew Member Duty and Rest Requirements Notice of Proposed Rulemaking (NPRM) 

published by the FAA on September 14, 2010 (the NPRM) proposed new regulations applicable 

to certificate holders and their flightcrew members operating under 14 CFR Part 121. The 

purpose of the proposed regulations was to reduce the risk to aviation safety of flightcrew 

member fatigue. The proposed rules and regulations would replace the existing flight time 

limitations and rest requirements contained in 14 CFR Part 121 Subparts Q, R and S (the FAR).

After reviewing the comments received from the aviation community and the results of detailed 

analyses of the differences in air carrier flightcrew member scheduling cost and predicted 

flightcrew member fatigue resulting from the adoption of the NPRM, the FAA produced an 

internal pre-decision draft of the regulations (the Final Rule) in April 2011. The Final Rule was 

significantly different from the NPRM. As a whole, the changes resulted in the Final Rule being 

less costly in terms of air carrier flightcrew member scheduling than the NPRM.

The FAA published the final Flightcrew Member Duty and Rest Requirements in December 

2011. The rule elements of the published Final Rule were nearly identical to the internal predecision Final Rule. However, the set of carriers required to comply with the published Final 

Rule was different from the set of carriers required to comply with either the NPRM or internal 

pre-decision Final Rule. Only air carriers that conducted passenger operations under 14 CFR Part 

121 were required to comply with the published Final Rule. Air carriers that conducted all-cargo 

operations under 14 CFR Part 121 were not required to comply with the published Final Rule, as 

they were under the NPRM.

GRA, Incorporated, in support of the FAA, subcontracted with CrewPairings, Inc. to analyze the 

air carrier flightcrew member scheduling impact of the NPRM and Final Rule. CrewPairings 

selected a representative set of air carrier flight and flightcrew member schedules for in-depth 

analysis. The air carriers selected included passenger short-haul, long-haul, regional and 

supplemental operators and all-cargo operators. 

This report is a summary of CrewPairings’ Final Rule analysis prepared by GRA, Incorporated 

and reviewed by CrewPairings. The CrewPairings Final Rule results are considered to be 

accurate representations of the impact of the Final Rule on flightcrew member scheduling.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 4

OBJECTIVES

The FAA estimated the costs of the NPRM in a Regulatory Impact Analysis (RIA) published in 

September 2010 with the NRPM. Costs were categorized in four main components: flight 

operations, schedule reliability, fatigue training and rest facilities. Flight operations accounted 

for approximately 60 percent ($760 million) of the total nominal cost of the NPRM ($1,254 

million). The flight operations component was composed of several sub-components, with 

flightcrew member scheduling cost accounting for the majority of flight operations costs.

Numerous commenters objected to the NPRM RIA cost estimate. For example, the Air Transport 

Association of America, Inc. (ATA)1 estimated that the nominal flight operations cost of the 

NPRM would be $8,759.0 million, or more than 11 times the cost estimated by the FAA, even 

though ATA’s cost estimate included only mainline, low cost and large cargo carriers while the 

NPRM RIA cost estimate included all carriers subject to the rule.2 American Airlines, Inc. 

estimated that its nominal flight operations cost to comply with the NPRM would be $4,970 

million, or more than six times the cost estimated by the FAA for the entire Part 121 industry.3

Commenters asserted that the NPRM RIA cost estimate was based on faulty assumptions and 

cost inputs. For instance, ATA stated that, “Unsupportable assumptions include, but are not 

limited to... Collective bargaining agreement adjustments to comply with Proposal assumed to 

have no cost; and, Ability of carriers to optimize their results to reduce cost assumed without 

factual bases or modeling.”4 In particular, commenters objected to the FAA’s assumption that 

optimization would reduce carriers’ flightcrew scheduling compliance cost by 25 percent in the 

short-term. As stated in the NPRM RIA, “This discount off of raw costs approximates the 

savings expected from the computer models used to build schedules; flight schedules will be 

rearranged into new trips that meet the new constraints of the rule.”5

The objective of contracting with CrewPairings was to respond to commenters by developing 

better flightcrew member scheduling cost estimates. The CrewPairings results eliminated the 

need for FAA to make assumptions regarding flightcrew member scheduling actions that carriers 

may take by using a commercial flightcrew member scheduling model used by carriers in realworld operations. The CrewPairings results reflected the outcome of the process by which 

carriers create the most efficient flightcrew member schedule possible, in compliance with 

numerous constraints, including federal regulations, labor agreements, market demands and 

operational requirements.

 1 The ATA changed its name to Airlines for America (A4A) in 2012.

2 Comments of the Air Transport Association of America, Inc. in the matter of Notice of Proposed Rulemaking for 

Flightcrew Member Duty and Rest Requirements, November 15, 2010. 3 Comments of American Airlines, Inc. in the matter of Notice of Proposed Rulemaking for Flightcrew Member 

Duty and Rest Requirements, November 15, 2010.

4 Comments of the Air Transport Association of America, Inc. in the matter of Notice of Proposed Rulemaking for 

Flightcrew Member Duty and Rest Requirements, November 15, 2010.

5 Federal Aviation Administration, Regulatory Impact Analysis of Flightcrew Member Duty and Rest Requirements 

Notice of Proposed Rulemaking, September 3, 2010, p.85.
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Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 5

The FAA used the CrewPairings results to develop the Regulatory Impact Analysis for the Final 

Rule.6 The FAA calculated the change in crew scheduling cost per flightcrew member 

attributable to the Final Rule by multiplying FAA-estimated unit costs by CrewPairingscalculated changes in various crew scheduling metrics. Every Part 121 carrier was matched to 

the most similar CrewPairings case or combination of cases based on characteristics such as 

fleet, operation type and labor agreement. The change in cost per flightcrew member from the 

CrewPairings analysis was then extrapolated to the number of flightcrew members employed by 

each Part 121 carrier.

CREWPAIRINGS BACKGROUND

CrewPairings, Inc. provides crew pairing and schedule optimization services to airlines and is 

owned by Dr. Robert Gerbracht and Candler Brooks. The firm has more than 70 years of 

combined experience providing crew pairing optimization services to the airline industry.

CrewPairings uses the Cygnus system, which consists of a pairing and bid line optimizer, to 

create production-caliber solutions for its clients.

Dr. Gerbracht developed the Cygnus system over a period of 40 years. The system has been 

implemented at more than 30 major airlines worldwide. Cygnus has been used at all types of 

airlines, including global, national, regional and freight airlines.

CREWPAIRINGS METHODOLOGY

Isolating the impact of the flightcrew member duty and rest regulations from the various other 

scheduling practices and constraints is essential for an accurate assessment of the impact of the 

Final Rule. CrewPairings achieved this objective by including all of the regulatory, contractual 

and discretionary scheduling practices used by each carrier during the flightcrew member 

scheduling process. Cygnus settings were validated by independently creating a Baseline 

Solution and comparing it with the Production Solution provided by each carrier. Cygnus 

settings were considered validated once the Baseline Solution was equivalent to the Production 

Solution in terms of cost and productivity. After validation of the Baseline Solution, the Final 

Rule Solution was created by substituting the Final Rule for the FARs. Any observed change in 

crew scheduling metrics between the Baseline Solution and Final Rule Solution was solely 

attributable to the Final Rule. Figure 1 provides an overview of CrewPairings’ methodology.

 6 Federal Aviation Administration, Regulatory Impact Analysis of Flightcrew Member Duty and Rest Requirements 

Final Rule, November 18, 2011.
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Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 6

Figure 1: CrewPairings Methodology Overview

CrewPairings obtained a set of data files from each of the carriers selected for analysis and 

imported the files into Cygnus. The carrier-provided data files included flight schedules, aircraft 

flow information, a set of production pairings (the Production Solution) and the carrier’s rule set 

(contractual, management and discretionary rules). Typical carrier rule sets included crew base

locations and aircraft types, minimum and maximum block hours within each crew base, 

minimum ground time for an aircraft swap, and scheduling buffers for maximum and/or 

minimum flight time, rest time and duty time. Existing FARs were already included in Cygnus.

After importing the data files into Cygnus, CrewPairings executed the Cygnus optimization 

models to produce the Baseline Solution. The Baseline Solution was compared with the 

Production Solution to verify that CrewPairings accurately inputted all of the carrier-provided 

data files. Metrics such as the amounts of credit hours, duty periods, hotel room nights, 

distribution of time among bases and number of aircraft swaps were compared between the 

solutions. In all cases, the Baseline Solution was virtually identical to the Production Solution in 

terms of cost and productivity. Essentially, this meant that the CrewPairings-generated Baseline 

Solution could be flown by the carrier in full compliance with all contractual, management, 

discretionary and existing regulatory constraints with no significant differences from the 

Production Solution.

The Final Rule Solution was created after validation of the Baseline Solution by replacing the 

FARs with the Final Rule. Several elements of the Final Rule were buffered to reflect the fact 

that the Final Rule applied to actual, rather than planned, flight, duty and rest times. The specific 
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 7

buffers were chosen based on conversations with crew schedulers at the carriers. No substantial 

changes were made to flight schedules, aircraft flow or carrier rule sets.7

The Final Rule was responsible for changes in crew scheduling metrics between the Baseline 

Solution and Final Rule Solution because the only change was replacement of the FARs with the 

Final Rule. The Final Rule Solution consisted of production-ready pairings and bid lines. The 

carrier could load the Final Rule Solution into its crew management system and operate the exact 

same schedule as in the Production Solution, while being in full compliance with all contractual, 

management, discretionary and Final Rule regulatory constraints.

The number of flight segments and aircraft block hours differed slightly between the Baseline 

Solution and Final Rule Solution for most cases because of the issue of carry-in and carry-out 

flight segments. As previously described, Cygnus output consisted of production-ready pairings 

and bid lines. Due to the replacement of the FAR with the Final Rule, the flight segments placed 

in the carry-in and/or carry-out sets were not necessarily identical in the Baseline Solution and 

Final Rule Solution. Carry-in flight segments were those flight segments that started in the 

calendar month of the scheduling period of analysis, but were included in pairings from the 

preceding scheduling period. Carry-out flight segments were those flight segments that started in 

the calendar month of the scheduling period of analysis, but were included in the subsequent 

scheduling period. For all cases, the differences in carry-in and carry-out flight segments for each 

case were small and did not significantly impact the outcome of the CrewPairings analysis.

This report presents crew scheduling metrics for each solution that relate to how flightcrew 

members are compensated. Flightcrew members are compensated based on the number of credit 

hours worked, which include flight time, credit for other types of work and credit subject to 

minimum guarantees, depending on labor agreements. Per diem is paid based on time away from 

base (TAFB), depending on labor agreements. Carriers incur costs for hotel rooms provided for 

flightcrew members during trips. More details on flightcrew member pay practices are available 

in Appendix 1.

CASES

CrewPairings selected eight “cases”, each consisting of a carrier fleet type, designed to be 

representative of the Part 121 industry. In addition, a “synthetic” supplemental carrier case was 

created based on one of the eight cases. The procedures described in the CrewPairings 

Methodology section were carried out for each of the nine cases and Final Rule results were 

calculated.

The cases consisted of two mainline passenger narrow-body fleets operating mainly domestic 

short-haul service, two mainline passenger wide-body fleets operating mainly international longhaul service, two regional passenger fleets, one all-cargo narrow-body fleet operating mainly 

 7 In an extremely limited number of situations, flight schedules were changed by a small amount to reflect the fact 

that carriers are likely to make slight adjustments to flight schedules rather than incur large increases in flightcrew 

member scheduling costs.
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Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 8

domestic short-haul service, one all-cargo wide-body fleet operating mainly international longhaul service and one supplemental wide-body fleet operating mainly international long-haul 

service.

For a few cases, unique or temporary carrier scheduling constraints were eliminated to make the 

results more applicable to the industry. In these cases, the constraints were eliminated for both 

the Baseline and Final Rule Solutions, so that the impact of the Final Rule could be isolated.

OVERVIEW OF RESULTS

Since the objective of this analysis was to determine the impact of the Final Rule on carrier 

flightcrew member scheduling cost, this report presents results in terms of their impact on carrier 

flightcrew member scheduling cost. Terms such as “more constraining”, “less efficient” and 

“negative impact” mean that the Final Rule will result in carriers expending more resources (i.e. 

credit hours, TAFB and/or hotel rooms) to operate the same flight schedule as under the FAR. 

Terms such as “less constraining”, “more efficient” and “positive impact” mean that the Final 

Rule will result in carriers expending fewer resources (i.e. credit hours, TAFB and/or hotel 

rooms) to operate the same flight schedule as under the FAR.

The impact of the Final Rule depended greatly on the operation type. The Final Rule slightly 

improved crew scheduling results for one passenger wide-body case and one passenger narrowbody case, while it made results slightly worse for the other passenger wide-body case and other 

passenger narrow-body case. The Final Rule worsened crew scheduling results for the regional 

passenger cases because of their use of short rest periods which were not possible under the Final 

Rule. The impact on crew scheduling was more double layovers and/or crew staging for regional 

carriers. The Final Rule worsened crew scheduling results for the all-cargo operator cases 

because of reduced maximum flight time limits for international operations, reduced maximum 

flight duty period limits and consecutive nighttime operations limitations. The Final Rule

reduced crew scheduling results for the supplemental case because the Final Rule was

considerably more constraining than the supplemental FARs and typical supplemental carrier 

labor agreement. 

UNCERTAINTIES

Flight duty period time, flight time and rest time buffers will become essential flightcrew 

member scheduling considerations because the Final Rule limits are based on actual, rather than 

scheduled, times. Carrier flightcrew schedulers will need to apply buffers during the scheduling 

process to ensure that operational delays do not cause crewmember schedules to become illegal 

at sub-optimal rates. CrewPairings explored different amounts of buffering; the results can vary 

significantly depending on the buffers.

CrewPairings’ results were based on buffers chosen during consultation with the flightcrew 

schedulers at the carriers that provided data. However, it is reasonable to expect that flightcrew 

schedulers will experiment with and refine buffers as they gain experience with the Final Rule 

and its impacts on flightcrew member scheduling.
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Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 9

Case A: Mainline Passenger Narrow-Body

SUMMARY

Case A consisted of the short-haul operations of a mainline passenger carrier using narrow-body 

aircraft. The Final Rule Solution was less efficient in terms of credit hours than the Baseline 

Solution mainly because of the increased minimum rest period. This resulted in longer layovers 

for flightcrew members, which increased the number of credit hours, TAFB and hotel rooms 

required. The changes in maximum flight time and maximum FDP time limits had little impact 

on Case A.

DETAILED RESULTS

Case A consisted of a subset of the short-haul operations of a mainline passenger carrier using 

narrow-body aircraft during the January 2010 scheduling period. There were more than 16,000 

flight segments during the scheduling period, most of which were domestic. However, there were 

also some flight segments to Mexico and the Caribbean. Since the carrier mixed domestic and 

international flying in its crew pairings, all of these flight segments were included in the study.

The augmentation and acclimation elements of the Final Rule did not affect Case A, as all of the 

flight segments operated with an unaugmented crew and all of the flightcrew members remained

acclimated at all times. Case A did not have any split duty periods.

Buffers

The three main Final Rule rule elements that affected Case A were the maximum unaugmented 

flight time, maximum unaugmented FDP time and minimum rest period limits. CrewPairings 

applied buffers to both the maximum flight time and FDP time limits to reflect the fact that they 

applied to actual, rather than planned, operations. In Figure 2, the CrewPairings buffer is shown 

in the “CP Buffer” column, which, when applied to the “Final Rule” limit, resulted in the 

“Effective Final Rule” limit that was actually used when creating pairings for the Final Rule

Solution. However, if the contractual rule shown in the “Current CBA” column less the debrief 

time shown in the “Debrief” column was more restrictive than the “Effective Final Rule” limit, 

the contractual rule was shown in the “Effective Final Rule” column.

Figure 2 includes an “Effective Current Rule” column for comparison to the “Effective Final 

Rule” column. The “Effective Current Rule” is the more restrictive of the “Current FAR” 

column or “Current CBA” column, after applying the buffer in the “Current Buffer” column and 

the debrief time in the “Debrief” column.
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Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 10

Figure 2: Case A Buffers

Pairings

The Baseline Solution pairings (equivalent to the Production Solution) were constructed with the 

constraints of the “Effective Current Rule” column in Figure 2, in addition to all other FAR, 

contractual, management and discretionary constraints not shown. The Final Rule Solution 

pairings were constructed with the constraints of the “Effective Final Rule” column in Figure 2, 

in addition to all other Final Rule, contractual, management and discretionary constraints not 

shown.

The maximum flight time limit applicable to the Baseline Solution was 7:50 hours, which was

the FAR limit less the ten minute buffer used by the carrier in practice. The maximum flight time 

limit applicable to the Final Rule Solution was between 7:30 hours and 8:30 hours, depending on 

FDP start time, after application of a 30 minute buffer. The maximum flight time limit of the 

Final Rule was therefore expected to have a mixed impact on the Final Rule Solution pairings; in 

some situations the Effective Final Rule limit was more constraining than the Effective Current 

Rule and in other cases it was less constraining.

The maximum FDP limit applicable to the Baseline Solution was 8:00-12:30 hours, which was

the CBA limit less a 30 minute debrief period. The maximum FDP limit applicable to the Final 

Rule Solution was the same as the maximum FDP limit applicable to the Baseline Solution, 

because the CBA less a 30 minute buffer applied by CP was more constraining than the Final 

Rule. The maximum FDP limit of the Final Rule was therefore expected to have no impact on 

the Final Rule Solution pairings.

The minimum rest period applicable to the Baseline Solution was 9:00-12:00 hours, depending 

on the amount of flight time in the previous 24 hour period. The CBA minimum rest period was

9:00 hours, but the FAR required additional rest time if the amount of flight time in the 

Current FAR Current CBA Debrief Carrier 

Buffer

Effective 

Current Rule1 Final Rule CP 

Buffer

Effective Final 

Rule2

Maximum 

Unaugmented 

Flight Time

8:00 - - 0:10 7:50 8:00 - 9:00 0:30 7:30 - 8:30

Maximum 

Unaugmented

FDP Time6

16:00 8:30 - 13:00 0:30 - 8:00 - 12:30 9:00 - 14:003 0:305 8:00 - 12:303

Minimum 

Unaugmented

Rest Time

8:00 - 12:004 9:00 - - 9:00 - 12:00 10:00 - 10:00

6 The FDP concept does not exist in current FARs; therefore the Current columns in this row refer to duty time

Rule Element

Time in Hours:Minutes

1 The more restrictive of the current CBA, less debrief, or the FAR (adjusted for carrier buffer)

2 The more restrictive of the current CBA, less debrief, or the Final Rule (adjusted for CP buffer)

3

 Depending on FDP start time; Maximum show n is for 1 segment during FDP, reduced if 3 or more segments during FDP

4 Depending on the amount of flight time in the past 24-hour period

5 Plus the 0:30 de facto buffer resulting from §117.19 for a total of 1:00
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September 2012 Page 11

preceding 24 hour period exceeded eight hours. The minimum rest period applicable to the Final 

Rule Solution was 10:00 hours, which was expected to have a negative impact on the Final Rule

Solution pairings because the Final Rule required an additional hour of rest in most situations.

Bid Lines

The Cygnus system was used to construct a complete set of bid lines for both the Baseline and 

Final Rule Solutions using the pairings from the solutions. The Baseline Solution bid lines were 

constructed in compliance with all FAR, contractual, management and discretionary constraints. 

The Final Rule Solution bid lines were constructed in compliance with all Final Rule, 

contractual, management and discretionary constraints.

Although the carrier used a preferential bidding system instead of bid lines, the basic line 

constraints were applicable to bid line construction as well. The primary rules used for 

construction of both Baseline and Final Rule Solution bid lines were:

• Minimum of 14 days off,

• No single days off,

• No single working days, except at the beginning/ending of the month,

• A target of 80 credit hours, with a maximum of 92,

• Minimize the amount of open time,

• No reserve days on any flying line, and

• All lines were valid for one captain and one first officer.

In addition to these rules, some common rules intended to improve flightcrew members’ quality 

of life were imposed, including:

• At least one block of three consecutive days off,

• Blocks of two consecutive working days were allowed, but penalized, with no more 

than two in any line,

• Trips were put into morning (report 05:00-12:30) and afternoon families, with mixing 

of different families allowed, but penalized, in any line, and

• No more than five blocks of consecutive working days during the month, to reduce 

the need for commuters to commute to/from their base.

Results

The Final Rule significantly impacted the practice of scheduling flightcrew members to the 

contract minimum 9:00 rest period to efficiently crew overnight aircraft due to the one hour 

increase in the minimum rest period. Many stations had two or more aircraft overnights and it 

was common practice to arrange the overnight ground times such that the earliest arriving 

aircraft could take the latest departing morning flight with the minimum 9:00 hour rest period. 

The other aircraft’s crew did not have enough time for a minimum overnight rest period and 

typically required midday staged crews. Often there were just enough midday flights to provide 
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September 2012 Page 12

staging for the aircraft that required it. Most of the Baseline Solution short layovers were no 

longer feasible for the Final Rule Solution. 

To maximize efficiency, Cygnus attempted to stage the crews on a midday flight, turning one 

layover into two. However, there frequently were no midday flights available for staging, 

necessitating either daily deadhead flights or double layovers of around 33 hours. The average 

layover time increased from 15:00 in the Baseline Solution to 16:46 in the Final Rule Solution, 

which was a significant increase of nearly two hours. The result was a sizeable increase in the 

number of required hotel rooms, deadhead time and overall synthetic time.8

None of the Final Rule cumulative flight or flight duty time constraints adversely affected the bid 

lines for the Final Rule Solution.

The Final Rule Solution was approximately three percent less efficient in terms of credit hours

than the Baseline Solution, as shown in Figure 3. The average number of duty hours and block 

hours per duty period decreased, which meant that the average flightcrew member had to work 

slightly more days per month. The Final Rule Solution required 4.5 percent more flightcrew 

member working days to complete the same flight schedule as in the Baseline Solution.

Figure 3: Case A Monthly Results

Credit hours consisted of the total number of hours for which flightcrew members were paid. 

Case A flightcrew members were paid full credit for all block hours and deadhead hours. They 

also received a 1-for-3.5 trip rig and a duty rig of 1-for-2 during the day or 1-for-1.75 at night. 

The average duty period minimum was 5:15.

 8 Synthetic time is the difference between block hours and credit hours and is primarily generated by deadhead 

credit, duty rigs, minimum guarantee, and/or trip rig.

Metric Crew 

Position Baseline Final Rule

Lines CA or FO 462 477 15 3.2%

Credit Hours All 74,274 76,461 2,187 2.9%

Block Hours All 71,303 71,288 -15 0.0%

Aircraft Block Hours N/A 35,652 35,644 -8 0.0%

Domestic TAFB All 251,500 270,160 18,660 7.4%

International TAFB All 0 0 0 N/A

Hotel Rooms All 8,772 9,432 660 7.5%

Average Duty Hours 

per Duty Period CA or FO 9.2 8.8 -0.4 -4.3%

Average Block Hours 

per Duty Period CA or FO 5.5 5.4 -0.1 -1.8%

Average Days Off per 

Month CA or FO 15.3 15.1 -0.2 -1.1%

Change
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September 2012 Page 13

Time away from base was all time spent away from a flightcrew member’s base while on a trip, 

from the time he reported for his first duty period until the end of his debrief period at his last 

duty period of the trip. All TAFB was domestic and increased by more than seven percent.

Hotel rooms were the number of hotel room nights associated with the layovers (duty breaks) in 

the solution plus any day rooms contractually required for long sit times between flights. The 

Final Rule Solution resulted in the use of more than seven percent more hotel rooms.
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Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 14

Case B: Mainline Passenger Narrow-Body

SUMMARY

Case B consisted of the short-haul operations of a mainline passenger carrier using narrow-body 

aircraft. Although the effective Final Rule maximum FDP time and minimum rest period limits 

were more restrictive than current practice, the Final Rule Solution was actually slightly more 

efficient in terms of credit hours than the Baseline Solution. Cygnus was able to re-optimize 

flightcrew member schedules to take advantage of less restrictive maximum flight time limits in 

a significant number of situations.

DETAILED RESULTS

Case B consisted of a subset of the short-haul operations of a mainline passenger carrier using 

narrow-body aircraft during the July 2010 scheduling period. There were more than 20,000 flight 

segments during the scheduling period, most of which were domestic. However, there were also 

some flight segments in Canada, Mexico, the Caribbean, Central America and South America. 

Since the carrier mixed domestic and international flying in its crew pairings, all of these flight

segments were included in the study. 

The augmentation and acclimation elements of the Final Rule did not affect Case B, as all of the 

flight segments operated with an unaugmented crew and all of the flightcrew members remained

acclimated at all times. The Baseline Solution did contain a significant number of split duties 

because a number of redeye flights operated nightly.

Buffers

The three main Final Rule rule elements that affected Case B were the maximum unaugmented 

flight time, maximum unaugmented FDP time and minimum rest period limits. CrewPairings 

applied buffers to both the maximum flight time and FDP time limits to reflect the fact that they 

applied to actual, rather than planned, operations. In Figure 4, the CrewPairings buffer is shown 

in the “CP Buffer” column, which, when applied to the “Final Rule” limit, resulted in the 

“Effective Final Rule” limit that was actually used when creating pairings for the Final Rule

Solution. However, if the contractual rule shown in the “Current CBA” column less the debrief 

time shown in the “Debrief” column was more restrictive than the “Effective Final Rule” limit, 

the contractual rule is shown in the “Effective Final Rule” column.

Figure 4 includes an “Effective Current Rule” column for comparison to the “Effective Final 

Rule” column. The “Effective Current Rule” is the more restrictive of the “Current FAR” 

column or “Current CBA” column, after applying the buffer in the “Current Buffer” column and 

the debrief time in the “Debrief” column.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 15

Figure 4: Case B Buffers

Pairings

The Baseline Solution pairings (equivalent to the Production Solution) were constructed with the 

constraints of the “Effective Current Rule” column in Figure 4, in addition to all other FAR, 

contractual, management and discretionary constraints not shown. The Final Rule Solution 

pairings were constructed with the constraints of the “Effective Final Rule” column in Figure 4, 

in addition to all other Final Rule, contractual, management and discretionary constraints not 

shown.

The maximum flight time limit applicable to the Baseline Solution was 8:00 hours, which was

the FAR limit. The maximum flight time limit applicable to the Final Rule Solution was between 

7:30 hours and 8:30 hours, depending on FDP start time, after application of a 30 minute buffer. 

The maximum flight time limit of the Final Rule was therefore expected to have a mixed impact 

on the Final Rule Solution pairings; in some situations the Effective Final Rule limit was more 

constraining than the Effective Current Rule and in other cases it was less constraining.

The maximum FDP limit applicable to the Baseline Solution was 10:15-13:15 hours, which was

the CBA limit, less a 15 minute debrief. The maximum FDP limit applicable to the Final Rule

Solution was 8:30-13:15 hours, depending on FDP start time, after application of a 30 minute 

buffer. The low end was the buffered Final Rule and the high end was the CBA limit. The 

maximum FDP limit of the Final Rule was therefore expected to have a negative impact on the 

Final Rule Solution pairings; the Effective Final Rule limit was more constraining than the 

Effective Current Rule in most situations.

The minimum rest period applicable to the Baseline Solution was 8:15-12:00 hours, depending 

on the amount of flight time in the previous 24 hour period, which was the buffered FAR 

requirement. The minimum rest period applicable to the Final Rule Solution was 10 hours. The 

Current FAR Current CBA Debrief Carrier 

Buffer

Effective 

Current Rule1 Final Rule CP 

Buffer

Effective Final 

Rule2

Maximum 

Unaugmented 

Flight Time

8:00 - - - 8:00 8:00 - 9:00 0:30 7:30 - 8:30

Maximum 

Unaugmented6

FDP Time

16:00 10:30 - 13:30 0:15 - 10:15 - 13:15 9:00 - 14:003 0:305 8:30 - 13:153

Minimum 

Unaugmented

Rest Time

8:00 - 12:004 8:00 - 0:15 8:15 - 12:004 10:00 - 10:00

4 Depending on the amount of flight time in the past 24-hour period

5 Plus the 0:30 de facto buffer resulting from §117.19 for a total of 1:00

6 The FDP concept does not exist in current FARs; therefore the Current columns in this row refer to duty time

1 The more restrictive of the current CBA, less debrief, or the FAR (adjusted for carrier buffer)

2 The more restrictive of the current CBA, less debrief, or the Final Rule (adjusted for CP buffer)

3

 Depending on FDP start time; Maximum show n is for 1 segment during FDP, reduced if 3 or more segments during FDP

Rule Element

Time in Hours:Minutes
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Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 16

minimum rest period of the Final Rule was therefore expected to have a negative impact on the 

Final Rule Solution pairings because the Effective Final Rule required minimum rest period was

nearly two hours greater than the Effective Current Rule in most situations.

Bid Lines

The Cygnus system was used to construct a complete set of bid lines for both the Baseline and 

Final Rule Solutions using the pairings from the solutions for Case B. The Baseline Solution bid 

lines were constructed in compliance with all FAR, contractual, management and discretionary 

constraints. The Final Rule Solution bid lines were constructed in compliance with all Final 

Rule, contractual, management and discretionary constraints.

The only Final Rule constraint that would potentially have had a significant impact on the Final 

Rule Solution bid lines was the consecutive nighttime operations limit. This constraint limited

flightcrew members to three consecutive flight duty periods that impinge on the window of 

circadian low unless the carrier provided the flightcrew member with a minimum two hour rest 

opportunity in a suitable accommodation during each FDP, in which case five consecutive flight 

duty periods were permitted. 

Although the carrier used a preferential bidding system instead of bid lines, the basic line 

constraints were applicable to bid line construction as well. The primary rules used for 

construction of both Baseline and Final Rule Solution bid lines were:

• Minimum of 12 days off,

• No single days off,

• No single working days, except at the beginning/ending of the month,

• A target of 83 credit hours, with a maximum of 92,

• Minimize the amount of open time,

• No reserve days on any flying line, and

• All lines are valid for one captain and one first officer.

In addition to these rules, some common rules intended to improve flightcrew members’ quality 

of life were imposed, including:

• At least one block of three consecutive days off,

• Blocks of two consecutive working days were allowed, but penalized, with no more 

than two in any line,

• Trips were put into morning (report 05:00-12:30) and afternoon families, with mixing 

of different families allowed, but penalized, in any line, and

• No more than five blocks of consecutive working days during the month, to reduce 

the need for commuters to commute to/from their base.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 17

Results

The Final Rule Solution was slightly more efficient in terms of credit hours than the Baseline 

Solution, as shown in Figure 5. Re-optimization of flightcrew member schedules under the Final 

Rule resulted in almost three percent less TAFB (net of domestic and international TAFB) and 

nearly six percent fewer hotel room nights required.

The increased minimum rest requirement (from 8:15 to 10:00) had the largest negative impact on 

the Final Rule Solution. The average layover time increased from 17:26 to 18:11, which reflected 

the increased usage of double layovers in the Final Rule Solution. The number of duty periods in 

the Final Rule Solution decreased relative to the Baseline Solution but the number of calendar 

days increased. This translated to 1.2 percent fewer days off per month per bid line.

Despite the negative impacts of the minimum rest requirement, the Final Rule had a positive 

impact as a whole because Cygnus was able to take advantage of the increased maximum flight 

time limit (maximum buffered flight time limit of 8:30 for duty periods beginning between 05:00 

and 19:59 base time) to create more efficient pairings. In the Final Rule Solution, 13 percent of 

duty periods exceeded eight hours of block time. The average block time per duty period 

increased by 3.4 percent from the Baseline Solution to the Final Rule Solution.

The Final Rule split duty constraint did not impact the Final Rule because each split duty had at 

least six hours of time between flight segments, which was much more than the three hours 

minimum rest opportunity required by the Final Rule, even after accounting for the 1:45 of 

debrief, transfer to rest facility and brief time.

The consecutive nighttime operations constraint did not ultimately have a negative impact on the 

Final Rule Solution, as Cygnus was able to create bid lines with no loss of productivity resulting 

from that constraint relative to the Baseline Solution.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 18

Figure 5: Case B Monthly Results

Credit hours consisted of the total number of hours for which flightcrew members were paid. 

Case B flightcrew members were paid full credit for all block hours and deadhead hours. They 

also received a 1-for-4 trip rig for trips with a duty break of more than 29 hours.

Time away from base was all time spent away from a flightcrew member’s base while on a trip, 

from the time he reported for his first duty period until the end of his debrief period at his last 

duty period of the trip. Domestic TAFB decreased by more than four percent and international 

TAFB increased by almost one percent.

Hotel rooms were the number of hotel room nights associated with the layovers (duty breaks) in 

the solution plus any day rooms contractually required for long sit times between flights.

Metric Crew 

Position Baseline Final Rule

Lines CA or FO 849 843 -6 -0.7%

Credit Hours All 140,975 140,547 -429 -0.3%

Block Hours All 138,313 138,386 73 0.1%

Aircraft Block Hours N/A 69,157 69,193 37 0.1%

Domestic TAFB All 355,923 340,888 -15,035 -4.2%

International TAFB All 156,387 157,417 1,030 0.7%

Hotel Rooms All 15,900 14,956 -944 -5.9%

Average Duty Hours 

per Duty Period CA or FO 8.1 8.5 0.4 4.9%

Average Block Hours 

per Duty Period CA or FO 5.8 6.0 0.2 3.4%

Average Days Off per 

Month CA or FO 14.7 14.6 -0.2 -1.2%

Change
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 19

Case C: Mainline Passenger Wide-Body

SUMMARY

Case C consisted of the long-haul operations of a mainline passenger carrier using wide-body 

aircraft. The Final Rule Solution was slightly more efficient in terms of credit hours than the 

Baseline Solution. The increased minimum rest period resulted in longer layovers for flightcrew 

members, which increased credit hours, TAFB and hotel rooms. However, these impacts were

mostly offset by the decreased credit hours, TAFB and hotel rooms that resulted from the ability 

to reduce the number of flightcrew members on some augmented operations because of 

increased maximum flight time limits and increased maximum flight time limits for 

unaugmented operations.

DETAILED RESULTS

Case C consisted of a subset of the long-haul operations of a mainline passenger carrier using 

wide-body aircraft during the January 2010 scheduling period. There were more than 6,000 flight 

segments during the scheduling period, most of which were domestic. However, there were also 

flight segments to Mexico, the Caribbean South America, Europe, Africa, the Middle East and 

Asia. Since the carrier mixed domestic and international flying in its crew pairings, all of these 

flight segments were included in the study.

Nearly all of the Final Rule constraints affected Case C, as many flight segments were operated 

with augmented crews. Case C had only a few split duty periods.

Buffers

The six main Final Rule rule elements that affected Case C were the maximum unaugmented and 

augmented flight time, maximum unaugmented and augmented FDP time and minimum 

unaugmented and augmented rest period limits. CrewPairings applied buffers to the maximum 

flight time and FDP time limits to reflect the fact that they applied to actual, rather than planned, 

operations. In Figure 6, the CrewPairings buffer is shown in the “CP Buffer” column, which, 

when applied to the “Final Rule” limit, resulted in the “Effective Final Rule” limit that was 

actually used when creating pairings for the Final Rule Solution. However, if the contractual rule 

shown in the “Current CBA” column less the debrief time shown in the “Debrief” column was 

more restrictive than the “Effective Final Rule” limit, the contractual rule is shown in the 

“Effective Final Rule” column.

Figure 6 includes an “Effective Current Rule” column for comparison to the “Effective Final 

Rule” column. The “Effective Current Rule” is the more restrictive of the “Current FAR” 

column or “Current CBA” column, after applying the buffer in the “Current Buffer” column and 

the debrief time in the “Debrief” column.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 20

Figure 6: Case C Buffers

Pairings

The Baseline Solution pairings (equivalent to the Production Solution) were constructed with the 

constraints of the “Effective Current Rule” column in Figure 6, in addition to all other FAR, 

contractual, management and discretionary constraints not shown. The Final Rule Solution 

pairings were constructed with the constraints of the “Effective Final Rule” column in Figure 6, 

in addition to all other Final Rule, contractual, management and discretionary constraints not 

shown.

The maximum unaugmented flight time limit applicable to the Baseline Solution was the FAR 

limit of 8:00 hours. The maximum unaugmented flight time limit applicable to the Final Rule

Solution was between 7:30 hours and 8:30 hours, depending on FDP start time, after application 

of a 30 minute buffer. The maximum unaugmented flight time limit of the Final Rule was

therefore expected to have a mixed impact on the Final Rule Solution pairings; in some 

situations the Effective Final Rule limit was more constraining than the Effective Current Rule 

and in other cases it was less constraining.

The maximum augmented flight time limit applicable to the Baseline Solution was the FAR limit 

of 12:00 hours for crews with one additional pilot or the FAR limit of 16:00 hours for crews with 

two additional pilots, less a ten minute buffer. The maximum augmented flight time limit 

applicable to the Final Rule Solution was the Final Rule limit of 13:00 hours for crews with one 

Current FAR Current CBA Debrief Carrier 

Buffer

Effective 

Current Rule1 Final Rule CP 

Buffer Effective Final Rule2

Maximum 

Unaugmented 

Flight Time

8:00 - - - 8:00 8:00 - 9:00 0:30 7:30 - 8:30

Maximum 

Augmented 

Flight Time

(3 crew) 12:00

(4 crew) 16:00 - - 0:10 (3 crew) 11:50

(4 crew) 15:50

(3 crew) 13:00

(4 crew) 17:00 0:30 (3 crew) 12:30(4 crew) 16:30

Maximum 

Unaugmented8

FDP Time

16:00 8:30 - 13:00 0:30 - 8:00 - 12:30 9:00 - 14:003 0:304 8:00 - 12:303

Maximum 

Augmented

FDP Time8

(3 crew) 16:00

(4 crew) no limit

(3 crew) 16:00

(4 crew) 18:00 - - (3 crew) 16:00(4 crew) 18:00

(3 crew) 15:00 - 17:005

(4 crew) 17:00 - 19:005 0:304 (3 crew) 14:30 - 16:005(4 crew) 16:30 - 18:005

Minimum 

Unaugmented

Rest Time

8:00 - 12:006 9:00 - - 9:00 - 12:006 10:00 - 10:00

Minimum 

Augmented

Rest Time

8:00 - 18:007 9:00 - - 9:00 - 18:007 10:00 - 10:00

8 The FDP concept does not exist in current FARs; therefore the Current columns in this row refer to duty time

1 The more restrictive of the current CBA, less debrief, or the FAR (adjusted for carrier buffer)

Rule Element

Time in Hours:Minutes

5 Depending on FDP start time; Maximum show n is for aircraft equipped w ith Class 1 rest facility, reduced if aircraft is equipped w ith low er class rest facility

2 The more restrictive of the current CBA, less debrief, or the Final Rule (adjusted for CP buffer)

3

 Depending on FDP start time; Maximum show n is for 1 segment during FDP, reduced if 3 or more segments during FDP

6 Depending on the amount of flight time in the past 24-hour period

7 Flag rules, including double out if crew exceeds 8-in-24, 18:00 after breaking 8-in-24, 20-in-48 or 24-in-72

4 Plus the 0:30 de facto buffer resulting from §117.19 for a total of 1:00
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 21

additional pilot or the Final Rule limit of 17:00 hours for crews with two additional pilots, less a 

30 minute buffer. The maximum augmented flight time limit of the Final Rule was therefore 

expected to have a positive impact on the Final Rule Solution pairings because the Effective 

Final Rule maximum augmented flight time was 40 minutes greater than the Effective Current 

Rule.

The maximum unaugmented FDP limit applicable to the Baseline Solution was 8:00-12:30 

hours, which was the CBA limit less a 30 minute debrief period. The maximum unaugmented 

FDP limit applicable to the Final Rule Solution was the same as the maximum unaugmented 

FDP limit applicable to the Baseline Solution, because the CBA less a 30 minute debrief period

was more constraining than the Final Rule. The maximum unaugmented FDP limit of the Final 

Rule was therefore expected to have no impact on the Final Rule Solution pairings.

The maximum augmented FDP limit applicable to the Baseline Solution was 16:00 hours for 

crews with one additional pilot and 18:00 hours for crews with two additional pilots, which were

the CBA limits. The maximum augmented FDP limit applicable to the Final Rule Solution was

the Final Rule less the 30 minute buffer applied by CrewPairings. The maximum augmented 

FDP limit of the Final Rule was therefore expected to have a negative impact on the Final Rule

Solution pairings because the Effective Final Rule was more restrictive than the Effective 

Current Rule in most situations.

The minimum rest period applicable to the Baseline Solution was 9:00-18:00 hours, depending 

on the amount of flight time in the previous 24 hour period. The CBA minimum rest period was

9:00 hours, but the FAR required additional rest time if the amount of flight time in the 

preceding 24 hour period exceeded eight hours. The minimum rest period applicable to the Final 

Rule Solution was 10:00 hours, which was expected to have a negative impact on the Final Rule

Solution pairings because the Final Rule required an additional one hour of rest in most 

situations.

Bid Lines

The Cygnus system was used to construct a complete set of bid lines for both the Baseline and 

Final Rule Solutions using the pairings from the solutions. The Baseline Solution bid lines were 

constructed in compliance with all FAR, contractual, management and discretionary constraints. 

The Final Rule Solution bid lines were constructed in compliance with all Final Rule, 

contractual, management and discretionary constraints.

Although the carrier used a preferential bidding system instead of bid lines, the basic line 

constraints were applicable to bid line construction as well. The primary rules used for 

construction of both Baseline and Final Rule Solution bid lines were:

• Minimum of 14 days off,

• No single days off,

• No single working days, except at the beginning/ending of the month,

• A target of 76 credit hours, with a maximum of 84,

• Minimize the amount of open time,
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 22

• No reserve days on any flying line,

• Two-day blocks of both work and days off prohibited in most cases, and

• Blocks of work normally limited to a maximum of six days, although individual trips 

longer than six days are allowed to exceed the limit.

Lines were built separately for each base and crew type.

Results

The Final Rule Solution was slightly more efficient in terms of credit hours than the Baseline 

Solution, as shown in Figure 7. Re-optimization of flightcrew member schedules under the Final 

Rule resulted in almost four percent more TAFB and almost ten percent more hotel room nights.

Figure 7: Case C Monthly Results

The increased minimum rest period and increased augmented flight time limits had the greatest 

impact during creation of the Final Rule Solution pairings. The increased minimum rest period 

negatively impacted the pairings while the increased augmented flight time limits positively 

impacted the pairings; the net impact was a slight decrease in credit hours.

The increased minimum rest period negatively impacted domestic operations pairings for the 

most part because the carrier created flight schedules that were designed to optimize flightcrew 

member scheduling given the minimum 9:00 hour rest period prescribed by the labor agreement. 

Metric Crew 

Position Baseline Final Rule

CA or FO 451 457 6 1.3%

IO 205 202 -3 -1.5%

RC 14 8 -6 -42.9%

Credit Hours All 85,806 85,736 -70 -0.1%

Block Hours All 80,754 77,264 -3,490 -4.3%

Aircraft Block Hours N/A 32,412 32,424 13 0.0%

Domestic TAFB All 126,747 130,610 3,863 3.0%

International TAFB All 205,626 213,974 8,348 4.1%

Hotel Rooms All 8,241 9,032 791 9.6%

CA or FO 9.3 9.5 0.2 2.2%

IO 10.8 11.0 0.2 1.9%

RC 13.6 14.0 0.4 2.9%

CA or FO 6.9 6.9 0.0 0.0%

IO 9.1 7.4 -1.7 -18.7%

RC 12.1 6.5 -5.6 -46.3%

CA or FO 16.5 16.8 0.3 1.6%

IO 16.7 17.0 0.3 1.8%

RC 15.1 18.1 3.1 20.3%

Lines

Average Duty Hours 

per Duty Period

Average Block Hours 

per Duty Period

Average Days Off per 

Month

Change
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 23

Many stations had two or more aircraft overnights and it was common practice to arrange the 

overnight ground times such that the earliest arriving aircraft could take the latest departing 

morning flight with a minimum nine hour rest period. The other aircraft’s crew did not have 

enough time for a minimum overnight and typically required midday staged crews. Often there 

were just enough midday flights to provide staging for the aircraft that required it.

The Final Rule significantly impacted this practice due to the one hour increase in the minimum 

rest period. Most of the planned short layovers were no longer feasible in the Final Rule

Solution. To maximize efficiency, Cygnus attempted to stage the crews on a midday flight, 

turning one layover into two. However, there frequently were no midday flights available for 

staging, necessitating either daily deadhead flights or double layovers of around 33 hours. The 

number of layovers of 30 hours or more increased from 59 to 147. This was reflected in the 

increased average number of days per trip, which increased from 3.75 in the Baseline Solution to 

4.23 in the Final Rule Solution. The result was a sizeable increase in the number of required 

hotel rooms, deadhead time and overall synthetic time.

This negative impact was offset by the positive impacts associated with the increased maximum 

augmented flight time limits of the Final Rule. Even after application of a 30 minute buffer, the 

Effective Final Rule allowed 40 additional minutes of flight time for crews with both one and 

two additional flightcrew members. This allowed the carrier to reduce the number of flightcrew 

members on some trips to Europe from the East Coast from three to two. Similarly, the number 

of flightcrew members on some trips to Asia from the West Coast was reduced from four to 

three.

The average block hours per duty period decreased dramatically for the additional flightcrew 

member positions. This was because Cygnus scheduled additional flightcrew members on 

deadhead flights if they were not required to operate the flight in the Final Rule Solution, which 

was in contrast to the practice in the Baseline Solution of scheduling additional flightcrew 

members to operate the flight even if it was not required. Since flightcrew members received full 

credit for deadhead time, the impact on the average credit hours per duty period was much less 

dramatic. Average credit hours per duty period decreased by 2.1 percent for IOs and 0.8 percent 

for RCs.

None of the Final Rule cumulative flight or flight duty constraints adversely affected the bid 

lines for the Final Rule Solution.

Credit hours consisted of the total number of hours for which flightcrew members were paid. 

Case C flightcrew members were paid full credit for all block hours and deadhead hours. They 

also received a 1-for-3.5 trip rig and a duty rig of 1-for-2 during the day or 1-for-1.75 at night. 

The average duty period minimum was 5:15.

Time away from base was all time spent away from a flightcrew member’s base while on a trip, 

from the time he reported for his first duty period until the end of his debrief period at his last 

duty period of the trip. Domestic TAFB increased by three percent and international TAFB 

increased by four percent.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 24

Hotel rooms were the number of hotel room nights associated with the layovers (duty breaks) in 

the solution plus any day rooms contractually required for long sit times between flights. The 

number of required hotel rooms increased by nearly ten percent.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 25

Case D: Mainline Passenger Wide-Body

SUMMARY

Case D consisted of the long-haul operations of a mainline passenger carrier using wide-body 

aircraft. Although the effective Final Rule maximum augmented FDP time and minimum rest 

period limits were more restrictive than current practice, the Final Rule Solution was more 

efficient in terms of credit hours than the Baseline Solution. Cygnus was able to re-optimize 

flightcrew member schedules to take advantage of less restrictive maximum flight time limits in 

some situations, resulting in fewer credit hours, TAFB and hotel rooms for the Case D Final Rule

Solution. 

DETAILED RESULTS

Case D consisted of a subset of the long-haul operations of a mainline passenger carrier using 

wide-body aircraft during the July 2010 scheduling period. There were nearly 1,000 flight 

segments during the scheduling period, all of which were international. Each trip consisted of a 

single flight segment between a domestic location and an international location in Europe, the 

Middle East or Asia. Almost every trip used an augmented flightcrew.

Buffers

The six main Final Rule rule elements that affected Case D were the maximum unaugmented and 

augmented flight time, maximum unaugmented and augmented FDP time and minimum 

unaugmented and augmented rest period limits. CrewPairings applied buffers to the maximum 

flight time and FDP time limits to reflect the fact that they applied to actual, rather than planned, 

operations. In Figure 8, the CrewPairings buffer is shown in the “CP Buffer” column, which, 

when applied to the “Final Rule” limit, resulted in the “Effective Final Rule” limit that was 

actually used when creating pairings for the Final Rule Solution. However, if the contractual rule 

shown in the “Current CBA” column less the debrief time shown in the “Debrief” column was 

more restrictive than the “Effective Final Rule” limit, the contractual rule was shown in the 

“Effective Final Rule” column.

Figure 8 includes an “Effective Current Rule” column for comparison to the “Effective Final 

Rule” column. The “Effective Current Rule” is the more restrictive of the “Current FAR” 

column or “Current CBA” column, after applying the buffer in the “Current Buffer” column and 

the debrief time in the “Debrief” column.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 26

Figure 8: Case D Buffers

Pairings

The Baseline Solution pairings (equivalent to the Production Solution) were constructed with the 

constraints of the “Effective Current Rule” column in Figure 8, in addition to all other FAR, 

contractual, management and discretionary constraints not shown. The Final Rule Solution 

pairings were constructed with the constraints of the “Effective Final Rule” column in Figure 8, 

in addition to all other Final Rule, contractual, management and discretionary constraints not 

shown.

The maximum unaugmented flight time limit applicable to the Baseline Solution was 7:50 hours, 

which was the FAR limit less a ten minute buffer. The maximum unaugmented flight time limit 

applicable to the Final Rule Solution was between 7:30 hours and 8:30 hours, depending on FDP 

start time, after application of a 30 minute buffer. The maximum flight time limit of the Final 

Rule was therefore expected to have a possible positive impact on the Final Rule Solution 

pairings; in some situations the Effective Final Rule limit could allow flights currently operating 

with one additional flightcrew member to operate with no additional flightcrew members.

The maximum augmented flight time limits applicable to the Baseline Solution were 11:50 

hours, which was the FAR limit less a ten minute buffer, for flights with one additional 

flightcrew member and 16 hours, which was the FAR limit, for flights with two additional 

flightcrew members. The maximum augmented flight time limits applicable to the Final Rule

Solution were 12:30 hours for flights with one additional flightcrew member and 16:30 hours for 

Current FAR Current CBA Debrief Carrier 

Buffer

Effective 

Current Rule1 Final Rule CP 

Buffer Effective Final Rule2

Maximum 

Unaugmented 

Flight Time

8:00 - - 0:10 7:50 8:00 - 9:00 0:30 7:30 - 8:30

Maximum 

Augmented 

Flight Time

(3 crew) 12:00

(4 crew) 16:00 - - (3 crew) 0:10

(4 crew) 0:00

(3 crew) 11:50

(4 crew) 16:00

(3 crew) 13:00

(4 crew) 17:00 0:30 (3 crew) 12:30

(4 crew) 16:30

Maximum 

Unaugmented8

FDP Time

16:00 10:30 - 13:30 0:30 - 10:00 - 13:00 9:00 - 14:003 0:304 8:30 - 13:303

Maximum 

Augmented

FDP Time8

(3 crew) 16:00

(4 crew) no limit

(3 crew) 16:00

(4 crew) 18:00 - - (3 crew) 16:00

(4 crew) 18:00

(3 crew) 15:00 - 17:005

(4 crew) 17:00 - 19:005 0:304 (3 crew) 14:30 - 16:005(4 crew) 16:30 - 18:005

Minimum 

Unaugmented

Rest Time

8:00 - 12:006 8:00 - 0:15 8:15 - 12:006 10:00 - 10:00

Minimum 

Augmented

Rest Time

8:00 - 18:007 8:00 - 1:00 9:00 - 18:007 10:00 - 10:00

8 The FDP concept does not exist in current FARs; therefore the Current columns in this row refer to duty time

1 The more restrictive of the current CBA, less debrief, or the FAR (adjusted for carrier buffer)

Rule Element

Time in Hours:Minutes

5 Depending on FDP start time; Maximum show n is for aircraft equipped w ith Class 1 rest facility, reduced if aircraft is equipped w ith low er class rest facility

2 The more restrictive of the current CBA, less debrief, or the Final Rule (adjusted for CP buffer)

3

 Depending on FDP start time; Maximum show n is for 1 segment during FDP, reduced if 3 or more segments during FDP

6 Depending on the amount of flight time in the past 24-hour period

7 Flag rules, including double out if crew exceeds 8-in-24, 18:00 after breaking 8-in-24, 20-in-48 or 24-in-72

4 Plus the 0:30 de facto buffer resulting from §117.19 for a total of 1:00
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 27

flights with two additional flightcrew members, which were the Final Rule limits, after 

application of a 30 minute buffer. The maximum augmented flight time limits of the Final Rule

were therefore expected to have a positive impact on the Final Rule Solution pairings, as they 

allowed between 30 and 40 additional minutes of flight time.

The maximum unaugmented FDP limit applicable to the Baseline Solution was 10:00-13:00

hours, which was the CBA limit, less a 30 minute international debrief. The maximum

unaugmented FDP limit applicable to the Final Rule Solution was 8:30-13:00 hours, depending 

on FDP start time, after application of a 30 minute buffer. The low end was the buffered Final 

Rule and the high end was the CBA limit. The maximum unaugmented FDP limit of the Final 

Rule was therefore expected to have a negative impact on the Final Rule Solution pairings; the 

Effective Final Rule limit was more constraining than the Effective Current Rule in most 

situations.

The maximum augmented FDP limit applicable to the Baseline Solution was 16:00 hours for 

flights with one additional flightcrew member and 18:00 hours for flights with two additional 

flightcrew members, which were the CBA limits. The maximum augmented FDP limits

applicable to the Final Rule Solution were 14:30-16:00 hours for flights with one additional 

flightcrew members and 16:30-18:00 hours for flights with two additional flightcrew members, 

depending on FDP start time, after application of a 30 minute buffer. The maximum augmented 

FDP limits of the Final Rule were therefore expected to have a negative impact on the Final Rule

Solution pairings; the Effective Final Rule limits were more constraining than the Effective 

Current Rule in most situations.

The minimum rest periods applicable to the Baseline Solution were 8:15-12:00 hours for 

unaugmented operations and 9:00-18:00 hours for augmented operations, depending on the 

amount of flight time in the previous 24 hour period, which were the buffered FAR 

requirements. The minimum rest period applicable to the Final Rule Solution was 10:00 hours. 

The minimum rest period of the Final Rule was therefore expected to have a negative impact on 

the Final Rule Solution pairings; the Effective Final Rule period was between one and two hours 

greater than the Effective Current Rule in most situations.

Bid Lines

The Cygnus system was used to construct a complete set of bid lines for both the Baseline and 

Final Rule Solutions using the pairings from the solutions. The Baseline Solution bid lines were 

constructed in compliance with all FAR, contractual, management and discretionary constraints. 

The Final Rule Solution bid lines were constructed in compliance with all Final Rule, 

contractual, management and discretionary constraints.

Although the carrier used a preferential bidding system instead of bid lines, the basic line 

constraints were applicable to bid line construction as well. The primary rules used for 

construction of both Baseline and Final Rule Solution bid lines were:

• Minimum of 12 days off,

• No single days off,
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 28

• No single working days, except at the beginning/ending of the month,

• A target of 83 credit hours, with a maximum of 92,

• Minimize the amount of open time, and

• No reserve days on any flying line.

Results

The Final Rule Solution was able to reduce the use of TAFB and hotel rooms by a full 30 days 

for the scheduling period for a particular pairing between the East Coast and the Middle East, 

because of the change in minimum duty break regulations. The FAR required a longer duty break 

for flightcrew members that flew more than eight hours in a 24 hour period. The Final Rule

replaced that provision with a uniform minimum duty break of 10 hours. This change allowed 

the optimizer to create 13-18 hour layovers in the Final Rule Solution, rather than the 25-30 hour 

layovers in the Baseline Solution. 

There was an increase in credit hours, TAFB and hotel rooms associated with the need for a third 

flightcrew member for a particular pairing between the East Coast and Western Europe in the 

Final Rule Solution. The block time for this pairing was less than the eight hour maximum flight 

time limit permitted by the FAR and Final Rule, but was more than the buffered Effective Final 

Rule maximum flight time limit of 7:30.

The increase in credit hours, TAFB and hotel rooms associated with the third pilot was more 

than outweighed by the decrease associated with the fourth pilot. The effective maximum flight 

time limit for an augmented flight with three flightcrew members increased from 11:50 to 12:30. 

This change meant that the previously referenced pairing between the East Coast and the Middle 

East could be completed with an augmented flightcrew of three flightcrew members rather than 

four.

Cygnus was able to re-optimize pairings to eliminate nearly all conflicts with maximum flight 

time, maximum FDP time and minimum rest period limits while reducing credit hours, TAFB 

and hotel rooms relative to the Baseline Solution. The Final Rule Solution was almost three

percent more efficient in terms of credit hours than the Baseline Solution, as shown in Figure 9.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 29

Figure 9: Case D Monthly Results

Credit hours consisted of the total number of hours for which flightcrew members were paid. 

Case D flightcrew members were paid full credit for all block hours and deadhead hours. They 

also received a 1-for-4 trip rig for trips with a duty break of more than 29 hours. The difference 

in block hours was greater than the difference in credit hours because flightcrew members were

paid at the same credit hour rate for deadhead flights.

Time away from base was all time spent away from a flightcrew member’s base while on a trip, 

from the time he reported for his first duty period until the end of his debrief period at his last 

duty period of the trip. All TAFB in Case D was international.

Hotel rooms were the number of hotel room nights associated with the layovers (duty breaks) in 

the solution plus any day rooms contractually required for long sit times between flights. The 

number of required hotel rooms decreased by about nine percent.

Metric Crew 

Position Baseline Final Rule

CA or FO 117 116 -1 -0.9%

IO 111 116 5 4.5%

RC 85 70 -15 -17.6%

Credit Hours All 35,863 34,898 -965 -2.7%

Block Hours All 35,863 33,753 -2,111 -5.9%

Aircraft Block Hours N/A 9,725 9,699 -26 -0.3%

Domestic TAFB All 0 0 0 N/A

International TAFB All 114,962 112,221 -2,741 -2.4%

Hotel Rooms All 1,620 1,586 -34 -2.1%

CA or FO 13.2 13.2 0.0 0.0%

IO 13.6 13.2 -0.4 -2.9%

RC 14.9 15.5 0.6 4.0%

CA or FO 12.0 12.0 0.0 0.0%

IO 12.3 11.4 -0.9 -7.3%

RC 13.6 12.6 -1.0 -7.4%

CA or FO 18.9 18.8 -0.1 -0.4%

IO 19.1 19.1 0.0 0.0%

RC 19.9 20.2 0.3 1.6%

Change

Lines

Average Duty Hours 

per Duty Period

Average Block Hours 

per Duty Period

Average Days Off per 

Month
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 30

Case E: Regional Passenger

SUMMARY

Case E consisted of the operations of a regional passenger carrier using regional jet aircraft. The 

Final Rule Solution was slightly less efficient in terms of credit hours and significantly less 

efficient in terms of TAFB and hotel rooms than the Baseline Solution mainly because of the 

increased minimum rest period. This resulted in longer layovers for flightcrew members, which 

increased TAFB and hotel rooms. The changes in maximum flight time and maximum FDP time 

limits had little impact on Case E.

DETAILED RESULTS

Case E consisted of a subset of the operations of a regional passenger carrier using regional jet

aircraft during the July 2010 scheduling period. The Case consisted of all flight segments 

operated for one mainline passenger carrier client. The Case E carrier maintained complete 

separation between sub-fleets operated for mainline passenger carrier clients when scheduling 

flightcrew members. There were nearly 6,000 flight segments during the scheduling period, all of 

which were domestic. Flights to Canada were considered domestic for flightcrew member 

scheduling purposes by the carrier.

The augmentation and acclimation elements of the Final Rule did not affect Case E, as all of the 

flight segments were operated with an unaugmented crew and all of the flightcrew members 

remained acclimated at all times. Case E did not have any split duty periods.

Buffers

The three main Final Rule rule elements that affected Case E were the maximum unaugmented 

flight time, maximum unaugmented FDP time and minimum rest period limits. CrewPairings 

applied buffers to both the maximum flight time and FDP time limits to reflect the fact that they 

applied to actual, rather than planned, operations. In Figure 10, the CrewPairings buffer is shown 

in the “CP Buffer” column, which, when applied to the “Final Rule” limit, resulted in the 

“Effective Final Rule” limit that was actually used when creating pairings for the Final Rule

Solution. However, if the contractual rule shown in the “Current CBA” column less the debrief 

time shown in the “Debrief” column was more restrictive than the “Effective Final Rule” limit, 

the contractual rule is shown in the “Effective Final Rule” column.

Figure 10 includes an “Effective Current Rule” column for comparison to the “Effective Final 

Rule” column. The “Effective Current Rule” is the more restrictive of the “Current FAR” 

column or “Current CBA” column, after applying the buffer in the “Current Buffer” column and 

the debrief time in the “Debrief” column.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 31

Figure 10: Case E Buffers

Pairings

The Baseline Solution pairings (equivalent to the Production Solution) were constructed with the 

constraints of the “Effective Current Rule” column in Figure 10, in addition to all other FAR, 

contractual, management and discretionary constraints not shown. The Final Rule Solution 

pairings were constructed with the constraints of the “Effective Final Rule” column in Figure 10, 

in addition to all other Final Rule, contractual, management and discretionary constraints not 

shown.

The maximum flight time limit applicable to the Baseline Solution was 8:00 hours, which was

the FAR limit. The maximum flight time limit applicable to the Final Rule Solution was between 

7:30 hours and 8:30 hours, depending on FDP start time, after application of a 30 minute buffer. 

The maximum flight time limit of the Final Rule was therefore expected to have a mixed impact 

on the Final Rule Solution pairings; in some situations the Effective Final Rule limit was more 

constraining than the Effective Current Rule and in other cases it was less constraining.

The maximum FDP limit applicable to the Baseline Solution was 13:45 hours, which was the 

CBA limit less a 15 minute debrief period. The maximum FDP limit applicable to the Final Rule

Solution was between 8:30 and 13:30, which was the Final Rule less a 30 minute buffer. The 

maximum FDP limit of the Final Rule was expected to have a negative impact on the Final Rule

Solution pairings because the Effective Final Rule limit was more constraining than the Effective 

Current Rule in all situations.

The minimum rest period applicable to the Baseline Solution was 8:30-12:00 hours, depending 

on the amount of flight time in the previous 24 hour period. The CBA minimum rest period was

8:00 hours, but the FAR required additional rest time if the amount of flight time in the 

preceding 24 hour period exceeded eight hours. The carrier applied a 30 minute buffer. The 

Current FAR Current CBA Debrief Carrier 

Buffer

Effective 

Current Rule1 Final Rule CP 

Buffer

Effective Final 

Rule2

Maximum 

Unaugmented 

Flight Time

8:00 - - - 8:00 8:00 - 9:00 0:30 7:30 - 8:30

Maximum 

Unaugmented

FDP Time6

16:00 14:00 0:15 - 13:45 9:00 - 14:003 0:305 8:30 - 13:303

Minimum 

Unaugmented

Rest Time

8:00 - 12:004 8:00 - 0:30 8:30 - 12:00 10:00 - 10:00

6 The FDP concept does not exist in current FARs; therefore the Current columns in this row refer to duty time

Rule Element

Time in Hours:Minutes

1 The more restrictive of the current CBA, less debrief, or the FAR (adjusted for carrier buffer)

2 The more restrictive of the current CBA, less debrief, or the Final Rule (adjusted for CP buffer)

3

 Depending on FDP start time; Maximum show n is for 1 segment during FDP, reduced if 3 or more segments during FDP

4 Depending on the amount of flight time in the past 24-hour period

5 Plus the 0:30 de facto buffer resulting from §117.19 for a total of 1:00
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 32

minimum rest period applicable to the Final Rule Solution was 10:00 hours, which was expected 

to have a negative impact on the Final Rule Solution pairings because the Final Rule required an

additional ninety minutes of rest in most situations.

Bid Lines

The Cygnus system was used to construct a complete set of bid lines for both the Baseline and 

Final Rule Solutions using the pairings from the solutions. The Baseline Solution bid lines were 

constructed in compliance with all FAR, contractual, management and discretionary constraints. 

The Final Rule Solution bid lines were constructed in compliance with all Final Rule, 

contractual, management and discretionary constraints.

Although the carrier used a preferential bidding system instead of bid lines, the basic line 

constraints were applicable to bid line construction as well. The primary rules used for 

construction of both Baseline and Final Rule Solution bid lines were:

• Minimum of 12 days off,

• At least one block of three consecutive days off,

• No single days off,

• No single working days, except at the beginning/ending of the month,

• A target of 85 credit hours, with a maximum of 92,

• Minimize the amount of open time,

• No reserve days on any flying line, and

• All lines are valid for one captain and one first officer.

In addition to these rules, some common rules intended to improve flightcrew members’ quality 

of life were imposed, including:

• Blocks of two consecutive working days were allowed, but penalized, with no more 

than two in any line,

• Trips were put into morning (report 05:00-12:30) and afternoon families, with mixing 

of different families allowed, but penalized, in any line, and

• No more than five blocks of consecutive working days during the month, to reduce 

the need for commuters to commute to/from their base.

Results

The Final Rule Solution was slightly less efficient in terms of credit hours than the Baseline 

Solution, as shown in Figure 3. Re-optimization of flightcrew member schedules under the Final 

Rule resulted in more than eight percent more hotel room nights required and six percent more 

TAFB. 

The increased minimum rest period had the greatest impact on the Case E pairings because the 

carrier created flight schedules that were designed to optimize flightcrew member scheduling 

given the minimum 8:00 hour rest period required by the FAR plus a 30 minute buffer applied by 
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 33

the carrier. At many stations, the aircraft overnight time was less than the 10:00 hours required 

by the Final Rule. CrewPairings increased the standard maximum allowed duty break from 27:00 

to 33:00 hours to address this problem. Increasing the maximum allowed duty break added the 

alternative of double layovers9 to the options of staging crews using midday flights or using 

deadhead flights. 

The number of layovers of 30 hours or more increased from 0 in the Baseline Solution to 239 in 

the Final Rule Solution. The average layover increased from 16:15 to 19:39, which was a 

significant increase of more than three hours. The result was a sizeable increase in the number of 

required hotel rooms, deadhead time and TAFB. Although the Baseline Solution contained a 

number of split duties, the Final Rule did not adversely affect them, because there was enough 

time between flight segments to satisfy the Final Rule split duty constraint.

The Final Rule maximum flight time limit of nine hours (8:30 buffered limit) had a positive 

impact on the pairings. Nearly eight percent of Final Rule Solution duty periods had flight time 

in excess of eight hours.

The net impact of the longer average layovers and increased maximum flight time limit was that 

flightcrew members had to work about six percent more duty and block hours per duty period, 

but had nearly five percent fewer average days off per month.

None of the Final Rule cumulative flight or flight duty time constraints adversely affected the bid 

lines for the Final Rule Solution.

Figure 11: Case E Monthly Results

 9 Double layovers are duty breaks of 27:00 to 33:00 hours.

Metric Crew 

Position Baseline Final Rule

Lines CA or FO 150 152 2 1.3%

Credit Hours All 25,763 25,820 57 0.2%

Block Hours All 24,998 24,987 -11 0.0%

Aircraft Block Hours N/A 12,499 12,494 -6 0.0%

Domestic TAFB All 96,243 102,054 5,812 6.0%

International TAFB All 0 0 0 N/A

Hotel Rooms All 3,344 3,624 280 8.4%

Average Duty Hours 

per Duty Period CA or FO 8.2 8.7 0.5 6.1%

Average Block 

Hours per Duty CA or FO 5.3 5.6 0.3 5.7%

Average Days Off 

per Month CA or FO 14.9 14.2 -0.7 -4.7%

Change
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 34

Credit hours consisted of the total number of hours for which flightcrew members were paid. 

Case E flightcrew members were paid full credit for all block hours and 75 percent credit for 

deadhead hours.

Time away from base was all time spent away from a flightcrew member’s base while on a trip, 

from the time he reported for his first duty period until the end of his debrief period at his last 

duty period of the trip.

Hotel rooms were the number of hotel room nights associated with the layovers (duty breaks) in 

the solution plus any day rooms contractually required for long sit times between flights.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 35

Case F: Regional Passenger

SUMMARY

Case F consisted of the operations of a regional passenger carrier using regional jet aircraft. The 

Final Rule Solution was slightly less efficient in terms of credit hours than the Baseline Solution 

mainly because of the increased minimum rest period. This resulted in longer layovers for 

flightcrew members, which increased credit hours, TAFB and hotel rooms. The changes in 

maximum flight time and maximum FDP time limits had little impact on Case F.

DETAILED RESULTS

Case F consisted of a subset of the operations of a regional passenger carrier using regional jet 

aircraft during the November 2010 scheduling period. The Case consisted of all flight segments 

operated for one mainline passenger carrier client. The Case F carrier maintained complete 

separation between sub-fleets operated for mainline passenger carrier clients when scheduling 

flightcrew members. There were more than 6,000 flight segments during the scheduling period, 

most of which were domestic. However, there were also some flight segments to Mexico. Since 

the carrier mixed domestic and international flying in its crew pairings, all of these flight 

segments were included in the analysis.

The augmentation and acclimation elements of the Final Rule did not affect Case F, as all of the 

flight segments were operated with an unaugmented crew and all of the flightcrew members 

remained acclimated at all times. Case F did not have any split duty periods.

Buffers

The three main Final Rule rule elements that affected Case F were the maximum unaugmented 

flight time, maximum unaugmented FDP time and minimum rest period limits. CrewPairings 

applied buffers to both the maximum flight time and FDP time limits to reflect the fact that they 

applied to actual, rather than planned, operations. In Figure 12, the CrewPairings buffer is shown 

in the “CP Buffer” column, which, when applied to the “Final Rule” limit, resulted in the 

“Effective Final Rule” limit that was actually used when creating pairings for the Final Rule

Solution. However, if the contractual rule shown in the “Current CBA” column less the debrief 

time shown in the “Debrief” column was more restrictive than the “Effective Final Rule” limit, 

the contractual rule is shown in the “Effective Final Rule” column.

Figure 12 includes an “Effective Current Rule” column for comparison to the “Effective Final 

Rule” column. The “Effective Current Rule” is the more restrictive of the “Current FAR” 

column or “Current CBA” column, after applying the buffer in the “Current Buffer” column and 

the debrief time in the “Debrief” column.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 36

Figure 12: Case F Buffers

Pairings

The Baseline Solution pairings (equivalent to the Production Solution) were constructed with the 

constraints of the “Effective Current Rule” column in Figure 12, in addition to all other FAR, 

contractual, management and discretionary constraints not shown. The Final Rule Solution 

pairings were constructed with the constraints of the “Effective Final Rule” column in Figure 12, 

in addition to all other Final Rule, contractual, management and discretionary constraints not 

shown.

The maximum flight time limit applicable to the Baseline Solution was 8:00 hours, which was

the FAR limit. The maximum flight time limit applicable to the Final Rule Solution was between 

7:30 hours and 8:30 hours, depending on FDP start time, after application of a 30 minute buffer. 

The maximum flight time limit of the Final Rule was therefore expected to have a mixed impact 

on the Final Rule Solution pairings; in some situations the Effective Final Rule limit was more 

constraining than the Effective Current Rule and in other cases it was less constraining.

The maximum FDP limit applicable to the Baseline Solution was 13:15-13:40 hours, which was

the CBA limit less a 15 minute debrief period and five to thirty minute buffer. The maximum 

FDP limit applicable to the Final Rule Solution was between 8:30 and 13:30, which was the 

Final Rule less a 30 minute buffer. The maximum FDP limit of the Final Rule was expected to 

have a negative impact on the Final Rule Solution pairings because the Effective Final Rule limit 

was more constraining than the Effective Current Rule in all situations.

The minimum rest period applicable to the Baseline Solution was 8:50-12:00 hours, depending 

on the amount of flight time in the previous 24 hour period. The CBA minimum rest period was

8:00 hours, but the FAR required additional rest time if the amount of flight time in the 

preceding 24 hour period exceeded eight hours. The carrier applied a 50 minute buffer to the 

minimum rest period. The minimum rest period applicable to the Final Rule Solution was 10:00

Current FAR Current CBA Debrief Carrier 

Buffer

Effective 

Current Rule1 Final Rule CP 

Buffer

Effective Final 

Rule2

Maximum 

Unaugmented 

Flight Time

8:00 - - - 8:00 8:00 - 9:00 0:30 7:30 - 8:30

Maximum 

Unaugmented

FDP Time6

16:00 14:00 0:15 0:05 - 0:30 13:15 - 13:40 9:00 - 14:003 0:305 8:30 - 13:303

Minimum 

Unaugmented

Rest Time

8:00 - 12:004 8:00 - 0:50 8:50 - 12:004 10:00 - 10:00

6 The FDP concept does not exist in current FARs; therefore the Current columns in this row refer to duty time

Rule Element

Time in Hours:Minutes

5 Plus the 0:30 de facto buffer resulting from §117.19 for a total of 1:00

1 The more restrictive of the current CBA, less debrief, or the FAR (adjusted for carrier buffer)

2 The more restrictive of the current CBA, less debrief, or the Final Rule (adjusted for CP buffer)

3

 Maximum for 1 segment during FDP, reduced if 3 or more segments during FDP

4 Depending on the amount of flight time in the past 24-hour period
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 37

hours, which was expected to have a negative impact on the Final Rule Solution pairings because 

the Final Rule required an additional 70 minutes of rest in most situations.

Bid Lines

The Cygnus system was used to construct a complete set of bid lines for both the Baseline and 

Final Rule Solutions using the pairings from these solutions. The Baseline Solution bid lines 

were constructed in compliance with all FAR, contractual, management and discretionary 

constraints. The Final Rule Solution bid lines were constructed in compliance with all Final 

Rule, contractual, management and discretionary constraints.

Although the carrier used a preferential bidding system instead of bid lines, the basic line 

constraints were applicable to bid line construction as well. The primary rules used for 

construction of both Baseline and Final Rule Solution bid lines were:

• Minimum of 11 days off,

• At least one block of three consecutive days off,

• No single days off,

• No single working days, except at the beginning/ending of the month,

• A target of 83 credit hours, with a maximum of 98,

• Minimize the amount of open time,

• No reserve days on any flying line, and

• All lines are valid for one captain and one first officer.

In addition to these rules, some common rules intended to improve flightcrew members’ quality 

of life were imposed, including:

• Blocks of only two consecutive working days were allowed, but penalized, with no 

more than two in any line, and

• Trips were put into morning (report 05:00-12:30) and afternoon families, with mixing 

of different families allowed, but penalized, in any line.

Results

The Final Rule Solution was slightly less efficient in terms of credit hours than the Baseline 

Solution, as shown in Figure 13. Re-optimization of flightcrew member schedules under the 

Final Rule resulted in a slight increase in credit hours, nearly five percent more hotel room nights 

required and more than five percent more TAFB. 

The increased minimum rest period had the greatest impact on the Case F pairings because the 

carrier created flight schedules that were designed to optimize flightcrew member scheduling 

given the minimum 8:00 hour rest period required by the FAR with a 50 minute buffer applied 

by the carrier. At many stations, the aircraft overnight time was less than the 10:00 hours 

required by the Final Rule. CrewPairings increased the standard maximum allowed duty break 

from 22:00 to 33:00 hours to address this problem. Increasing the maximum allowed duty break 
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 38

added the alternative of double layovers10 to the options of staging crews using midday flights or 

using deadhead flights. 

The number of layovers of 24 hours or more increased from 27 in the Baseline Solution to 62 in 

the Final Rule Solution. The average layover increased from 14:43 to 15:20. The result was a 

sizeable increase in the number of required hotel rooms, deadhead time and overall synthetic 

time.

Average duty hours per duty period decreased more than three percent and average block hours 

per duty period decreased two percent. Since the number of lines did not change, the average 

number of days off per month in the Final Rule Solution decreased nearly five percent so that the 

same amount of flying could be completed as in the Baseline Solution.

None of the Final Rule cumulative flight time or flight duty time constraints adversely affected

the bid lines for the Final Rule Solution.

Figure 13: Case F Monthly Results

Credit hours consisted of the total number of hours for which flightcrew members were paid. 

Case F flightcrew members were paid full credit for all block hours and 50 percent credit for 

deadhead hours.

Time away from base was all time spent away from a flightcrew member’s base while on a trip, 

from the time he reported for his first duty period until the end of his debrief period at his last 

duty period of the trip. Domestic TAFB increased by more than five percent and international 

TAFB decreased by nearly three percent.

 10 Double layovers are duty breaks of 27:00 to 33:00 hours.

Metric Crew 

Position Baseline Final Rule

Lines CA or FO 120 120 0 0.0%

Credit Hours All 20,272 20,309 37 0.2%

Block Hours All 20,062 20,062 0 0.0%

Aircraft Block Hours N/A 10,031 10,031 0 0.0%

Domestic TAFB All 77,596 81,744 4,148 5.3%

International TAFB All 575 560 -16 -2.7%

Hotel Rooms All 2,948 3,092 144 4.9%

Average Duty Hours 

per Duty Period CA or FO 8.7 8.4 -0.3 -3.4%

Average Block Hours 

per Duty Period CA or FO 5.1 5.0 -0.1 -2.0%

Average Days Off per 

Month CA or FO 13.5 12.8 -0.6 -4.8%

Change
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 39

Hotel rooms were the number of hotel room nights associated with the layovers (duty breaks) in 

the solution plus any day rooms contractually required for long sit times between flights. The use 

of hotel rooms increased by nearly five percent.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 40

Case G: All-Cargo Narrow-Body

SUMMARY

Case G consisted of the operations of a short-haul all-cargo carrier using narrow-body aircraft. 

The Final Rule Solution was less efficient in terms of credit hours than the Baseline Solution 

mainly because of the reduced maximum flight time limit for international operations, maximum 

FDP limits and consecutive nighttime operations constraint. This resulted in increased credit 

hours, TAFB and hotel rooms. 

DETAILED RESULTS

Case G consisted of a subset of the operations of a short-haul all-cargo carrier using narrow-body 

aircraft during the August 2010 scheduling period. There were more than 2,000 flight segments 

during the scheduling period, most of which were domestic, with a few international 

destinations. Since the carrier mixed domestic and international flying in its crew pairings, all of 

these flight segments were included in the study.

Case G was a representative example of the short-haul operations of all-cargo carriers. The 

nature of operations differed greatly from the typical passenger carrier. The levels of aircraft and 

flightcrew member utilization were much lower than the levels at passenger carriers. This was

because the majority of duty periods consisted of a flight segment from an outstation to a sort 

facility, an approximately four hour period during which the aircraft was unloaded and reloaded

and a flight segment back to the same outstation from which it arrived.

Nearly all duty periods occurred during nighttime hours and most duty periods infringed on the 

window of circadian low (WOCL).

11 For this reason, the Case G carrier’s collective bargaining 

agreement and flightcrew member scheduling rules contained many measures designed to 

mitigate fatigue-inducing conditions characteristic of nighttime flight operations.

Case G included a number of scheduling rules that were designed to enhance the quality of life 

for its flightcrew members. The first major scheduling rule was the requirement that the majority 

of flight legs must be contained in “city pure pairings.” City pure pairings consisted of four or 

five consecutive duty periods that consisted of a flight from an outstation to a sort facility and a 

flight back to the same outstation. Thus, flightcrew members had layovers at the same outstation 

every rest period of a trip. 

The second major scheduling rule was the prohibition on trips transiting the major sort facility, 

excluding those pairings created through the city pure pairings rule. Thus, the trip consisted of a 

flight segment from the main sort facility to an outstation and a flight segment back to the main 

sort facility. The legal duty break occurred during the layover at the outstation. The intent was

that several of these trips would be placed consecutively during bid line construction with only a 

few hours between trips, which had the same ultimate effect as the city pure pairing rule.

 11 The WOCL is the period of maximum sleepiness that occurs between 0200 and 0559 during a physiological night.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 41

Buffers

The three main Final Rule rule elements that affected Case G were the maximum unaugmented 

flight time, maximum unaugmented FDP time and minimum rest period limits. CrewPairings 

applied buffers to both the maximum flight time and FDP time limits to reflect the fact that they 

applied to actual, rather than planned, operations. In Figure 14, the CrewPairings buffer is shown 

in the “CP Buffer” column, which, when applied to the “Final Rule” limit, results in the 

“Effective Final Rule” limit that was actually used when creating pairings for the Final Rule

Solution. However, if the contractual rule shown in the “Current CBA” column less the debrief 

time shown in the “Debrief” column was more restrictive than the “Effective Final Rule” limit, 

the contractual rule is shown in the “Effective Final Rule” column.

Figure 14 includes an “Effective Current Rule” column for comparison to the “Effective Final 

Rule” column. The “Effective Current Rule” is the more restrictive of the “Current FAR” 

column or “Current CBA” column, after applying the buffer in the “Current Buffer” column and 

the debrief time in the “Debrief” column.

Figure 14: Case G Buffers

Pairings

The Baseline Solution pairings (equivalent to the Production Solution) were constructed with the 

constraints of the “Effective Current Rule” column in Figure 14, in addition to all other FAR, 

contractual, management and discretionary constraints not shown. The Final Rule Solution 

pairings were constructed with the constraints of the “Effective Final Rule” column in Figure 14, 

Current FAR Current 

CBA Debrief Carrier 

Buffer

Effective 

Current Rule1 Final Rule CP 

Buffer

Effective Final 

Rule2

Maximum 

Unaugmented 

Flight Time

8:00/12:003 - - 0:25/0:003 7:35/12:003 8:00 - 9:00 0:30 7:30 - 8:30

Maximum 

Unaugmented10

FDP Time

16:00 5:00 - 13:004 0:30 - 4:30 - 12:304 9:00 - 14:005 0:308 4:30 - 12:304,5

Minimum 

Unaugmented

Rest Time

8:00 - 12:006 10:157 - - 10:15-12:007 10:00 - 10:159

10 The FDP concept does not exist in current FARs; therefore the Current columns in this row refer to duty time

8 Plus the 0:30 de facto buffer resulting from §117.19 for a total of 1:00

1 The more restrictive of the current CBA, less debrief, or the FAR (adjusted for carrier buffer)

4

 Domestic limits depending on report time. International limits vary betw een 11 and 13 hours depending on previous rest period

5

 Maximum for 1 segment during FDP, reduced if 3 or more segments during FDP

7 9:00 minimum rest before all deadhead duty, except only 8:00 before all deadhead duty to base at the end of a trip

2 The more restrictive of the current CBA, less debrief, or the Final Rule (adjusted for CP buffer)

3 Domestic/international

9 10:00 minimum rest if rest period is before all deadhead duty

Rule Element

Time in Hours:Minutes

6 Depending on the amount of flight time in the past 24-hour period
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 42

in addition to all other Final Rule, contractual, management and discretionary constraints not 

shown.

The maximum unaugmented flight time limits applicable to the Baseline Solution were 7:35

hours for domestic operations and 12:00 hours for international operations, which were the 

buffered FAR limits. The maximum flight time limit applicable to the Final Rule Solution was

between 7:30 hours and 8:30 hours, depending on FDP start time, after application of a 30 

minute buffer.

The maximum FDP limit applicable to the Baseline Solution was 4:30-12:30 hours, which was

the CBA limit less a 30-minute debrief period. The maximum FDP limit applicable to the Final 

Rule Solution was also between 4:30 and 12:30, which was the lower of the Final Rule less a 30 

minute buffer and the CBA limit less a 30 minute debrief period.

The minimum rest period applicable to the Baseline Solution was 10:15-12:00 hours. The lower 

end was the CBA minimum rest period and the higher end was the FAR if the amount of flight 

time in the preceding 24 hour period exceeded eight hours. The minimum rest period applicable 

to the Final Rule Solution was 10:15 hours, which was the CBA minimum rest period. The Final 

Rule minimum rest period was expected to have a slightly positive impact on the Final Rule

Solution pairings because the Final Rule removed the requirement for additional rest if flight 

time exceeded eight hours in the preceding 24 hour period.

The Final Rule limited flightcrew members to three consecutive flight duty periods that 

impinged on the window of circadian low unless the carrier provided the flightcrew member with 

a minimum two hour rest opportunity in a suitable accommodation during each FDP, in which 

case five consecutive flight duty periods were permitted. The consecutive nighttime operations 

constraint was very important for Case G because the vast majority of duty periods impinged on 

the WOCL.

Since the Final Rule required a minimum two hour rest opportunity during each FDP to qualify 

for five consecutive FDPs, transfer time to and from the suitable accommodation had to be 

accounted for, in addition to debrief/brief times. The Case G carrier informed CrewPairings that 

a total of 30 minutes for transfer to and from the suitable accommodation would be appropriate 

assumptions to use in the analysis. In addition, CrewPairings estimated the total debrief/brief 

times to be 45 minutes. This meant that each FDP had to have a total of 3:15 hours between 

flight segments to qualify for five consecutive FDPs. 

Bid Lines

The Cygnus system was used to construct a complete set of bid lines for both the Baseline and 

Final Rule Solutions using the pairings from the solutions. The Baseline Solution bid lines were 

constructed in compliance with all FAR, contractual, management and discretionary constraints. 

The Final Rule Solution bid lines were constructed in compliance with all Final Rule, 

contractual, management and discretionary constraints.

The primary rules used for construction of both Baseline and Final Rule Solution bid lines were:
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 43

• Minimum of 13 days off

• No single days off

• No single working days

• No double working days, except at the beginning/ending of the month

• A target of 74 credit hours, with a maximum of 84

• Minimize the amount of open time

• No reserve days on any flying line

• All lines are valid for one captain, one first officer and one flight engineer.

In addition to these rules, some common rules intended to improve flightcrew members’ quality 

of life were imposed, including:

• At least one block of three consecutive days off

• At most six consecutive working days, except for the trips that themselves range up to 

12 days in duration

• A penalty for base layovers near 24 hours in duration, because it is better to run trips 

back-to-back with shorter layovers

• Trips were put into morning (report 05:00-12:30) and afternoon families, with mixing 

of different families allowed, but penalized, in any line

• No more than five blocks of consecutive working days during the month, to reduce 

the need for commuters to commute to/from their base. 

Results

The Final Rule Solution was more than two percent less efficient in terms of credit hours than 

the Baseline Solution, as shown in Figure 15. Re-optimization of flightcrew member schedules 

under the Final Rule resulted in more than one percent more hotel room nights required and more 

than three percent more TAFB.

The maximum flight time limit of the Final Rule only impacted one international route because 

of the replacement of the effective current rule maximum limit for international operations of 

12:00 hours with the uniform effective Final Rule limit of 8:30 hours for all operations. 

However, this led to a significant negative impact as two sets of flightcrew members were 

needed to do the same amount of flying previously accomplished by one set of flightcrew 

members. The Final Rule maximum flight time limit did not impact any other Final Rule 

Solution pairings because the nature of all-cargo operations resulted in few flight hours per duty 

period.

Although the buffered maximum FDP limit of the Final Rule was similar to the current CBA, 

there were certain times of the day during which the buffered Final Rule limit was less than the 

current CBA, leading to negative impacts on pairings.

There were five city pure pairings that did not have the required ground time, leading to negative 

impacts on pairings. These pairings had ground time of 2:44 to 3:10, which was less than the 

required minimum buffered 3:15 ground time.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 44

The augmentation and acclimation elements of the Final Rule did not affect Case G, as all of the 

flight segments were operated with an unaugmented crew and all of the flightcrew members 

remained acclimated at all times. The split duty rule was not particularly important because the 

specific instances that would allow split duties already complied with the maximum 

unaugmented FDP limits.

Figure 15: Case G Monthly Results

Credit hours consisted of the total number of hours for which flightcrew members are paid. Case 

G flightcrew members were paid full credit for all block and deadhead hours. Duty rig was paid 

at the rate of 1-for-2 during the day and 1-for-1.92 during the night. Trip rig was paid at the rate 

of 1-for-3.75. Minimum duty period guarantees ranged from 3:00 to 6:00 hours per duty period.

Time away from base was all time spent away from a flightcrew member’s base while on a trip, 

from the time he reported for his first duty period until the end of his debrief period at his last 

duty period of the trip. Domestic TAFB increased by one percent and international TAFB 

increased by more than forty percent.

Hotel rooms were the number of hotel room nights associated with the layovers (duty breaks) in 

the solution plus any day rooms contractually required for long sit times between flights.

Metric Crew 

Position Baseline Final Rule

Lines CA, FE or FO 110 113 3 2.7%

Credit Hours All 24,551 25,110 560 2.3%

Block Hours All 10,844 10,829 -15 -0.1%

Aircraft Block Hours N/A 3,615 3,610 -5 -0.1%

Domestic TAFB All 89,276 90,166 890 1.0%

International TAFB All 5,846 8,237 2,390 40.9%

Hotel Rooms All 3,837 3,891 54 1.4%

Average Duty Hours 

per Duty Period CA, FE or FO 4.8 4.8 0.0 0.0%

Average Block Hours 

per Duty Period CA, FE or FO 2.0 1.9 -0.1 -5.0%

Average Days Off per 

Month CA, FE or FO 14.5 14.4 -0.1 -0.5%

Change
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 45

Case H: All-Cargo Wide-Body

SUMMARY

Case H consisted of the operations of an all-cargo carrier using wide-body aircraft. The Final 

Rule Solution was less efficient in terms of credit hours than the Baseline Solution mainly 

because of the maximum FDP limits and consecutive nighttime operations constraint. This 

resulted in more TAFB and hotel rooms. 

DETAILED RESULTS

Case H consisted of a subset of the operations of an all-cargo carrier using wide-body aircraft 

during the August 2010 scheduling period. There were more than 6,000 flight segments during 

the scheduling period. Approximately 70 percent of the flight segments were short-haul domestic 

operations and 30 percent were long-haul international operations. Since the carrier mixed

domestic and international flying in its crew pairings, all of these flight segments were included 

in the study.

Case H was a representative example of the wide-body aircraft operations of all-cargo carriers. 

The domestic short-haul operations generally occurred from Monday afternoon to Saturday 

afternoon while the international short-haul operations occurred throughout the week. 

The nature of short-haul domestic operations differed greatly from the typical passenger carrier. 

The levels of aircraft and flightcrew member utilization were much lower than the levels at 

passenger carriers. This was because the majority of duty periods consisted of a flight segment 

from an outstation to a sort facility, an approximately four hour period during which the aircraft 

was unloaded and reloaded and a flight segment back to the same outstation from which it 

arrived.

The nature of long-haul international operations also differed greatly from the typical passenger 

carrier. The routes were long and thin international routes throughout the entire Northern 

Hemisphere that circled the globe in both directions from bases in the United States. The flights 

operated infrequently and in many cases with at least one additional flightcrew member. The 

majority of duty periods consisted of a single flight segment. Deadheading was common because 

flights on these routes were infrequent. The international flights also operated to military fields, 

which obviously did not offer the possibility of deadheading on scheduled passenger flights. 

Many duty periods occurred during nighttime hours and most duty periods infringed on the

window of circadian low.

12 For this reason, the Case H carrier’s collective bargaining agreement 

and flightcrew member scheduling rules contained many measures designed to mitigate fatigueinducing conditions characteristic of nighttime flight operations.

 12 The WOCL is the period of maximum sleepiness that occurs between 0200 and 0559 during a physiological night.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 46

Case H included a number of scheduling rules that were designed to enhance the quality of life 

for its flightcrew members. The first major scheduling rule was the requirement that the majority 

of flight legs had to be contained in “city pure pairings.” City pure pairings consisted of four or 

five consecutive duty periods that consisted of a flight from an outstation to a sort facility and a 

flight back to the same outstation. Thus, flightcrew members had layovers at the same outstation 

during every rest period of a trip. 

The second major scheduling rule was the prohibition on trips that transited the major sort 

facility, excluding those pairings created through the city pure pairings rule. Thus, the trip would

consist of a flight segment from the main sort facility to an outstation and a flight segment back 

to the main sort facility. The legal duty break occurred during the layover at the outstation. The 

intent was that several of these trips would be placed consecutively during bid line construction 

with only a few hours between trips, which had the same ultimate effect as the city pure pairing 

rule.

Buffers

The three main Final Rule rule elements that affected Case H were the unaugmented and 

augmented maximum flight time, maximum FDP time and minimum rest period limits. 

CrewPairings applied buffers to the maximum flight time and FDP time limits to reflect the fact 

that they applied to actual, rather than planned, operations. In Figure 16, the CrewPairings buffer 

is shown in the “CP Buffer” column, which, when applied to the “Final Rule” limit, resulted in 

the “Effective Final Rule” limit that was actually used when creating pairings for the Final Rule

Solution. However, if the contractual rule shown in the “Current CBA” column less the debrief 

time shown in the “Debrief” column was more restrictive than the “Effective Final Rule” limit, 

the contractual rule is shown in the “Effective Final Rule” column.

Figure 16 includes an “Effective Current Rule” column for comparison to the “Effective Final 

Rule” column. The “Effective Current Rule” is the more restrictive of the “Current FAR” 

column or “Current CBA” column, after applying the buffer in the “Current Buffer” column and 

the debrief time in the “Debrief” column.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 47

Figure 16: Case H Buffers

Pairings

The Baseline Solution pairings (equivalent to the Production Solution) were constructed with the 

constraints of the “Effective Current Rule” column in Figure 16, in addition to all other FAR, 

contractual, management and discretionary constraints not shown. The Final Rule Solution 

pairings were constructed with the constraints of the “Effective Final Rule” column in Figure 16, 

in addition to all other Final Rule, contractual, management and discretionary constraints not 

shown.

The maximum unaugmented flight time limits applicable to the Baseline Solution were 7:35 

hours for domestic operations and 12:00 hours for international operations, which were the 

buffered FAR limits. The maximum flight time limit applicable to the Final Rule Solution was

between 7:30 hours and 8:30 hours, depending on FDP start time, after application of a 30 

minute buffer. The maximum unaugmented flight time limit of the Final Rule was therefore 

expected to have a mixed impact on the Final Rule Solution pairings; in some situations the 

Effective Final Rule limit was more constraining than the Effective Current Rule and in other 

cases it was less constraining.

Current FAR Current CBA Debrief Carrier 

Buffer

Effective 

Current Rule1 Final Rule CP 

Buffer Effective Final Rule2

Maximum 

Unaugmented 

Flight Time

8:00/12:009 - - 0:25/0:009 7:35/12:009 8:00 - 9:00 0:30 7:30 - 8:30

Maximum 

Augmented 

Flight Time

(3 crew) 12:00

(4 crew) 18:00 - - - (3 crew) 12:00(4 crew) 18:00

(3 crew) 13:00

(4 crew) 17:00 0:30 (3 crew) 12:30

(4 crew) 16:30

Maximum 

Unaugmented12

FDP Time

16:00 5:00 - 13:006 0:30 - 4:30 - 12:306 9:00 - 14:003 0:304 4:30 - 12:303,6

Maximum 

Augmented

FDP Time12

(3 crew) 18:00

(4 crew) 20:00

(3 crew) 18:00

(4 crew) 20:00 0:30 - (3 crew) 17:30(4 crew) 19:30

(3 crew) 15:00 - 17:005

(4 crew) 17:00 - 19:005 0:304 (3 crew) 14:30 - 16:305(4 crew) 16:30 - 18:305

Minimum 

Unaugmented

Rest Time

8:00 - 12:0010 10:157 - - 10:15 - 12:007,10 10:00 - 10:15

Minimum 

Augmented

Rest Time

8:00 - 18:0011 12:00 - - 12:00 - 18:0011 10:00 - 12:00

8 10:00 minimum rest if rest period is before all deadhead duty

Rule Element

Time in Hours:Minutes

1 The more restrictive of the current CBA, less debrief, or the FAR (adjusted for carrier buffer)

4 Plus the 0:30 de facto buffer resulting from §117.19 for a total of 1:00

5 Depending on FDP start time; Maximum show n is for aircraft equipped w ith Class 1 rest facility, reduced if aircraft is equipped w ith low er class rest facility

2 The more restrictive of the current CBA, less debrief, or the Final Rule (adjusted for CP buffer)

3

 Depending on FDP start time; Maximum show n is for 1 segment during FDP, reduced if 3 or more segments during FDP

10 Depending on the amount of flight time in the past 24-hour period

11 Flag rules, including double out if crew exceeds 8-in-24, 18:00 after breaking 8-in-24, 20-in-48 or 24-in-72

6

 Domestic limits depending on report time. International limits vary betw een 11 and 13 hours depending on previous rest period

7 9:00 minimum rest before all deadhead duty, except only 8:00 before all deadhead duty to base at the end of a trip

9 Domestic/international

12 The FDP concept does not exist in current FARs; therefore the Current columns in this row refer to duty time
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 48

The maximum augmented flight time limits applicable to the Baseline Solution were 12:00 hours 

for flights with one additional flightcrew member and 18:00 hours for flights with two additional 

flightcrew members, which were the FAR limits. The maximum flight time limits applicable to 

the Final Rule Solution were 12:30 hours for flights with one additional flightcrew member and 

16:30 hours for flights with two additional flightcrew members, which were the Final Rule limits 

after application of a 30 minute buffer. The maximum augmented flight time limits of the Final 

Rule were therefore expected to have a mixed impact on the Final Rule Solution pairings; in 

some situations the Effective Final Rule limit was more constraining than the Effective Current 

Rule and in other cases it was less constraining.

The maximum unaugmented FDP limit applicable to the Baseline Solution was 4:30-12:30 

hours, which was the CBA limit less a 30 minute debrief period. The maximum FDP limit 

applicable to the Final Rule Solution was also between 4:30 and 12:30, which was the smaller of 

the Final Rule less a 30 minute buffer and the CBA limit less a 30 minute debrief period. 

Although the buffered maximum FDP limit of the Final Rule was similar to the current CBA, 

there were certain times of the day during which the buffered Final Rule limit was less than the 

current CBA.

The maximum augmented FDP limits applicable to the Baseline Solution were 17:30 hours for 

flights with one additional flightcrew member and 19:30 for flights with two additional 

flightcrew members, which were the CBA limits less a 30 minute debrief period. The maximum 

FDP limits applicable to the Final Rule Solution were between 14:30 and 16:30 for flights with 

one additional flightcrew member and between 16:30 and 18:30 hours for flights with two 

additional flightcrew members, which were the Final Rule limits less a 30 minute buffer. The 

Effective Final Rules limits were significantly less than the Effective Current Rule in all 

situations.

The minimum unaugmented rest period applicable to the Baseline Solution was 10:15-12:00 

hours. The lower end was the CBA minimum rest period and the higher end was the FAR if the 

amount of flight time in the preceding 24 hour period exceeded eight hours. The minimum rest 

period applicable to the Final Rule Solution was 10:15 hours, which was the CBA minimum rest 

period. The Final Rule minimum augmented rest period was expected to have a slightly positive 

impact on the Final Rule Solution pairings because the Final Rule removed the requirement for 

additional rest if flight time exceeded eight hours in the preceding 24 hour period.

The minimum augmented rest period applicable to the Baseline Solution was 12:00-18:00 hours. 

The lower end was the CBA minimum rest period and the higher end was the FAR if the amount 

of flight time in the preceding 24 hour period exceeded eight hours. The minimum rest period 

applicable to the Final Rule Solution was 12:00 hours, which was the CBA minimum rest period. 

The Final Rule minimum augmented rest period was expected to have a slightly positive impact 

on the Final Rule Solution pairings because the Final Rule removed the requirement for 

additional rest if flight time exceeded eight hours in the preceding 24 hour period.

The Final Rule limited flightcrew members to three consecutive flight duty periods that 

impinged on the window of circadian low unless the carrier provided the flightcrew member with 

a minimum two hour rest opportunity in a suitable accommodation during each FDP, in which 
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 49

case five consecutive flight duty periods were permitted. The consecutive nighttime operations 

constraint was very important for Case H because the vast majority of domestic duty periods 

impinged on the WOCL.

Since the Final Rule required a minimum two hour rest opportunity during each FDP to qualify 

for five consecutive FDPs, transfer time to and from the suitable accommodation had to be 

accounted for, in addition to debrief/brief times. The Case H carrier informed CrewPairings that 

a total of 30 minutes for transfer to and from the suitable accommodation would be appropriate 

assumptions to use in the analysis. In addition, CrewPairings estimated the total debrief/brief 

times to be 45 minutes. This meant that each FDP had to have a total of 3:15 hours between 

flight segments to qualify for five consecutive FDPs.

Bid Lines

The Cygnus system was used to construct a complete set of bid lines for both the Baseline and 

Final Rule Solutions using the pairings from the solutions. The Baseline Solution bid lines were 

constructed in compliance with all FAR, contractual, management and discretionary constraints. 

The Final Rule Solution bid lines were constructed in compliance with all Final Rule, 

contractual, management and discretionary constraints.

The primary rules used for construction of both Baseline and Final Rule Solution bid lines were:

• Minimum of 13 days off,

• No single days off,

• No single working days,

• No double working days, except at the beginning/ending of the month,

• A target of 74 credit hours, with a maximum of 84,

• Minimize the amount of open time,

• No reserve days on any flying line, and

• All lines are valid for one captain and one first officer, one relief first officer or one 

relief captain.

In addition to these rules, some common rules intended to improve flightcrew members’ quality 

of life were imposed, including:

• At least one block of three consecutive days off,

• At most six consecutive working days, except for the trips that themselves range up to 

12 days in duration, and

• A penalty for base layovers near 24 hours in duration, because it is better to run trips 

back-to-back with shorter layovers

• Trips were put into morning (report 05:00-12:30) and afternoon families, with mixing 

of different families allowed, but penalized, in any line

• No more than five blocks of consecutive working days during the month, to reduce 

the need for commuters to commute to/from their base. 
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 50

Results

The Final Rule Solution was slightly more than one percent less efficient in terms of credit hours

than the Baseline Solution, as shown in Figure 17. Re-optimization of flightcrew member 

schedules under the Final Rule resulted in a two percent increase in TAFB and more than two

percent more hotel room nights required. 

There were a number of city pure pairings that did not have enough ground time between flight 

segments to meet the rest requirements of the consecutive nighttime operations rule. There were 

a number of pairings that exceeded the buffered 8:30 maximum flight duty period limit for flight 

duty periods that began during the early morning. These two constraints caused a significant 

number of pairings of five to six days in the Baseline Solution to be broken up into multiple

pairings of fewer days in the Final Rule Solution. In the Baseline Solution, 77 percent of trips 

were one to four day trips. In the Final Rule Solution, 81 percent of trips were one to four day 

trips.

The cumulative flight duty period and flight time limits did not affect Case H because flightcrew 

members had low levels of flight duty period and flight time in the Baseline Solution.

Figure 17: Case H Monthly Results

Credit hours consisted of the total number of hours for which flightcrew members were paid. 

Case H flightcrew members were paid full credit for all block and deadhead hours. Duty rig was

Metric Crew 

Position Baseline Final Rule

CA or FO 473 480 7 1.5%

IO 99 102 3 3.0%

RC 8 7 -1 -12.5%

Credit Hours All 79,164 80,148 984 1.2%

Block Hours All 51,348 51,509 161 0.3%

Aircraft Block Hours N/A 22,910 22,902 -9 0.0%

Domestic TAFB All 128,231 134,428 6,197 4.8%

International TAFB All 217,279 218,140 862 0.4%

Hotel Rooms All 9,696 9,936 240 2.5%

CA or FO 7.1 6.8 -0.3 -4.2%

IO 10.2 10.2 0.0 0.0%

RC 12.2 13.2 1.0 8.2%

CA or FO 4.1 3.9 -0.2 -4.9%

IO 6.4 6.4 0.0 0.0%

RC 3.9 4.9 1.0 25.6%

CA or FO 14.4 14.1 -0.3 -2.0%

IO 15.3 15.4 0.0 0.3%

RC 17.0 17.1 0.1 0.8%

Change

Lines

Average Duty Hours 

per Duty Period

Average Block 

Hours per Duty 

Period

Average Days Off 

per Month
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 51

paid at the rate of 1-for-2 during the day and 1-for-1.92 during the night. Trip rig was paid at the 

rate of 1-for-3.75. Minimum duty period guarantees ranged from 3:00 to 6:00 hours per duty 

period.

Time away from base was all time spent away from a flightcrew member’s base while on a trip, 

from the time he reported for his first duty period until the end of his debrief period at his last 

duty period of the trip. Domestic TAFB increased by nearly five percent and international TAFB 

increased slightly.

Hotel rooms were the number of hotel room nights associated with the layovers (duty breaks) in 

the solution plus any day rooms contractually required for long sit times between flights.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 52

Case I: Supplemental Wide-Body

SUMMARY

Case I consisted of the operations of a representative supplemental carrier using wide-body 

aircraft. The Final Rule Solution was less efficient in terms of credit hours than the Baseline 

Solution because of nearly all of the Final Rule elements. The Final Rule was significantly more 

constraining than current FAA Part 121 Subpart S supplemental rules and supplemental carrier 

labor agreements. This resulted in more credit hours, TAFB and hotel rooms. 

DETAILED RESULTS

Since CrewPairings was not provided with data from an actual supplemental carrier, a 

representative supplemental carrier was created using the flight schedule and crew bases from 

Case H, along with a representative supplemental carrier CBA and FAR Part 121 Subpart S 

supplemental flight, duty and rest rules. 

The flight schedule consisted of more than 6,000 flight segments during the scheduling period. 

Approximately 70 percent of the flight segments were short-haul domestic operations and 30 

percent were long-haul international operations. Since the carrier mixed domestic and 

international flying in its crew pairings, all of these flight segments were included in the study. 

The domestic short-haul operations occurred from Monday afternoon to Saturday afternoon 

while the international short-haul operations occurred throughout the week. 

The nature of short-haul domestic operations differed greatly from the typical passenger carrier. 

The levels of aircraft and flightcrew member utilization were much lower than the levels at 

passenger carriers. This was because the majority of duty periods consisted of a flight segment 

from an outstation to a sort facility, an approximately four hour period during which the aircraft 

was unloaded and reloaded and a flight segment back to the same outstation from which it 

arrived.

The nature of long-haul international operations also differed greatly from the typical passenger 

carrier. The routes were long and thin international routes throughout the entire Northern 

Hemisphere that circled the globe in both directions from bases in the United States. The flights 

operated infrequently, frequently with at least one additional flightcrew member. The majority of 

duty periods consisted of a single flight segment. Deadheading was common because flights on 

these routes were infrequent. The international flights also operated to military fields, which 

obviously did not offer the possibility of deadheading on scheduled passenger flights. 

The representative supplemental carrier CBA permitted much more flight and duty time than the 

typical passenger or all-cargo carrier CBA. Similarly, the supplemental flight, duty and rest rules 

permitted much more flight and duty time than the flag flight, duty and rest rules that scheduled 

passenger carriers and many all-cargo carriers operated under.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 53

Buffers

All of the Final Rule elements significantly impacted Case I. Three of the main rule elements 

that affected Case I were the maximum flight time, maximum FDP time and minimum rest 

period limits shown in Figure 18. CrewPairings applied buffers to the maximum flight time and 

FDP time limits to reflect the fact that they applied to actual, rather than planned, operations. In

Figure 18, the CrewPairings buffer is shown in the “CP Buffer” column, which, when applied to 

the “Final Rule” limit, resulted in the “Effective Final Rule” limit that was actually used when 

creating pairings for the Final Rule Solution. However, if the contractual rule shown in the 

“Current CBA” column less the debrief time shown in the “Debrief” column was more restrictive 

than the “Effective Final Rule” limit, the contractual rule is shown in the “Effective Final Rule” 

column.

Figure 18 includes an “Effective Current Rule” column for comparison to the “Effective Final 

Rule” column. The “Effective Current Rule” is the more restrictive of the “Current FAR” 

column or “Current CBA” column, after applying the buffer in the “Current Buffer” column and 

the debrief time in the “Debrief” column.

Figure 18: Case I Buffers

Current FAR Current CBA Debrief Carrier 

Buffer

Effective 

Current Rule1 Final Rule CP 

Buffer Effective Final Rule2

Maximum 

Unaugmented 

Flight Time

8:00 - - - 8:00 8:00 - 9:00 0:30 7:30 - 8:30

Maximum 

Augmented 

Flight Time

(3 crew) 18:00

(4 crew) 22:00 - - - (3 crew) 12:00(4 crew) 16:00

(3 crew) 13:00

(4 crew) 17:00 0:30 (3 crew) 12:30(4 crew) 16:30

Maximum 

Unaugmented8

FDP Time

16:00 16:00 0:15 - 15:45 9:00 - 14:003 0:304 8:30 - 13:303

Maximum 

Augmented

FDP Time8

(3 crew) 18:00

(4 crew) 22:00

(3 crew) 18:00

(4 crew) 22:00 0:15 - (3 crew) 17:45(4 crew) 21:45

(3 crew) 15:00 - 17:005

(4 crew) 17:00 - 19:005 0:304 (3 crew) 14:30 - 16:305(4 crew) 16:30 - 18:305

Minimum 

Unaugmented

Rest Time

8:00 9:00/12:007 - - 9:00/12:007 10:00 - 10:00/12:007

Minimum 

Augmented

Rest Time

8:00 - 18:006 12:00 - - 12:00 - 18:006 10:00 - 12:00

8 The FDP concept does not exist in current FARs; therefore the Current columns in this row refer to duty time

5 Depending on FDP start time; Maximum show n is for aircraft equipped w ith Class 1 rest facility, reduced if aircraft is equipped w ith low er class rest facility

6 Supplemental rules, including double out if crew exceeds 8-in-24, 18:00 after breaking 8-in-24, 20-in-48 or 24-in-72

7 Domestic/international

Rule Element

4 Plus the 0:30 de facto buffer resulting from §117.19 for a total of 1:00

Time in Hours:Minutes

1 The more restrictive of the current CBA, less debrief, or the FAR (adjusted for carrier buffer)

2 The more restrictive of the current CBA, less debrief, or the Final Rule (adjusted for CP buffer)

3

 Depending on FDP start time; Maximum show n is for 1 segment during FDP, reduced if 3 or more segments during FDP
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 54

Pairings

The Baseline Solution pairings were constructed with the constraints of the “Effective Current 

Rule” column in Figure 18, in addition to all other FAR, contractual, management and 

discretionary constraints not shown. The Final Rule Solution pairings were constructed with the 

constraints of the “Effective Final Rule” column in Figure 18, in addition to all other Final Rule, 

contractual, management and discretionary constraints not shown.

The maximum unaugmented flight time limit applicable to the Baseline Solution was the FAR 

limit of 8:00 hours. The maximum flight time limit applicable to the Final Rule Solution was

between 7:30 hours and 8:30 hours, depending on FDP start time, after application of a 30 

minute buffer. The maximum unaugmented flight time limit of the Final Rule was therefore 

expected to have a mixed impact on the Final Rule Solution pairings; in some situations the 

Effective Final Rule limit was more constraining than the Effective Current Rule and in other 

cases it was less constraining.

The maximum augmented flight time limits applicable to the Baseline Solution were 18:00 hours 

for flights with one additional flightcrew member and 22:00 hours for flights with two additional 

flightcrew members, which were the FAR limits. The maximum flight time limits applicable to 

the Final Rule Solution were 12:30 hours for flights with one additional flightcrew member and 

16:30 hours for flights with two additional flightcrew members, which were the Final Rule limits 

after application of a 30 minute buffer. The maximum augmented flight time limits of the Final 

Rule were therefore expected to have a negative impact on the Final Rule Solution pairings; the 

Effective Final Rule limits were much more constraining than the Effective Current Rule.

The maximum unaugmented FDP limit applicable to the Baseline Solution was 15:45 hours, 

which was the FAR and CBA limit less a 15 minute debrief period. The maximum FDP limit 

applicable to the Final Rule Solution was between 8:30 and 13:30, which was the Final Rule less 

a 30 minute buffer. The maximum unaugmented FDP limit of the Final Rule was therefore 

expected to have a significant negative impact on the Final Rule Solution pairings because the 

Effective Final Rule was much more constraining than the Effective Current Rule.

The maximum augmented FDP limits applicable to the Baseline Solution were 17:45 hours for 

flights with one additional flightcrew member and 21:45 for flights with two additional 

flightcrew members, which were the FAR and CBA limits less a 15 minute debrief period. The 

maximum FDP limits applicable to the Final Rule Solution were between 14:30 and 16:30 for 

flights with one additional flightcrew member and between 16:30 and 18:30 hours for flights 

with two additional flightcrew members, which were the Final Rule limits less a 30 minute 

buffer. The Effective Final Rules limits were significantly less than the Effective Current Rule in 

all situations.

The minimum unaugmented rest periods applicable to the Baseline Solution were 9:00 hours for 

rest periods preceding a domestic duty period and 12:00 hours for rest periods preceding an 

international duty period, which were the CBA minimums. The minimum rest periods applicable 

to the Final Rule Solution were 10:00 hours for rest periods preceding domestic duty periods, 

which was the Final Rule minimum, and 12:00 hours for rest periods preceding international 
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 55

duty periods, which was the CBA minimum. The Final Rule minimum augmented rest period 

was expected to have a slightly negative impact on the Final Rule Solution pairings because the 

Final Rule minimum for rest periods preceding domestic duty periods was one hour greater than 

the Effective Current Rule.

The minimum augmented rest period applicable to the Baseline Solution was 12:00-18:00 hours. 

The lower end was the CBA minimum rest period and the higher end was the FAR if the amount 

of flight time in the preceding 24 hour period exceeded eight hours. The minimum rest period 

applicable to the Final Rule Solution was 12:00 hours, which was the CBA minimum rest period. 

The Final Rule minimum augmented rest period was expected to have a slightly positive impact 

on the Final Rule Solution pairings because the Final Rule removed the requirement for 

additional rest if flight time exceeded eight hours in the preceding 24 hour period.

The Final Rule limited flightcrew members to three consecutive flight duty periods that 

impinged on the window of circadian low unless the carrier provided the flightcrew member with 

a minimum two hour rest opportunity in a suitable accommodation during each FDP, in which 

case five consecutive flight duty periods were permitted. The consecutive nighttime operations 

constraint was very important for Case I because the vast majority of domestic duty periods 

impinged on the WOCL.

Since the Final Rule required a minimum two hour rest opportunity during each FDP to qualify 

for five consecutive FDPs, transfer time to and from the suitable accommodation had to be 

accounted for, in addition to debrief/brief times. The Case H carrier informed CrewPairings that 

a total of 30 minutes for transfer to and from the suitable accommodation would be appropriate 

assumptions to use in their analysis. These values were also used for Case I. In addition, 

CrewPairings estimated the total debrief/brief times to be 45 minutes. This meant that each FDP 

had to have a total of 3:15 hours between flight segments to qualify for five consecutive FDPs. 

Bid Lines

The Cygnus system was used to construct a complete set of bid lines for both the Baseline and 

Final Rule Solutions using the pairings from the solutions. The Baseline Solution bid lines were 

constructed in compliance with all FAR, contractual, management and discretionary constraints. 

The Final Rule Solution bid lines were constructed in compliance with all Final Rule, 

contractual, management and discretionary constraints.

The primary rules used for construction of both Baseline and Final Rule Solution bid lines were:

• Minimum of 11 days off

• Single and double days off were allowed, but penalized

• Single and double working days were allowed, but penalized

• A target of 80 credit hours, with a maximum of 100.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 56

Results

The Final Rule Solution was seven percent less efficient in terms of credit hours than the 

Baseline Solution, as shown in Figure 19. Re-optimization of flightcrew member schedules 

under the Final Rule resulted in nearly four percent more TAFB and eight percent more hotel 

room nights required. The Final Rule constraints were more restrictive in almost every situation. 

The Final Rule solution used less crew augmentation than the Baseline Solution, primarily 

because the Baseline Solution took advantage of the supplemental rules to create a significant 

number of multi-segment augmented duties. The share of single-segment duty periods increased 

from 52 percent to 65 percent. These duties were not possible in the Final Rule Solution because 

of maximum FDP time constrains.

Overall, 774 of the 1,044 Baseline Solution CA/FO trips violated at least one of the Final Rule 

constraints and had to be re-optimized for the Final Rule Solution. Exceeding the Final Rule 

maximum FDP time limit was the most common reason that Baseline Solution trips were not 

possible in the Final Rule Solution. The average duty hours and block hours per duty period 

decreased dramatically in the Final Rule Solution for all crew positions.

The Final Rule limited cumulative FDP time to 60 hours during any consecutive 168 hour 

period. A number of trips in the Baseline Solution violated this constraint and had to be reoptimized for the Final Rule Solution. A number of trips also violated the consecutive nighttime 

operations constraint and the 30 hours of rest in 168 consecutive hours constraint of the Final 

Rule. The net impact of all of these constraints was that the average number of days off per 

month for flightcrew members decreased, because they needed to work more days per month to 

complete the same flight schedule as in the Baseline Solution.
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 57

Figure 19: Case I Monthly Results

Credit hours consisted of the total number of hours for which flightcrew members were paid. 

Case I flightcrew members were paid full credit for all block and deadhead hours. Duty rig was

paid at the rate of 1-for-2. Trip rig was paid at the rate of 1-for-4.

Time away from base was all time spent away from a flightcrew member’s base while on a trip, 

from the time he reported for his first duty period until the end of his debrief period at his last 

duty period of the trip. Domestic TAFB increased by almost three percent and international 

TAFB increased by five percent.

Hotel rooms were the number of hotel room nights associated with the layovers (duty breaks) in 

the solution plus any day rooms contractually required for long sit times between flights.

Metric Crew 

Position Baseline Final Rule

CA or FO 341 386 45 13.2%

IO 119 78 -41 -34.5%

RC 5 8 3 60.0%

Credit Hours All 64,235 68,876 4,642 7.2%

Block Hours All 52,793 50,864 -1,929 -3.7%

Aircraft Block Hours N/A 22,933 22,928 -5 0.0%

Domestic TAFB All 114,951 118,109 3,159 2.7%

International TAFB All 196,677 206,436 9,759 5.0%

Hotel Rooms All 9,582 10,338 756 7.9%

CA or FO 10.2 8.1 -2.1 -20.6%

IO 11.4 10.2 -1.2 -10.5%

RC 14.2 12.3 -1.9 -13.4%

CA or FO 5.9 4.7 -1.2 -20.3%

IO 6.9 6.8 -0.1 -1.4%

RC 6.5 2.8 -3.7 -56.9%

CA or FO 12.5 12.0 -0.5 -3.8%

IO 14.0 13.8 -0.2 -1.2%

RC 17.4 15.4 -2.0 -11.6%

Lines

Average Duty Hours 

per Duty Period

Average Block Hours 

per Duty Period

Average Days Off per 

Month

Change
Summary of CrewPairings, Inc. Economic Analysis of 

Flightcrew Member Duty and Rest Requirements Rulemaking

September 2012 Page 58

Appendix 1: Pay Variables

Block Hours Hours during which a flightcrew member operates an aircraft. Also commonly 

called flight hours although taxi times are included.

Credit Hours Hours for which a flightcrew member is paid. Credit hours can include block 

hours, deadhead credit, duty rig, trip rig, and minimum guarantees.

Deadhead Credit Credit based on some fraction of the time spent deadheading. Carriers

typically credit flightcrew members with 50 – 100 percent of the flight time of a deadhead flight, 

sometimes subject to a minimum guarantee per deadheading occasion. Ground transportation via 

limousine, train, or water transport to move a flightcrew member from one airport to another is 

also subject to deadhead credit.

Duty Rig Credit for hours spent on duty. Duty rig was created to prevent carriers from 

scheduling a flightcrew member with long duty periods but only a small amount of block time. 

Hotel Room Nights The number of hotel room nights associated with the layovers (duty 

breaks) in the solution plus any day rooms contractually required for long sit times between 

flights. In the absence of specific carrier-supplied data for early check-in and late check-out rules 

at each hotel, all cases used a simple rule specifying one room per flightcrew member for every 

X hours of duty break time or fraction thereof (for example, a new room cost for every 24 hours 

of layover). X typically ranges from 24 – 30 hours.

Minimum Guarantee Minimum pay guarantee for each duty period or working day.

Per Diem A fixed amount of compensation paid to flightcrew members per unit of time 

(typically per hour or per day). In this report, per diem is calculated based on TAFB. The per 

diem rate typically differs based on whether a trip is domestic or international.

Synthetic Time Synthetic time is the difference between block hours and credit hours and is

primarily generated by deadhead credit, duty rigs, minimum guarantee, and/or trip rig.

Trip Rig Credit for hours away from base spent on a trip. Trip rig was created to prevent carriers

from scheduling a flightcrew member to fly to a destination and spend days there before 

returning home with little compensation.

TAFB (Time Away From Base) All time spent away from a flightcrew member’s base while 

on a trip, from the time he reports for his first duty period until the end of his debrief period at 

his last duty period of the trip.

Ticket Costs The actual ticket costs paid to other carriers for deadheading on that carrier’s

flights. Such ‘offline’ deadhead flights are mostly avoided, each carrier preferring to deadhead 

on their own flights or at least on flights flown by their regional partners. Some all-cargo 

operators are an exception to this rule and will deadhead solely on offline flights.