June 2013

NASA/TM−2013-216533

Precision Departure Release Capability (PDRC)

Final Report

Shawn A. Engelland

Ames Research Center, Moffett Field, California

Alan Capps, Kevin Day, and Matthew Kistler

Mosaic ATM, Leesburg, Virginia

Frank Gaither and Greg Juro

Federal Aviation Administration, Dallas/Fort Worth, Texas
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June 2013

NASA/TM−2013-216533

Precision Departure Release Capability (PDRC)

Final Report

Shawn A. Engelland

Ames Research Center, Moffett Field, California

Alan Capps, Kevin Day, and Matthew Kistler

Mosaic ATM, Leesburg, Virginia

Frank Gaither and Greg Juro

Federal Aviation Administration, Dallas/Fort Worth, Texas
Available from:

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7115 Standard Drive 5301 Shawnee Road

Hanover, MD 21076-1320 Alexandria, VA 22312

This report is also available in electronic form at

http://www.aviationsystemsdivision.arc.nasa.gov/
i

Table of Contents

ABSTRACT................................................................................................................................... 1

1 INTRODUCTION................................................................................................................... 1

2 TACTICAL DEPARTURE SCHEDULING CHARACTERISTICS AND 

SHORTFALLS.............................................................................................................................. 3

2.1 TACTICAL DEPARTURE SCHEDULING.............................................................................................3

2.2 PRESENT-DAY SYSTEM CHARACTERISTICS AND SHORTFALLS .....................................................4

3 CONCEPT AND RESEARCH PROTOTYPE OVERVIEW ............................................ 5

3.1 CONCEPT OVERVIEW.......................................................................................................................6

3.2 PDRC RESEARCH PROTOTYPE IMPLEMENTATION OVERVIEW....................................................7

4 TECHNOLOGY DEVELOPMENT..................................................................................... 8

4.1 OVERVIEW .......................................................................................................................................9

4.2 DOUBLE-HEADED ARROW .............................................................................................................10

4.3 ALL FLIGHTS ALL TRACKS ............................................................................................................10

4.4 SCHEDULER MODIFICATIONS........................................................................................................11

4.5 DEPARTURE ROUTING ...................................................................................................................11

4.6 OFF TIME PREDICTION IMPROVEMENTS .....................................................................................11

4.7 AIR CARRIER TWO-WAY INTERFACE............................................................................................11

4.8 MULTI-DOMAIN ‘WHAT IF’ SCHEDULER ......................................................................................12

4.9 MULTI-AIRPORT, MANY-TO-MANY INTERFACE ARCHITECTURE ...............................................12

5 FIELD EVALUATION SETUP .......................................................................................... 12

5.1 PHYSICAL LAYOUT ........................................................................................................................12

5.1.1 ZFW Center TMU.....................................................................................................................13

5.1.2 DFW Towers.............................................................................................................................13

5.1.3 AA DFW Ramp Tower .............................................................................................................14

5.1.4 NTX Laboratory........................................................................................................................14

5.2 APPARATUS ....................................................................................................................................14

5.3 AGILE AND OPPORTUNISTIC EVALUATION METHODOLOGY.......................................................15

5.4 INBOUND SCENARIO FIELD EVALUATION CHALLENGES..............................................................16

6 FIELD EVALUATION OBSERVATIONS AND FINDINGS ......................................... 16

6.1 EVALUATION OVERVIEWS.............................................................................................................17

6.1.1 July 2011 shadow evaluation.....................................................................................................17

6.1.2 Block 1 operational evaluation..................................................................................................17

6.1.3 Block 2 operational evaluation..................................................................................................18

6.1.4 March 2013 shadow evaluation.................................................................................................19

6.2 COMMUNICATION UNCERTAINTY.................................................................................................19

6.3 CHARACTERIZING CFR SCHEDULING OPERATIONS AT DFW....................................................22

6.4 SUBJECT-MATTER EXPERT FEEDBACK.........................................................................................27

6.4.1 Identifying eligible ratings ........................................................................................................27

6.4.2 DFW ratings and discussion......................................................................................................29
ii

6.4.3 ZFW ratings and discussion ......................................................................................................29

6.5 OFF TIME COMPLIANCE................................................................................................................31

6.6 AIRBORNE TRANSIT TIME PREDICTIONS AND THE ‘HIT SLOT’ METRIC .....................................36

7 NEXT STEPS ........................................................................................................................ 39

7.1 AIR CARRIER COLLABORATION....................................................................................................39

7.2 PDRC ENHANCED SCHEDULING ..................................................................................................40

7.3 TRACON DEPARTURE SCHEDULING ..........................................................................................40

8 CONCLUDING REMARKS ............................................................................................... 41

ACKNOWLEDGEMENTS ....................................................................................................... 42

REFERENCE DOCUMENTS................................................................................................... 43

GLOSSARY................................................................................................................................. 47

9 APPENDIX A: AUXILIARY FIGURES............................................................................ 49

9.1 PDRC CONOPS FIGURE 3:1..........................................................................................................49

9.2 PDRC TECHNOLOGY DESCRIPTION FIGURE 3:4 ........................................................................50

9.3 CFR PROCEDURE WITH PDRC.....................................................................................................51

9.4 TMC FEEDBACK FORMS................................................................................................................51

10 APPENDIX B – TRACON TRANSIT TIME PREDICTION IMPROVEMENT ....... 54

10.1 THE PROBLEM..............................................................................................................................55

10.2 THE SOLUTION .............................................................................................................................56

10.3 RESULTS .......................................................................................................................................58

11 APPENDIX C – AMA TAXI TIME PREDICTION IMPROVEMENT....................... 59

11.1 APPROACH....................................................................................................................................59

11.2 DETERMINING SPOT-TO-QUEUE DISTANCES.............................................................................59

11.3 DETERMINE AMA SPEEDS BY GROUPS......................................................................................60

11.4 DATA FILTERS..............................................................................................................................61

11.5 RESULTS .......................................................................................................................................61

11.6 RECOMMENDATIONS BASED ON MULTIVARIATE REGRESSION ANALYSIS ...............................65

11.7 IMPLEMENTATION CHALLENGES................................................................................................65

11.8 POST-IMPLEMENTATION ANALYSIS............................................................................................65

11.8.1 Spot-to-Queue Taxi Time Error ..............................................................................................66

11.8.2 OFF time error.........................................................................................................................67

12 APPENDIX D: BLOCK 1 OPERATIONAL EVALUATION DATA........................... 69

13 APPENDIX E: BLOCK 2 OPERATIONAL EVALUATION DATA ........................... 74

14 APPENDIX F: BASELINE DATA.................................................................................... 79
iii

List of Figures

Figure 2:1 ‒ Illustration of simultaneous inbound and outbound tactical departures from DFW 

International Airport. ...................................................................................................................... 4

Figure 3:1 ‒ Precision Departure Release Capability (PDRC) system overview........................... 6

Figure 3:2 – PDRC prototype applied to present-day tactical departure scheduling operations. ... 7

Figure 4:1 ‒ PDRC prototype software architecture diagram marked up for technology 

development survey discussion..................................................................................................... 10

Figure 5:1 ‒ PDRC field evaluation positions in the vicinity of DFW airport............................. 13

Figure 6:1 – Significant communication uncertainty exists in the manual communication of CFR 

times.............................................................................................................................................. 20

Figure 6:2 ‒ CFR scheduling locations for 342 departures during PDRC Baseline data collection 

at DFW airport. ............................................................................................................................. 24

Figure 6:3 ‒ CFR scheduling locations for 198 departures during PDRC Block 1 & 2 operational 

evaluations at DFW....................................................................................................................... 25

Figure 6:4 ‒ Normalized OFF time compliance distributions for Block 1 and Block 2 evaluations 

compared to the Baseline data set................................................................................................. 35

Figure 6:5 ‒ Normalized absolute OFF time compliance distributions for Block 1 and Block 2 

evaluations compared to the Baseline data set.............................................................................. 36

Figure 6:6 – Uncertainty associated with Tactical Departure Scheduling.................................... 37

Figure 9:1 – Strategic and tactical departure scheduling for January 2011.................................. 49

Figure 9:2 – PDRC prototype software architecture..................................................................... 50

Figure 9:3 – Center and Tower tactical departure scheduling actions with PDRC to implement 

the CFR procedure. ....................................................................................................................... 51

Figure 9:4 – Feedback form for DFW TMCs, STMCs and FLMs. .............................................. 52

Figure 9:5 – Feedback form for ZFW TMCs and STMCs. .......................................................... 53

Figure 10:1 ‒ DARTZ3 DFW RNAV departure procedure. ........................................................ 54

Figure 10:2 – TMA departure route predictions before and after implementation of an 

adaptation-based solution.............................................................................................................. 55

Figure 10:3 – TMA ETA error before and after adaptation solution............................................ 56

Figure 10:4 ‒ rTMA analysis_categories for implemented solution. ........................................... 57

Figure 10:5 ‒ rTMA category_definitions for implemented solution. ......................................... 57

Figure 11:1 ‒ Locating the queue entry for DFW runway 17R.................................................... 60

Figure 11:2 ‒ Box plot of Real AMA Taxi Time Error................................................................ 62

Figure 11:3 ‒ Box plot of Absolute AMA Taxi Time Error......................................................... 62

Figure 11:4 – AMA taxi time prediction errors for 16 cases – median. ....................................... 63

Figure 11:5 – AMA taxi time prediction errors for 16 cases – mean. .......................................... 64

Figure 11:6 – AMA taxi time prediction errors for 16 cases (standard deviation)....................... 64

Figure 11:7 – AMA taxi time prediction errors for 16 cases (interquartile range)....................... 65

Figure 11:8 – Spot-to-queue taxi time error for all flights............................................................ 66

Figure 11:9 – Spot-to-queue taxi time error for AAL flights only. .............................................. 67

Figure 11:10 – OFF time accuracy plotted as a function of time-to-OFF for Block 1 evaluation 

and a portion of the Block 2 evaluation........................................................................................ 68
iv

List of Tables

Table 6:1 – Phraseology and interpretations in communication of Coordinated Release Time 

windows. ....................................................................................................................................... 22

Table 6:2 – DFW CFR scheduling operations by side and flow. ................................................. 23

Table 6:3 – CFR scheduling delta time statistics.......................................................................... 26

Table 6:4 – Feedback forms received for Block 1 & 2 evaluations.............................................. 28

Table 6:5 – DFW feedback........................................................................................................... 29

Table 6:6 – ZFW feedback data.................................................................................................... 30

Table 6:7 – OTC comparison descriptive statistics. ..................................................................... 33

Table 11:1 – TrajectoryDashboard values (gate A19, spot 10, rwy 17R) .................................... 59

Table 11:2 – Test Set Data............................................................................................................ 60

Table 11:3 ‒ Grouping Variables.................................................................................................. 61

Table 12:1 – Column definitions for Block 1 evaluations data. ................................................... 69

Table 12:2 – DFW departures scheduled with PDRC during Block 1 evaluation........................ 69

Table 12:3 – PDRC Block 1 flight counts by date and destination. ............................................. 73

Table 13:1 – Column definitions for Block 2 evaluation data...................................................... 74

Table 13:2 – DFW departures scheduled with PDRC during Block 2 evaluation........................ 74

Table 13:3 – PDRC Block 2 flight counts by date and destination. ............................................. 78

Table 14:1 – Baseline data culling summary................................................................................ 79

Table 14:2 – Column definitions for Baseline data. ..................................................................... 79

Table 14:3 – DFW departures scheduled with TMA/EDC during Baseline period. .................... 80
1

Abstract

After takeoff, aircraft must merge into en route (Center) airspace traffic flows that may be 

subject to constraints that create localized demand/capacity imbalances. When demand exceeds 

capacity, Traffic Management Coordinators (TMCs) and Frontline Managers (FLMs) often use 

tactical departure scheduling to manage the flow of departures into the constrained Center traffic 

flow. Tactical departure scheduling usually involves a Call for Release (CFR) procedure wherein 

the Tower must call the Center to coordinate a release time prior to allowing the flight to depart. 

In present-day operations release times are computed by the Center Traffic Management Advisor 

(TMA) decision support tool, based upon manual estimates of aircraft ready time verbally 

communicated from the Tower to the Center. The TMA-computed release time is verbally 

communicated from the Center back to the Tower where it is relayed to the Local controller as a 

release window that is typically three minutes wide. The Local controller will manage the 

departure to meet the coordinated release time window. Manual ready time prediction and verbal 

release time coordination are labor intensive and prone to inaccuracy. Also, use of release time 

windows adds uncertainty to the tactical departure process. Analysis of more than one million 

flights from January 2011 indicates that a significant number of tactically scheduled aircraft 

missed their en route slot due to ready time prediction uncertainty. Uncertainty in ready time 

estimates may result in missed opportunities to merge into constrained en route flows and lead to 

lost throughput. Next Generation Air Transportation System plans call for development of Tower 

automation systems capable of computing surface trajectory-based ready time estimates. NASA 

has developed the Precision Departure Release Capability (PDRC) concept that improves tactical 

departure scheduling by automatically communicating surface trajectory-based ready time 

predictions and departure runway assignments to the Center scheduling tool. The PDRC concept 

also incorporates earlier NASA and FAA research into automation-assisted CFR coordination. 

The PDRC concept reduces uncertainty by automatically communicating coordinated release 

times with seconds-level precision enabling TMCs and FLMs to work with target times rather 

than windows. NASA has developed a PDRC prototype system that integrates the Center’s TMA 

system with a research prototype Tower decision support tool. A two-phase field evaluation was 

conducted at NASA's North Texas Research Station in Dallas/Fort Worth. The field evaluation 

validated the PDRC concept and demonstrated reduced release time uncertainty while being used 

for tactical departure scheduling of more than 230 operational flights over 29 weeks of 

operations. This paper presents research results from the PDRC research activity. Companion 

papers present the Concept of Operations and a Technology Description.

1 Introduction

Future air traffic demands are expected to require a greater degree of integration among the 

automation systems used to manage arrival, departure and surface traffic. The next generation air 

transportation system (NextGen) envisions Integrated Arrival/Departure/Surface (IADS) 

operations as described in the Joint Planning and Development Office (JPDO) Integrated Work 

Plan [38] and in the FAA's NextGen Mid-Term Concept of Operations [35]. Various NextGen 

concepts [28, 31, 32] describe IADS operations that feature a greater degree of automated 
2

coordination as traffic flows from one control domain to the next in the tactical air traffic control 

environment.

A logical step towards the NextGen vision of fully-integrated arrival/departure/surface 

operations is to automate tactical scheduling of departure traffic that will join a constrained en 

route traffic flow. A commonly used tactical Traffic Management Initiative (TMI) is the Call 

For Release (CFR) procedure, which is also known as the Approval Request (APREQ) 

procedure. CFR procedures vary from facility to facility; however, they generally require the Air 

Traffic Control Tower (i.e., Tower) to request approval from the Air Route Traffic Control 

Center (i.e., Center) prior to releasing departures destined to specified airports. Earlier research 

[20, 21] at NASA Ames focused on automating inter-facility coordination during CFR 

procedures. An FAA-led effort built on this work to develop and evaluate the Departure Flow 

Management prototype [13].

Presently, en route tactical departure scheduling to meet CFR restrictions is often accomplished 

with the TMA decision support tool. Tactical departure scheduling with TMA is thoroughly 

described in Section 3 of the PDRC ConOps [1]. The PDRC concept combines the automated 

coordination demonstrated in the previous research [13,20,21] with the use of surface trajectorybased takeoff (OFF) time predictions and departure runway assignments to improve en route 

tactical departure scheduling with TMA during CFR procedures.

The PDRC research activity is an element of the Systems Analysis Integration and Evaluation 

(SAIE) Project of NASA’s Airspace Systems Program. The Aviation Systems Division at NASA 

Ames Research Center is conducting the PDRC research activity based out of NTX. This

research activity is also being accomplished using NASA Research Announcement contract 

(NNA11AC17C), which was awarded on 23 Sep 2011. Mosaic ATM, Inc. is the prime contractor 

for this work and CSC and Veracity Engineering are subcontractors. This document is a joint 

effort between NASA and contractor personnel.

NASA and the FAA are coordinating NextGen technology transfer via Research Transition 

Teams (RTTs). The RTTs have defined Research Transition Products (RTPs), consisting of 

distinct concept and/or technology elements that can be transferred as a package. PDRC is one 

of four RTPs currently being coordinated by the IADS RTT. NASA delivered an initial PDRC 

RTP package to the FAA in July 2012. Formal delivery of the core PDRC RTP package is slated 

for the summer of 2013. This final report will be one element of the PDRC RTP package. The 

FAA has identified the Time Based Flow Management (TBFM) Program and the Terminal 

Flight Data Manager (TFDM) Program as recipients of the PDRC RTP.

The research presented in this paper was conducted at NASA’s North Texas Research Station 

(NTX) and associated FAA air traffic control facilities in the Dallas/Fort Worth area. 

Consequently, the examples and discussions in this paper primarily focus on the north Texas air 

traffic environment. Every effort has been made to ensure that the research results are applicable 

throughout the National Airspace System.

This final report provides an overview of the research activity and presents field evaluation 

results. Companion documents describe the concept of operations [1] and the technology 

development [2]. Effectively, these three documents comprise a three-volume report and the 

reader is urged to have all three papers at hand. Section 2 of this report provides an overview of 

present-day tactical departure scheduling operations and summarizes an analysis of shortfalls 

conducted at the outset of the PDRC research activity. Section 3 provides an overview of the 
3

PDRC concept and shows how PDRC technology may be applied to existing tactical departure 

scheduling operations. Section 4 surveys the technology developed under this research activity. 

Section 5 describes the setup used for the PDRC field evaluations. Section 6 presents field 

evaluation observations and findings. Section 7 provides a preview of PDRC follow-on 

research. Finally, concluding remarks are offered in Section 8.

2 Tactical departure scheduling characteristics and shortfalls

This section presents an overview of present-day tactical departure scheduling operations and 

summarizes results of a shortfalls analysis. This material was originally published in two 2011 

AIAA conference papers [4, 5] and is discussed in much greater detail in the PDRC Concept of 

Operations [1].

2.1 Tactical departure scheduling

Tactical departure scheduling is a process used by TMCs and FLMs to regulate air traffic flow to 

eliminate local demand/capacity imbalances and adhere to local traffic management initiatives 

(TMIs). Tactical departure scheduling is not required during normal NAS operations, as the 

airspace into which a flight is being released generally has sufficient capacity to accommodate 

the departure. However, during periods of high demand or low capacity for the airspace being 

scheduled into, tactical departure scheduling may be utilized.

Tactical and strategic departure scheduling processes are distinct from one another and are 

currently not directly integrated. Tactical departure scheduling is distinguished from strategic 

departure scheduling based upon scope (both temporal and geographic), precision requirements, 

and the decision support tools used. Strategic departure scheduling primarily uses the Traffic 

Flow Management (TFM) tool suite, while tactical departure scheduling is typically 

accomplished with the TMA decision support tool. Please consult References 1 and 5 for a more 

complete discussion of the differences between tactical and strategic departure scheduling.

It has been helpful to categorize tactical departure scheduling operations as either inbound or 

outbound depending on the TMA function used for scheduling. These scenarios are thoroughly 

discussed in Section 3.3 of the PDRC ConOps [1]. A brief overview will be provided here.

Figure 2:1 illustrates both scenarios for traffic in Fort Worth Center (ZFW). The blue arrows 

show various traffic streams inbound to Houston’s George Bush Intercontinental Airport (IAH). 

These streams pass through ZFW airspace and converge at the TORNN meter arc. The green 

arrows depict a cross-country, overhead traffic stream outbound to Atlanta’s Hartsfield-Jackson 

International Airport (ATL). DFW departures (broad gold arrows) seeking to join these streams 

must be merged with the en route traffic at meter points shown in red near the ZFW boundary.
4

The IAH stream is categorized as inbound because tactical departure scheduling is performed 

with the arrival-focused “internal departure” scheduling functions in the TMA system 

performing metering for IAH arrivals. This TMA system is “owned” by Houston Center (ZHU),

although ZFW controllers perform some of the metering and ZFW TMCs can interact with the 

system. The ATL stream shown in Figure 2:1 is categorized as outbound because tactical 

departure scheduling is performed with the En Route Departure Capability (EDC) functions in 

the ZFW TMA system.

In either scenario, ZFW TMCs use TMA tactical departure scheduling functions to compute CFR 

times for DFW departures seeking to join the constrained en route streams. The scheduling 

process and coordination between ZFW TMCs and DFW Tower personnel is described in 

Section 3.3 of the PDRC ConOps [1].

2.2 Present-day system characteristics and shortfalls

The PDRC research activity characterized present-day tactical departure scheduling operations 

and identified shortfalls in the current system. This analysis is detailed in Reference 5 and the 

results are summarized in this section.

Reference 5 examines operational TMA and EDC data from all NAS facilities where the tools 

were deployed. The data included 1,082,000 flights operating during January 2011. The analysis 

indicates that these TMA and EDC tactical departure scheduling capabilities are widely used in 

the NAS today with over 65,000 scheduled aircraft per month using these methods. Increased 

utilization of tactical departure scheduling decision support tools has been fueled by expansion 

of adjacent center metering and nation-wide deployment of the EDC capability.

The PDRC ConOps [1] summarizes this analysis in a Venn diagram that has been excerpted in 

Appendix A (Figure 9:1) for easy reference. This diagram highlights the finding that tactical 

Figure 2:1 ‒ Illustration of simultaneous inbound and outbound tactical departures 

from DFW International Airport.
5

departure scheduling is used 3.5 times more often than strategic departure scheduling. The Venn 

diagram also shows that the inbound scenario described above occurs 5 times more often than 

the outbound scenario.

Although tactical departure scheduling with TMA and EDC has become a widely used 

component in NAS operations today and represents a significant improvement over the previous 

process, which lacked trajectory-based ascent modeling, analysis of the current system

performance indicates that significant room for improvement exists by reducing departure time 

uncertainty. Based upon operational data analysis described in Reference 5, 6,792 inbound 

tactically scheduled aircraft and 1,911 outbound tactically scheduled aircraft in January 2011 

NAS-wide are estimated to have missed the airspace slot they were scheduled into, due to 

departure time prediction uncertainty. Missed scheduled departure slots often lead directly to lost

NAS capacity, most notably in the case in which an aircraft is scheduled frozen into an arrival 

TMA slot but does not meet its expected departure time window. Reference 5 proposes metrics 

measuring missed overhead stream slots; however, measuring the impact to the NAS of a missed 

departure slot is not always straightforward as some ability to recover the airspace resources 

exists, often at the cost of additional TMC or controller workload and/or inefficient flight paths.

Before concluding this discussion of present-day operations, note one highlight of an additional 

finding from Reference 5. The aforementioned Venn diagram (Figure 9:1) notes that “1 in 4 

arrival metered flights is a tactical departure.” Stated another way, this means that 25% of 

inbound flights metered by an arrival TMA system are scheduled (i.e., have slots reserved) in the 

overhead stream while they are still on the surface at the origination airport. The 25% figure is 

a NAS-wide average. For some facilities nearly half of their TMA metered arrivals are 

scheduled as tactical departures. This is primarily due to the fact that TMA’s adjacent center 

metering capability has greatly extended the scheduling time horizon.

TMA development is continuing under the FAA’s Time Based Flow Management (TBFM) 

program. The TBFM program office is introducing new concepts designed at further extending 

the range of arrival metering. This increased range will be achieved through use of new concepts 

such as ‘Coupled Scheduling’ [25] and ‘Extended Metering.’ TBFM estimates of the maximum 

nominal metering range of an ‘Extended Metering’ system are approximately 725 nmi. As has 

been demonstrated with TBFM’s adjacent center metering systems, when the metering geometry 

expands, more airports enter the metering system from the airport surface (i.e., tactical departure 

scheduling). Due to the emerging demand for tactical departure scheduling and the significant 

uncertainty these flights represent to the en route schedule, the future need for integrating surface 

information into departure scheduling is expected to increase as well.

3 Concept and research prototype overview

NASA has developed the PDRC concept to address the shortfalls in present-day tactical 

departure scheduling operations. This section provides an overview of the PDRC concept and 

shows how PDRC technology may be applied to existing tactical departure scheduling 

operations. The companion ConOps document [1] provides additional details on this concept.
6

3.1 Concept overview

Figure 3:1 provides a high-level overview of the PDRC operational concept. This figure is 

applicable to both the outbound and inbound tactical departure scheduling situations described 

above. The right side of the figure depicts departure traffic operating under the CFR procedure 

where departures must be merged into constrained en route traffic flows. The left side of the 

figure shows the PDRC decision support tools used for tactical departure scheduling.

The upper portion of the figure depicts a traffic stream in the en route domain that is under a 

CFR constraint. PDRC builds on an existing tactical departure scheduling decision support tool 

used by the Center to schedule departures into this constrained overhead stream. Ascent 

modeling in the en route decision support tool enables precise time-based scheduling and deconfliction at the meter point. The modeled ascent trajectory is illustrated by the gold line in

Figure 3:1.

The lower portion of Figure 3:1 depicts the Tower environment where a NextGen surface 

trajectory-based decision support tool is in use. NextGen surface trajectory-based operations are 

enabled by a surface surveillance system and air carrier data sharing that provides intent and 

status information (e.g., gate assignments, estimated and actual pushback times). The surface 

trajectories computed and used by this decision support tool are represented by the blue and red 

lines in this figure.

Figure 3:1 ‒ Precision Departure Release Capability (PDRC) system overview.
7

PDRC focuses on the automated communication and use of surface trajectory-based OFF time 

predictions and runway assignments for tactical departure scheduling in CFR situations. In 

present-day operations, OFF time prediction and communication is manual. Automated PDRC 

communication is illustrated by the double-headed arrow on the left side of Figure 3:1. The 

Center decision support tool uses surface trajectory-based OFF time predictions for departure 

scheduling and coordinates release times with the Tower surface trajectory-based decision 

support tool. The Tower tool predicts OFF times and runway assignments for use by the Center

tool in tactical departure scheduling and coordinates release times with the Center decision tool.

The focal point for PDRC is the OFF event in Figure 3:1 where the red trajectory joins with the 

gold trajectory on the departure runway. The Tower decision support tool computes surface 

trajectories to this point to develop OFF time estimates. The Center decision support tool 

computes airborne trajectories from the surface specified runway to the merge point in the 

overhead stream for tactical departure scheduling.

3.2 PDRC research prototype implementation overview

As discussed above, the PDRC concept calls for integrating the Center’s tactical departure 

scheduling system with a surface decision support tool capable of providing trajectory-based 

OFF time predictions and departure runway assignments. Figure 3:2 illustrates the PDRC 

concept applied to present-day tactical departure scheduling operations.

The PDRC prototype uses a Research TMA (rTMA) system derived from operational FAA TMA 

software for Center tactical departure scheduling. The Surface Decision Support System (SDSS) 

serves as a surrogate for a NextGen trajectory-based surface management system. These and 

Figure 3:2 – PDRC prototype applied to present-day tactical departure scheduling 

operations.
8

other elements of the PDRC prototype are described in Section 4 and in the companion 

Technology Description document [2].

The upper portion of Figure 3:2 illustrates present-day tactical departure scheduling operations

for both the inbound and outbound scenarios described in Section 2.1. The tactical departure 

trajectory is shown in gold and merges with the constrained overhead flow at a meter point 

shown in red. The departure airport is on the left located inside the departure Center shown in 

blue. The arrival airport is on the right located inside the arrival Center shown in green.

The constrained overhead stream is shown flowing from left to right from the blue Center to the 

green Center where the stream becomes an arrival flow to the airport on the right side of the 

figure. Two separate TMA systems are depicted by the timeline user interface icons with 

“Center DST” labels. The TMA icons have a color-coded borders to depict which Center 

“owns” which TMA system.

Consider first the outbound tactical departure scenario. In this case traffic managers at the blue 

Center would use the blue TMA/EDC system to schedule CFR departures from the airport on the 

left into the constrained overhead stream. The traffic managers are using their own TMA/EDC 

system to schedule traffic outbound from their own Center. In this case, the constrained 

overhead flow happens to be an arrival stream for an airport in the adjacent Center, but it is 

treated like any other outbound flow for scheduling purposes.

Now consider the inbound tactical departure scenario. In this case, the departure from the 

airport on the left (in the blue Center) is scheduled into the green TMA system, which is being 

used by the green Center to meter the arrival stream to the airport on the right. The CFR call and 

tactical departure scheduling action is most likely being performed by traffic managers in the 

blue Center using an interface to the green Center TMA system. Thus, the blue Center traffic 

managers are using the green Center TMA system to schedule traffic inbound to the airport on 

the right.

The lower portion of Figure 3:2 shows PDRC applied to tactical departure scheduling operations. 

PDRC’s double-headed arrows connect a trajectory-based surface system at the departure airport 

to inbound and outbound TMA systems. The PDRC concept and technology have been 

developed for both the inbound and outbound tactical departure scheduling scenarios. 

In Section 2.2 it was noted that FAA TBFM program Adjacent Center Metering developments 

have significantly extended the reach of TMA arrival metering. Future TBFM developments in 

the areas of Coupled Scheduling and Extended Metering are expected to further extend the TMA 

arrival metering scheduling horizon. One can visualize this in terms of Figure 3:2 by imagining 

a much longer double-headed arrow connected to the green arrival metering TMA system 

thereby extending the reach of tactical departure scheduling.

4 Technology development

This section presents a survey of PDRC prototype technology development to highlight some of 

the more important accomplishments. Complete details regarding the PDRC prototype software 

are provided in the Technology Description companion document [2].
9

4.1 Overview

As described in Section 3, the PDRC concept integrates an en route tactical departure scheduling 

decision support tool (DST) with a NextGen surface trajectory-based DST. OFF time 

predictions and departure runway predictions from the surface tool are provided to the en route 

tool to improve departure scheduling calculations. The concept also facilitates coordination 

between Center and Tower TMCs/FLMs via the digital interface between the DSTs.

Design decisions for the PDRC prototype were driven by two primary considerations: (1) 

minimize technology transfer barriers, and (2) maximize the likelihood that FAA TMCs/FLMs 

would be willing to use the prototype during operational field evaluations. Both of these 

considerations weighed heavily in the decision to develop a research version of FAA TMA (i.e.,

rTMA) rather than use NASA’s in-house TMA prototype (i.e., the Center TRACON Automation 

System or CTAS). The extra effort required to develop rTMA has paid dividends many times 

over both in technology transfer coordination and in TMC/FLM acceptance of the PDRC 

prototype. Use of rTMA also reduced the training required and enabled the team to take 

advantage of unexpected field evaluation opportunities involving unusual traffic configurations 

that likely would not have been adapted in a CTAS-based PDRC prototype.

The decision to use SDSS for the Tower tool was made for similar reasons. Although SDSS is 

not operationally deployed, it is used for research and development by various FAA 

organizations. This provides a common frame of reference for technology transfer coordination. 

Additionally, SDSS has benefitted from many years of NASA/FAA joint development, which 

has produced features and overall system robustness that helped the PDRC prototype system win 

acceptance with Tower TMCs/FLMs.

Figure 4:1 depicts a survey of PDRC technology development. This is a marked-up version of 

Figure 3:4 from the PDRC Technology Description [2]. A clean copy of this figure is provided 

in Appendix A (Figure 9:2) for easy reference. These figures are organized into three main 

sections according to the software systems being depicted. The left side of the diagram (in 

green) shows processes associated with SDSS. The right side of the diagram (in blue) shows 

software processes associated with rTMA. There are actually two rTMA systems shown on the 

right side of the diagram. The upper right portion of the diagram shows the rTMA system used 

for the outbound tactical departure scheduling scenario. This rTMA was configured as ZFW 

TMA/EDC. The lower right portion of the diagram shows the rTMA system used for the 

inbound tactical departure scheduling scenario. This rTMA was configured as ZHU arrival 

metering TMA.
10

4.2 Double-headed arrow

The signature piece of PDRC technology is the “double-headed arrow” of Figure 3:1 that 

represents two-way communications between the surface and en route components of the system. 

Two callout boxes in Figure 4:1 are labeled “double-headed arrow” and point to the software 

processes that enabled this new, two-way communications interface. On the SDSS (left/green) 

side a new TMA Connect process was created to handle all communications with TMA. On the 

rTMA (right/blue) side a new surface data interface (SDIF) process was created to receive data 

from SDSS. TMA’s existing Collaborative Arrival Planner (CAP) data-sharing interface was 

extended to send data to SDSS.

4.3 All flights all tracks

Early in the PDRC prototype development process it was determined that it would be necessary 

for the en route and surface components to operate from a single, authoritative set of flight plan 

and airborne surveillance track data. The simplest solution was to have rTMA provide airborne 

flight plan and surveillance data to SDSS via the existing CAP interface. However, unlike 

NASA’s CTAS prototype system, flight plan and track data is compartmentalized in the FAA’s 

TMA system. The “all flights all tracks” callout on the rTMA (right/blue) side of Figure 4:1

denotes changes that were made to the rTMA input source manager (ISM) process to enable the 

full set of airborne flight plan and surveillance data to be delivered to SDSS.

Figure 4:1 ‒ PDRC prototype software architecture diagram marked up for 

technology development survey discussion.
11

4.4 Scheduler modifications

PDRC leverages existing TMA departure scheduling functionality. SDSS-computed Predicted 

Coordinated Off Time (PCOT) and Undelayed Coordinated Off Time (UCOT) values are 

delivered to rTMA via the double-headed arrow interface for use in scheduling by the dynamic 

planner (DP) and meter point dynamic planner (MPDP) processes. Both the UCOT and PCOT 

times were necessary so that rTMA could give credit to flights that encountered surface delays. 

This reduces the chance that a flight might be double-penalized by both a surface delay and a 

tactical departure delay. The “scheduler modifications” callout on the rTMA (right/blue) side of 

Figure 4:1 indicates that changes were required to the DP/MPDP and the departure scheduling 

user interface on the timeline graphical user interface (TGUI) process to enable automatic use of 

these SDSS-predicted OFF times.

4.5 Departure routing

The “departure routing” callout on the rTMA (right/blue) side of Figure 4:1 denotes 

improvements that were made to rTMA airborne departure routing within TRACON airspace. 

These improvements are particularly noteworthy because they were made possible by SDSS 

departure runway predictions communicated to rTMA via the PDRC double-headed arrow 

technology. The improvements were implemented via changes to the adaptation files used by 

rTMA’s route analyzer (RA) and trajectory synthesizer (TS) processes. A description of these 

changes and the supporting analysis is provided in Appendix B (Section 10) of this paper. The 

Appendix B analysis shows TRACON flight time prediction errors have been reduced by up to a 

factor of 6 (i.e., average errors of 176 seconds reduced to 28 seconds) depending on the 

departure runway and departure fix combination. This analysis was conducted for the DFW 

North Flow configuration and a single southern departure fix (DARTZ) because this departure 

route was used frequently in the PDRC operational evaluations. However, the implemented 

solution provides TRACON flight time prediction improvements for all flows and departure 

fixes, and the error reduction will be comparable for flows and fixes with similar geometries.

4.6 OFF time prediction improvements

The “OFF time prediction improvements” callout on the SDSS (left/green) side of Figure 4:1

points to the SDSS Surface Model process and highlights numerous changes that have been 

implemented to improve SDSS OFF time predictions. Some of these changes were introduced 

when SDSS was up-leveled to version 9.x, which featured a redesigned Surface Model. The 

v9.x SDSS model includes additional instrumentation (e.g., the TrajectoryDashboard-1.0 tool) to 

support data collection and analysis.

Section II-E of the 2012 AIAA paper [6] identifies Aircraft Movement Area (AMA) taxi time 

predictions as a major contributor to OFF time prediction uncertainty. The paper recommends 

pursuing a more sophisticated model for AMA taxi operations. Appendix C (Section 11) of this 

paper describes the multivariate regression analysis that was conducted using outputs of the new

TrajectoryDashboard tool mentioned above. Appendix C (Section 11) also addresses SDSS 

implementation details.

4.7 Air carrier two-way interface

The “air carrier two-way interface” callout on the SDSS (left/green) side of Figure 4:1 denotes 

the new two-way, Tactical Surface Data Exchange (TSDE) interface with American Airlines that 

was implemented to improve SDSS OUT time predictions and to capture actual OUT events for 
12

data analysis. This interface was developed in collaboration with the FAA’s Surface Trajectory 

Based Operations (STBO) Project.

4.8 Multi-domain ‘what if’ scheduler

The “multi-domain ‘what if’ scheduler” callout on the SDSS (left/green) side of Figure 4:1

points to the completely new TMA Scheduler process that was developed specifically to support 

PDRC research. The SDSS TMA Scheduler process collects internal rTMA scheduling 

information and makes it available to Tower TMCs/FLMs for ‘what-if’ analyses and better 

visibility into the en route portion of the tactical departure scheduling problem. This multidomain scheduler performs the specified hypothetical scheduling tasks (e.g., ‘what if’

scheduling) and presents the results to the user. This new process supports the enhanced 

scheduling capabilities research that is briefly discussed in Section 7.2 of this paper.

4.9 Multi-airport, many-to-many interface architecture

The “multi-airport, many-to-many interface architecture” callout on the SDSS (left/green) side of 

Figure 4:1 denotes a capability developed in PDRC that allows the surface system to connect to 

multiple en route systems for PDRC data exchange. The end state integration of PDRC 

capability in the NAS envisions many-to-many connections from/to surface and en route 

systems.

Planned PDRC follow-on research addresses more complex scheduling constraints (e.g.,

TRACON-level flow constraints) and lesser-equipped airports. The TRACON Departure 

Scheduling research activity, briefly discussed in Section 7.3 of this paper, will build on the 

multi-airport, many-to-many capabilities developed in PDRC.

This completes the survey of PDRC technology development. Please consult the Technology 

Description document [2] for a more detailed description of the technology associated with 

PDRC.

5 Field evaluation setup

Three PDRC field evaluations have been conducted at NASA’s North Texas Research Station 

(NTX) field site. A live-data, operational environment shadow evaluation was conducted in July 

2011 [4]. This was followed by two operational evaluations (Block 1 & 2) conducted in the 

summer of 2012 and the winter of 2012/2013. The Block 1 & 2 operational evaluations were 

essentially a single operational evaluation with a built-in pause to allow for interim data analysis 

and system enhancements. Since the evaluation setup was generally similar in all three cases it 

will be described here to avoid repetition in the analysis and results sections that follow.

5.1 Physical layout

Figure 5:1 depicts the physical layout for the PDRC field evaluations. In this figure, DFW 

airport runways are highlighted in yellow in the center of the figure. ZFW and the NTX 

laboratory are located about 3 miles southwest of the airport. PDRC installations are shown in 

the inset images.
13

5.1.1 ZFW Center TMU

This location corresponds to the Center role in the PDRC operational scenario described in 

Section 6 of the PDRC Concept of Operations [1]. ZFW’s PDRC user interface is installed in 

the Traffic Management En Route Coordinator (TMEC or EC1) position shown in the lower left 

portion of Figure 5:1. The PDRC user interface was located at the EC1 position during both 

operational evaluations. During the July 2011 shadow evaluation the PDRC user interface was 

installed in a non-operational position in the TMU.

As is typical for Centers, the ZFW TMU is physically separate from the specialties where sector 

controllers work. The TMU is staffed by TMCs and Supervisory TMCs (i.e., STMCs) and only 

these personnel interacted with the PDRC prototype system. NASA personnel provided PDRC 

prototype training for all ZFW TMCs and STMCs – approximately 30 individuals. Most of the 

TMU staff participated in both Block 1 & 2 operational evaluations.

5.1.2 DFW Towers

This location corresponds to the Tower role in the PDRC operational scenario described in 

Section 6 of the PDRC Concept of Operations [1]. PDRC user interfaces are installed at the 

TMC desks at both East and West Towers at DFW. The inset image in the upper right portion of

Figure 5:1 shows the East Tower PDRC installation. The West Tower installation is similar.

The TMU functions in the Tower are much less segregated than they are in the Center. 

Consequently, all Tower personnel were involved in the PDRC field test, some directly and 

others indirectly. The direct involvement was managed by Tower TMCs who are part of the 

Figure 5:1 ‒ PDRC field evaluation positions in the vicinity of DFW airport..
14

Metroplex Traffic Management Unit that also contains STMCs and TMCs from DFW 

TRACON.

5.1.3 AA DFW Ramp Tower

The PDRC user interface at American Airlines’ DFW Ramp Tower is shown in the top left 

corner of in of Figure 5:1. This position was established for the July 2011 shadow evaluation to 

gain a better understanding of the available air carrier data and to experiment with it through 

manual data entry into the PDRC system. In essence, the NASA observer at this position acted 

as a surrogate for the TSDE data interface mentioned in Section 4.7 and detailed in the 

companion Technology Description document [2]. American Airlines continues to provide 

valuable data and support for the PDRC research activity.

5.1.4 NTX Laboratory

The NTX Laboratory shown in the lower right corner of Figure 5:1 served as the command 

center for the Block 1 & 2 operational evaluations just as it did for the July 2011 shadow 

evaluation [4]. Due to the target-of-opportunity nature of the operational evaluations, services 

provided by the NTX lab had to be virtualized and automated to a greater extent than for the 

shadow evaluation to support the agile evaluation methodology described below.

5.2 Apparatus

The primary apparatus for the Block 1 & 2 operational evaluations was the PDRC prototype 

system itself. Complete details are provided in the companion Technology Description 

document [2] and can be summarized as follows:

• rTMA decision support tool including GUI clients (typically 3 per system)

• SDSS decision support tool including GUI clients (typically 4 per system)

• Live data feeds for rTMA and SDSS including Center, TRACON, and ASDE-X 

surveillance, Rapid Refresh forecast winds aloft, and air carrier data

• PDRC two-way interface connecting rTMA and SDSS

For the Block 1 & 2 operational evaluations, the PDRC prototype system was hosted on a 

dedicated Linux server configured with two 2.5 GHz quad-core CPUs and 48GB RAM. Each 

PDRC server ran all of the rTMA and SDSS computational processes hosted on one virtual 

machine (VM) with a second VM hosting the associated rTMA and SDSS GUI clients, and 

services for distributing the GUI clients to remote user displays.

The PDRC Block 1 & 2 operational evaluation depended upon a number of NTX-built research 

support systems. One of the most important is the NextGen Emulation System (NEXUS)

desktop distribution system, which uses a graphical desktop sharing utility (i.e., Virtual Network 

Computing) to distribute all PDRC GUI clients to the various end-user display machines. The 

NEXUS desktop distribution system also provides for digital video recording of all displays for 

post-test review.

The PDRC research team also used the NTX-developed Terminal Area Radio Telecast System 

(TARTS) and TowerCam systems to support Block 1 & 2 operational evaluation data collection. 

TARTS provides streaming audio of controller/pilot radio transmissions received over-the-air at

the NTX laboratory. TowerCam consists of remote control pan/tilt/zoom cameras mounted on 

DFW’s central Tower.
15

5.3 Agile and opportunistic evaluation methodology

A key observation from the July 2011 shadow evaluation experience [4] was the need for an 

agile and opportunistic evaluation methodology for the operational tests that were to follow. 

Tactical departure scheduling situations are dependent on unpredictable weather and traffic 

volume factors making it necessary for the research team to adopt a target-of-opportunity 

mentality towards data collection. Since data collection “runs” could not be scheduled in 

advance, the team could not count on having research observers on position to collect data. 

Likewise, it was simply impractical to have a small, dedicated cadre of TMCs/FLMs to work 

with the research team as was done in past NASA operational evaluations. Even without 

considering cost, it was concluded that it would be logistically impossible to have the 

participation of research observers on position and a small cadre of TMCs/FLMs for the entire 

evaluation.

Consequently, the PDRC research team developed an agile and opportunistic data collection 

system to partially compensate for the target-of-opportunity evaluation challenges noted above. 

A key aspect of this system involved immediate notification via email and text message when a 

tactical departure scheduling opportunity arose. Upon receiving this notification, PDRC 

evaluation team members coordinated with each other via email and/or text message to identify 

who would monitor the system. The designated system monitor would be ready to offer 

assistance should the TMCs require technical support and the monitor ensured that research data 

was collected.

The PDRC prototype systems are, of course, fully instrumented. Every input and output and a 

wide array of internal parameters are recorded and archived. Additional instrumentation is 

provided by the NEXUS desktop distribution system (Section 5.2), which enables research 

observers to remotely monitor and analyze TMC/FLM interactions with PDRC. This “video 

replay” capability has proven to be immensely valuable for filling gaps when an observer was 

unable to monitor the CFR event live and for following up on TMC/FLM feedback.

The target-of-opportunity evaluation methodology is highly dependent on participant training. 

Since a dedicated cadre was not an option, the PDRC team trained more than 30 ZFW 

TMCs/STMCs on use of the PDRC prototype over the course of the research activity. This 

challenging task was made manageable thanks to the decision to use rTMA for the en route 

portion of PDRC. Since rTMA was derived directly from a recent version of FAA TMA, nearly 

all features and functions are the same. This allowed the trainers to focus just on PDRC-specific 

features. NASA was also fortunate to have several ZFW TMCs/STMCs assist with training their 

colleagues.

NASA personnel provided PDRC prototype training for all DFW TMCs and STMCs. DFW 

Tower participation in the July 2011 shadow evaluation and the Block 1 operational evaluation 

was limited to TMCs and STMCs. For the Block 2 operational evaluation, the DFW Tower 

FLMs were included in the group of evaluation participants. DFW TMCs conducted the training 

for the FLMs. DFW STMCs also developed briefings on PDRC operational evaluation 

procedures and delivered these to all DFW Tower controllers.

Gathering feedback from TMCs/FLMs as they used PDRC was a primary evaluation objective. 

This task was particularly challenging with no on-position observers and without the luxury of 

dedicated debriefing sessions with a controller cadre. The PDRC team compensated for these 

shortcomings by creating several avenues for TMC/FLM feedback:
16

• Electronic feedback forms accessible directly from PDRC user interfaces

• NTX technical support hotline

• Periodic “how goes it” meetings

TMC/FLM feedback will be examined more thoroughly in Section 6.4

5.4 Inbound scenario field evaluation challenges

Section 2.2 summarized research conducted in 2011 that examined shortfalls in present-day 

tactical departure scheduling operations. This research identified a large benefits pool for 

improved tactical departure scheduling and showed that the majority of the potential benefits are 

associated with the inbound scenario. Additionally, it is expected that FAA TBFM 

developments will continue increasing inbound usage at the expense of outbound usage. One 

can easily envision a future where the outbound scenario no longer exists. These factors made 

the inbound scenario an enticing target for PDRC field evaluations.

However, the very factors that make the inbound scenario more interesting also make it more 

difficult to evaluate. The inbound scenario involves TMA arrival metering, which operates in a 

closed-loop mode (i.e., meter times displayed on sector controllers’ radar scopes). In contrast, 

the outbound scenario utilizes the TMA/EDC function which, in current practice, operates in 

open-loop mode. TMCs in the TMU use TMA/EDC to provide the sector controllers with a 

workable traffic situation, but sector controllers are not required to meet TMA/EDC meter times.

The closed-loop operation of TMA arrival metering requires a two-way interface to the Center 

Host or ERAM computer so that meter times can be delivered to the sector controller scopes. 

Even though rTMA is derived directly from FAA TMA it is still a research system and has not 

been approved for two-way Host or ERAM interface. An additional complication is illustrated 

in Figure 3:2, which shows that the inbound scenario requires the rTMA portion of PDRC to be 

deployed at the arrival Center. Consequently, the field evaluation threshold is much higher for 

the inbound scenario with TMA arrival metering.

This threshold difference may cause one to question the value of evaluating only the outbound

scenario, but there are two main reasons for doing so. First, as shown in Figure 3:2, the surface 

portion of the evaluation is virtually identical between the inbound and outbound cases. This is 

particularly true for the common case of DFW-to-IAH tactical departures scheduling, which 

sometimes operates inbound and sometimes outbound. During the Block 1 field evaluation

there were numerous occasions where the Tower TMCs attempted to use PDRC for an inbound

IAH scenario because they didn’t have visibility into which scenario was in play – it all looked 

the same from the Tower side. Thus, all research on the surface component of PDRC applies 

equally to the outbound and inbound cases and the outbound scenario is satisfactory for 

evaluating any enhancements or extensions made on the surface side. Second, although there are 

distinct differences between the scenarios on the Center side, the TMC role is very similar 

between the two scenarios.

6 Field evaluation observations and findings

This section presents observations and findings, quantitative and qualitative, collected during the 

PDRC shadow and operational evaluations.
17

6.1 Evaluation overviews

The brief overviews for each of the PDRC evaluations provide the necessary background for the 

observations and findings presented in subsequent sections. The overviews document the 

number of tactical departures that were scheduled with the PDRC prototype. For a flight to 

count as a PDRC-scheduled flight, both the Tower and Center TMCs/FLMs had to schedule the

flight using the PDRC system and the scheduling procedure described in Section 6.1 of 

Reference 1. A summary of the PDRC scheduling procedure is provided in Appendix A (Figure 

9:3) for easy reference.

6.1.1 July 2011 shadow evaluation

The July 2011 shadow evaluation has been thoroughly documented in Reference 4, so only a 

brief summary will be given in this paper. As previously noted, this was primarily a training and 

shakedown evaluation session. NASA observers were stationed at operational positions at ZFW 

and the DFW East Tower to provide training and technical support and to record observations 

and feedback as TMCs operated the system in shadow mode. The NASA observer at American 

Airlines DFW ramp tower was tasked with transferring updated OUT estimates from AA

systems to the PDRC prototype (in lieu of the not-yet-implemented TSDE interface) and 

recording observations from that unique perspective.

Notably, this was the only evaluation where PDRC was operated in the inbound scenario (see 

discussion in Section 5.4). TMCs provided feedback on PDRC performance (shadow mode 

only) in this scenario, and the evaluation team explored potential workarounds for inbound 

scenario operational evaluations. None proved satisfactory. On the final day of the evaluation 

the test shifted from shadow to operational mode wherein the PDRC prototype system was used 

to schedule five actual DFW departures using the outbound scenario.

6.1.2 Block 1 operational evaluation

Dates: 13 – 29 Jul 2011

Duration: 61 hours of on-position observations over 12 days

Participants: ZFW and DFW TMCs/STMCs

Flight count: 5 operational departures scheduled in the outbound scenario

Objectives:

• PDRC prototype and test apparatus shakedown

• TMC training

• Live-traffic shadow evaluations with TMCs in their operational environment

Dates: 30 Apr 2012 – 26 Jul 2012

Duration: 13 weeks of continuous target-of-opportunity evaluations

Participants: ZFW and DFW TMCs/STMCs

Flight count: 120 operational departures scheduled in the outbound scenario

Objectives:

• Validate the PDRC concept

• Demonstrate PDRC prototype system performance

• Identify and quantify sources of uncertainty in the tactical departure scheduling process
18

Key changes since July 2011 shadow evaluation are summarized below. See the Technology 

Description document [2] for complete details.

• The PDRC surface component (i.e., SDSS) was upgraded to version 9.x, which features 

an improved trajectory-based airport surface model. The improved model provides better 

OFF time predictions and has additional instrumentation to support data collection and 

analysis.

• The PDRC en route component (i.e., rTMA) was re-derived from FAA TMA version 

3.12. Also, rTMA now has the ability to use departure runway from SDSS to improve 

airborne route models.

• A new two-way TSDE interface with American Airlines was implemented to improve 

SDSS OUT time predictions and to capture actual OUT events for data analysis. This 

interface was developed in collaboration with the FAA’s STBO Project and is discussed 

in Section 4.7.

Data from the Block 1 evaluation are collected in Appendix D (Section 12). Table 12:3 provides 

a count of PDRC-scheduled flights by date and destination airport. This table shows that the two 

Houston-area airports (IAH and HOU) accounted for about 78% of the flights scheduled with 

PDRC during the Block 1 evaluation.

Twenty-seven feedback forms were received during the Block 1 evaluation. These are discussed 

in Section 6.4. TMC feedback was also gathered at team “how goes it” meetings on May 14, 

May 31, and June 11. Clarity of communications during CFR coordination was a major topic of 

discussion at the initial Block 1 “how goes it” meetings. See Section 6.2 for a discussion of 

findings on this topic.

6.1.3 Block 2 operational evaluation

Key changes since the Block 1 evaluation are as follows:

• Merged with latest SDSS baseline (v9.2.x) to leverage FAA investments.

• New adaptation logic to improve taxi time predictions.

• Completely new SDSS software to enable Tower display of overhead stream slot 

information.

• User interface changes (e.g., colors, layout) to address TMC feedback.

• New “go/no go” status panel to improve TMC coordination.

• rTMA improvement to correct a scheduling anomaly.

Dates: 5 Nov 2012 – 28 Feb 2013

Duration: 16 weeks of continuous target-of-opportunity evaluations (~150 hours of CFR)

Participants: ZFW TMCs/STMCs and DFW TMCs/STMCs/FLMs

Flight count: 118 operational departures scheduled in the outbound scenario

Objectives:

• Validate the PDRC concept

• Demonstrate PDRC prototype system performance

• Evaluate improvements to PDRC Core technology.
19

Data from the Block 2 evaluation are collected in Appendix E (Section 13). Table 13:3 provides 

a count of PDRC-scheduled flights by date and destination airport. This table shows that the two 

Houston-area airports (IAH and HOU) still account for the majority of PDRC flights; however 

Denver (DEN) now ranks 2nd with 22 PDRC-scheduled flights while it had none in the Block 1 

evaluation. The increase in CFR instances for DEN may be related to increased use of

Optimized Profile Descent (OPD) arrival procedures at that airport. DFW traffic management 

experts report early indications that increased arrival stream compression apparently associated 

with OPDs is resulting in more frequent and extensive restrictions at airports with more OPD 

arrivals like DEN. It should also be noted that the Block 2 operational evaluation had about 83% 

more (24 vs. 14) west-side departures than the Block 1 evaluation and virtually all DEN flights 

would depart on the west side of DFW. More analysis is required to verify a correlation between 

DEN OPD arrival operations and DFW-to-DEN CFR frequency.

For the 16 week Block 2 evaluation, the PDRC prototype was estimated to have operated in CFR 

mode for approximately 150 hours. This estimate was made possible by the new CFR two-way 

status indication system (i.e., “thumbs up/down” indicator) described in Section 6.4 of Reference 

2. Logging features built into the status indicator record when both facilities have selected a 

“thumbs up” status. The total “two thumbs up” time for Block 2 amounted to a little more than 

150 hours over the 16 week evaluation period. Twenty-three feedback forms were received 

during the Block 2 evaluation, discussed in Section 6.4. TMC feedback was also gathered at 

team “how goes it” meetings on Dec 18 and Feb 14.

6.1.4 March 2013 shadow evaluation

Live traffic shadowing sessions and storyboard-driven structured interviews were used to obtain 

early feedback on PDRC enhanced scheduling concepts from a focus group of four ZFW and 

DFW subject-matter experts. See Section 7.2 for a discussion of this research thread.

6.2 Communication uncertainty 

A key finding from the July 2011 PDRC shadow evaluation [4] was that there may be varying 

interpretations and practices regarding the actual target release time within the CFR compliance 

window. Consequently, the PDRC research team worked with ZFW and DFW TMCs to reduce 

this source of uncertainty for the operational evaluations. The diagram shown in Figure 6:1 was 

developed to facilitate communication between the researchers and TMCs regarding CFR time. 

This diagram was used during test preparation and training for the Block 1 operational 

evaluation.

The bottom portion of Figure 6:1 provides a pictorial representation of key events for a departing 

flight. The upper portion shows these same events mapped to a timeline similar to those 

Dates: 25 – 29 Mar 2013

Duration: 3 shadow evaluation and structured interview sessions

Participants: ZFW TMC, ZFW STMC and two DFW TMCs

Objectives: obtain early feedback on PDRC enhanced scheduling concepts.
20

displayed on the rTMA and SDSS decision support tools used for PDRC. The left side of the 

timeline shows these events from the human (i.e., TMC) perspective while the right side of the 

timeline shows them from the PDRC software system perspective. The discussion that follows 

will center on four events depicted in Figure 6:1. Considering the events chronologically, the 

first is “Cleared for T/O,” which is simply the time at which the Tower Local controller issues 

the takeoff clearance. At this point control over the actual departure time is ceded to the pilot. 

The next significant event is “Start of Roll,” which will occur at some variable interval after the 

takeoff clearance. The “Start of Roll” variability is due to a combination of human factors and 

aircraft characteristics. The next key event is “Wheels OFF,” which is the time at which an 

onboard weight-on-wheels switch would indicate that the aircraft is airborne. The interval 

between “Start of Roll” and “Wheels OFF” is almost entirely a function of aircraft takeoff 

weight and performance characteristics. The final event of interest is labeled “Tagged Up.” This 

corresponds to the time at which the departing flight is acquired by the TRACON surveillance 

radar and “tags up” on the radar scope. In communications with flight crews, Tower personnel 

often use “wheels in the well” (i.e., landing gear fully retracted) as a useful approximation for the 

“Tagged Up” event.

Uncertainty in CFR communications begins with varying interpretations and/or assumptions 

concerning the four key events described in the preceding paragraph and shown in Figure 6:1. 

Achieving higher precision in tactical departure scheduling requires that the Tower and Center 

TMCs/FLMs and their software tools all be on the same page when exchanging information 

about these events. The SDSS predicted surface trajectory (i.e., the red trajectory in Figure 3:1) 

ends at the runway threshold at the “Start of Roll” event. The rTMA software uses “Wheels 

OFF” as the starting point for airborne trajectory computations (i.e., the gold trajectory in Figure 

Figure 6:1 – Significant communication uncertainty exists in the manual 

communication of CFR times.
21

3:1). PDRC software provides an adjustable “Roll Buffer” parameter to compensate for the 

difference between the “Start of Roll” and “Wheels OFF” events thereby connecting the red and 

gold trajectories of Figure 3:1.

On the human side of the Figure 6:1 timeline, Center TMCs primarily focus on the “Wheels 

OFF” event because this is the starting point of the airborne trajectory computed by their TMA 

tool. TMA requires an “aircraft ready time” to be entered via the departure scheduling user 

interface. This ready time is the predicted “Wheels OFF” time. Without PDRC, the “aircraft 

ready time” is manually estimated by the Tower TMC/FLM and verbally communicated to the 

Center TMC for entry into TMA/EDC. With PDRC, the “aircraft ready time” estimate is 

automatically set to the current SDSS OFF time prediction. See Section 6.2.4 of the ConOps [1] 

for a detailed description of this portion of the PDRC scheduling process.

Tower TMCs/FLMs simultaneously consider multiple events on the Figure 6:1 timeline during 

CFR operations. They must meet the release time coordinated with the Center TMC by 

communicating a target time (or window) to the Local controller that accounts for other 

departure and arrival traffic, takeoff clearance reaction time, and takeoff roll time. Remember 

that positive control of OFF time is ceded to the pilot at the “Cleared for T/O” event, so the 

Tower TMC/FLM and Local controller must account for all of the other factors when issuing the 

takeoff clearance.

Discussions with Tower TMCs led to an important finding that influenced the PDRC software 

design. Specifically, it was found that the Tower was aiming for “Tagged Up” instead of 

“Wheels OFF” in meeting the release times coordinated with the Center. Although the Center 

and Tower TMCs appear to have been operating with different definitions for Coordinated 

Release Times, the discrepancy was not large enough to impact Baseline CFR operations. Data 

collected during the Block 1 evaluation show the “Tagged Up” event is, on average, 25 seconds 

later than the observed “Wheels OFF” time. This 25-second difference only became significant 

with the push for higher precision during the PDRC operational evaluations. The PDRC 

software easily accommodates the different Coordinated Release Time definitions with the “CFR 

Buffer” parameter shown in the Figure 6:1. This buffer allowed the Center and Tower 

TMCs/FLMs to continue using their standard CFR procedures. Note that the value of the “CFR 

Buffer” parameter may be different from one facility to the next.

A more significant source of uncertainty involves the use of Coordinated Release Time windows 

and verbal communication of the start/stop times for those windows. In present-day (i.e., nonPDRC) CFR operations, the Coordinated Release Time is communicated verbally over facility 

inter-phone from the Center to the Tower. A recent FAA Notice [39] has amended the FAA 

7110.65 standing order to establish standard compliance window dimensions. The Notice states 

“when CFR is in effect, release aircraft so they are airborne within a window that extends from 2 

minutes prior and ends 1 minute after the assigned time, unless otherwise coordinated.” This 

standardized window is consistent with the -2/+1 window that was observed in use at ZFW and 

DFW during non-PDRC operations. The new order does not specify phraseology for 

communicating the time window.

Use of a Coordinated Release Time window automatically introduces release time uncertainty 

equivalent to the size of the window. However, observations and interviews with Center and 

Tower TMCs revealed even more uncertainty than expected associated with use of windows. To 

begin with, the –2/+1 window is often, in practice, a 3 minute 59 second window due to frequent 
22

inclusion of the termination minute 

in the window itself. Also, 

variations in the phraseology used 

to verbally communicate window 

start/stop times that contributed to 

CFR uncertainty were observed.

Table 6:1 provides a hypothetical 

example that is representative of 

actual observed variations. Note 

that the TMA/EDC Coordinated 

Release Times are displayed to 

Center TMCs at minutes-level 

granularity.

After receiving the time window 

verbally from the Center, the 

Tower TMC/FLM may apply 

different interpretations to the 

information. In some cases the 

TMC receiving the information 

may assume the beginning of the first minute to the end of the last minute given. In the case of 

the time communicated at 17:23 to 17:26, this interpretation would be 17:23:00 to 17:26:59, 

which would mean a 3:59 departure window.

PDRC reduces the ambiguity in CFR coordination communications via a digital interface (i.e.,

the PDRC double-headed arrow) between the Tower and Center decision support tools. Section 

6.2.5 of the ConOps [1] describes how the Coordinated Release Time (a.k.a. Scheduled 

Departure Time in PDRC software terminology) is delivered from rTMA/EDC to SDSS where it 

is displayed at seconds-level precision. For the Table 6:1 example, PDRC presents the Tower 

TMC/FLM with an unambiguous Coordinated Release Time of 17:25:26 to use for CFR 

coordination with the Local controller. In the present-day environment (i.e., without Tower 

electronic flight strips) the Tower TMC/FLM will round the seconds-level precision PDRC time 

to the appropriate minute and communicate this target time to the Local controller per standard 

procedures.

6.3 Characterizing CFR scheduling operations at DFW

A significant event of interest for tactical departure scheduling is when (and where) the 

scheduling decision is being made. Previous observations have shown that the CFR scheduling 

decision is often made at or near the spot, but there is significant variability in the timing of this 

scheduling decision. Performance goals for the Block 1 & 2 operational evaluations were for 

PDRC-enabled tactical departure scheduling to conform to present-day standard operating 

procedures and meet or exceed the performance of manual tactical departure scheduling. In 

other words, TMCs were not asked to make the CFR scheduling decision any earlier than they 

would without PDRC.

Before a detailed discussion of the evaluation results, it will be helpful to characterize CFR 

scheduling operations for the Baseline, Block 1, and Block 2 data sets. DFW International 

Airport is distinguished by two operational Towers and a centrally-located terminal complex 

Table 6:1 – Phraseology and interpretations in 

communication of Coordinated Release Time windows.

Center receives a time 

from TMA/EDC

Times(s) communicated to Tower 

have various interpretations

Coord. Release Time First time Second time(?)

17:25:26

TMA/EDC computes a 

time to seconds-level

precision but display is 

limited to minutes-level 

precision:

1725

1723 1726

1723 “void at” 1726

1725 1727

1725 “void at” 1727

1725 1726

1725 “void at” 1726

1725 None 

communicated
23

served by a north/south freeway (International Parkway) that bisects the airport property. 

Consequently, DFW is often characterized as two airports in very close proximity. The east-side 

“airport” has a control tower and four runways. The west-side airport has a control tower and 

three runways. The east and west sides are linked by four bridges (a pair to the north and a pair 

to the south) that carry taxiways over International Parkway.

DFW primarily operates in either south flow or north flow runway configuration. Thus, it is 

helpful to sort DFW CFR scheduling operations into four categories: east side vs. west side and 

south flow vs. north flow. Table 6:2 shows the distribution of Baseline, Block 1, and Block 2 

departures amongst these four categories. Note that the data presented in this section correspond 

to the sets used for the OFF time compliance comparisons of Section 6.5.

Figure 6:2 plots the 342 Baseline departures on a surface map of DFW. The symbol positions 

represent the point at which the Center scheduled the departure with TMA/EDC. Circles 

represent flights departing the east side and triangles show west-side departures. South flow is 

shown in blue and north flow in red.

Table 6:2 – DFW CFR scheduling operations by side and flow.

DFW category

Baseline Block 1 Block 2

count % count % count %

east side / south flow 170 49.7 71 68.9 36 35.0

east side / north flow 60 17.5 18 17.5 35 34.0

west side / south flow 84 24.6 12 11.7 15 14.6

west side / north flow 28 8.2 2 1.9 9 8.7

total 342 103 95
24

This plot represents one year (Nov 2010 – Oct 2011) of tactical departure scheduling operations 

at DFW.

Figure 6:3 plots the 198 Block 1 & 2 departures on a map of DFW. As before, circles represent 

flights departing the east side and triangles show west-side departures. In this figure color has 

been used to distinguish both flow and evaluation block. South flow is shown in either blue or 

green, while north flow departures are either red or orange. Block 1 flights are shown in blue 

and red. Block 2 flights are shown in green and orange.

Figure 6:2 ‒ CFR scheduling locations for 342 departures during PDRC Baseline 

data collection at DFW airport.
25

A notable difference between Figure 6:2 and Figure 6:3 is the meaning of the position symbols. 

In both figures the symbols are intended to indicate the point at which the CFR scheduling 

decision was made. For the Baseline data set the only available information on this decision was 

the time at which the Center scheduled the departure with TMA/EDC. For the Block 1 and 

Block 2 flights there was the option of using that same TMA/EDC scheduling event or the time 

at which the Tower electronically requested the CFR via PDRC. The latter time is plotted due to 

widespread interest in knowing when and where CFR scheduling decisions are made. A 

consequence of this data presentation decision is that the figures are not directly comparable –

the symbols plotted in Figure 6:2 are from a point later in a flight’s progression to the departure 

threshold than those in Figure 6:3.

Researcher observations, supported by reports from Tower TMCs/FLMs, indicated that CFR 

scheduling decisions at DFW are typically made at or near the Apron Entry/Exit Point (AEP) or 

“spot.” To reduce clutter, the spots have not been depicted in these figures, but they are located 

along the outer edges of the aprons where the darker gray of the apron touches the lighter gray of 

the taxiways. For flights departing on the opposite side from their parking gate, the CFR 

decision is usually made as they cross the bridge (i.e., taxiways A, B, Y, and Z). The data 

presented in Figure 6:2 and Figure 6:3 generally confirm these expectations. The Baseline data 

Figure 6:3 ‒ CFR scheduling locations for 198 departures during PDRC Block 1 & 2 

operational evaluations at DFW.
26

in Figure 6:2 clearly has a higher percentage of scheduling events on the hold pads near the 

departure thresholds than does Figure 6:3. One might be tempted to conclude that CFR 

scheduling was performed later in the Baseline case than with PDRC; however, this difference is 

more likely attributable to the data source differences described in the previous paragraph. 

Further analysis is required to determine if there was any real difference in the CFR scheduling 

decision point between the Baseline and PDRC cases.

These results lead to a consideration of the temporal characteristics of the CFR scheduling 

process. Table 6:3 presents summary statistics from three time difference (i.e., delta time) 

calculations that may be useful metrics for the CFR scheduling process. The two left columns 

present statistics from the Block 1 & 2 evaluations for the delta time between the first surface 

surveillance track and the Tower Request For Release Time (RFRT). Larger mean and median 

values are desirable, as this typically indicates earlier scheduling of CFR flights. Earlier 

scheduling is helpful in finding available slots in the overhead stream earlier and achieving a 

stable schedule. The significance of the maximum value for this delta time is debatable. An 

aircraft could be powered up and generating ASDE-X track data for an indefinite period before 

the Tower chose to initiate an RFRT. However, the minimum values for this delta time are of 

significant interest for tactical departure scheduling. Surveillance acquisition is a key event for 

trajectory-based decision support tools like SDSS. With surveillance-based state information 

predictive accuracy is greatly increased. A closer examination of the data shows only two out of 

the 198 Block 1 & 2 flights had CFR requests prior to ASDE-X surveillance acquisition.

The third and fourth columns in Table 6:3 characterize the delta time between the Tower RFRT

and the Center completion of the CFR scheduling action with rTMA/EDC. This is an important 

metric for tools designed to facilitate CFR coordination. A lower time indicates a faster response 

by the Center TMC to the scheduling request. The Center CFR scheduling will normally occur 

some finite delta time after the Tower RFRT. The zero minimum values reflect seven flights (six 

for Block 1 and 1 for Block 2) where PDRC scheduling was initiated by the Center – in these 

cases there was no Tower request. As one might expect, as the operational evaluation continued 

and the TMCs gained familiarity with the PDRC prototype, the Center response time improved 

and also became more consistent.

The PDRC concept and prototype builds on previous CFR/APREQ coordination research [13,

20, 21] and takes the next step by automatically providing surface trajectory-based OFF time and 

departure runway predictions. Since the value of automated CFR/APREQ coordination had 

Table 6:3 – CFR scheduling delta time statistics.

Tower RFRT minus 

First surface track

Center schedule 

minus Tower RFRT

Actual OFF minus

Center schedule

Block 1 Block 2 Block 1 Block 2 Block 1 Block 2 Baseline

Count 103 95 103 95 103 95 342

Max (sec) 1404 4411 872 562 1203 2607 1461

Min (sec) -7 -36 0 0 62 79 80

Mean (sec) 187 323 93 60 325 377 369

Median (sec) 125 156 49 42 289 304 345

Std. Dev. (sec) 195 698 138 72 175 328 183
27

already been demonstrated in field evaluation [13], the PDRC team elected not to collect

additional quantitative baseline data on the manual CFR coordination process at DFW and ZFW. 

The previous section (Section 6.2) examined the impact of verbal communications uncertainty 

on CFR coordination.

The last three columns in Table 6:3 show lead time between the completion of the CFR 

scheduling process and the actual OFF event. This is likely the best metric for comparing CFR 

scheduling decisions between the Baseline and PDRC cases. The minimum, mean, and median

values are all quite comparable between the three cases. The maximum value PDRC Block 2 is 

about 19 minutes (i.e., 80%) earlier than the maximum value for the Baseline. Before drawing 

conclusions based upon this difference one must understand that the Baseline data set has been 

culled to remove OFF time compliance (OTC) outliers beyond one and one-half the interquartile 

range (i.e., 1.5 x IQR). The Baseline data set culling process is described in Section 6.5. These 

OTC outliers are the ones most likely to have earlier CFR scheduling decisions. Consequently, 

the data presented here lead to the conclusion that the CFR scheduling decision point was very 

similar between the Baseline and PDRC cases. This finding is consistent with expectations since 

pre-evaluation training stressed that TMCs were not to push for earlier CFR scheduling 

decisions.

6.4 Subject-matter expert feedback

The subject-matter experts for these evaluations were TMCs, STMCs, and FLMs who used the 

PDRC prototype while conducting CFR operations at DFW and ZFW. For brevity these test 

participants will be referred to as TMCs throughout this section. As discussed earlier (Section 

5.3), these target-of-opportunity evaluations presented particular challenges to acquiring TMC

feedback. Consider that 238 flights were scheduled with PDRC during 29 weeks of Block 1 & 2 

evaluations – an average of 8 data points per week on a highly variable schedule. Additionally, 

more than 40% of these PDRC scheduling events occurred outside of regular work hours (before 

8:00am, after 6:00pm, or on weekends). Consequently the PDRC team developed alternative 

mechanisms for acquiring TMC feedback. These included the NTX technical support hotline, 

periodic “how goes it” meetings, personal interactions with researchers, and electronic, web-style 

feedback forms accessible directly from PDRC user interfaces. This section primarily focuses on 

data collected via the electronic feedback forms.

Screenshots of the electronic feedback forms are shown in Appendix A (Section 9). Figure 9:4

shows the Tower form and Figure 9:5 shows the Center form. These feedback forms were 

designed to facilitate systematic data collection while keeping the reporting burden as low as 

possible. The latter point is particularly important as TMCs were being asked to voluntarily 

provide feedback while conducting tactical departure scheduling operations – by definition a 

very busy time at their positions. To facilitate communications and promote use of the feedback 

form mechanism, TMCs were encouraged to use the forms to report any and all feedback and not 

just ratings. Consequently, only a portion of the submitted forms contained quantitative user 

feedback for eligible PDRC-scheduled flights.

6.4.1 Identifying eligible ratings

Table 6:4 summarizes all of the feedback forms received during the PDRC operational 

evaluations. The left half of the table summarizes feedback received for Block 1 and the right 

half summarizes Block 2. The far left column shows designators for each of the TMCs that 
28

submitted feedback. The far right column shows the total number for forms submitted by each 

TMC. The overall totals are shown on the bottom row – twenty-seven forms were submitted 

during Block 1 and twenty-three during Block 2 for an overall total of fifty forms.

The second line in the Table 6:4 heading shows that feedback forms were sorted into two 

categories: those with numeric ratings and those without (i.e., forms reporting PDRC issues). 

The third line of the Table 6:4 heading shows that the feedback was further categorized by 

whether or not the submitted form applied to a PDRC-scheduled flight. Fourteen different TMC 

identifiers are listed in the far left column of Table 6:4. Two of these (DFW5 and ZFW8) 

represent three forms received from unknown TMCs (i.e., there were no identifiers on the form).

Seven feedback forms (five for Block 1 and two for Block 2) were submitted for flights that did 

not meet the PDRC scheduling criteria discussed in Section 6.1. Four of these ratings were for 

flights that did not depart DFW. The rTMA/EDC component of PDRC at the Center was used 

for tactical departure scheduling from all airports and not just DFW. This feedback was helpful 

for understanding rTMA/EDC scheduling performance, but the ratings are not directly applicable 

to PDRC. Of the three remaining ineligible rating forms, two were submitted in situations when 

only the Center was using PDRC and one was for a situation where the CFR was cancelled prior 

to departure. That leaves thirty-one eligible ratings (sixteen for Block 1 and fifteen for Block 2) 

to discuss in the following sections.

Despite some significant PDRC prototype software changes between Blocks 1 & 2, the 

evaluations were very similar from the TMC’s perspective. Thus, the ratings from the two 

evaluations will be considered together. However, because the Tower and Center forms had 

different questions they will be discussed separately.

Table 6:4 – Feedback forms received for Block 1 & 2 evaluations.

TMC

Block 1 Block 2

issue rate overall

total

issue rate

total

other pdrc other pdrc other pdrc other pdrc

DFW1 1 2 3 2 2 5

DFW2 3 3 2 2 5

DFW3 5 5 1 1 6

DFW4 1 1 1

DFW5 1 1 1

ZFW1 1 4 4 9 2 1 8 11 20

ZFW2 1 1 1

ZFW3 1 1 1

ZFW4 1 1 1

ZFW5 1 1 1 1 2

ZFW6 1 1 2 2 3

ZFW7 1 1 1

ZFW8 1 1 2 2

ZFW9 1 1 1

overall 6 5 16 27 5 1 2 15 23 50
29

6.4.2 DFW ratings and discussion

This section addresses the DFW ratings for the Block 1 & 2 evaluations. The four ratings 

questions on this form are shown below. The TMCs were asked to rate each question on a 1 

(bad) to 5 (good) scale. Please consult the DFW feedback form screenshot (Figure 9:4) for the 

exact presentation of the rating scale.

Q1 Was the initial PDRC OFF time PREDICTION reasonable in this situation?

Q2 Was the release time coordinated with ZFW via PDRC acceptable in this situation?

Q3 How did PDRC scheduling EFFORT compare to your baseline procedure?

Q4 Was the PDRC system HELPFUL in this departure scheduling situation?

Five DFW TMCs submitted feedback forms during the Block 1 & 2 evaluations. Table 6:5

shows that three of those five are responsible for the ratings that described below. Each row in 

the table represents a single feedback form. The four columns on the right correspond to the four 

questions shown above. 

Meaningful statistical results 

cannot be interpreted from such a 

small sample size; however the 

average and median ratings for 

each question are shown to suggest 

potential trends.

Overall, the ratings are very 

positive. One that deserves more 

discussion is the January 9th rating 

for AAL1919 from DFW2. This 

particular TMC was highly 

experienced with the PDRC 

prototype, and had provided 

significant valuable feedback 

throughout the Block 1 & 2 

evaluations. The DFW2 feedback 

prompted an investigation that 

turned up a lurking software error 

in SDSS logic that handled 

coordination of release times with 

rTMA/EDC. Put simply, the software error would allow coordinated release times to become 

stale in situations where the Center/Tower scheduling coordination was not promptly completed 

or where the traffic situation on the surface was very dynamic. The odds of encountering this 

error were relatively low, and the troubleshooting analysis showed the January 9th situation to be 

a near worst-case scenario for this logic flaw. A fix for this error was developed, tested, and 

deployed on January 23rd. Note that DFW2 provided a very favorable rating for the PDRC 

prototype on February 21st.

6.4.3 ZFW ratings and discussion

This section addresses the ZFW ratings for the Block 1 & 2 evaluations. The four ratings 

questions on this form are shown below. The TMCs were asked to rate each question on a 

Table 6:5 – DFW feedback.

Date Callsign TMC Q1 Q2 Q3 Q4

Block 1

06/15/12 SKW5169 DFW1 5 5 2 4

06/15/12 AAL1001 DFW1 3 3 1 2

07/15/12 ASQ4239 DFW3 4 4 2 5

07/15/12 ASQ4209 DFW3 5 5 5 5

07/15/12 AAL1604 DFW3 5 5 5 5

07/15/12 AAL1897 DFW3 5 5 5 5

07/15/12 DAL1675 DFW3 5 5 5 5

Block 2

12/04/12 AAL1335 DFW3 4 5 5 5

01/09/13 AAL1919 DFW2 1 1 3 1

02/21/13 N769M DFW2 5 5 5 5

Count 10 10 10 10

Average 4.2 4.3 3.8 4.2

Median 5 5 5 5
30

1 (bad) to 5 (good) scale. Please consult the ZFW feedback form screenshot (Figure 9:5) for the 

exact presentation of the rating scale.

Q1 Was the PDRC meter point crossing PREDICTION reasonable?

Q2 Was the final MERGE into the overhead traffic stream acceptable?

Q3 How did PDRC departure scheduling EFFORT compare to baseline TMA?

Q4 Was the PDRC system HELPFUL in this departure scheduling situation?

Nine ZFW TMCs submitted feedback forms during the Block 1 & 2 evaluations. Table 6:6

shows that seven of those nine are responsible for the ratings described below. As in the 

previous section, the rows in this table correspond to individual feedback forms and the columns 

to the four questions shown above. Average and median ratings for each question are provided 

to suggest potential trends.

Note that not every question has been rated on every feedback form. As shown in the feedback 

form screenshot (Figure 9:5), the form is launched with a default setting of “not rated” for each 

of the questions. Values of “NR” 

in Table 6:6 indicate that a TMC 

elected not to rate that particular 

question on that form. The TMC 

had the option to explain the “not 

rated” in the free-form comments; 

however, none of these were 

explained.

Overall, the ratings are very 

positive; however, a couple of the 

lower-rated flights deserve a closer 

look. The June 11th rating for 

DAL2210 included the following 

comment:

A/C WAS RLS WITH A TWO MIN 

DELAY IN THE OVERHEAD 

STREAM SHOULD HAVE BEEN 

TWO MIN LATER DELAY SHOULD 

HAVE ON THE GROUND

Investigation of this issue led to the 

discovery of an rTMA scheduling 

software errror. The problem was 

most pronounced during period of 

extremely high demand with low 

capacity, which could be repeated 

by applying very high MIT (e.g.,

50 MIT) on busy streams. The 

scheduling issue discovered could 

lead to STA instability, treating a 

departure flight as an airborne 

flight and causing errors in the 

allocated delay. The scheduling 

Table 6:6 – ZFW feedback data.

Date Callsign TMC Q1 Q2 Q3 Q4

Block 1

05/10/12 SKW5187 ZFW1 1 5 3 3

05/10/12 ASQ4430 ZFW1 5 5 3 NR

05/20/12 AAL2448 ZFW2 5 5 5 5

06/10/12 AAL1884 ZFW1 NR 4 3 3

06/11/12 DAL2210 ZFW3 1 1 3 1

06/13/12 SKW5173 ZFW4 5 5 3 4

06/19/12 AAL1604 ZFW5 5 5 3 5

07/08/12 TFC3514 ZFW6 1 1 3 1

07/08/12 AAL2362 ZFW1 NR 3 3 3

Block 2

11/08/12 EGF3219 ZFW1 5 5 5 5

11/14/12 AAL1794 ZFW1 5 5 5 5

11/14/12 DAL865 ZFW1 5 5 5 5

11/18/12 AAL1731 ZFW6 5 5 5 5

11/18/12 AAL1625 ZFW6 5 5 5 5

11/27/12 NKS832 ZFW1 NR 5 5 5

11/27/12 AAL547 ZFW5 5 5 5 NR

12/06/12 EGF3219 ZFW1 5 5 5 5

12/19/12 UAL33 ZFW9 NR 3 3 3

12/20/12 AAL1831 ZFW1 5 5 5 5

12/31/12 UAL249 ZFW1 5 5 5 5

01/10/13 ASQ4674 ZFW1 5 5 5 5

Count 17 21 21 19

Average 4.3 4.4 4.1 4.1

Median 5 5 5 5
31

issue was resolved and verified by Center personnel. The improved rTMA software was 

introduced prior to the beginning of the Block 2 operational evaluation.

The July 8th rating for TCF3514 is also worth a closer look. This feedback form included a 

comment that the overhead stream required a three-minute delay to accommodate this flight. A 

check of the OFF time compliance shown in Table 12:2 shows actual OFF to be 42 seconds later 

than the coordinated release time, which is well within the standard –2/+1 compliance window. 

Analysis of the airborne portion of this flight showed an unusual TRACON flight path that may 

have contributed to this issue, but there was insufficient data to fully analyze this finding.

Finally, it is worth presenting a day during the Block 1 evaluation when no ratings were 

submitted. Table 12:2 shows that June 18th was a banner day. Nine flights were scheduled with 

the PDRC prototype system that day and the OFF time compliance values indicate that the 

system was performing well. ZFW submitted no feedback forms on this date. A DFW TMC 

(DFW2) did submit one feedback form. However, this feedback contained no ratings or 

comments directly relating to the PDRC prototype. DFW2 feedback indicated that UAL1407 

could not be tagged up (i.e., registered as an identified target) in the surface surveillance system,

which prevented this flight from being scheduled with PDRC. This anecdote highlights the 

challenges of gathering systematic TMC feedback during target-of-opportunity operational 

evaluations. An old adage claims that no news is good news, but this is not true from a research 

data collection perspective. However, the fact that the PDRC prototype was used regularly for a 

total of 29 weeks with positive feedback (provided via a limited number of forms, the five “how 

goes it” meetings, and through personal interactions with the TMCs and FLMs) is considered a 

positive finding.

6.5 OFF time compliance

One objective of the Block 1 & 2 operational evaluations was to demonstrate system 

performance in real-world operations. The PDRC concept seeks to improve upon schedule 

compliance by reducing uncertainty inherent in manually computed ready time estimates and 

manual coordination of release times. Thus, OFF time compliance is an important system 

performance metric for PDRC.

Preliminary OFF time compliance results comparing Block 1 data to a Baseline data set were 

reported in Reference 6. The analysis used for that report has been refined and extended to 

include the Block 2 data. In simplest terms, OFF time compliance (OTC) is the difference 

between the Coordinated Release Time (CRT) discussed in Section 6.2 and the actual OFF time:

OTC = OFF – CRT

Negative OTC values indicate departures that were earlier than the Coordinated Release Time. 

Values for the Coordinated Release Time are easily obtained for both the Baseline and PDRC 

cases as they are recorded by the TMA/EDC. The challenging aspects of this analysis are 

detecting the actual OFF event and determining which flights are valid for OTC comparison 

purposes.

One difference between this analysis and that done for Reference 6 involves the actual OFF time 

computations for the Baseline data set. The earlier analysis relied on a departure message 

delivered to TMA/EDC by the Center Host computer. For this analysis, pseudo-OFF times were 

used as detected from ASDE-X surface surveillance track data by the Surface Operations Data 

Analysis and Adaptation (SODAA) tool [49]. The SODAA-detected pseudo-OFF times are 
32

more comparable to the SDSS-detected pseudo-OFF times used for the PDRC data. Both SDSS 

and SODAA compute a pseudo-OFF time by detecting start of takeoff roll from surface 

surveillance data. These values are referred to as “pseudo-OFF” instead of “start-of-roll” to be 

consistent with SDSS and SODAA parameter naming conventions.

For PDRC OFF time compliance analyses, an OFF time value is preferred that is as close as 

possible to the time that would have been recorded by the aircraft weight-on-wheels sensor. 

Section I-G of Reference 6 examines the uncertainty associated with predicting takeoff roll 

times. In that analysis takeoff roll times (both mean and median) were found to be 38 seconds 

with a small standard deviation. Since SODAA’s pseudo-OFF time is very close to the start of 

takeoff roll, a 38-second bias was applied to SODAA pseudo-OFF times to approximate actual 

OFF for the Baseline data set shown in Table 14:3.

SDSS uses a different algorithm than SODAA does, and it produces pseudo-OFF times that are 

typically 10–20 seconds after the start of takeoff roll. For this analysis visually-determined OFF 

times were compared with SDSS pseudo-OFF times for all Block 2 PDRC flights and the 

difference (both mean and median) was found to be 23 seconds with a very small standard 

deviation. Thus, a 23-second bias was applied to SDSS pseudo-OFF to approximate actual OFF 

for the Block 1 & 2 data sets shown in Table 12:2 and Table 13:2. Statistical comparison of the 

times from OFF to first airborne surveillance track was found to be a useful sanity check for the 

pseudo-OFF bias values. Mean and median OFF-to-first-track times are within 2 seconds

between the Block 1 and Block 2 data sets. Comparing Baseline OFF-to-first-track times to

those for Block 1 & 2, the means and medians differ by 9–10 seconds. This difference could be 

reduced by applying a larger bias to the Baseline pseudo-OFF times; however, there is 

insufficient data to justify a deviation from the 38 seconds average takeoff roll time reported in 

Reference 6.

Armed with near apples-to-apples actual OFF time computations, the valid flights for OTC 

comparison purposes are considered. This process was relatively straightforward for the Block 1 

& 2 data sets. The research team observed all flights scheduled during these evaluations, and 

thus was able to use firsthand knowledge to determine which flights were valid for OTC 

comparison purposes. For example, one PDRC-scheduled flight that was subject to a CFR 

procedure was later expedited in order to prevent potential hail damage. At the point that verbal 

direction was given to expedite the flight, the CFR time was no longer valid. However, no 

electronic commands were issued for this flight and, had the team not been aware of this 

occurrence, this flight would have inappropriately skewed the OTC comparisons.

After culling flights where the CFR restriction was explicitly or implicitly removed, any flight 

subject to a strategic TMI (i.e., flights assigned EDCT times) was removed from the OTC 

analysis. Flights with EDCTs were not counted in the primary compliance measure because they 

introduced variation due to procedural differences that were not the focus of this research. 

Occasionally, individual controllers were observed following different procedures in situations 

where flights were simultaneously subject to strategic and tactical TMIs.

The culling process was more challenging for the Baseline data set since the firsthand 

observations were not available. This OTC analysis used the same Baseline data set as in 

Reference 6. This set was obtained from operational TMA/EDC recordings beginning in 

November 2010 and running through October 2011. This set included 451 DFW departures that 

were tactically scheduled with ZFW’s operational TMA/EDC system. Fifty-two of these flights 
33

had assigned EDCT times and were removed from consideration per the rationale given above. 

This left 399 flights in the Baseline dataset as candidates for the OTC comparison.

Use of SODAA for pseudo-OFF detection resulted in 20 additional flights being culled from the 

Baseline set as these flights did not have the necessary surface surveillance data. A final round 

of sanity checking removed 8 more flights from the Baseline set because the TMA/EDC 

scheduling action was deemed to be too close (less than 30 seconds) to the SODAA pseudo-OFF 

time. This round of culling left 371 flights in the baseline data set.

As noted above with the flight expedited due to hail, many events can effectively cancel a CFR 

without leaving an electronic record. Given that this large sample of Baseline data covered a 

long duration in which unknown circumstances might have been involved without a PDRC 

observer to report them, the outliers beyond 1.5 times the interquartile range (i.e., 1.5xIQR) were 

removed. This established the outlier cutoffs at +403 seconds and -278 seconds and reduced the 

baseline data set to 342 flights.

The three data sets used in the OTC comparison are presented in Appendices D, E, and F. As 

noted above the actual OFF times shown in these tables were computed by applying a bias 

(either 23 seconds or 38 seconds) to the pseudo-OFF times detected by SDSS and SODAA, 

respectively. Table 6:7 presents descriptive statistics for the OTC comparison. Since OTC can 

be either negative or positive, the standard deviation and absolute mean were found to be the 

most meaningful indicators of system performance. The OTC standard deviation for the Block 1 

& 2 sets is approximately 43% lower than the standard deviation for the Baseline set. The OTC 

absolute mean for Block 1 & 2 is about 43% lower than the absolute mean for the Baseline set.

Another useful system performance metric is OFF time compliance as commonly measured in 

present-day NAS operations. In this measure, a flight is said to be compliant if it fits within the 

standard –2/+1 Coordinated Release Time compliance window [39]. This system performance 

metric is helpful because it simultaneously captures both the real mean error as well as the 

variation in a readily-visualized manner. The last two rows of Table 6:7 compare the –2/+1

window compliance results for the Baseline, Block 1, and Block 2 data sets. The results show

Table 6:7 – OTC comparison descriptive statistics.

Baseline Block 1 Block 2

Count 342 103 95

OTC maximum 376 157 101

OTC minimum -225 -150 -197

OTC mean (sec, negative is early) 54 19 -9

OTC median (sec) 37 23 1

OTC standard deviation (sec) 115 65 63

Absolute OTC mean (sec) 95 54 51

Comply with -2/+1 min release window (count) 186 76 79

Comply with -2/+1 min release window (%) 54 74 83
34

that 54% of the Baseline flights met the –2/+1 window – remember that this is with outliers 

removed, as described above. The Block 1 data exhibited 74% compliance against the standard 

window while Block 2 had 83% compliance. By this performance measure, PDRC Block 2

exhibited approximately 53% improvement over Baseline compliance with the standard window.

Distributions for the three data sets are shown in the following figures. These distributions are 

plotted as histograms with a bin size of 20 seconds. The distributions have been normalized as 

percentages (area under the curve sums to 100) to facilitate comparison of distributions with 

different sample sizes.

Figure 6:4 presents the OTC distribution that corresponds to the mean, median, and standard 

deviation values presented in Table 6:7. As expected from the descriptive statistics, the Block 1 

& 2 distributions are significantly tighter than the Baseline distribution. As noted above, outliers 

beyond 1.5xIQR (+403 seconds and –278 seconds) were removed from the Baseline data set; 

however, outliers have not been removed from the Block 1 & 2 data.

This discussion of outliers draws attention to the Block 2 OTC minimum value of –197 seconds 

shown in Table 6:7 and in Figure 6:4. This data point is 30 seconds beyond the 1.5xIQR cutoff 

of –166 seconds had the outliers been removed from this data set. However, flights were 

removed from the Block 1 & 2 OTC analysis only when there was evidence that the CFR had 

effectively been cancelled or that PDRC scheduling procedures were not being followed. Since 

this flight departed more than 3 minutes earlier than the PDRC-scheduled release time, it is 

strongly suspected that the CFR was canceled in this case, but there was insufficient evidence for 

it to be removed.

Figure 6:4 ‒ Normalized OFF time compliance distributions for Block 1 and Block 2 

evaluations compared to the Baseline data set.
35

Since OTC may be either positive (late) or negative (early), it is instructive to consider the 

absolute OTC in addition to the real OTC. The absolute OTC mean values were presented in 

Table 6:7 with the other descriptive statistics. Figure 6:5 shows the distribution for the absolute 

OTC. As expected, Block 1 & 2 both show markedly better performance than the Baseline. 

Comparing the absolute distributions for Block 1 and Block 2, one can see that Block 1 has about 

4% more flights in the 20-second bin while Block 2 has 6% more flights in the 40-second bin 

and more than 6% more flights in the 60-second bin. Counts for the 80-second bin are 

comparable. While these results appear to favor Block 1 they really highlight a shortcoming off 

the absolute value OTC measure. In CFR operations, it is generally better to be early than late 

because it is easier and more fuel efficient for controllers to slow a flight to fit into a slot than it 

is to speed one up. The absolute OTC measure treats early and late compliance errors equally. 

Reviewing Figure 6:4, it can be seen that the Block 2 distribution is generally biased earlier than 

the Block 2 distribution. This is confirmed by the fact that the Block 2 mean value of –9 seconds 

is 28 seconds earlier than the Block 1 mean value of 19 seconds.

To summarize, PDRC improved tactical departure scheduling performance by reducing the 

uncertainty the process. The focal point of tactical departure scheduling is the OFF event where 

the surface trajectory ends and the airborne trajectory begins. This is also the point around 

which Tower and Center TMCs coordinate release times. Consequently, reducing the OFF time 

compliance error was a primary objective for PDRC. The OTC descriptive statistics and 

distributions presented in this section demonstrate that PDRC provides significant improvement 

over Baseline levels of OFF time compliance.

Figure 6:5 ‒ Normalized absolute OFF time compliance distributions for Block 1 

and Block 2 evaluations compared to the Baseline data set.
36

6.6 Airborne transit time predictions and the ‘hit slot’ metric

The PDRC concept seeks to improve scheduling of tactical departures into available capacity in 

the en route air traffic flow. This scheduling process encompasses uncertainty in the OFF time 

as well as airborne transit time prediction, as illustrated by Figure 6:6. The OFF time 

compliance was discussed in the previous section. This section discusses the airborne transit 

time prediction accuracy for Block 1 & 2 operational evaluations. The airborne transit time 

consists of both TRACON transit time and Center transit time uncertainty.

At the beginning of the PDRC research activity it was initially assumed that the flight time

predictions provided by the en route scheduling system (i.e., TMA/EDC) were sufficiently 

accurate to enable tactical departures to ‘hit the slot’ reserved in the overhead traffic flow. This 

assumption was based primarily upon the fact that TMA/EDC was operationally deployed to all 

Centers and had a reputation among subject-matter experts for accurate flight time estimates. As 

PDRC research progressed, it was discovered that the error associated with the airborne 

predictions was more significant than initially envisioned. The first indication of this error came 

during the shortfalls analysis research [5] in which it was discovered that the majority of flights 

did not hit the slot they were scheduled into even after the first airborne surveillance. This 

research, which analyzed all TMA/EDC sites across the NAS for the month of January 2011, 

indicated that over 60% of flights did not hit the slot predicted by arrival TMA after initial 

airborne (TRACON and/or Center) surveillance. Thus, the portion of ‘hit slot’ error associated 

with airborne transit time prediction was significant.

The ‘hit slot’ metric used in the shortfalls analysis [5] revealed a lower percentage of success 

than expected, however, it did not provide insight into where the error was occurring. By design, 

the ‘hit slot’ measure emulated what operational Center TMCs do and thus incorporated 

uncertainty from the departing flight through all phases of flight up to the meter point crossing. 

The ‘hit slot’ metric also incorporates uncertainty associated with predictions for the leading and 

trailing aircraft in the overhead traffic flow that the tactical departure is being scheduled between

(i.e., uncertainties regarding the slot itself). Therefore if the TMA/EDC airborne transit time 

prediction was exactly correct to the second, but the predictions for the leading or trailing flights 

that define the slot were not accurate, the tactical departure would not hit its slot.

To learn more about these ‘hit slot’ metric errors, tools were developed to capture and analyze 

the information needed to isolate airborne flight time prediction errors. First, the airborne flight 

Figure 6:6 – Uncertainty associated with Tactical Departure Scheduling.
37

metrics were divided into TRACON transit time versus Center transit time estimates. This 

division was logical because the tactical departure encounters very different traffic situations in 

these two operational environments. That is, TRACON flight time estimates that terminate at the 

departure fix are rarely affected by merging/conflicting flights, whereas merging and sequencing 

commonly have a large impact on Center flight time estimates.

The TRACON transit time is defined as the duration in seconds from wheels OFF to crossing the 

departure fix, which resides on the boundary of TRACON/Center airspace. A TRACON transit 

time analysis showed that significant errors may exist in the predicted horizontal flight profiles

used by TMA/EDC to compute ETAs at downstream fixes. Results from this analysis were 

reported in the 2012 AIAA paper [6], and the complete analysis is presented in Appendix B 

(Section 10). 

To briefly summarize, the Appendix B analysis shows large TRACON transit prediction errors 

due to TMA/EDC’s lack of detailed departure routing adaptation within the TRACON. The 

authors believe that this detailed adaptation was intentionally omitted from TMA/EDC because it 

depends on knowledge of the specific departure runway. The TMC must manually enter 

departure runway into the present-day TMA/EDC system. Since this entry is not commonly 

made, it is logical not to invest in the detailed TRACON departure adaptation that depends on 

the runway entry. However, with PDRC, the predicted departure runway is automatically and 

continuously transmitted from the surface system to TMA/EDC. The analysis shows that the 

PDRC-provided predicted departure runway plus relatively minor TMA/EDC adaptation changes 

enable significant improvements in TRACON transit time predictions. The results presented in 

Figure 10:3 show a six-fold reduction in average TRACON transit time prediction error for the 

largest group of flights affected by this problem. These improvements were incorporated into 

the PDRC prototype (specifically the rTMA/EDC adaptation) and used for both the Block 1 & 2 

operational evaluations.

The uncertainty analysis depicted in Figure 6:6 was conducted in parallel with the Block 1 

operational evaluation and documented in the 2012 AIAA paper [6]. This analysis attempted to 

quantify uncertainty in all phases of the departure process, including the TRACON and Center 

transit time prediction errors. For the PDRC scheduled flights in the Block 1 evaluation, the 

mean absolute error was 25 seconds with a median TRACON transit time error of 21 seconds 

[6]. The mean absolute Center transit time error for all PDRC scheduled flights was 49 seconds 

with a median error of 32 seconds. Note that the mean error is approximately twice as high for 

the Center transit time error compared to the TRACON transit time error, despite the fact that the 

flight distance for these two measures are approximately the same.

As noted in Section 5.4, the PDRC operational evaluations have involved only outbound tactical 

departure scheduling using the TMA/EDC decision support tool. Currently, the FAA operates 

TMA/EDC in an open-loop mode. Unlike arrival metering with TMA, TMA/EDC schedule 

times and sequence information are not displayed on sector controllers’ radar scopes. Center 

TMCs use TMA/EDC to manage constrained traffic flows in order to provide sector controllers 

with a workable traffic situation. Sector controllers solve the traffic puzzle with no knowledge of 

the TMA/EDC planned solution. This has been a significant factor in the high Center transit 

flight time errors noted in the PDRC evaluations.

Observations of PDRC-scheduled flights and discussions with Center TMCs also revealed other 

factors, including significant speed fluctuations in the overhead stream, flights that cut corners 
38

off of the nominal route, pop-up flights that were scheduled after the PDRC scheduled flights, 

and altitude error. In the case of altitude error, the primary challenge was that the TMA/EDC

predictive models do not reflect the Letter of Agreement between ZFW and ZHU in which 

aircraft are delivered to ZHU at flight level 290 if IAH is in East flow and flight level 310 if IAH 

is in West flow. Without this detailed information concerning crossing altitude restrictions, 

TMA/EDC computes meter point ETAs based on filed flight plan altitudes, which could have

significant differences in wind speed and/or take some time to maneuver to.

This discussion of airborne transit time prediction errors can be recapped with reference to the 

PDRC concept overview diagram (Figure 3:1). PDRC research began with the assumption that 

the TMA/EDC airborne trajectory (shown as gold in the figure) was acceptably accurate and that 

the primary contribution to tactical departure scheduling would be to provide a more accurate 

initial time (i.e., T0) for this trajectory. The improved initial time for the airborne trajectory

would be courtesy of a more accurate predicted final time (i.e., TF) for the surface trajectory 

shown in red – a better OFF time prediction. Reduced uncertainty in OFF times has been 

demonstrated; however, it has also been discovered that more work is required on the airborne 

side of the problem. Some contributions in this area have been made by using PDRC technology 

to give TMA/EDC knowledge of the departure runway. Thus, the PDRC prototype improves

both the initial time and the initial location (i.e., spatial origin) for the gold airborne trajectory.

However, analysis [6] shows that even these improvements are not enough to suggest use of the 

airborne ‘hit slot’ metric proposed in the original shortfalls analysis paper [5]. Given the timing 

associated with widespread deployment of a surface capability that could supply the OFF times 

required, it is likely better to assume a metering environment in which times are presented to the 

controllers with tighter tolerances (e.g., ±30 seconds), as has been demonstrated by NASA’s

Efficient Descent Advisor (EDA) [10]. Assuming this environment is available along with OFF 

times and departure runway assignments provided by surface automation, ‘hit slot’ measures 

taken in a field environment are much more likely to yield improved results.

7 Next steps

This final report and companion documents [1, 2, 4, 5, 6] comprise the PDRC research transition 

package that NASA will deliver to the FAA to support TFDM and TBFM system acquisition and 

implementation efforts. This technology transfer will conclude the core PDRC research activity; 

however, much work remains to be done in the tactical departure scheduling arena. During the 

course of the PDRC development and evaluation the NASA research team and FAA subjectmatter experts and stakeholders developed several compelling ideas for follow-on research. 

These ideas generally coalesce into three threads: air carrier collaboration, PDRC Enhanced 

Scheduling, and TRACON Departure Scheduling. Recommendations for future work in these 

areas will be discussed in the following sections.

7.1 Air carrier collaboration

As shown in Section 6.3, CFR scheduling decisions with PDRC are made at or near the Apron 

Entry/Exit Point (AEP) or spot, consistent with present-day tactical departure scheduling 

practices. The 2012 paper on prediction uncertainty [6] examined the feasibility of making the 

CFR scheduling decision earlier (i.e., moving the decision point closer to the gate). The paper 

concluded that earlier scheduling with PDRC might be feasible; however, it seems likely that 

active air carrier participation will be required for effective CFR scheduling in the ramp area.
39

Active air carrier participation in the management of departure is currently being studied on 

many fronts, including the NASA Spot and Runway Departure Advisor (SARDA) concept [17], 

the Surface Collaborative Decision Making effort [34], and the Collaborative Departure Queue 

Management (CDQM) research [8] led by the FAA’s STBO project. Throughout the PDRC 

research activity NASA has collaborated with the FAA’s STBO project to further develop the 

Tactical Surface Data Exchange (TSDE) interface that was discussed in Section 4.7. With 

support from FAA STBO, a TSDE interface with American Airlines was developed for the 

PDRC prototype and this interface provided valuable input for Off-Block Time predictions 

during the Block 1 & 2 evaluations.

Although TSDE is specified as a two-way interface, the data flow was one-way (air carrier to 

PDRC) during the Block 1 & 2 evaluations. In parallel with the evaluations, NASA and FAA 

STBO continued development of the PDRC-to-air carrier side of the TSDE interface. The next 

steps for this effort will be to share PDRC data elements with air carrier ATC coordinators to 

assess the value of this information in the air carrier environment.

7.2 PDRC Enhanced Scheduling

Section 6.1.4 summarized a shadow evaluation conducted in March 2013. This evaluation can 

be described as a series of focus group sessions that used live-traffic shadowing and storyboards 

to motivate structured interviews concerning PDRC Enhanced Scheduling. This is a collection 

of ideas that build on the core PDRC concept to further improve tactical departure scheduling by 

leveraging the power of Center/Tower information exchange demonstrated by PDRC. The ideas 

are in various stages of maturity, and the purpose of the March 2013 shadow evaluation was to 

gather subject-matter expert feedback to guide further development of these ideas.

The Enhanced Scheduling ideas are related by the goal to reduce unnecessary CFR constraints, 

reduce ground delay, improve automation, and enable greater situational awareness. Most of the 

Enhanced Scheduling ideas center on the new prototype multi-domain “what if” scheduler

discussed in Section 4.8. This new software process was used for live-traffic demonstrations of 

some of the more mature ideas during the March 2013 focus group sessions. The following is a 

list of the ideas under consideration:

• Early Indication of Tactical Delay

• Size of an Assigned Slot (e.g., Can I Leave Early/Late?)

• Release Flights with a Large Center-Approved Window

• Schedule but Look for a Better Time

• Automatic Scheduling Based Upon Actual OUT Notification

• Center Decision Support Tool for CFR constraint planning

NASA is currently evaluating which of these ideas merit further research.

One of the enhanced scheduling ideas has been developed into a proposed concept for Tactical 

Departure Scheduling Control by Exception. This new concept seeks to address a shortfall in 

current-day tactical departure scheduling operations wherein CFR restrictions are applied 

uniformly over broad time periods, resulting in unnecessary delay to some flights. NASA 

recently awarded a SBIR Phase I contract to pursue the Control by Exception idea. This research 

activity will include shortfalls analysis, concept development, identification of required 

operational metrics, and a concept feasibility assessment.
40

7.3 TRACON Departure Scheduling

In the introduction, PDRC was described as “a logical step towards the NextGen vision of fullyintegrated arrival/departure/surface operations.” Tactical departure scheduling coordination 

between a well-equipped airport Tower and its home Center seemed a logical starting point for 

several reasons:

• The Center portion of the process was already supported by a widely-deployed decision 

support tool (TMA/EDC)

• Manually computed and communicated OFF time inputs to TMA/EDC were an obvious 

shortfall and trajectory-based Tower tools were on the not-too-distant horizon

• Previous research had established the value of automating CFR release time coordination

• Decisions to implement tactical TMIs (i.e., CFR) are local and therefore accessible to the 

research team

The PDRC concept intentionally focused on applying NextGen trajectory-based technology to a 

portion of the tactical departure scheduling problem that analysis [5] showed to be commonly 

occurring in present-day NAS operations. Now that the first step has been taken, other tactical 

departure scheduling challenges can be addressed by building on the PDRC foundation.

Feedback from stakeholders and experiences conducting the Block 1 & 2 evaluations have 

strongly suggested that the next step needs to address the challenges of TRACON-level 

constraints and departures from less-equipped airports. These needs have been a recurring theme 

in PDRC team interactions with FAA stakeholders dating back to 2010 and they have been 

reinforced by feedback received from Block 1 & 2 evaluation participants during the PDRC 

“how goes it” meetings.

Work on the TRACON Departure Scheduling research is currently underway. Section 4.9

discussed new multi-airport capabilities that have been developed to gather quantitative 

shortfalls analysis data and that will serve as the foundation for a prototype TRACON departure 

scheduling system. Additionally, NASA observers are spending time on position at D10 

TRACON during dynamic weather and traffic events to thoroughly characterize the present-day 

system and shortfalls. Lessons learned from these D10 observations will be validated with data 

from other facilities throughout the NAS. Finally, NASA has been coordinating with subjectmatter experts and stakeholders to ensure that this new work is well-conceived and aligned with 

needs. It is expected that this line of research will contribute to future developments for the 

TBFM Integrated Departure Arrival Capability (IDAC).

8 Concluding remarks

This is the final report for a multi-year concept and technology development and evaluation 

activity directed towards improving tactical departure scheduling operations. The research 

commenced with a study of the present-day system to characterize the operation and identify 

shortfalls. A key finding from this study was that tactically-scheduled departures occur 3.5 times 

as often as departures subject to strategic constraints. Another key finding was that 25% of 

flights subject to arrival metering are scheduled into the system as tactical departures while still 

on the airport surface. This percentage is expected to increase as the TBFM program continues 

to expand the range of metering through more development of adjacent center metering, coupled 

scheduling, and extended metering functions.
41

The initial study identified shortfalls in present-day tactical departure scheduling wherein a 

significant number of flights missed their reserved slot in the en route traffic flow due to 

uncertainty in the tactical departure scheduling process. NASA developed the PDRC concept to 

address these shortfalls and assembled a prototype system to validate the concept and 

demonstrate system performance in operational field evaluations.

The PDRC prototype utilized a research version of the FAA’s operational TMA (rTMA) and a 

research surface management system (SDSS); the latter served as a surrogate for anticipated 

NextGen trajectory-based surface decision support tools (e.g., TFDM). PDRC technology 

development included a two-way interface between rTMA and SDSS. The two-way interface 

enabled trajectory-based OFF time and departure runway predictions to be delivered from SDSS 

to rTMA and a full complement of rTMA scheduling information to be delivered to SDSS. The 

PDRC two-way interface also enabled electronic CFR coordination between the Center TMC 

and the Tower TMC/FLM.

NASA conducted two operational evaluations of PDRC. The evaluations were based at NASA’s 

NTX Research Station and included participation from TMCs and FLMs at Fort Worth Center 

and DFW’s East and West Towers. The evaluations ran for a total of 29 weeks in 2012 and early 

2013. During these evaluations more than 230 flights were scheduled with the PDRC prototype. 

Positive subject-matter expert feedback was received throughout the evaluation and significant

improvements in tactical departure OFF time compliance were demonstrated.

Off-time Compliance (OTC) results from the two PDRC evaluations were compared against a 

year-long sample of baseline data. Since the goal is to reduce uncertainty, key OTC metrics are 

the standard deviation and the absolute average error. PDRC showed a 43% improvement over 

the baseline standard deviation and a 43% improvement in absolute average error.

A key feature of the PDRC concept is coordination and communication based on a single target 

release time rather than a release window. The PDRC target time (with seconds-level resolution) 

is used throughout the process and a single time (with appropriate rounding) is communicated by 

the Tower TMC/FLM to the local controller. When comparing PDRC evaluation results against 

a present-day standard -2/+1 OFF time compliance window, PDRC Block 2 exhibited 

approximately 53% improvement over Baseline compliance.

In addition to the new two-way communications interface between rTMA and SDSS, the PDRC 

research activity produced several other important technology developments and improvements. 

The PDRC research activity developed rTMA to reduce technology transfer risk and facilitate 

field evaluations. The rTMA has become an integral element in several other NASA research 

activities. In collaboration with the FAA STBO office the TSDE air carrier interface was 

extended and specialized to provide PDRC with data from American Airlines. PDRC research 

identified improvements in SDSS modeling of Aircraft Movement Area taxi operations to 

improve OFF time predictions. Analysis of airborne time-to-fly uncertainty uncovered large 

errors in TMA modeling of TRACON departure routes. New adaptation leveraged PDRCprovided departure runway information to reduce average TRACON time-to-fly prediction errors 

by up to a factor of 6 (i.e., average errors of 176 seconds reduced to 28 seconds) depending on 

departure runway and departure fix combination. A new multi-domain, “what-if” scheduler was 

developed to explore ideas for PDRC scheduling enhancements. Finally, a new multi-airport 

data processing system was developed to support follow-on research into TRACON departure 

scheduling.
42

Acknowledgements

This work was supported by the NASA NextGen Systems Analysis, Integration and Evaluation 

(SAIE) Project. The authors would like to acknowledge the substantial support provided by 

FAA personnel at the Fort Worth Center Traffic Management Unit, Dallas/Fort Worth Towers, 

and Metroplex Traffic Management Unit. Support for development of the two-way air carrier 

interface was provided by the FAA Surface Trajectory Based Operations project. We would also 

like to thank the management and staff at American Airlines DFW Ramp Tower for their kind 

hospitality. Finally, we wish to thank our outstanding colleagues and friends at NTX who were 

essential to the success of the PDRC research activity.

Reference documents

This section provides a list of references, applicable documents, and related research for the 

PDRC-IADS research activity. To facilitate document tracking, identical reference lists are 

being maintained across the PDRC-IADS document family [1, 2, 3]. Consequently, this list 

should be treated as a bibliography of relevant documents instead of a strict list of references. 

Documents are listed by category rather than in order of citation, and some documents in the 

bibliography may not be directly referenced in this document.

PDRC documents:

1. Engelland, S.A., Capps, A., and Day, K., “Precision Departure Release Capability 

(PDRC) Concept of Operations,” NASA/TM-2013-216534, June 2013.

2. Engelland, S.A., Capps, A., Day, K., Robinson, C., and Null, J.R., “Precision Departure 

Release Capability (PDRC) Technology Description,” NASA/TM-2013-216531, June 

2013.

3. Engelland, S.A., Capps, A., Day, K., Kistler, M., Gaither, F., and Juro, G., “Precision 

Departure Release Capability (PDRC) Final Report,” NASA/TM-2013-216533, June 

2013.

4. Engelland, S.A. and Capps, A., “Trajectory-Based Takeoff Time Predictions Applied to 

Tactical Departure Scheduling: Concept Description, System Design, and Initial 

Observations,” AIAA-2011-6875, 11th AIAA Aviation Technology, Integration, and 

Operations (ATIO) Conference, Virginia Beach, VA, September 20–22, 2011.

5. Capps, A. and Engelland, S.A., “Characterization of Tactical Departure Scheduling in the 

National Airspace System,” AIAA-2011-6835, 11th AIAA Aviation Technology, 

Integration, and Operations (ATIO) Conference, Virginia Beach, VA, September 20–22, 

2011.

6. Capps, A., Day, K., Walenciak, E., and Engelland, S.A., “Impact of Departure Prediction 

Uncertainty on Tactical Departure Scheduling System Performance,” AIAA-2012-5674, 

12th AIAA Aviation Technology, Integration, and Operations (ATIO) Conference, 

Indianapolis, IN, September 17–19, 2012.

Research and technical papers:

7. Atkins, S., Jung, Y., Brinton, C., Stell, L., and Rogowski, S., “Surface Management 

System Field Trial Results,” AIAA 2004-6241, 4th AIAA Aviation Technology, 

Integration, and Operations (ATIO) Forum, Chicago, Illinois, September 20–22, 2004.
43

8. Brinton, C., Lent, S., and Provan, C., “Field Test Results of Collaborative Departure 

Queue Management,” 29th Digital Avionics Systems Conference, Salt Lake City, Utah, 

October 3–7, 2010.

9. Cook, L., Atkins, S., and Jung Y., “Improved Prediction of Gate Departure Times Using 

Pre-Departure Events,” AIAA 2008-8919, 26th Congress of International Council of the 

Aeronautical Sciences (ICAS) including the 8th AIAA Aviation Technology, Integration, 

and Operations (ATIO) Conference, Anchorage, AK, September 14–19, 2008.

10. Coppenbarger, R., Dyer, G., Hayashi, M., Lanier, R., Stell, L., Sweet, D., “Development 

and Testing of Automation for Efficient Arrivals in Constrained Airspace,” 27th 

International Congress of the Aeronautical Sciences (ICAS), Nice, France, September 

19–24, 2010.

11. de Jonge, H., Tuinstra, E., and Seljée, R., “Outbound Punctuality Sequencing by 

Collaborative Departure Planning,” 6th USA/Europe ATM 2005 Seminar, Baltimore, 

Maryland, June 2005.

12. de Jonge, H., Tuinstra, E., and Seljée, R., “Outbound Punctuality Sequencing by 

Collaborative Planning,” NLR-TP-2005-013, National Aerospace Laboratory of the 

Netherlands (NLR), July 2005.

13. Doble, N., Timmerman, J., Carniol, T., Klopfenstein, M., Tanino, M., and Sud, V., 

“Linking Traffic Management to the Airport Surface: Departure Flow Management and 

Beyond,” Eighth USA/Europe Air Traffic Management Research and Development 

Seminar (ATM2009), Napa, CA, June 29 – July 2, 2009.

14. Farley, T. C., Landry, S. J., Hoang, T., Nickelson, M., Levin, K. M., Rowe, D., and 

Welch, J. D., "Multi-Center Traffic Management Advisor: Operational Test Results," 

AIAA-2005-7300, 5th AIAA Aviation Technology, Integration, and Operations (ATIO) 

Conference, Arlington, VA, September 26–28, 2005. 

15. Futato, S., McMillan, K., Callon, S., “TMA En Route Departure Capability Jacksonville 

ARTCC and Orlando ATCT Usage Data”, April 8, 2008.

16. Grabbe, S., “Traffic Management Advisor Flow Programs: an Atlanta Case Study”, AIAA 

Guidance, Navigation, and Control Conference, Portland, Oregon, August 8–11, 2011.

17. Hoang, T., Jung, Y., Holbrook, J., and Malik, W., “Tower Controllers’ Assessment of the 

Spot and Runway Departure Advisor (SARDA) Concept,” 9th USA/Europe ATM R&D 

Seminar (ATM2011), Berlin, Germany, June 14–17, 2011.

18. Jung, Y. C., and Isaacson, D. R., "Design Concept and Development Plan of the Expedite 

Departure Path (EDP)," AIAA Aircraft Technology, Integration, and Operations (ATIO) 

Conference, Los Angeles, CA, October 1–3, 2002. 

19. Jung, Y., and Monroe, G., “Development of Surface Management System Integrated with 

CTAS Arrival Tool,” AIAA 2005-7334, 5th AIAA Aviation Technology, Integration, and 

Operations (ATIO) Conference, Arlington, Virginia, September 26–28, 2005.

20. Kopardekar, P., Green, S., Brinkman, C., Thompson, P., Evans, M., and Davis, D., 

“Making Internal Departure Release Operations More Efficient,” AIAA 2004-6346, 4th

AIAA Aircraft Technology, Integration, and Operations (ATIO) Forum, Chicago, Illinois, 

September 20–22, 2004.
44

21. Kopardekar, P., Green, S., and Thompson, P. “Improving Efficiency of Departure 

Release Communications for En Route Overhead Traffic Flow Management,” 23rd

Digital Avionics Systems Conference, Salt Lake City, Utah, October 24–28, 2004. 

22. Krozel, J., Rosman, D., and Grabbe, S., “Analysis Of En Route Sector Demand Error 

Sources”, AIAA-2002-5016, AIAA Guidance, Navigation, and Control Conference and 

Exhibit, Monterey, California, August 5–8, 2002.

23. Landry, S. J., and Villanueva, A., AIAA-2007-7713, “Mitigating the Effect of Demand 

Uncertainty Due to Departures in a National Time-Based Metering System”. 7th AIAA 

Aviation Technology, Integration, and Operations (ATIO) Technical Forum, Belfast,

Northern Ireland, September 18–20, 2007.

24. Palopo, K., Lee, H, and Chatterji, G., “Benefit Assessment of the Precision Departure 

Release Capability Concept”, 11th AIAA Aviation Technology, Integration, and 

Operations (ATIO) Conference, Virginia Beach, VA., September 20–22, 2011.

25. Stein, B., Ceniccola, D., and Vincent, D., “TBFM Coupled Scheduling,” 56th Annual 

ATCA Conference and Exposition, National Harbor, Maryland, October 2–5, 2011.

26. Swenson, H. N., Hoang, T., Engelland, S., Vincent, D., Sanders, T., Sanford, B., and 

Heere, K., “Design and Operational Evaluation of the Traffic Management Advisor at the 

Ft. Worth Air Route Traffic Control Center,” First USA/Europe Air Traffic Management 

R&D Seminar, Saclay, France, June 1997. 

27. Thipphavong, J., and Landry, S. J., “Effects of the uncertainty of departures on multicenter traffic management advisor scheduling.”, AIAA-2005-7301, 5th AIAA Aviation 

Technology, Integration, and Operations (ATIO) Technical Forum, Arlington, VA., 

September 26–28, 2005.

Related NextGen initiatives:

28. MITRE CAASD MTR110240R1 A Concept for Integrated Arrival, Departure, and 

Surface (IADS) Operations for the Mid-Term, January 2012.

29. MITRE CAASD MTR100349R1 A Functional Analysis of Integrated Arrival, Departure, 

and Surface (IADS) Operations, March 2012.

30. MITRE CAASD MTR110156R1 Integrated Arrival, Departure, and Surface (IADS): 

Research Gaps and Recommendations, January 2012.

31. MITRE CAASD MP090230 Surface Trajectory-Based Operations (STBO) Mid-Term 

Concept of Operations Overview and Scenarios, September 2009.

32. MITRE CAASD MP090169 A Mid-Term Concept of Operations for a Tower Flight Data 

Manager (TFDM), September 2009.

33. FAA ATO System Operations Services, Operational Concept for Departure Flow 

Management, June 29, 2007.

34. FAA ATO Surface Operations Office, U.S. Airport Surface Collaborative Decision 

Making (CDM) Concept of Operations (ConOps) in the Near-Term – Application of 

Surface CDM at United States Airports, June 15, 2012.

35. FAA, “NextGen Mid-Term Concept of Operations for the National Airspace System,” 

version 2.1, September 2010.
45

36. DFM System Requirements, Version 1.0, September 15, 2008.

37. FAA System Wide Information Management (SWIM) http://www.swim.gov/

38. JPDO, “Integrated Work Plan for the Next Generation Air Transportation System,”

version FY13, http://jpe.jpdo.gov/ee/request/home

Software documents, specifications and standards:

39. FAA NOTICE N JO 7110.612 amends FAA Order JO 7110.65 concerning Traffic 

Management Advisor (TMA) Departure Restrictions, Clearance Void Times, Hold for 

Release, and Release Times, January 30, 2013, 

http://www.faa.gov/documentLibrary/media/Notice/N7110.612.pdf

40. TMA/EDC System/Subsystem Design Description, September 2008.

41. Computer Sciences Corporation, “Traffic Management Advisor (TMA) Interface Control 

Document (ICD) for the TMA Collaborative Arrival Planning (CAP) Tool,” Contract No. 

DTFA03-02-D-00001, May 31, 2007. 

42. FAA ICD NAS-IC-82392403-04, TMA CAP to Volpe's TMA Collector ICD.

43. VNTSC-TFM-07-01, ICD: Flow of TMA Data from Volpe to CDM Participants, V1.6 

Draft A.

44. Raytheon, “CTO-05 Surface Management System, CTOD 5-24-1 Final Report,” 2004. 

45. Louisville SMS User’s Guide, Version 7.0, October 16, 2006.

46. FAA IRD NAS-IR-XXXXX, NextGen Surface Prototype System (NSPS) Tactical 

Surface Data Exchange (TSDE) Interface Requirements Document (IRD), draft version 

5.1, January 3, 2013.

47. FAA ConUse, Flight Operator Surface Application (FOSA) Concept of Use, version 1.0, 

November 30, 2010, draft.

48. FOSA API Overview, Version 1.0, undated.

49. Surface Operations Data Analysis and Adaptation (SODAA) User’s Guide, Version 

2.10.0, April 30, 2013.

50. ISO 8601, Data Elements and Interchange Formats - Representation of Dates and Times, 

2004.

51. RFC 2616, Hypertext Transport Protocol -- HTTP/1.1, June 1999.

52. IEEE-STD 1362-1998, Guide for Information Technology, System Definition – Concept 

of Operations, 1998.

53. FAA, National Airspace System (NAS) System Engineering Manual, Version 3.1, June 6, 

2006.

54. NASA SP-2007-6105, Systems Engineering Handbook, Rev 1, December 2007.
46

Glossary

This section provides a list of acronyms and terms relevant to the PDRC-IADS research activity. 

Identical glossaries are being maintained across the PDRC-IADS document family [1, 2, 3].

ADIF ARTS Data Interface

APREQ Approval Request – see CFR

ARTCC Air Route Traffic Control Center – one of twenty FAA facilities responsible for 

En Route ATC in the NAS

ATC Air Traffic Control

ATCT Air Traffic Control Tower

CAP Collaborative Arrival Planning

CDIF CAP Data Interface

CDQM Collaborative Departure Queue Management

CFR Call For Release – a TMI used to regulate the flow of departures into a 

constrained overhead stream (also known as APREQ).

ConOps Concept of Operations

CRT Coordinated Release Time – the target release time negotiated between Tower 

and Center during CFR operations (see SDT).

CTD Concept and Technology Development (NASA Project)

DFM Departure Flow Management

EDC En Route Departure Capability

EDIF ETMS Data Interface

ETMS Enhanced Traffic Management System – see TFMS

FLM Frontline Manager

FOSA Flight Operator Surface Application – see TSDE

GUI Graphical User Interface

HDIF Host Data Interface

IADS Integrated Arrival/Departure/Surface

NAS National Airspace System

NextGen The next generation air transportation system

OFF Aircraft takeoff time

OTC Off time compliance

PCOT Predicted Coordinated OFF Time

PDRC Precision Departure Release Capability
47

PGUI Planview GUI

RFRT Request For Release Time

RMP Research Management Plan

rTMA Research TMA

RTT Research Transition Team – a joint NASA/FAA activity to facilitate NextGen 

technology transfer

SADD Schedule a Departure Dialog

SAIE System Analysis Integration and Evaluation (NASA Project)

SDIF Surface Data Interface

SDSS Surface Decision Support System – often used interchangeably with the original 

SMS name

SDT Scheduled Departure Time – proposed Coordinated Release Time (see CRT) 

computed by TMA and communicated to SDSS by PDRC.

SMS Surface Management System – see SDSS

STBO Surface Trajectory-Based Operations

TARTS Terminal Area Radio Telecast System

TBFM Time Based Flow Management

TFMS Traffic Flow Management System – replaces ETMS

TGUI Timeline GUI

TMA Traffic Management Advisor

TMC Traffic Management Coordinator

TMI Traffic Management Initiative

TMU Traffic Management Unit

TRACON Terminal RADAR Approach Control

TSDE Tactical Surface Data Exchange – replaces FOSA
48

9 Appendix A: Auxiliary Figures

This appendix contains auxiliary figures that are believed to be helpful supplements to the report, 

but have been located here to improve readability. Some of these auxiliary figures have been 

excerpted from the companion documents (i.e., ConOps and Technology Description) to 

facilitate easy reference. In those cases, the figure excerpts include a few paragraphs of 

descriptive text from the companion document.

9.1 PDRC ConOps Figure 3:1

This excerpt is from section 3.1 of Reference 1.

The study of January 2011 NAS operational data also examined the relative frequency of tactical 

and strategic departure scheduling. Figure 9:1 uses the large gray ellipse to depict the entire set 

of domestic flights in the NAS (more than 1 million) for that month. Departures subject to 

strategic traffic management initiatives are shown in the orange ellipse. Tactical departures are 

shown in the 3 green ellipses. There were approximately 3.5 times as many tactical departures as 

strategic departures in January 2011.

The results shown in Figure 9:1 distinguish between inbound and outbound tactical departures. 

These two types of tactical departure scheduling are described in detail in Section 3.3. Inbound 

is associated with TMA arrival metering and outbound is associated with TMA’s En Route 

Departure Capability (EDC) function.

Figure 9:1 – Strategic and tactical departure scheduling for January 2011.
49

For this analysis, an aircraft was counted as being tactically scheduled only if the aircraft was 

both scheduled and ‘accepted’ or ‘frozen’ into the TMA Arrival or EDC system. A significant 

number of aircraft (approximately 18,489 during January, 2011) were initially scheduled in the 

TMA system, but the scheduling process was not finalized by either “accepting” or “freezing” it. 

This suggests an even larger pool of tactical departure operations may exist.

It is worth noting that inbound tactical departure scheduling occurred about five times more 

frequently than outbound tactical departure scheduling in January 2011 operations.

9.2 PDRC Technology Description Figure 3:4

This excerpt is from Section 3.4 of Reference 2.

A high-level diagram of the architecture used in PDRC is depicted in Figure 9:2. This diagram 

depicts the primary PDRC components involved in a configuration in which a single surface 

system connects to a single rTMA system. The architecture however is capable of supporting 

multiple rTMA systems connected to a single SDSS, as well as daisy-chaining data to multiple 

downstream instances of PDRC.

Figure 9:2 – PDRC prototype software architecture
50

9.3 CFR procedure with PDRC

This excerpt is from section 6.1 of Reference 1.

Figure 9:3 presents an overview of the Tower and Center interactions involved in tactical 

departure scheduling with PDRC to implement the CFR procedure. The left side of the figure 

shows the Center TMC interacting with the rTMA user interface. The right side of the figure 

shows the Tower TMC interacting with the SDSS user interface. Center and Tower TMC 

actions are listed in the center portion of the figure.

9.4 TMC feedback forms

This subsection contains screenshots of the electronic forms used to gather feedback from the 

TMCs, STMCs, and FLMs at DFW and ZFW. These webpage-style forms could be completed 

directly from the PDRC user interface.

Figure 9:3 – Center and Tower tactical departure scheduling actions with PDRC to 

implement the CFR procedure.
51

Figure 9:4 – Feedback form for DFW TMCs, STMCs and FLMs.
52

Figure 9:5 – Feedback form for ZFW TMCs and STMCs.
53

10 Appendix B – TRACON transit time prediction improvement

This appendix presents analysis conducted in Nov-Dec 2011 that supported improvements in 

rTMA predictions of TRACON transit time. Highlights from this work were published in 

Reference 6, but the complete analysis has not been published before now. The purpose of the 

departure route adherence accuracy metric is to assess the predicted horizontal departure route 

versus the actual route the flights follow and determine the effect such differences may have on 

flight time estimates.

Analysis of departure route prediction accuracy was performed on departures to Houston 

Intercontinental (IAH) which is the tactical departure route associated with the highest departure 

delay at DFW. For this route, DARTZ is the DFW departure fix and is the easternmost fix on 

the south departure gate of D10 TRACON. The primary departure route filed for the DFW to 

IAH departure is the DARTZ RNAV. The departure procedure is shown in Figure 10:1(a).

Note that the DARTZ3 procedure is no longer current. Since this analysis was performed with 

DARTZ3 data, the older departure procedure plate will be used to be consistent with the data. 

Figure 10:1(b) illustrates actual departure traffic that flew the DARTZ3 departure route in the 

Figure 10:1 ‒ DARTZ3 DFW RNAV departure procedure.
54

Nov 1–6, 2011 timeframe. The red track is of AAL1560, which is a representative nominal 

flight used throughout this analysis.

10.1 The problem

Currently, departure logic in PDRC’s TMA/EDC component predicts that the flight will fly an 

adaptable number of nautical miles in the direction of departure and then acquire the first 

departure fix in the departure route. Analysis of the DFW departure data revealed that the first 

fix was significantly downstream in the aircraft’s route of flight. Due to this, the en route transit 

time predicted by TMA/EDC assumed that the flight would head directly toward this fix instead 

of capturing the nominal waypoints along the RNAV departure route. Figure 10:2(a) illustrates 

the horizontal profile of the TMA/EDC predictions for the AAL1560 flight mentioned earlier. 

The predictions for AAL1560 are representative of the current operational system logic. In this 

diagram, DFW is the green dot and DARTZ (red X) is the first fix in TMA’s estimated route.

The thick, dull gray line is the actual track. The various colored lines that extend from the gray 

route are the TMA/EDC provided estimated routes at each point in time. Ideally the colored

lines would overlay the thick gray route as they do in the Figure 10:2(b) “after” plot.

Figure 10:2 – TMA departure route predictions before and after implementation of an 

adaptation-based solution.
55

Figure 10:2(a) illustrates the problem from 

a route geometry perspective, but it does 

not reflect the impact to the estimated time 

of arrival. To determine ETA impacts, the 

actual fly time was taken for a sample of 

109 flights from DFW to IAH. Figure 10:3

plots the difference between the actual and 

estimated fly times taken at first track to 

the TRACON departure fix (DARTZ). 

The data in this figure is stratified by 

departure runway – runway 35 departures 

are plotted on the left while runway 36 

departures are plotted on the right. The 

actual transit time was defined as the time 

between the first radar track and the time 

when the flight crosses the departure fix.

The “before” data is plotted as blue 

diamonds for both runways. The green 

triangles show “after” data and will be 

discussed later. The red X symbols show 

the average TMA Estimated Time-ofArrival (ETA) error for each of the data 

sets.

Figure 10:3 shows that ETAs for Runway 

35 departures exhibited a mean error of 

176 seconds prior to the solution. The 

“before” sample size for Runway 36 is 

quite small; however, the two data points 

are tightly clustered near 235 seconds of 

ETA error.

10.2 The solution

Reducing routing error within the TRACON is straightforward – simply have rTMA implement 

the expected departure procedures. The challenge is how to implement the departure procedures. 

The solution selected was to create a more specific departure routing that includes the expected 

TRACON departure fixes from the RNAV departure route. The routing assignment in adaptation 

was linked to the departure runway, which is automatically passed to TMA/EDC from PDRC’s 

SDSS component.

The solution leverages existing capability within the rTMA analysis_categories and 

category_definitions adaptation files (with a change also made to the initial heading/distance 

values in satellite_category_definitions). There are some downsides to this approach. The 

number of points (fixes) in the route is limited, and the solution diverges from how other 

arrival/departure procedures are implemented within rTMA. Figure 10:4 (analysis_categories) 

and Figure 10:5 (category_definitions) provide an example of the solution for the DARTZ3 

RNAV departure procedure.

Figure 10:3 – TMA ETA error before and after 

adaptation solution.

235

176

62

28

-100

-50

0

50

100

150

200

250

300

Error

(sec)

Runway

35 36
56

Figure 10:4 ‒ rTMA analysis_categories for 

implemented solution.

Figure 10:5 ‒ rTMA category_definitions for 

implemented solution.
57

A final note about the PDRC implementation of TRACON departure routing is appropriate. The 

PDRC solution implemented the routes using decision_tree logic simply because it was the 

quickest, no-software-change solution that would suffice, albeit with limitations. It is the norm,

however, for rTMA routing to be directly derived from the Host Computer System (HCS) 

adaptation and more specifically from the HCS files PAR, PDR, and PDAR (preferred arrival 

route, preferred departure route, and preferred departure/arrival route, respectively). These are 

implemented in rTMA as nas_pars, nas_pdrs, and nas_pdars. The TRACON departure routes are 

contained within PDAR, but since this is Center adaptation, the first fix in the route begins at the 

departure fix and thus does not include the interior TRACON fixes. A suggested final 

implementation is to use the same or similar syntax as found in the nas_pdars file for a 

TRACON departure routes file. This would allow reuse, with slight modifications, of the 

existing software ingest and all of the associated route processing logic.

10.3 Results

The “after” portions of previous figures will now be examined to see the effect of implementing 

the interim, adaptation-only solution in rTMA. Figure 10:2(b) provides a graphical view of 

rTMA route predictions for a DFW departure after implementing this solution. As illustrated,

the predictions and the actual tracks align closely. When compared with the “before,” 

immediately to the left, the improvement is striking.

However, the horizontal route predictions are only a means to computing ETAs at downstream 

fixes. The green triangles in Figure 10:3 show the difference between the actual time of flight 

and the TMA predicted time of flight to the departure point after the solution was implemented. 

The “after” data sample consists of 53 flights. Mean ETA error for runway 35 departures has 

been reduced from 176 seconds to 28 seconds. Runway 36 demonstrated similar improvement,

with a mean error of 235 seconds prior to the routing solution that was reduced to 62 seconds 

after the solution.
58

11 Appendix C – AMA taxi time prediction improvement

This appendix presents research performed to improve SDSS predictions of Aircraft Movement 

Area (AMA) taxi times. This work has not been published elsewhere. The specific objective of 

this work was to determine the best possible speed to use when modeling departure taxi 

operations in the AMA.

11.1 Approach

A multivariate regression analysis methodology will be used. The dependent variable will be the 

spot-to-queue taxi time (AMA), with independent variables being aircraft type, carrier, spot 

group, runway. The independent variables to form a matrix of possible factors that influence

AMA taxi time. The best possible speed will be the one that reduces the spot-to-queue taxi time 

error, as well as the standard deviation of that error. The current default taxi speed used by SDSS 

for all departure flights is 17 knots.

To find the best possible AMA taxi speed to use, first the difference in predicted spot-to-queue

taxi time and actual spot-to-queue time is minimized. The actual spot-to-queue time is defined as 

the Queue Entry Time minus the Spot Crossing Time. The Spot Crossing time is the time at 

which the flight crosses the spot and enters the Aircraft Movement Area. The Queue Entry time 

is the first time at which the flight status changes in SDSS to “In Queue.” The predicted spot-toqueue time is derived using the TrajectoryDashboard-1.0 tool – an analysis companion to SDSS. 

This returns a set of intersections, time and distances from each gate node to each runway. The 

values of interest correspond with the spot to the 

queue entry polygon, but there is no intersection that 

rests exactly at the entry of the queue polygon. To 

solve this problem, the intersection closest to the 

queue entry polygon is used, and then a buffer 

distance is added or subtracted to end up with the 

exact distance (using the node-link SDSS model) from 

the spot to the queue entry. An example of how this is 

done is shown in the following section.

11.2 Determining Spot-to-Queue Distances

Table 11:1 shows a set of intersections and distances 

from the TrajectoryDashboard-1.0 tool. The geometry 

for this example is shown in Figure 11:1. The 

intersection closest to the queue entry polygon is 

found. In the example shown, this is intersection “LY”. The total spot-to-queue distance is “distance at LY” minus “distance at “A-010-K5” (spot) minus 

distance between queue polygon and intersection “LY”. These “buffer” distances are stored for each route, 

and then applied during the calculation of predicted 

AMA taxi times. To derive the taxi time, simply

divide distance by speed. This allows insertion of

different values for the speed to determine which one 

will minimize error.

Table 11:1 – TrajectoryDashboard 

values (gate A19, spot 10, rwy 17R)

Intersection Distance (nm)

A19 0

A0035 0.0515

K-K5 0.0818

A-010-K5 0.1097

K-009-A 0.1459

K-Z 0.2888

Z-new2 0.3061

Z-ZA-0 0.3227

Z-ZA-1 0.3312

Z-ZA-2 0.3398

Z-ZA-3 0.3494

L-Z-ZA-4 0.3589

L-Z-ZA-2 0.3789

L-Y 0.3997

L-EH 0.6441

EH0-4 0.7168

EH0-3 0.7296

EH0-2 0.7384

EH0-1 0.7475

EH0-0 0.7585
59

To find the set of speeds that minimize AMA taxi time error and standard deviation, actual flight 

data are categorized by different combinations of aircraft type, carrier, runway, and spot groups 

(ramp areas). This analysis will be explained in the next section.

11.3 Determine AMA Speeds by Groups

To determine AMA taxi speeds for use in this analysis, actual flight data is taken from 11/5/2012 

to 12/13/2012. The data is split into training and test sets. The training set is used to derive speed 

values, which are then used by the test set to determine the error in predicted and actual spot-toqueue taxi times. The test set, which was chosen at random, 

contains flight data from the days listed in Table 11:2.

Figure 11:1 ‒ Locating the queue entry for DFW runway 17R.

Table 11:2 – Test Set Data

Day Departure 

Flight Count

11/13/2012 418

11/14/2012 440

11/17/2012 379

11/24/2012 377

11/27/2012 452

12/03/2012 453

12/11/2012 413
60

Using the training set, data is grouped using the categories listed in Table 11:3 below. For each 

unique category grouping, the median spot-to-queue taxi speed is stored. This value is then 

applied to the test data set to determine the difference in predicted and actual spot-to-queue taxi 

time.

11.4 Data Filters

Filters are applied to the actual flight data to ensure the predicted and actual spot-to-queue taxi 

times are relevant to the analysis. The following filters are applied:

• Actual spot crossed must not be <null>

• The predicted runway at time of spot crossing must equal the actual runway used

• The predicted spot at time of spot crossing must equal the actual spot used

• The flight must not have an EDCT associated with it

11.5 Results

The results of the analysis are shown in this section. From these results the variable grouping 

with the minimum error and standard deviation is chosen as the new set of AMA taxi speeds to 

be used by SDSS.

Figures 11:2 and 11:3 show the real and absolute error in AMA taxi times as a box plot. The 

variable combination number can be linked to the category grouping in Table 11:3. A visual 

check of the data shows that each combination performs better than the default 17 knots by 

bringing the mean and median error near 0. The default 17 knots return an error closer to -30 

seconds. Also, the absolute error appears to be reduced. A more detailed depiction of the mean, 

median, standard deviation, and inter-quartile range are shown later in this section to facilitate 

choosing the category grouping with the most improved performance.

Table 11:3 ‒ Grouping Variables

Group # Group Variables

1 N/A (default 17 knots)

2 Aircraft Type

3 Aircraft Type, Runway

4 Aircraft Type, Runway, Spot Group

5 Aircraft Type, Spot Group

6 Carrier

7 Carrier, Aircraft Type

8 Carrier, Aircraft Type, Runway

9 Carrier, Aircraft Type, Runway, Spot Group

10 Carrier, Aircraft Type, Spot Group

11 Carrier, Runway

12 Carrier, Runway, Spot Group

13 Carrier, Spot Group

14 Runway

15 Runway, Spot Group

16 Spot Group
61

Figure 11:2 ‒ Box plot of Real AMA Taxi Time Error

Figure 11:3 ‒ Box plot of Absolute AMA Taxi Time Error
62

The charts in Figure 11:4 depict the real and absolute median error for each variable 

combination. All combinations results in a decreased value of real and absolute error when 

compared to the default speed of 17 knots. In terms of real median error, combination 7 (Carrier, 

Aircraft Type) results in the least amount of error. In terms of absolute median error, 

combinations 4 (Aircraft Type, Runway, Spot Group), 9 (Carrier, Aircraft Type, Runway, Spot 

Group), and 12 (Carrier, Runway, Spot Group) share the smallest value.

The next set of charts (Figure 11:5) shows the real and absolute mean error in AMA taxi time. 

Once again, combination 7 (Carrier, Aircraft Type) has the smallest actual (real) error. The 

smallest mean absolute error is shared between combinations 4 (Aircraft Type, Runway, Spot 

Group), 9 (Carrier, Aircraft Type, Runway, Spot Group), and 12 (Carrier, Runway, Spot Group).

Figure 11:4 – AMA taxi time prediction errors for 16 cases – median.
63

The “tightness” of the errors is shown in the next two figures in terms of standard deviation and 

inter-quartile range. Figure 11:6 shows the real and absolute standard deviation of the errors, 

while Figure 11:7 shows the interquartile range of the real and absolute errors. Excluding 

combination 14 (Runway), all other combinations show similar values for standard deviation. 

The smallest inter-quartile range values are achieved using combinations 4 (Aircraft Type, 

Runway, Spot Group), 9 (Carrier, Aircraft Type, Runway, Spot Group), or 12 (Carrier, Runway, 

Spot Group).

Figure 11:5 – AMA taxi time prediction errors for 16 cases – mean.

Figure 11:6 – AMA taxi time prediction errors for 16 cases (standard deviation).
64

11.6 Recommendations based on multivariate regression analysis

The variable combinations that exhibit the overall smallest amount of error and “tightness” are

• combination 4: Aircraft Type, Runway, Spot Group

• combination 9: Carrier, Aircraft Type, Runway, Spot Group

• combination 12: Carrier, Runway, Spot Group

With regards to implementation, either combination 4 or combination 12 would be the least 

difficult to accomplish. Combination 9 would add complexity to the 

departure_taxi_speed_decision tree without adding any more reduction in error.

11.7 Implementation challenges

The recommended three-variable solution led to large adaptation decision trees, which negatively

impacted SDSS processing speed. Consequently, the team elected to use a less-demanding twovariable solution. Aircraft type and carrier were selected as the variables.

Implementation of the new decision tree involved additional design decisions for specific 

variables. For example, a B350 aircraft was found to be used only 4 times throughout the 

original multivariate analysis, each with a different carrier. Instead of splitting the decision tree 

by carrier, in this case the mean value between the carriers was used in order to avoid creating a 

larger file size that could potentially decrease SDSS system performance. This methodology was 

used for various other aircraft types when it was clear that a single value would be fine.

11.8 Post-implementation analysis

This follow-up analysis documented the impact of the new AMA departure taxi speed logic

implemented in SDSS. The analysis examined the accuracy of SDSS AMA taxi time calculations 

Figure 11:7 – AMA taxi time prediction errors for 16 cases (interquartile range).
65

during the first three weeks (11/5/2012 to 11/27/2012) of the PDRC Block 2 operational 

evaluation. The analysis also examined the accuracy of OFF time predictions from the PDRC 

Block 1 operational evaluation (4/30/2012 – 7/26/2012), compared to partial results from the 

Block 2 operational evaluation. The OFF time error is shown as an aggregate value (median) as a 

function of time-to-OFF.

11.8.1 Spot-to-Queue Taxi Time Error

Data from 11/5/2012 to 11/27/2012 (a portion of Block 2 operational evaluation) were analyzed 

to find the spot-to-queue taxi time error. The actual spot-to-queue taxi time was compared to two 

sets of predicted values, one using the new departure_taxi_speed_decision_tree and one using 

the default value of 17 knots for taxi speed. The following filters were applied to the data before 

the plots were created:

• Actual spot crossed must not be <null>

• The predicted runway at time of spot crossing must equal the actual runway

• The predicted spot at time of spot crossing must equal the actual spot

• The flight must not have an EDCT time

After these filters were applied, the AMA taxi time error was calculated as the predicted spot-toqueue taxi time minus the actual spot-to-queue taxi time. Flights with absolute taxi time error 

greater than the 75th percentile of the absolute error were removed from the analysis.

Figure 11:8 shows the spot-to-queue taxi time error for data from 11/5/2012 – 11/27/2012. The 

“Improved” dataset used the new departure_taxi_speed_decision_tree, while the “Old” dataset 

used a default value of 17 knots for taxi speed. Considering first the actual or real values plotted 

in Figure 11:8(a), the median error shifts from –21.7 to 6.2 seconds. Predicted taxi times from 

the spot to the queue are now more centered around 0 seconds. The IQR and standard deviation 

stay about the same. The total range decreases by about 20 seconds.

Turning attention to the comparison of absolute values shown in Figure 11:8(b) note the 

following differences:

• Decreased median absolute error by ~6 seconds

Figure 11:8 – Spot-to-queue taxi time error for all flights.
66

• Standard deviation decreased by ~3 seconds

• Inter-quartile range decreased by ~4 seconds

• Total range decreased by ~10 seconds

Figure 11:9 presents the same spot-to-queue taxi time comparisons but for American Airlines 

flights only. These results show even greater improvement than the overall results discussed 

above.

11.8.2 OFF time error

The spot-to-queue predictions are but one piece of the total prediction accuracy that could be

improved. Overall, an improvement in the OFF time accuracy of all flights is desired. The 

following plots show the OFF time error as a function of time-to-OFF for the Block 1 operational 

evaluation compared to data from a portion (11/5/2012 – 11/27/2012) of the Block 2 evaluation. 

The errors shown are the median values at each time-to-OFFF value.

Figure 11:9 – Spot-to-queue taxi time error for AAL flights only.
67

Figure 11:10 – OFF time accuracy plotted as a function of time-to-OFF for Block 1 

evaluation and a portion of the Block 2 evaluation.
68

12 Appendix D: Block 1 operational evaluation data

This appendix contains data from the PDRC Block 1 operational evaluation. These data were 

used in the OFF time compliance comparison and other analyses.

Table 12:1 – Column definitions for Block 1 evaluations data.

Column label Definition

Date (L) Local date on which the flight departed DFW (mm/dd/yy US Central TZ)

Callsign ATC callsign for the flight.

Type ATC equipment type for the flight.

Dest Destination airport.

Rwy Actual departure runway detected from surface surveillance tracks.

CFR init Time at which CFR scheduling was initiated (UTC hh:mm:ss)

CFR done Time at which CFR scheduling was completed (UTC hh:mm:ss).

Release Coordinated release time resulting from PDRC scheduling process (UTC hh:mm:ss).

OFF Actual OFF time detected from surface surveillance tracks (UTC hh:mm:ss).

OTC? Eligibility of flight for OFF time compliance comparison.

OTC OFF – Release (seconds)

Table 12:2 – DFW departures scheduled with PDRC during Block 1 evaluation.

Date (L) Callsign Type Dest Rwy CFR init CFR done Release OFF OTC? OTC

05/10/12 SKW5187 CRJ7 IAH 17R 15:59:10 16:08:16 16:22:35 16:20:16 NO n/a

05/10/12 ASQ4430 E145 IAH 17R 16:23:51 16:24:39 16:29:00 16:29:32 1 32

05/10/12 AAL1560 MD83 IAH 17R 17:31:32 17:32:06 17:33:01 17:34:16 2 75

05/10/12 AAL1897 MD82 IAH 17R 20:24:43 20:25:39 20:29:23 20:41:12 NO n/a

05/10/12 AAL1001 MD83 IAH 17R 21:18:33 21:20:20 21:51:03 21:32:22 NO n/a

05/11/12 AAL2385 MD82 IAH 17R 12:35:26 12:35:47 12:41:11 12:39:57 3 -74

05/11/12 AAL1599 MD82 IAH 17R 14:43:47 14:44:35 14:48:32 14:49:51 4 79

05/12/12 UAL1014 B738 IAH 35L 13:29:59 13:30:34 13:35:19 13:35:12 5 -7

05/12/12 SKW5235 CRJ2 IAH 35L 14:03:52 14:04:17 14:08:12 14:09:08 6 56

05/12/12 AAL1599 MD82 IAH 35C 14:57:13 15:11:07 15:13:21 15:12:09 7 -72

05/15/12 ASQ4087 E145 IAH 35L 21:40:02 21:41:24 21:44:07 21:45:45 8 98

05/20/12 AAL2448 B738 DCA 17R 00:37:18 00:43:18 00:44:47 00:44:34 9 -13

05/22/12 AAL2025 B763 MIA 17R 13:05:47 13:05:46 13:12:35 13:17:04 NO n/a

05/22/12 AAL1976 B752 MIA 17R 13:59:30 14:00:12 14:03:12 14:03:56 10 44
69

Date (L) Callsign Type Dest Rwy CFR init CFR done Release OFF OTC? OTC

05/22/12 AAL1652 B738 MCO 17R 14:41:27 14:41:26 14:43:26 14:43:49 11 23

05/22/12 AAL1327 B738 MIA 17R 16:17:07 16:17:45 16:21:15 16:19:53 12 -82

05/24/12 EGF2883 E145 HOU 18L 22:47:41 22:48:28 22:53:27 22:53:30 13 3

05/31/12 EGF3254 E145 HOU 36R 21:31:27 21:31:26 21:36:18 21:36:05 14 -13

05/31/12 AAL1897 MD83 IAH 35L 22:28:59 22:32:41 22:40:16 22:40:24 15 8

05/31/12 AAL1001 MD83 IAH 35L 22:27:11 22:27:09 22:38:58 22:37:22 16 -96

05/31/12 ASQ4087 E145 IAH 35L 21:43:01 21:43:33 21:47:19 21:47:47 17 28

05/31/12 SKW5176 CRJ7 IAH 36R 19:33:08 19:35:38 19:39:37 19:40:28 18 51

06/10/12 AAL1884 MD82 ATL 17R 20:27:02 20:29:52 20:31:38 20:32:20 19 42

06/11/12 DAL1910 B752 ATL 17R 21:11:03 21:12:25 21:32:06 21:32:28 20 22

06/11/12 DAL2210 A320 ATL 17R 22:26:35 22:26:33 22:29:41 22:30:07 21 26

06/13/12 AAL1560 MD82 IAH 17R 17:33:34 17:34:55 17:37:11 17:37:42 22 31

06/13/12 SKW5173 CRJ7 IAH 17R 19:01:48 19:03:17 19:08:59 19:10:09 23 70

06/13/12 AAL1897 MD83 IAH 17R 19:34:16 19:34:54 19:39:19 19:38:30 24 -49

06/14/12 AAL2385 MD83 IAH 17C 12:11:53 12:13:54 12:14:16 12:15:03 25 47

06/14/12 AAL1001 MD83 IAH 17R 21:17:58 21:19:17 21:22:21 21:24:51 26 150

06/14/12 SKW5169 CRJ7 IAH 17R 21:45:36 21:45:55 21:51:21 21:52:39 27 78

06/14/12 AAL653 MD83 IAH 17R 23:10:55 23:12:13 23:16:37 23:16:15 28 -22

06/15/12 SKW5169 CRJ7 IAH 17R 21:55:42 21:56:14 22:00:43 22:00:38 29 -5

06/15/12 AAL1001 MD83 IAH 17R 22:27:31 22:27:54 22:33:53 22:34:07 30 14

06/15/12 AAL653 MD83 IAH 17R 23:22:40 23:22:36 23:26:27 23:26:15 31 -12

06/16/12 UAL1407 B739 IAH 17R 11:38:29 11:40:02 11:43:38 11:43:46 32 8

06/16/12 AAL2385 MD83 IAH 17C 12:01:42 12:02:05 12:07:15 12:07:13 33 -2

06/16/12 AAL1001 MD83 IAH 17R 21:12:19 21:13:51 21:17:18 21:17:15 34 -3

06/16/12 SKW5169 CRJ7 IAH 17R 22:08:11 22:09:39 22:15:58 22:16:16 35 18

06/16/12 AAL653 MD83 IAH 17R 23:09:47 23:10:38 23:15:25 23:15:11 36 -14

06/18/12 AAL2385 MD83 IAH 17C 12:00:38 12:03:03 12:06:33 12:07:17 37 44

06/18/12 AAL1599 MD82 IAH 17R 14:43:15 14:47:37 14:50:39 14:49:12 38 -87

06/18/12 SKW5206 CRJ7 IAH 17R 14:46:55 14:47:20 14:53:52 14:54:18 39 26

06/18/12 ASQ4534 E145 IAH 17R 16:19:43 16:20:08 16:26:03 16:26:28 40 25

06/18/12 AAL1604 MD83 IAH 17R 17:31:08 17:31:44 17:36:14 17:36:27 41 13

06/18/12 SKW5173 CRJ7 IAH 17R 18:20:54 18:21:12 18:26:01 18:26:01 42 0

06/18/12 AAL1897 MD82 IAH 17R 19:28:25 19:29:28 19:34:53 19:35:08 43 15

06/18/12 AAL1001 MD83 IAH 17R 21:14:41 21:15:30 21:21:02 21:22:44 44 102

06/18/12 SKW5169 CRJ7 IAH 17R 21:47:41 21:51:03 21:53:16 21:53:55 45 39

06/19/12 AAL1604 MD82 IAH 17R 18:37:27 18:39:21 18:44:10 18:43:20 46 -50

06/19/12 AAL653 MD83 IAH 17R 00:31:22 00:31:47 00:41:43 00:41:42 NO n/a

06/23/12 DAL2165 A319 DTW 17R 18:09:01 18:09:01 18:15:39 18:15:35 47 -4

06/29/12 AAL1599 MD82 IAH 17R 15:07:00 15:13:00 15:13:49 15:14:49 48 60
70

Date (L) Callsign Type Dest Rwy CFR init CFR done Release OFF OTC? OTC

06/29/12 ASQ4534 E145 IAH 17R 16:26:38 16:28:09 16:32:39 16:32:01 49 -38

07/01/12 ASQ4693 E145 IAH 17R 13:57:01 13:57:18 14:01:14 14:00:36 50 -38

07/01/12 AAL2352 MD82 ORD 17R 19:10:55 19:11:38 19:14:01 19:15:20 51 79

07/01/12 AAL2350 MD83 ORD 18L 19:10:56 19:20:45 19:20:38 19:23:00 52 142

07/01/12 ASH3772 CRJ7 ORD 18L 19:19:49 19:20:19 19:24:20 19:24:57 53 37

07/01/12 AAL2354 MD83 ORD 18L 19:26:38 19:27:06 19:31:19 19:33:07 54 108

07/01/12 AAL1001 MD82 IAH 18L 21:42:20 21:46:00 21:52:51 21:52:46 55 -5

07/01/12 AAL848 MD83 ATL 17R 23:09:40 23:10:51 23:14:48 23:14:46 56 -2

07/01/12 DAL1810 MD88 ATL 17R 23:33:32 23:33:59 23:39:21 23:40:00 57 39

07/01/12 NKS948 A320 ORD 17R 00:25:56 00:27:37 00:31:45 00:34:21 NO n/a

07/01/12 AAL2374 MD82 ORD 18L 01:23:50 01:24:14 01:25:49 01:26:22 58 33

07/07/12 ASQ4376 E145 IAH 17R 18:14:11 18:15:03 18:19:15 18:19:58 59 43

07/07/12 AAL1897 MD82 IAH 17R 19:31:37 19:32:30 19:38:14 19:38:27 60 13

07/07/12 SKW5188 CRJ7 IAH 17R 19:38:55 19:39:18 19:44:33 19:45:49 61 76

07/08/12 ASQ4698 E145 IAH 17R 14:10:45 14:25:17 14:25:55 14:27:58 62 123

07/08/12 ASQ4707 E145 IAH 17R 18:09:05 18:09:38 18:14:24 18:14:47 63 23

07/08/12 AAL1604 MD82 IAH 17R 18:21:32 18:21:55 18:25:25 18:26:25 64 60

07/08/12 TCF3514 E170 ORD 17R 21:40:55 21:42:48 21:46:55 21:47:37 65 42

07/08/12 AAL2362 MD83 ORD 17R 21:47:41 21:49:50 21:59:05 21:57:32 66 -93

07/08/12 AAL1001 MD83 IAH 18L 23:03:29 23:07:15 23:11:25 23:11:21 67 -4

07/10/12 SKW5195 CRJ7 IAH 35L 16:49:31 16:51:37 16:55:25 16:54:14 68 -71

07/10/12 AAL1604 MD83 IAH 35L 17:45:10 17:45:57 17:55:40 17:55:58 69 18

07/10/12 ASQ4222 E145 IAH 35L 20:22:32 20:22:56 20:31:20 20:29:57 NO n/a

07/10/12 AAL1001 MD83 IAH 35L 21:19:59 21:20:58 21:27:21 21:28:50 70 89

07/10/12 DAL2210 MD90 ATL 35L 22:17:49 22:20:28 22:22:46 22:25:40 NO n/a

07/11/12 EGF3215 E145 HOU 35L 15:48:48 15:49:47 15:52:56 15:52:55 71 -1

07/11/12 SKW5195 CRJ7 IAH 35L 18:08:32 18:08:55 18:18:40 18:12:52 NO n/a

07/11/12 AAL1604 MD83 IAH 35L 19:03:04 19:04:19 19:09:47 19:09:52 NO n/a

07/11/12 AAL1897 MD82 IAH 35L 19:48:19 19:48:49 19:58:15 19:56:46 72 -89

07/11/12 AAL1001 MD82 IAH 35L 21:14:07 21:14:40 21:24:18 21:22:09 73 -129

07/11/12 AAL653 MD83 IAH 35L 23:14:08 23:14:44 23:25:09 23:24:35 74 -34

07/11/12 ASQ4211 E145 IAH 35L 01:30:15 01:32:01 01:34:43 01:36:25 75 102

07/12/12 EGF3219 E135 HOU 35L 14:47:01 14:48:08 14:51:22 14:52:57 76 95

07/12/12 EGF2855 E145 HOU 35L 18:15:06 18:15:46 18:22:07 18:20:50 77 -77

07/12/12 ASQ4607 E145 IAH 35L 18:44:59 18:47:10 18:58:17 18:56:56 NO n/a

07/12/12 AAL1897 MD82 IAH 35L 19:29:20 19:30:19 19:34:07 19:34:45 78 38

07/12/12 EGF3208 E145 HOU 18L 20:04:02 20:04:38 20:05:33 20:07:11 79 98

07/12/12 EGF3254 E145 HOU 18L 21:43:35 21:44:29 21:47:15 21:48:38 80 83

07/12/12 AAL1001 MD83 IAH 17R 21:45:40 21:46:42 21:53:12 21:52:31 81 -41
71

Date (L) Callsign Type Dest Rwy CFR init CFR done Release OFF OTC? OTC

07/13/12 AAL2385 MD83 IAH 17R 12:05:34 12:05:55 12:09:59 12:10:21 82 22

07/13/12 AAL1897 MD82 IAH 17R 21:05:23 21:05:56 21:09:35 21:10:22 NO n/a

07/13/12 DAL2010 B752 ATL 17R 21:10:19 21:11:08 21:15:09 21:17:27 83 138

07/13/12 AAL653 MD83 IAH 17R 23:13:33 23:17:47 23:22:28 23:23:48 84 80

07/15/12 ASQ4239 E45X IAH 17R 16:26:42 16:28:19 16:34:25 16:35:01 85 36

07/15/12 ASQ4209 E145 IAH 17R 18:29:52 18:30:43 18:37:25 18:37:16 86 -9

07/15/12 AAL1604 MD82 IAH 17R 18:42:37 18:43:08 18:50:23 18:51:16 87 53

07/15/12 DAL1675 MD88 IAH 17R 19:23:49 19:24:51 19:43:47 19:41:17 88 -150

07/15/12 AAL1897 MD82 IAH 17R 19:32:43 19:33:10 19:44:08 19:46:22 89 134

07/16/12 DAL2010 B752 ATL 17R 22:16:44 22:18:40 22:25:35 22:24:35 NO n/a

07/16/12 EGF3254 E145 HOU 17R 22:37:18 22:40:27 22:44:13 22:44:46 90 33

07/16/12 EGF2883 E145 HOU 17R 23:22:30 23:24:16 23:29:35 23:28:15 91 -80

07/18/12 AAL1897 MD82 IAH 17R 19:28:39 19:31:04 19:36:45 19:38:31 92 106

07/18/12 ASQ4682 E145 IAH 17R 19:28:08 19:31:16 19:38:04 19:40:41 93 157

07/18/12 AAL1001 MD83 IAH 17R 21:17:06 21:19:26 21:23:34 21:23:53 94 19

07/18/12 SKW5178 CRJ7 IAH 17R 21:57:59 21:58:37 22:11:55 22:10:02 95 -113

07/18/12 ASQ4211 E145 IAH 18L 00:06:39 00:07:46 00:20:13 00:18:56 96 -77

07/18/12 TCF5668 E170 IAH 17R 00:26:57 00:27:33 00:30:59 00:31:47 97 48

07/20/12 DAL1954 B752 ATL 17C 12:07:23 12:07:46 12:13:36 12:13:58 98 22

07/23/12 ASQ4376 E145 IAH 17R 19:04:17 19:04:41 19:10:39 19:12:11 99 92

07/23/12 AAL1070 MD82 PHL 17R 19:18:16 19:20:14 19:22:46 19:23:11 NO n/a

07/23/12 AAL1897 MD82 IAH 18L 19:30:33 19:30:50 19:35:46 19:34:31 100 -75

07/23/12 AAL1156 MD82 DCA 17R 19:26:23 19:26:50 19:31:03 19:39:57 NO n/a

07/23/12 EGF3208 E145 HOU 18L 19:59:10 19:59:26 20:05:40 20:04:38 101 -62

07/23/12 AAL1218 MD83 BWI 17R 20:00:21 20:00:47 20:16:35 20:18:19 NO n/a

07/23/12 ASQ4682 E145 IAH 17R 20:56:28 20:56:50 21:00:57 21:00:42 NO n/a

07/23/12 AAL1001 MD83 IAH 17R 21:33:32 21:34:05 21:39:45 21:41:26 102 101

07/23/12 SKW5178 CRJ7 IAH 17R 21:58:52 21:59:25 22:04:31 22:05:32 103 61
72

Table 12:3 – PDRC Block 1 flight counts by date and destination.

Date Destination Airport Total

ATL BWI DCA DTW HOU IAH MCO MIA ORD PHL

05/10/12 5 5

05/11/12 2 2

05/12/12 3 3

05/15/12 1 1

05/20/12 1 1

05/22/12 1 3 4

05/24/12 1 1

05/31/12 1 4 5

06/10/12 1 1

06/11/12 2 2

06/13/12 3 3

06/14/12 4 4

06/15/12 3 3

06/16/12 5 5

06/18/12 9 9

06/19/12 2 2

06/23/12 1 1

06/29/12 2 2

07/01/12 2 2 6 10

07/07/12 3 3

07/08/12 4 2 6

07/10/12 1 4 5

07/11/12 1 6 7

07/12/12 4 3 7

07/13/12 1 3 4

07/15/12 5 5

07/16/12 1 2 3

07/18/12 6 6

07/20/12 1 1

07/23/12 1 1 1 5 1 9

Totals 9 1 2 1 10 84 1 3 8 1 120
73

13 Appendix E: Block 2 operational evaluation data

This appendix contains data from the PDRC Block 2 operational evaluation. These data were 

used in the OFF time compliance comparison and other analyses.

Table 13:1 – Column definitions for Block 2 evaluation data.

Column label Definition

Date (L) Local date on which the flight departed DFW (mm/dd/yy US Central TZ)

Callsign ATC callsign for the flight.

Type ATC equipment type for the flight.

Dest Destination airport.

Rwy Actual departure runway detected from surface surveillance tracks.

CFR init Time at which CFR scheduling was initiated (UTC hh:mm:ss)

CFR done Time at which CFR scheduling was completed (UTC hh:mm:ss).

Release Coordinated release time resulting from PDRC scheduling process (UTC hh:mm:ss).

OFF Actual OFF time detected from surface surveillance tracks (UTC hh:mm:ss).

OTC? Eligibility of flight for OFF time compliance comparison.

OTC OFF – Release (seconds)

Table 13:2 – DFW departures scheduled with PDRC during Block 2 evaluation.

Date (L) Callsign Type Dest Rwy CFR init CFR done Release OFF OTC? OTC

11/08/12 EGF3219 E135 HOU 18L 14:48:05 14:48:34 14:54:34 14:53:14 1 -80

11/14/12 AAL1794 MD82 ATL 17R 16:42:13 16:42:36 16:50:09 16:49:41 2 -28

11/14/12 DAL865 MD90 ATL 17R 17:00:51 17:01:14 17:07:00 17:06:48 3 -12

11/14/12 AAL1472 MD82 ATL 17R 17:59:34 18:00:10 18:05:32 18:06:05 4 33

11/14/12 DAL1710 MD88 ATL 17R 18:28:04 18:28:36 18:42:26 18:35:10 NO n/a

11/14/12 AAL474 MD83 ATL 17R 18:55:36 18:56:10 19:00:24 19:00:04 5 -20

11/18/12 AAL1387 MD82 AUS 18L 20:12:08 20:12:56 20:15:45 20:16:08 6 23

11/18/12 AAL1731 MD83 AUS 18L 23:25:55 23:26:21 23:34:35 23:33:47 7 -48

11/18/12 AAL1625 MD83 AUS 18L 23:35:13 23:36:02 23:42:12 23:41:50 8 -22

11/25/12 ASQ4549 E145 IAH 17R 21:54:34 21:55:40 21:59:49 21:57:51 9 -118

11/27/12 UAL1096 B738 IAH 35L 12:40:31 12:40:55 12:45:14 12:46:11 10 57

11/27/12 AAL547 MD82 IAH 35L 13:35:56 13:36:35 13:41:53 13:40:51 11 -62
74

Date (L) Callsign Type Dest Rwy CFR init CFR done Release OFF OTC? OTC

11/27/12 NKS832 A319 IAH 35L 13:47:52 13:48:18 13:52:02 13:52:26 12 24

12/04/12 AAL1335 MD83 IAH 35L 18:58:43 19:02:09 19:02:52 19:04:20 13 88

12/04/12 EGF2855 E145 HOU 36R 19:15:51 19:17:19 19:20:15 19:22:58 NO n/a

12/06/12 EGF3219 E135 HOU 17R 14:50:23 14:51:01 14:55:05 14:55:06 14 1

12/09/12 AAL1583 MD82 DEN 35L 22:07:08 22:07:43 22:12:19 22:13:37 15 78

12/09/12 FFT661 A319 DEN 36R 22:48:37 22:49:00 22:51:11 22:52:25 16 74

12/09/12 NKS719 A319 DEN 36R 22:55:37 22:56:26 22:58:08 22:58:32 17 24

12/09/12 UAL288 A320 DEN 36R 23:02:32 23:02:58 23:04:56 23:05:32 18 36

12/10/12 DAL1910 MD90 ATL 35L 22:27:26 22:28:38 22:35:59 22:34:08 19 -111

12/10/12 AAL2222 MD82 ATL 35L 22:48:47 22:51:32 22:57:31 22:57:03 20 -28

12/16/12 FFT137 A319 DEN 36R 15:14:47 15:15:38 15:24:58 15:22:48 21 -130

12/16/12 AAL1241 MD83 DEN 18L 16:20:23 16:20:58 16:26:39 16:25:56 22 -43

12/16/12 UAL1700 B738 IAH 17R 16:27:09 16:28:30 16:35:06 16:35:58 23 52

12/16/12 AAL547 MD82 IAH 17R 16:45:35 16:46:17 16:58:50 16:56:15 24 -155

12/16/12 AAL1729 MD82 IAH 17R 16:45:53 16:46:39 17:02:27 17:00:20 25 -127

12/16/12 UAL1718 B738 IAH 17R 16:55:51 16:56:13 17:03:08 17:04:29 26 81

12/16/12 SKW5196 CRJ7 IAH 17R 18:05:42 18:06:22 18:11:47 18:11:45 NO n/a

12/16/12 JZA109 CRJ9 IAH 17R 18:17:51 18:18:22 18:34:11 18:33:45 27 -26

12/16/12 ASQ4606 E45X IAH 17R 18:26:27 18:28:35 18:53:18 18:53:14 NO n/a

12/16/12 AAL1335 MD83 IAH 17R 18:58:21 18:58:48 19:03:12 19:03:37 28 25

12/17/12 AAL1583 MD83 DEN 18L 22:19:55 22:20:21 22:22:27 22:22:45 29 18

12/17/12 RPA1125 E190 DEN 18L 22:39:30 22:39:54 22:51:38 22:48:21 30 -197

12/19/12 AAL1583 MD82 DEN 18L 22:17:01 22:18:39 22:22:19 22:22:17 31 -2

12/19/12 UAL33 B737 DEN 18L 22:55:29 22:56:11 23:05:10 23:05:57 32 47

12/19/12 NKS719 A319 DEN 18L 22:58:35 23:07:57 23:16:04 23:16:11 33 7

12/19/12 AAL1505 MD82 DEN 18L 23:18:50 23:20:02 23:24:17 23:25:58 34 101

12/20/12 AAL1381 MD82 DEN 36R 15:27:55 15:28:43 15:31:33 15:30:59 35 -34

12/23/12 NKS719 A319 DEN 36R 23:20:07 23:20:52 23:24:05 23:24:42 36 37

12/24/12 AAL1583 MD82 DEN 36R 22:34:01 22:35:52 22:39:02 22:38:32 37 -30

12/24/12 FFT125 A319 DEN 36R 22:40:51 22:41:23 22:45:09 22:45:14 38 5

12/24/12 NKS719 A319 DEN 36R 22:46:49 22:47:13 22:53:00 22:50:49 39 -131

12/28/12 NKS832 A319 IAH 35C 14:27:00 14:28:55 14:30:51 14:41:53 NO n/a

12/28/12 AAL1729 MD82 IAH 35L 15:43:15 15:45:17 15:47:29 15:48:03 40 34

12/28/12 ASQ4193 E45X IAH 35L 16:10:14 16:10:37 16:13:35 16:13:41 41 6

12/28/12 ASQ4655 E45X IAH 35L 17:48:00 17:48:54 17:53:30 17:53:26 42 -4

12/28/12 ASQ5662 E45X IAH 35L 18:00:18 18:02:12 18:02:38 18:03:31 43 53

12/31/12 UAL249 A319 DEN 18L 22:53:15 22:53:36 22:57:29 22:57:40 44 11

12/31/12 NKS719 A319 DEN 18L 22:53:18 22:57:51 22:59:00 23:00:04 NO n/a

01/09/13 AAL1335 MD83 IAH 35L 18:53:58 18:54:34 19:00:43 19:00:18 45 -25
75

Date (L) Callsign Type Dest Rwy CFR init CFR done Release OFF OTC? OTC

01/09/13 AAL1919 MD82 IAH 35L 20:13:26 20:14:31 20:22:48 20:21:27 46 -81

01/09/13 ASQ4476 E145 IAH 35L 20:23:34 20:25:10 20:28:43 20:28:31 47 -12

01/09/13 SKW4967 CRJ7 IAH 35L 20:50:34 20:51:17 20:56:08 20:54:48 48 -80

01/09/13 AAL463 MD82 IAH 35L 22:10:38 22:11:29 22:16:06 22:17:15 49 69

01/09/13 SKW5166 CRJ7 IAH 35L 22:14:52 22:15:48 22:21:15 22:21:49 50 34

01/10/13 AAL1729 MD82 IAH 17R 15:38:54 15:39:55 15:43:42 15:45:21 51 99

01/10/13 ASQ4674 E45X IAH 17R 17:10:03 17:10:42 17:16:30 17:17:56 52 86

01/10/13 SKW5258 CRJ2 IAH 17R 17:48:03 17:49:04 17:54:30 17:53:23 53 -67

01/10/13 AAL1335 MD82 IAH 17R 18:53:54 18:54:25 19:01:23 19:00:56 54 -27

01/10/13 ASQ4476 E45X IAH 17R 19:07:13 19:07:37 19:12:35 19:13:03 55 28

01/10/13 EGF3224 E145 HOU 17R 21:08:36 21:09:21 21:14:20 21:13:56 56 -24

01/13/13 AAL1729 MD82 IAH 35L 15:45:46 15:47:01 15:51:15 15:52:08 57 53

01/13/13 ASQ4258 E45X IAH 35L 16:55:04 16:55:42 16:59:06 16:58:37 58 -29

01/13/13 AAL1335 MD82 IAH 35L 18:58:02 18:58:47 19:03:16 19:03:19 59 3

01/20/13 AAL1729 MD82 IAH 17R 15:37:15 15:40:30 15:44:45 15:41:45 NO n/a

01/20/13 SKW5263 CRJ2 IAH 17R 17:30:33 15:40:01 15:41:01 17:31:30 NO n/a

01/20/13 EGF3219 E135 HOU 17R 16:29:01 16:29:01 16:29:46 16:31:41 NO n/a

01/20/13 UAL1427 B738 IAH 17R 17:30:59 17:32:56 18:21:35 17:46:22 NO n/a

01/20/13 UAL107 B735 IAH 17R 17:30:06 17:34:26 17:44:29 17:44:26 60 -3

01/20/13 SKW4966 CRJ7 IAH 17R 17:48:10 17:49:40 17:53:00 17:53:13 NO n/a

01/21/13 EGF3298 E145 HOU 36R 12:22:35 12:24:59 12:24:04 12:26:25 NO n/a

01/21/13 UAL531 A319 IAH 35L 12:33:41 12:34:08 12:37:58 12:39:48 NO n/a

01/24/13 AAL547 MD82 IAH 17R 13:01:48 13:02:08 13:03:54 13:04:01 61 7

02/01/13 NKS719 A319 DEN 18L 22:56:23 22:57:42 22:59:58 23:00:11 62 13

02/01/13 UAL617 A320 DEN 18L 22:58:12 22:58:11 23:03:21 23:03:19 63 -2

02/01/13 AAL1505 MD82 DEN 18L 23:33:46 23:33:48 23:39:30 23:39:47 64 17

02/05/13 EGF3224 E135 HOU 17R 21:25:08 21:25:56 21:30:00 21:30:43 65 43

02/05/13 EGF3448 E145 HOU 17R 22:31:42 22:32:24 22:37:03 22:37:27 66 24

02/06/13 EGF3219 E135 HOU 17R 14:53:05 14:53:57 15:02:11 15:00:18 67 -113

02/06/13 ASQ4453 E145 IAH 17R 17:04:13 17:04:12 17:22:34 17:22:10 NO n/a

02/06/13 EGF3214 E145 HOU 17R 17:51:20 17:51:40 18:05:44 18:01:18 NO n/a

02/06/13 SKW5248 CRJ2 IAH 17R 17:56:02 17:57:21 18:04:20 18:03:24 NO n/a

02/06/13 AAL1335 MD82 IAH 17R 18:53:20 18:54:39 18:57:59 18:57:47 68 -12

02/06/13 AAL1919 MD83 IAH 17R 20:15:46 20:16:28 20:20:01 20:20:46 69 45

02/06/13 SKW4967 CRJ7 IAH 17R 20:27:37 20:28:12 20:36:37 20:36:42 70 5

02/06/13 AAL463 MD82 IAH 17R 22:02:28 22:03:37 22:13:15 22:13:45 71 30

02/06/13 SKW5166 CRJ7 IAH 17R 22:13:58 22:14:27 22:58:42 22:57:54 72 -48

02/11/13 AAL1335 MD82 IAH 35L 18:52:02 18:53:32 18:58:18 18:57:36 73 -42

02/11/13 AAL1919 MD83 IAH 35L 20:19:34 20:20:32 20:26:41 20:27:13 74 32
76

Date (L) Callsign Type Dest Rwy CFR init CFR done Release OFF OTC? OTC

02/11/13 SKW4967 CRJ7 IAH 17R 20:44:40 20:45:15 20:52:27 20:51:49 75 -38

02/11/13 AAL463 MD82 IAH 17R 22:04:06 22:04:21 22:18:10 22:14:36 NO n/a

02/11/13 SKW5166 CRJ7 IAH 17R 22:19:55 22:20:50 22:39:35 22:35:04 NO n/a

02/18/13 AAL1335 MD82 IAH 17R 18:56:46 18:57:13 19:05:25 19:03:05 76 -140

02/18/13 SKW5165 CRJ7 IAH 17R 19:13:24 19:15:20 19:18:56 19:19:08 NO n/a

02/18/13 EGF3224 E145 HOU 35L 21:15:45 21:16:19 21:18:49 21:20:03 77 74

02/18/13 ASQ2519 CRJ2 HOU 35L 22:38:40 22:38:40 22:39:24 22:41:57 NO n/a

02/18/13 SKW5201 CRJ7 IAH 35L 22:40:53 22:42:10 23:07:15 23:06:06 78 -69

02/18/13 SKW5166 CRJ7 IAH 35L 22:40:59 22:46:57 23:13:28 23:12:10 79 -78

02/18/13 AAL463 MD82 IAH 35L 23:11:18 23:11:57 23:25:58 23:24:10 80 -108

02/18/13 AAL635 MD82 IAH 35L 00:46:00 00:46:47 00:50:56 00:51:47 81 51

02/18/13 ASQ2509 CRJ2 HOU 35L 00:47:23 00:47:23 00:53:48 00:52:56 NO n/a

02/19/13 SKW5166 CRJ7 IAH 17R 21:56:24 21:57:36 22:02:21 22:01:29 82 -52

02/19/13 AAL463 MD83 IAH 17R 22:05:12 22:05:28 22:08:14 22:09:21 83 67

02/20/13 AAL635 MD82 IAH 17R 00:03:12 00:05:36 00:10:04 00:10:25 NO n/a

02/20/13 ASQ2540 CRJ2 HOU 17R 00:12:10 00:12:56 00:21:38 00:20:26 84 -72

02/20/13 ASQ2509 CRJ2 HOU 17R 00:21:26 00:21:47 00:27:01 00:25:52 85 -69

02/20/13 SKW5172 CRJ7 IAH 17R 01:38:58 01:40:11 01:44:52 01:44:06 86 -46

02/20/13 NKS116 A319 IAH 17R 01:50:38 01:52:03 01:57:31 01:55:40 87 -111

02/21/13 AAL1335 MD82 IAH 35L 19:32:30 19:33:42 19:37:29 19:37:53 88 24

02/21/13 N769M WW24 HOU 35L 20:49:16 20:49:39 20:54:47 20:55:41 89 54

02/21/13 SKW5201 CRJ7 IAH 35L 21:10:01 21:10:37 21:16:02 21:16:51 90 49

02/21/13 ASQ2519 CRJ2 HOU 35L 21:48:14 21:48:41 21:53:48 21:54:46 91 58

02/21/13 SKW5165 CRJ7 IAH 35L 21:47:23 21:48:05 21:52:18 21:53:09 92 51

02/21/13 SKW5166 CRJ7 IAH 35L 22:18:15 22:18:37 22:36:40 22:36:05 93 -35

02/21/13 AAL1919 MD83 IAH 35L 22:48:20 22:48:42 22:56:12 22:55:31 94 -41

02/21/13 NKS948 A320 ORD 35L 23:52:54 23:53:40 23:56:18 23:57:12 95 54

02/21/13 ASQ2540 CRJ2 HOU 35L 00:17:21 00:18:03 00:34:05 00:29:35 NO n/a
77

Table 13:3 – PDRC Block 2 flight counts by date and destination.

Date Destination Airport Total

ATL AUS DEN HOU IAH ORD

11/08/12 1 1

11/14/12 5 5

11/18/12 3 3

11/25/12 1 1

11/27/12 3 3

12/04/12 1 1 2

12/06/12 1 1

12/09/12 4 4

12/10/12 2 2

12/16/12 2 8 10

12/17/12 2 2

12/19/12 4 4

12/20/12 1 1

12/23/12 1 1

12/24/12 3 3

12/28/12 5 5

12/31/12 2 2

01/09/13 6 6

01/10/13 1 5 6

01/13/13 3 3

01/20/13 1 5 6

01/21/13 1 1 2

01/24/13 1 1

02/01/13 3 3

02/05/13 2 2

02/06/13 2 7 9

02/11/13 5 5

02/18/13 3 6 9

02/19/13 2 2

02/20/13 2 3 5

02/21/13 3 5 1 9

Total 7 3 22 18 67 1 118
78

14 Appendix F: Baseline data

This appendix contains the Baseline data set used to compute OFF Time Compliance comparison 

statistics and histograms. These data were gathered from ZFW operational TMA/EDC 

recordings beginning in November 2010 and running through October 2011. The initial set 

consisted of 451 DFW departures that were tactically scheduled with the operational TMA/EDC 

system. The data have been culled as described below:

Table 14:1 – Baseline data culling summary.

Count Culling actions

451 Initial set of DFW tactical departures scheduled with TMA/EDC

399 Cull 52 that were also subject to EDCT times

379 Cull 20 with insufficient surface data for OFF time detection

371 Cull 8 with questionable times for TMA/EDC scheduling actions relative to actual OFF

342 Cull 29 with OTC < -293 or OTC > 388 (i.e., 1.5 x IQR outliers)

The last two rounds of culling summarized in Table 14:1 were to account for the absence of 

research observers during Baseline operations.

Table 14:2 – Column definitions for Baseline data.

Column label Definition

Date (L) Local date on which the flight departed DFW (mm/dd/yy US Central TZ)

Callsign ATC callsign for the flight.

Type ATC equipment type for the flight.

Dest Destination airport.

Rwy Actual departure runway detected from surface surveillance tracks.

CFR done Time at which CFR scheduling was completed (UTC hh:mm:ss).

Release Coordinated release time resulting from EDC scheduling process (UTC hh:mm:ss).

OFF Actual OFF time detected from surface surveillance tracks (UTC hh:mm:ss).

OTC? Eligibility of flight for OFF time compliance comparison.

OTC OFF – Release (seconds)
79

Table 14:3 – DFW departures scheduled with TMA/EDC during Baseline period.

Date (L) Callsign Type Dest Rwy CFR done Release OFF OTC? OTC

11/10/10 AAL1599 B738 IAH 17R 16:54:18 17:01:22 17:04:04 1 162

11/10/10 CHQ5873 EMBJ IAH 17R 17:04:34 17:11:10 17:11:15 2 5

11/11/10 AAL1098 MD8 IAH 17R 18:37:05 18:40:43 18:39:58 3 -45

11/11/10 BTA2957 EMBJ IAH 17R 19:18:53 19:23:00 19:25:03 4 123

11/11/10 AAL1897 MD8 IAH 17R 20:26:03 20:32:51 20:32:27 5 -24

11/11/10 COA807 B738 IAH 17R 21:39:38 21:47:40 21:46:35 6 -65

11/13/10 BTA2941 EMBJ IAH 35L 16:37:33 16:43:00 16:45:43 7 163

11/13/10 CHQ5805 EMBJ IAH 36R 19:12:19 19:20:13 19:19:38 8 -35

11/14/10 BTA2164 EMBJ IAH 17R 01:20:14 01:25:32 01:26:03 9 31

11/15/10 FFT557 EA32 DEN 18L 12:35:10 12:35:06 12:37:04 10 118

11/15/10 AAL393 B738 DEN 18L 12:40:57 12:45:00 12:50:03 11 303

11/15/10 UAL315 EA32 DEN 18L 15:29:27 15:33:14 15:33:12 12 -2

11/15/10 AAL1383 MD8 DEN 18L 15:44:50 15:47:36 15:47:12 13 -24

11/16/10 MES3234 CRJ MEM 35L 12:14:24 12:16:00 12:16:15 14 15

11/18/10 AWE583 B73S PHX 36R 14:33:08 14:36:21 14:34:51 15 -90

11/19/10 EGF3254 EMBJ HOU 18L 22:52:23 22:57:00 22:56:24 16 -36

11/24/10 AAL1695 B738 PHX 18L 14:34:03 14:34:02 14:36:08 17 126

11/29/10 MES3234 CRJ MEM 17R 12:14:26 12:20:48 12:21:07 18 19

11/29/10 BTA2047 EMBJ IAH 35L 22:29:40 22:35:00 22:34:49 19 -11

11/29/10 COA714 B738 IAH 35L 01:13:33 01:21:21 01:22:09 20 48

11/30/10 MES3234 CRJ MEM 35L 12:20:22 12:25:00 12:24:59 21 -1

12/01/10 CHQ5873 EMBJ IAH 17R 17:09:43 17:18:00 17:19:50 22 110

12/02/10 DAL2264 EA32 MEM 17R 12:01:50 12:07:00 12:09:10 23 130

12/03/10 EGF2855 EMBJ HOU 18L 19:14:38 19:17:00 19:18:46 24 106

12/07/10 EGF3219 EMBJ HOU 18L 14:44:41 14:44:36 14:46:58 25 142

12/15/10 EGF3254 EMBJ HOU 17R 23:50:40 23:52:00 23:54:01 26 121

12/15/10 EGF2883 EMBJ HOU 17R 00:08:06 00:10:00 00:12:08 27 128

12/24/10 COM674 CRJ MEM 17R 12:27:48 12:32:00 12:34:58 28 178

12/24/10 FDX472 DC10 MEM 17R 13:08:20 13:16:00 13:15:41 29 -19

12/29/10 COA1014 B738 IAH 17R 14:23:09 14:33:18 14:32:10 30 -68

12/29/10 BTA3091 EMBJ IAH 17R 23:30:14 23:37:44 23:36:23 31 -81
80

Date (L) Callsign Type Dest Rwy CFR done Release OFF OTC? OTC

12/29/10 EGF2883 EMBJ HOU 18L 00:04:44 00:05:00 00:06:17 32 77

12/29/10 AAL545 MD8 IAH 17R 00:40:53 00:46:00 00:46:46 33 46

12/30/10 AWE545 EA32 PHX 18L 00:36:10 00:40:00 00:39:04 34 -56

01/03/11 BTA2949 EMBJ IAH 17R 01:11:32 01:15:00 01:16:05 35 65

01/09/11 COA1014 B73V IAH 17R 13:08:13 13:14:39 13:11:43 36 -176

01/09/11 AAL2385 MD8 IAH 17R 13:55:39 14:02:00 13:59:45 37 -135

01/16/11 AAL1695 B738 PHX 36R 14:16:54 14:27:30 14:26:13 38 -77

01/16/11 AWE583 B73S PHX 36R 14:19:29 14:33:32 14:33:59 39 27

01/18/11 SKW1116 CRJ IAH 35L 19:11:21 19:17:56 19:17:06 40 -50

01/18/11 EGF3254 EMBJ HOU 36R 22:55:52 23:05:52 23:04:07 41 -105

01/18/11 EGF2883 EMBJ HOU 35L 00:05:29 00:10:00 00:12:29 42 149

01/25/11 COM674 CRJ MEM 35L 12:11:43 12:16:00 12:15:31 43 -29

01/27/11 AAL2385 MD8 IAH 35L 13:09:06 13:15:00 13:17:01 44 121

01/27/11 EGF3254 EMBJ HOU 35L 23:45:53 23:49:00 23:49:53 45 53

01/27/11 EGF2883 EMBJ HOU 36R 00:05:09 00:10:00 00:09:37 46 -23

01/30/11 BTA2725 EMBJ IAH 35L 17:53:58 17:58:00 17:58:04 47 4

01/30/11 AAL808 MD8 IAH 35L 18:08:33 18:12:00 18:11:54 48 -6

01/30/11 BTA2957 EMBJ IAH 35L 19:07:04 19:11:42 19:11:11 49 -31

01/30/11 AAL1034 MD8 IAH 35L 20:53:55 21:00:00 21:01:25 50 85

01/30/11 CHQ5833 EMBJ IAH 35L 21:00:20 21:05:00 21:08:02 51 182

01/30/11 AAL545 MD8 IAH 35L 00:11:11 00:16:00 00:17:30 52 90

01/31/11 AAL393 MD8 DEN 36R 12:48:40 12:55:00 12:53:02 53 -118

01/31/11 AAL2385 MD8 IAH 35L 13:36:17 13:44:22 13:44:20 54 -2

02/08/11 FFT127 EA32 DEN 18L 12:52:29 12:59:00 12:57:05 55 -115

02/08/11 EGF3254 EMBJ HOU 18L 22:57:29 23:01:00 23:02:35 56 95

02/11/11 COM674 CRJ MEM 17R 12:42:27 12:46:00 12:51:27 57 327

02/13/11 BTA3091 EMBJ IAH 17R 22:46:48 22:56:23 22:52:38 58 -225

02/15/11 BTA3091 EMBJ IAH 17R 22:44:36 22:51:26 22:53:13 59 107

02/15/11 EGF3254 EMBJ HOU 17R 22:57:59 23:00:00 23:03:15 60 195

02/17/11 EGF2855 EMBJ HOU 18L 19:43:19 19:48:00 19:50:27 61 147

02/17/11 EGF3254 EMBJ HOU 18L 22:57:11 23:01:00 23:00:14 62 -46

02/17/11 EGF2883 EMBJ HOU 18L 00:06:09 00:15:34 00:16:01 63 27
81

Date (L) Callsign Type Dest Rwy CFR done Release OFF OTC? OTC

02/18/11 EGF3215 EMBJ HOU 18L 16:40:05 16:44:00 16:45:46 64 106

02/18/11 EGF2855 EMBJ HOU 18L 19:21:37 19:24:10 19:24:43 65 33

02/23/11 EGF3254 EMBJ HOU 17R 23:18:42 23:22:00 23:24:18 66 138

02/24/11 CHQ5903 EMBJ IAH 35L 22:28:49 22:32:00 22:32:50 67 50

02/26/11 AWE583 B73S PHX 18L 14:22:33 14:32:00 14:30:59 68 -61

02/27/11 EGF3254 EMBJ HOU 18L 22:53:45 22:59:00 22:58:47 69 -13

02/28/11 AAL2385 MD8 IAH 35L 13:08:46 13:16:00 13:15:30 70 -30

02/28/11 EGF2883 EMBJ HOU 36R 00:24:51 00:30:00 00:31:51 71 111

03/03/11 EGF3298 EMBJ HOU 17R 14:39:44 14:48:33 14:48:14 72 -19

03/03/11 EGF3219 EMBJ HOU 17R 14:41:42 14:53:58 14:52:39 73 -79

03/07/11 EJA938 C750 HOU 17R 23:07:52 23:14:00 23:14:05 74 5

03/07/11 EGF3254 EMBJ HOU 17R 23:22:34 23:28:00 23:30:52 75 172

03/09/11 FFT127 EA32 DEN 36R 12:48:36 12:55:00 12:54:47 76 -13

03/13/11 EGF2855 EMBJ HOU 18L 18:19:42 18:23:00 18:22:33 77 -27

03/14/11 COM620 CRJ MEM 35L 11:12:20 11:12:46 11:16:14 78 208

03/14/11 COA214 B73V IAH 36R 15:19:31 15:23:00 15:22:34 79 -26

03/14/11 AAL1599 MD8 IAH 35L 15:21:18 15:29:53 15:28:26 80 -87

03/14/11 EGF3215 EMBJ HOU 35L 15:53:47 15:55:50 15:55:37 81 -13

03/21/11 AWE77 EA32 PHX 18L 23:43:01 23:47:00 23:47:04 82 4

03/26/11 AWE583 B73S PHX 18R 13:24:19 13:36:13 13:33:09 83 -184

03/26/11 AAL1695 MD8 PHX 18R 13:38:07 13:44:00 13:44:03 84 3

03/26/11 OAE366 DC10 ATL 35L 20:35:28 20:48:00 20:45:54 85 -126

03/28/11 DAL2510 MD8 ATL 17R 13:23:03 13:35:00 13:34:08 86 -52

03/31/11 EJA357 C650 HOU 35L 23:26:56 23:28:00 23:30:36 87 156

04/03/11 EGF3254 EMBJ HOU 18L 21:54:32 21:58:00 21:59:51 88 111

04/04/11 AAL1599 MD8 IAH 36R 15:45:02 15:45:00 15:49:37 89 277

04/04/11 EGF3215 EMBJ HOU 35L 15:57:02 16:01:00 16:03:28 90 148

04/04/11 EGF3254 EMBJ HOU 36R 22:11:33 22:16:00 22:17:57 91 117

04/04/11 EGF2883 EMBJ HOU 36R 23:34:20 23:38:00 23:37:58 92 -2

04/05/11 CHQ5853 EMBJ IAH 17R 16:31:09 16:38:00 16:37:50 93 -10

04/07/11 EGF2855 EMBJ HOU 17R 18:30:19 18:36:00 18:36:16 94 16

04/07/11 EGF3254 EMBJ HOU 18L 21:53:41 21:57:00 21:56:33 95 -27
82

Date (L) Callsign Type Dest Rwy CFR done Release OFF OTC? OTC

04/09/11 AAL1695 MD8 PHX 18L 13:28:29 13:33:00 13:32:51 96 -9

04/09/11 AWE583 B73S PHX 18L 13:28:57 13:54:35 13:53:18 97 -77

04/15/11 AAL2385 MD8 IAH 35L 12:10:55 12:16:00 12:18:12 98 132

04/23/11 AAL1695 MD8 PHX 18L 13:31:37 13:36:00 13:34:22 99 -98

04/23/11 AWE583 B73S PHX 18L 13:34:00 13:43:30 13:41:55 100 -95

04/24/11 AWE714 EMBJ PHL 17R 18:04:45 18:05:40 18:11:05 101 325

04/25/11 FDX1201 DC10 MEM 35L 04:06:48 04:17:48 04:18:02 102 14

04/25/11 FDX1365 DC10 MEM 35C 04:07:23 04:22:36 04:25:06 103 150

04/26/11 CHQ5853 EMBJ IAH 35L 16:05:37 16:16:27 16:17:33 104 66

05/02/11 FDX1201 DC10 MEM 35C 03:01:17 03:07:00 03:08:50 105 110

05/03/11 DAL2211 B738 ATL 17R 21:04:49 21:09:00 21:09:05 106 5

05/03/11 AAL2222 B738 ATL 17R 21:10:49 21:13:00 21:13:04 107 4

05/03/11 AAL832 B738 ATL 17R 22:32:59 22:38:00 22:37:47 108 -13

05/03/11 TRS110 B738 ATL 17R 22:37:29 22:45:00 22:43:38 109 -82

05/03/11 DAL1810 MD8 ATL 17R 00:10:17 00:15:00 00:13:51 110 -69

05/12/11 CHQ5942 EMBJ IAH 17R 16:17:19 16:33:44 16:35:22 111 98

05/12/11 AAL1560 MD8 IAH 17R 17:14:14 17:24:00 17:23:42 112 -18

05/12/11 COA469 B738 IAH 17R 17:21:14 17:25:59 17:31:03 113 304

05/12/11 EGF2883 EMBJ HOU 17R 01:52:03 01:58:58 01:57:04 114 -114

05/13/11 TRS106 MD8 ATL 35L 19:00:19 19:06:00 19:07:45 115 105

05/13/11 AAL1074 MD8 ATL 35L 19:22:29 19:27:00 19:31:35 116 275

05/13/11 DAL2211 EA32 ATL 35L 21:02:22 21:07:12 21:07:06 117 -6

05/13/11 AAL832 B738 ATL 35L 23:21:18 23:21:04 23:23:32 118 148

05/13/11 TRS110 MD8 ATL 35L 23:25:26 23:27:02 23:27:34 119 32

05/13/11 DAL2210 B757 ATL 35L 23:40:11 23:45:00 23:45:01 120 1

05/13/11 TRS102 B738 ATL 35L 00:15:45 00:21:26 00:20:44 121 -42

05/13/11 DAL2060 MD8 ATL 35L 00:46:14 00:51:17 00:52:28 122 71

05/16/11 ASQ4987 CRJ MEM 35L 11:25:33 11:35:47 11:35:10 123 -37

05/16/11 EGF2883 EMBJ HOU 36R 23:07:49 23:08:00 23:09:14 124 74

05/17/11 AAL2513 MD8 DEN 18L 00:44:19 00:54:53 00:53:00 125 -113

05/24/11 AWE77 EA32 PHX 18L 23:57:10 00:04:56 00:04:09 126 -47

05/26/11 AAL2364 MD8 ORD 36R 22:03:20 22:05:00 22:05:51 127 51
83

Date (L) Callsign Type Dest Rwy CFR done Release OFF OTC? OTC

05/26/11 SKW6751 CRJ ORD 36R 22:15:17 22:20:00 22:20:41 128 41

05/26/11 ASH3763 CRJ ORD 36R 23:03:06 23:07:00 23:07:19 129 19

05/30/11 EGF2883 EMBJ HOU 18L 23:17:01 23:20:00 23:24:36 130 276

05/31/11 EGF3219 EMBJ HOU 18L 13:48:03 13:51:00 13:52:25 131 85

06/03/11 FFT419 EA32 DEN 18L 00:43:19 00:53:00 00:50:39 132 -141

06/03/11 AAL2513 MD8 DEN 18L 01:26:46 01:34:54 01:32:49 133 -125

06/06/11 COA314 B73V IAH 17R 21:17:15 21:23:46 21:28:04 134 258

06/06/11 EGF3254 EMBJ HOU 17R 22:10:47 22:16:40 22:17:17 135 37

06/06/11 EGF2883 EMBJ HOU 18L 00:03:27 00:14:50 00:14:28 136 -22

06/08/11 EGF3254 EMBJ HOU 18L 23:01:27 23:04:00 23:04:17 137 17

06/08/11 EGF2883 EMBJ HOU 18L 23:05:02 23:06:39 23:08:04 138 85

06/08/11 UAL583 EA32 DEN 18L 00:19:35 00:23:41 00:24:51 139 70

06/08/11 AAL2513 MD8 DEN 18L 00:40:08 00:44:02 00:44:42 140 40

06/08/11 FFT419 EA32 DEN 18L 00:40:29 00:47:05 00:48:23 141 78

06/10/11 TCF3459 EMBJ ORD 18L 22:16:42 22:22:08 22:22:23 142 15

06/10/11 AAL2364 MD8 ORD 18L 22:01:30 22:05:00 22:05:39 143 39

06/10/11 DAL2210 EA32 ATL 17R 22:07:40 22:13:00 22:14:52 144 112

06/10/11 TRS110 MD8 ATL 17R 22:43:10 22:48:00 22:49:15 145 75

06/10/11 AAL1982 MD8 IAH 17R 23:15:37 23:20:00 23:20:41 146 41

06/11/11 DAL2210 EA32 ATL 17R 23:24:48 23:31:21 23:36:19 147 298

06/15/11 DAL910 MD8 ATL 17R 01:52:44 01:57:00 01:58:56 148 116

06/15/11 SKW6381 CRJ ORD 18L 01:55:55 02:02:54 02:00:56 149 -118

06/15/11 AAL1332 MD8 ATL 17R 01:58:28 02:01:00 02:03:08 150 128

06/16/11 COM544 CRJ MEM 17R 21:56:28 22:00:00 22:03:32 151 212

06/16/11 FDX1201 DC10 MEM 17C 02:45:37 02:49:38 02:49:08 152 -30

06/17/11 AAL1695 MD8 PHX 18L 13:38:08 13:39:00 13:44:47 153 347

06/17/11 AWE436 B73S PHX 18L 13:38:26 13:41:00 13:46:45 154 345

06/17/11 AAL1074 MD8 ATL 17R 19:35:55 19:42:32 19:43:08 155 36

06/17/11 DAL2010 MD8 ATL 17R 19:36:21 19:46:22 19:47:03 156 41

06/17/11 WOA8128 MD11 ATL 17R 20:27:12 20:31:00 20:30:44 157 -16

06/17/11 AAL2162 B738 ATL 17R 20:35:56 20:38:00 20:38:16 158 16

06/17/11 DAL1910 B757 ATL 17R 20:50:02 20:54:00 21:00:05 159 365
84

Date (L) Callsign Type Dest Rwy CFR done Release OFF OTC? OTC

06/17/11 DAL910 MD8 ATL 17R 01:20:15 01:25:07 01:26:16 160 69

06/17/11 AAL1306 MD8 ATL 17R 01:09:34 01:14:00 01:14:16 161 16

06/20/11 AAL808 MD8 DCA 17R 17:08:24 17:08:21 17:11:56 162 215

06/20/11 COA1758 B738 EWR 17R 17:34:28 17:40:00 17:42:41 163 161

06/20/11 AAL886 MD8 DCA 17R 17:48:10 17:48:08 17:51:48 164 220

06/20/11 AWE1154 EMBJ PHL 17R 17:53:30 18:05:37 18:05:33 165 -4

06/20/11 AAL730 MD8 LGA 17R 18:48:24 18:54:00 18:54:43 166 43

06/20/11 AAL2272 MD8 PHL 17R 18:50:01 18:57:00 18:58:01 167 61

06/20/11 MES2470 CRJ JFK 17R 18:45:10 18:50:00 18:52:35 168 155

06/20/11 AAL1250 MD8 EWR 17R 18:50:29 18:59:22 19:00:49 169 87

06/20/11 AAL688 B738 JFK 17R 19:28:57 19:34:00 19:38:56 170 296

06/20/11 AAL1156 MD8 DCA 17R 19:29:33 19:34:00 19:34:57 171 57

06/20/11 AAL1720 MD8 IAD 17R 20:08:05 20:11:00 20:13:12 172 132

06/20/11 AWE728 EA32 PHL 17R 19:56:48 19:59:00 20:02:19 173 199

06/21/11 COA540 B738 IAH 17R 16:19:33 16:34:20 16:33:54 174 -26

06/21/11 AAL1560 MD8 IAH 17R 18:09:34 18:14:00 18:12:50 175 -70

06/21/11 SKW1161 CRJ IAH 17R 19:32:17 19:35:00 19:35:56 176 56

06/21/11 AAL1897 MD8 IAH 17R 19:50:17 20:06:44 20:04:30 177 -134

06/21/11 EGF3254 EMBJ HOU 17R 22:06:31 22:09:00 22:09:33 178 33

06/21/11 AAL1982 MD8 IAH 17R 00:28:24 00:32:41 00:31:12 179 -89

06/22/11 COA1777 B738 IAH 17R 16:39:00 16:46:43 16:45:54 180 -49

06/22/11 BTA2725 EMBJ IAH 17R 16:37:13 16:44:14 16:42:50 181 -84

06/22/11 AAL1560 MD8 IAH 17R 17:40:45 17:45:00 17:44:10 182 -50

06/22/11 AAL1897 MD8 IAH 17R 20:04:06 20:11:27 20:11:12 183 -15

06/22/11 SKW1161 CRJ IAH 17R 20:41:58 20:47:00 20:47:22 184 22

06/22/11 AAL1367 MD8 IAH 17R 00:59:09 01:10:30 01:08:18 185 -132

06/23/11 COA1816 B73V IAH 17R 12:22:15 12:25:44 12:24:59 186 -45

06/23/11 AAL2385 MD8 IAH 17R 12:47:07 12:50:00 12:51:48 187 108

06/23/11 AAL1560 MD8 IAH 17R 17:41:29 17:45:48 17:45:23 188 -25

06/23/11 SKW1161 CRJ IAH 17R 19:54:15 20:00:00 19:58:03 189 -117

06/23/11 AAL1897 MD8 IAH 18L 19:59:25 20:01:35 20:02:03 190 28

06/27/11 TCF3480 EMBJ ORD 18L 12:03:24 12:06:04 12:05:01 191 -63
85

Date (L) Callsign Type Dest Rwy CFR done Release OFF OTC? OTC

06/27/11 AAL2324 MD8 ORD 18L 12:04:35 12:12:00 12:12:58 192 58

06/27/11 AAL2330 MD8 ORD 18L 13:31:45 13:37:00 13:37:29 193 29

06/28/11 AAL1897 MD8 IAH 18L 20:10:19 20:14:12 20:13:14 194 -58

06/30/11 EGF3215 EMBJ HOU 18L 15:19:28 15:23:00 15:23:00 195 0

06/30/11 N881A C25B HOU 17R 15:38:52 15:39:33 15:42:09 196 156

07/05/11 DAL1910 B757 ATL 17R 21:23:17 21:32:00 21:30:57 197 -63

07/05/11 TRS102 B738 ATL 17R 00:00:00 00:05:26 00:07:05 198 99

07/07/11 AAL745 B738 DEN 18L 22:21:57 22:27:00 22:27:24 199 24

07/07/11 TCF3547 EMBJ DEN 18L 22:12:04 22:16:00 22:15:59 200 -1

07/08/11 DAL2110 MD8 ATL 17R 18:17:23 18:23:00 18:22:08 201 -52

07/08/11 AAL1074 MD8 ATL 17R 19:39:50 19:43:03 19:45:17 202 134

07/08/11 DAL2010 MD8 ATL 17R 19:34:12 19:40:00 19:41:03 203 63

07/08/11 AAL2162 B738 ATL 17R 20:46:32 20:46:25 20:49:29 204 184

07/08/11 DAL1910 B757 ATL 17R 21:00:43 21:05:00 21:06:37 205 97

07/08/11 DAL2210 EA32 ATL 17R 22:07:20 22:11:00 22:13:43 206 163

07/08/11 TRS110 MD8 ATL 17R 22:45:32 22:50:00 22:52:31 207 151

07/12/11 EGF2883 EMBJ HOU 18R 23:15:25 23:19:00 23:19:22 208 22

07/12/11 AAL1982 MD8 IAH 17R 23:18:26 23:22:00 23:21:34 209 -26

07/12/11 AAL1306 MD8 ATL 17R 00:32:54 00:37:50 00:38:45 210 55

07/14/11 AAL162R B738 ATL 17R 21:07:13 21:12:20 21:12:45 211 25

07/14/11 DAL1910 B757 ATL 17R 21:03:07 21:03:05 21:09:15 212 370

07/14/11 NAO972 B767 ATL 17R 21:49:10 21:54:00 21:57:42 213 222

07/14/11 TRS110 MD8 ATL 17R 22:35:54 22:42:41 22:43:20 214 39

07/14/11 DAL1810 MD8 ATL 17R 23:27:59 23:32:00 23:30:15 215 -105

07/14/11 BTA3158 EMBJ IAH 17R 00:20:44 00:28:06 00:28:33 216 27

07/18/11 AAL1599 MD8 IAH 17R 14:57:34 15:04:00 15:04:55 217 55

07/18/11 EGF3215 EMBJ HOU 17R 15:15:43 15:20:00 15:19:34 218 -26

07/18/11 AAL1560 MD8 IAH 17R 17:41:36 17:47:00 17:51:43 219 283

07/18/11 AAL1897 MD8 IAH 17R 20:03:42 20:06:00 20:07:41 220 101

07/19/11 AAL1560 MD8 IAH 17R 17:55:53 18:05:17 18:02:03 221 -194

07/19/11 AAL1897 MD8 IAH 18R 20:01:26 20:05:00 20:07:43 222 163

07/19/11 AAL1982 MD8 IAH 17R 23:08:56 23:14:00 23:18:47 223 287
86

Date (L) Callsign Type Dest Rwy CFR done Release OFF OTC? OTC

07/22/11 SKW1162 CRJ IAH 17R 20:21:39 20:29:00 20:27:43 224 -77

07/22/11 AAL1897 MD8 IAH 17R 20:05:11 20:05:07 20:07:18 225 131

07/22/11 AAL736 MD8 LGA 17R 20:18:00 20:24:00 20:21:53 226 -127

07/22/11 COA1473 B73V EWR 17R 20:22:00 20:29:00 20:29:43 227 43

07/22/11 AAL738 B738 LGA 17R 20:28:32 20:36:00 20:34:35 228 -85

07/25/11 SKW1162 CRJ IAH 17R 19:28:28 19:29:02 19:32:23 229 201

07/25/11 EGF3254 EMBJ HOU 18R 21:56:29 21:56:15 21:59:08 230 173

07/25/11 AAL982Q MD8 IAH 17R 23:44:36 23:50:00 23:49:50 231 -10

07/25/11 BTA3158 EMBJ IAH 17R 00:11:08 00:16:00 00:16:10 232 10

07/25/11 AAL1367 MD8 IAH 17R 00:57:02 01:02:00 01:02:48 233 48

07/26/11 AAL1560 MD8 IAH 17R 17:42:14 17:42:13 17:43:37 234 84

07/26/11 SKW1162 CRJ IAH 17R 19:33:00 19:38:00 19:38:40 235 40

07/26/11 AAL1897 MD8 IAH 18R 19:50:08 19:57:00 19:59:01 236 121

07/26/11 AAL1982 MD8 IAH 17R 23:15:56 23:21:00 23:20:08 237 -52

07/26/11 BTA3158 EMBJ IAH 17R 00:28:52 00:34:28 00:37:06 238 158

07/26/11 AAL2513 MD8 DEN 18R 00:22:56 00:28:08 00:28:46 239 38

07/26/11 FFT419 EA32 DEN 18R 00:36:53 00:50:40 00:49:53 240 -47

07/26/11 UAL583 EA32 DEN 18R 00:58:00 01:09:51 01:07:24 241 -147

07/28/11 AAL1599 MD8 IAH 17R 14:57:26 15:04:14 15:04:57 242 43

07/28/11 COA1749 B73V IAH 17R 16:34:15 16:40:00 16:41:14 243 74

07/28/11 BTA2725 EMBJ IAH 17R 16:37:10 16:46:00 16:45:28 244 -32

07/28/11 AAL1560 MD8 IAH 17R 17:49:42 17:54:00 17:56:06 245 126

07/28/11 SKW1162 CRJ IAH 17R 19:59:05 20:04:00 20:07:07 246 187

07/28/11 AAL1897 MD8 IAH 17R 19:48:03 19:52:00 19:54:36 247 156

07/29/11 TCF3538 EMBJ ORD 17R 11:50:44 12:06:40 12:06:49 248 9

07/29/11 AAL2324 MD8 ORD 17R 12:01:29 12:15:04 12:16:49 249 105

07/29/11 AAL2328 MD8 ORD 18R 13:10:40 13:17:00 13:16:52 250 -8

07/29/11 AAL2330 MD8 ORD 17R 13:25:30 13:30:00 13:33:06 251 186

07/29/11 BTA2725 EMBJ IAH 17R 16:36:28 16:42:00 16:41:58 252 -2

07/29/11 EGF3254 EMBJ HOU 17R 22:14:43 22:17:00 22:18:24 253 84

07/29/11 EGF2883 EMBJ HOU 17R 23:10:02 23:12:00 23:16:19 254 259

07/29/11 AAL1367 MD8 IAH 17R 01:00:48 01:07:05 01:09:56 255 171
87

Date (L) Callsign Type Dest Rwy CFR done Release OFF OTC? OTC

07/30/11 AAL2385 MD8 IAH 17R 12:23:28 12:24:37 12:26:38 256 121

08/04/11 FFT419 EA32 DEN 18R 00:37:24 00:43:00 00:44:31 257 91

08/07/11 AAL2374 MD8 ORD 17R 01:10:17 01:15:00 01:16:56 258 116

08/08/11 AAL2328 MD8 ORD 18R 13:18:34 13:28:00 13:29:07 259 67

08/08/11 AAL2330 MD8 ORD 17R 13:40:37 13:45:00 13:45:01 260 1

08/09/11 EGF3254 EMBJ HOU 18R 21:57:50 22:03:00 22:02:50 261 -10

08/11/11 EGF3219 EMBJ HOU 18R 13:43:42 13:49:14 13:54:21 262 307

08/11/11 FLG3954 CRJ MEM 17R 16:45:27 16:50:00 16:49:18 263 -42

08/13/11 UAL301 EA32 ORD 18R 20:43:25 20:52:56 20:52:34 264 -22

08/17/11 TCF3542 EMBJ DEN 18R 22:19:54 22:19:53 22:23:18 265 205

08/17/11 AAL2477 MD8 LAX 18R 01:39:10 01:44:00 01:44:16 266 16

08/17/11 AAL2489 B757 LAX 18R 02:02:53 02:02:44 02:07:11 267 267

08/18/11 EGF3298 EMBJ HOU 18R 12:51:37 13:00:04 12:59:42 268 -22

08/18/11 EGF3215 EMBJ HOU 18R 15:25:41 15:31:00 15:31:10 269 10

08/23/11 SKW2030 CRJ IAH 17R 21:09:14 21:12:00 21:14:36 270 156

08/23/11 AAL1001 MD8 IAH 17R 23:05:15 23:05:00 23:08:35 271 215

08/25/11 COA1162 B73V IAH 17C 12:16:31 12:23:49 12:23:49 272 0

08/25/11 AAL2385 MD8 IAH 18R 12:47:23 12:52:00 12:56:56 273 296

08/25/11 EGF3298 EMBJ HOU 18R 13:03:58 13:07:00 13:07:13 274 13

08/25/11 AAL1591 MD8 IAH 17R 15:03:27 15:03:59 15:06:45 275 166

08/25/11 BTA2342 EMBJ IAH 17R 16:21:34 16:30:48 16:29:51 276 -57

08/25/11 BTA3071 EMBJ IAH 17R 16:34:28 16:40:00 16:39:27 277 -33

08/25/11 AAL1560 MD8 IAH 17R 17:39:29 17:42:00 17:42:35 278 35

08/28/11 AAL1591 MD8 IAH 17R 14:47:44 15:00:00 15:05:11 279 311

09/02/11 UAL370 EA32 IAD 17R 16:49:38 16:55:00 16:54:52 280 -8

09/03/11 AAL2366 MD8 ORD 36R 22:33:23 22:35:00 22:34:43 281 -17

09/05/11 DAL1910 B757 ATL 35L 20:49:58 20:54:00 20:53:32 282 -28

09/06/11 EGF3215 EMBJ HOU 36R 15:28:16 15:32:00 15:33:24 283 84

09/15/11 ATN517 DC8S IAH 36R 13:54:08 13:57:00 13:58:26 284 86

09/15/11 AAL1001 MD8 IAH 35L 00:38:38 00:43:00 00:44:53 285 113

09/15/11 SKW2009 CRJ IAH 35L 00:39:03 00:43:50 00:47:21 286 211

09/16/11 AAL1591 MD8 IAH 18L 15:10:40 15:15:00 15:13:38 287 -82
88

Date (L) Callsign Type Dest Rwy CFR done Release OFF OTC? OTC

09/18/11 AAL1560 MD8 IAH 17R 17:32:24 17:32:23 17:38:16 288 353

09/18/11 EGF2855 EMBJ HOU 18L 18:16:08 18:19:00 18:19:17 289 17

09/18/11 AAL1897 MD8 IAH 17R 19:55:59 20:01:03 19:59:50 290 -73

09/18/11 SKW5839 CRJ IAH 17R 20:17:20 20:29:27 20:27:39 291 -108

09/18/11 BTA1758 EMBJ IAH 17R 21:46:58 21:53:00 21:52:19 292 -41

09/18/11 SKW2045 CRJ IAH 17R 21:56:55 22:05:33 22:06:49 293 76

09/18/11 SKW2054 CRJ IAH 17R 22:55:14 23:01:00 23:02:29 294 89

09/18/11 AAL1001 MD8 IAH 17R 23:24:04 23:24:01 23:29:37 295 336

09/18/11 EGF2883 EMBJ HOU 18L 23:10:10 23:10:03 23:11:33 296 90

09/19/11 COA1032 B73V IAH 35L 11:56:57 12:01:00 12:03:05 297 125

09/19/11 AAL2385 MD8 IAH 35L 12:13:30 12:23:44 12:22:35 298 -69

09/21/11 BTA2342 EMBJ IAH 17R 16:14:30 16:21:00 16:21:22 299 22

09/21/11 SKW461L CRJ LAX 18L 01:29:18 01:34:00 01:35:31 300 91

09/22/11 AWE436 B73S PHX 36R 13:35:53 13:40:00 13:39:39 301 -21

09/22/11 AAL1695 MD8 PHX 36R 13:56:06 13:59:00 14:01:48 302 168

09/22/11 EGF3254 EMBJ HOU 35L 21:58:14 21:58:11 22:00:45 303 154

09/25/11 DAL2210 B757 ATL 35L 22:31:33 22:36:00 22:36:10 304 10

09/25/11 DAL1810 MD8 ATL 35L 23:28:25 23:33:00 23:32:09 305 -51

09/25/11 TRS102 MD8 ATL 35L 23:31:09 23:37:42 23:36:07 306 -95

09/26/11 SKW388L CRJ LAX 18L 01:36:15 01:37:00 01:37:44 307 44

09/29/11 COA1032 B73V IAH 17R 11:58:01 12:03:00 12:03:41 308 41

09/29/11 AAL2385 MD8 IAH 18L 12:16:07 12:19:00 12:19:53 309 53

09/29/11 SKW5839 CRJ IAH 17R 20:27:13 20:34:00 20:34:01 310 1

09/29/11 SKW2045 CRJ IAH 35L 00:40:22 00:49:12 00:53:21 311 249

09/29/11 AWE273 B73S IAH 35L 23:37:09 23:44:04 23:50:20 312 376

09/29/11 COA1183 B757 IAH 35L 00:37:27 00:41:06 00:43:29 313 143

09/29/11 SKW5846 CRJ IAH 35L 00:40:08 00:43:00 00:48:49 314 349

09/29/11 SKW4455 CRJ IAH 35L 00:23:17 00:29:00 00:28:40 315 -20

10/06/11 COA1502 B73V IAH 17R 21:42:07 21:47:00 21:49:00 316 120

10/06/11 EGF2883 EMBJ HOU 18L 23:05:23 23:09:00 23:11:51 317 171

10/07/11 ATN517 DC8S IAH 18R 13:22:06 13:34:23 13:34:58 318 35

10/09/11 BTA4326 EMBJ IAH 35L 16:36:57 16:40:00 16:41:10 319 70
89

Date (L) Callsign Type Dest Rwy CFR done Release OFF OTC? OTC

10/09/11 AAL1591 MD8 IAH 35L 16:09:26 16:19:46 16:18:52 320 -54

10/09/11 AAL1897 MD8 IAH 36R 19:51:07 19:56:00 19:54:35 321 -85

10/10/11 COA1502 B73V IAH 35L 21:35:38 21:36:00 21:39:45 322 225

10/10/11 EGF3254 EMBJ HOU 36R 22:14:18 22:20:00 22:20:41 323 41

10/10/11 AAL2489 B757 LAX 36R 01:32:13 01:37:00 01:40:23 324 203

10/10/11 SKW388L CRJ LAX 36R 01:42:35 01:42:30 01:44:06 325 96

10/11/11 DAL2110 B757 ATL 17R 18:18:11 18:25:00 18:23:13 326 -107

10/12/11 AAL1001 MD8 IAH 35L 23:11:03 23:15:00 23:14:22 327 -38

10/17/11 BTA4326 EMBJ IAH 17R 15:13:27 15:15:00 15:18:27 328 207

10/17/11 SKW5215 CRJ IAH 17R 15:09:33 15:09:00 15:13:45 329 285

10/17/11 AAL1591 MD8 IAH 17R 15:20:43 15:25:00 15:25:02 330 2

10/17/11 COA1239 B73V IAH 17R 15:35:49 15:39:00 15:40:53 331 113

10/18/11 EGF3254 EMBJ HOU 36R 21:58:35 22:00:04 22:01:42 332 98

10/19/11 DAL1564 EA32 DTW 35L 22:28:33 22:34:10 22:36:14 333 124

10/23/11 AAL1591 MD8 IAH 17R 14:58:35 15:05:39 15:05:19 334 -20

10/23/11 AAL2222 MD8 ATL 35L 21:20:16 21:26:00 21:25:48 335 -12

10/25/11 COA1096 B738 IAH 17R 11:56:30 12:01:00 12:01:19 336 19

10/25/11 AAL2385 MD8 IAH 17R 12:10:49 12:20:46 12:19:03 337 -103

10/25/11 EGF3298 EMBJ HOU 18L 12:45:07 12:53:53 12:53:08 338 -45

10/25/11 EGF3219 EMBJ HOU 18L 14:16:14 14:22:00 14:21:51 339 -9

10/25/11 EGF3215 EMBJ HOU 17R 15:15:15 15:17:00 15:18:19 340 79

10/27/11 EGF3219 EMBJ HOU 36L 14:01:45 14:07:00 14:07:11 341 11

10/27/11 AAL1001 MD8 IAH 35L 23:07:25 23:10:15 23:11:48 342 93