5027

NBSIR 75-783

Validation of the DELCAP

Airport Simulation Model

Judith F. Gilsinn

Institute for Basic Standards

Applied Mathematics Division

Operations Research Section

National Bureau of Standards

Washington, D. C. 20234

July 1975

Final Report

Technical Report to: Systems Research and Development Service

Federal Aviation Administration

Department of Transportation

Washington, D. C. 20590

Report No. FAA-RD-75-1 54

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1. PliHl.K A riON (IK KI- I^ORT NO. NBSIR-75-783

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3. Recipient's Accession No.

4. TITI.f- AND SUBTITI.t:

Valditation of the DELCAP Airport Simulation Model

5. Publication Date July 1975

6. Performing Organization (ode

7. AUTHOR(S)

Judith F. Gilsinn

8. Performing Organ. Report No.

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NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

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Systems Research and Development Service

Federal Aviation Administration

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Final

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15. SUPPLEMENTARY NOTES

16. ABSTRACT (A 200-word or less factual summary ol most sigriidcant information. If document includes a significant

bibliography or literature survey, mention it here.) This report documents exercises of the DELCAP airport simulation model

performed to validate the outputs of that model. Airport throughput levels were calculated by DELCAP for five runway configurations, with three or four appropriate operating policies chosen for each, and for three different

mixes of aircraft types. These estimates from DELCAP agreed well, generally

within 6 to 8 percent, with current values provided by the FAA. An attempt

at validating DELCAP's delay-figure output, using existing data on scheduled

and actual times of aircraft departures and arrivals, is also reported. It

proved unsuccessful, because available data are not sufficient to isolate

that portion of total delay which DELCAP is designed to measure, i.e.

terminal area ATC delay. A collection effort to accumulate the necessary

data is formulated. Appendices to the report contain program listing,

flowcharts, descriptions of program changes from earlier versions, and user instructions for the model's operation.

17. KEY WORDS (six to twelve entries; alphabetical order; capitalize only the first letter of the first key word unless a proper name; separated by semicolons) Airport; airport Capacity; airport simulation; models;

model validation; runway capacity; simulation; validation.

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USCOMM-DC 29042-P74

NBSIR 75-783

VALIDATION OF THE DELCAP

AIRPORT SIMULATION MODEL

Judith F. Gilsinn

Institute for Basic Standards

Applied Mathematics Division

Operations Research Section

National Bureau of Standards

Washington, D. C. 20234

July 1975

Final Report

Technical Report to: Systems Research and Development Service

Federal Aviation Administration

Department of Transportation

Washington, D. C, 20590

Report No. FAA-RD-75- 1 54

U.S. DEPARTMENT OF COMMERCE, Rogers C.B. Morton, Secretary

James A. Baker, III, Under Secretary

Dr. Betsy Ancker-Johnson, Assistant Secretary for Science and Tachnology

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Acting Director
I

I

ii

J
ABSTRACT

This report documents exercises of the DELCAP airport simulation

model performed to validate the outputs (delay and cap acity) of that

model. Airport throughput levels were calculated by DELCAP for five

runway configurations, with three or four appropriate operating policies

chosen for each, and for three different mixes of aircraft tjrpes. These

estimates from DELCAP agreed well, generally within 6 to 8 percent, with

current values provided by the FAA. An attempt at validating DELCAP 's delay-figure output, using existing data on scheduled and actual times

of aricraft departures and arrivals, is also reported. It proved unsuccessful, because available data are not sufficient to isolate that

portion of total delay which DELCAP is designed to measure, i.e.

terminal area ATC delay. A collection effort to accumulate the necessary

data is formulated. Appendices to the report contain program listing,

flowcharts, descriptions of program changes from earlier versions, and user instructions for the model's operation.

Key Words : Airport; airport capacity; airport simulation; models; model

validation; runway capacity; simulation; validation.

TABLE OF CONTENTS

page

1. Introduction 1

1.1 Background 1

1.2 The Validation Process 3

1.3 Description of DELCAP 3

1.4 Validating DELCAP 6

2. Validation of DELCAP Throughput Estimates 9

2.1 General Description 9

2.2 Validation Output 9

2.2.1 Single Runway 9

2.2.2 Intersecting Runways 15

2.2.3 Close Parallels 22

2.2.4 Close Parallels with an Intersecting Runway 24

2.2.5 Analysis of Results 25

2.3 Comparisons of Model Output with Available Data 29

3. Validation of Model's Delay Estimates 35

3.1 General Background 35

3.2 Traffic Input Data 37

3.3 Delay Analysis of the Input Data 39

3.4 DELCAP Input 44

3.5 DELCAP Output 50

3.6 Data Required for DELCAP Delay Validation 61

4. Conclusions 63

5. References 65

Appendix A. Changes and Additions to DELCAP 66

A.l Modifications in Output 66

A. 2 Changes in Separation Criteria 72

A. 3 Improved Random Number Generator 72

A. 4 Modifications in Operating Policy 72

A. 5 Changing Operating Policy During a Computer Run 75

A. 6 New Preprocessor Standard Values 76

Appendix B. Descriptions and Flowcharts of Simulation Events 78

B. l Event EXGEN 82

B.2 Event GEN 84

B.3 Event NXTOP 85

B.4 Function FREER 88

B.5 Event LAND 90

B.6 Event TOFF 93

B.7 Event FTIUP 97

B.8 Event CHGOP 97

B. 9 Event CDIR 97

Appendix C. Model Elements: Routines, Variables and Arrays,

Entities, and Sets 101

C. l Routines 101

C.2 Variables 101

i
page

Appendix D. Revised Input Formats 105

D.l Revised Preprocessor Input Formats 105

D. 2 Revised Input Formats for Exogenous Events 109

D.2.1 Flight Generation 109

D.2. 2 Policy Change 110

Appendix E. Program Listings Ill

E. l Listing of the Preprocessor Ill

E.2 Listing of the DELCAP Simulation 122

Appendix F. Processing the LGA Traffic Input Data 1A2

ii
LIST OF FIGURES

page

1.1 The Terminal Area as Seen by DELCAP 5 1.2 Flowchart of the DELCAP Simulation 7 2.1 Hourly Throughput for a Single Runway Handling Only Takeoff

s

or Only Landings 13

2.2 Close Parallels with an Intersecting Runway 24

2.3 O'Hare Four-Runway Configuration 28

3.1 Runway Configuration for LGA 37

3.2 Sample Schedule Data 38

3.3 Sample of Actual Traffic Data 40

3.4 Delay Profiles Using LGA Input Data 41

3.5 Preprocessor Output 46

3.6 DELCAP Summary Output 51

3.7 DELCAP Delay Profile 54

3.8 Computer Output: Detailed Trace , 57

3.9 Comparison of Delay Profiles 58

A.l Sample Preprocessor Output 67

A. 2 Sample Simulation Output 69

B. l Flowchart of the DELCAP Simulation Routines 79

B.2 Flowchart of Event BEGIN 80

B.3 Flowchart of Event CHOUR 81

B.4 Flowchart of Event EXGEN 83

B.5 Flowchart of Event GEN 86

B.6 Flowchart of Event NXTOP 87

B.7 Flowchart of Function FREER 89

B.8 Flowchart of Event LAND 91

B.9 Flowchart of Event TOFF 94

B.IO Flowchart of Event FTIUP 98

B.ll Flowchart of Event CHGOP 99

B.12 Flowchart of Event CDIR. 100

F.l Inconsistencies in Two Data Sources ^^-^ F.2 LGA Scheduled Flights Input to DELCAP

iii
LIST OF TABLES

page

2.1 Aircraft Characteristics for Validation Runs 10

2.2 Three Aircraft-Type Mixes Used 10

2.3 Configurations and Operating Policies for Validation Runs 11

2.4 Single Runway Throughput (per Hour) 16

2.5 Hourly Throughput for Near Intersection (V) With Interference. .. 18

2.6 Hourly Throughput for Near Intersection (V) Without

Interference 19

2.7 Hourly Throughput for Far Intersection (X) With Interf erence. . . . 20

2.8 Hourly Throughput for Far Intersection (X) Without

Interference 21

2.9 Hourly Throughput for Close Parallels 23

2.10 Hourly Throughput for Close Parallels Plus an Intersecting

Runway Without Interference 26

2.11 Hourly Throughput for Close Parallels Plus an Intersecting

Runway with Interference 27

2.12 Throughput for Several Configurations at Selected Airports 30

2.13 Sustainable Throughput Estimated by DELCAP 31

2.14 Comparison fo FAA Theoretical Throughput Estimates With Those

Calculated by DELCAP 31a

3.1 LGA General Aviation Traffic Levels by Hour 45

3.2 Operating Policies for LGA by Hour 49

3.3 Example of the Detailed Trace of Simulated Operations 56

3.4 Number of Flights Delayed Excessively in Each Hour 60

A.l Sample Operating Policies 74

iv
1. INTRODUCTION

1 . 1 Background

In 1969 the FAA asked the National Bureau of Standards (NBS) to

review its Airport Capacity Handbook, developed by Airborne Instruments

Laboratory (AIL) in June 1963, and to evaluate the possibility of

reapplying or extending that Handbook's airport capacity model so as

to account for new aircraft types and mixes of aircraft types. The

documentation proved insufficient to permit reconstructing the AIL

model, which in effect had been "lost" during the intervening years.

Consequently NBS developed an analytical model, for the simple case of

a single runway handling landings only, and documented it in [4] and

[7]. See also [8] and [9] for similar results. Subsequently NBS extended

the analytical model to dual-use runways and multi-runway configurations,

in [5] and [6]

.

In the process of carrying out the extension, it became evident that

the analysis for complex configurations was very difficult, and there was a possibility the analvtical expressions would prove intractable.

To ensure ability to handle a large range of configurations despite

possible difficulties in the analytical modeling, it was decided to develop

concurrently a simulation model. The DELCAP model, documented in [1], was the result of this effort. Its design principle, described in the

first chapter of that documentation, is the "model as little as you can"

philosophy under which only those system elements with direct influence

on stipulated output measures are included in the model. This philosophy

assijmes a well-defined set of applications for which a model is to be

designed, and recognizes that the resultant model may thus be unsuited

for other applications. Specifically, DELCAP was designed to calculate

average maximum throughputs and delays resulting from airport airside

operations in a terminal area.

Input parameters which were included in the model, and therefore

may be varied, include:

* separation rules,

aircraft type mix,

characteristics of each aircraft type,

traffic levels,

airport runway configuration,

operating policy.

DELCAP was commissioned as a planning tool, and so major criteria in its

design were that it be easy to use, have a short computer running time,

and be economical enough to encourage its use to answer a varietv of

"what if" questions concerning airport capacities and airside delays.

* The non-metric units, nautical miles, knots, feet and pounds, used

in this report are those customarily employed in aviation.
The design and development of DELCAP were completed in this first effort,

and the documentation was issued in May 1971. However, only illustrative

runs designed to demonstrate its versatility and scope were made at that

time.

In early 1974 the FAA's Air Traffic Service requested that the DELCAP

model be reactivated, some modifications be made in it, and that it be

validated for use in their Engineered Performance Standards (EPS) program

for calculating target throughput levels at busy airports. This report

documents that effort. An interim report [2] described the validation of

throughput output from DELCAP; the results reported there have been incorporated in the present document to make it self-contained.

One caveat should be noted at the outset. The validation exercises

reported here are aimed at assessing validity of DELCAP for a specific

application, that of setting ATC system performance standards. The

parameter ranges, configurations, and operating policies involved in the

exercises are those to be found in that application. Therefore, although

the validity of DELCAP has been established for input values in the

ranges required by this one application, validity has not been established

for all possible inputs and scenarios. The context of EPS presented a wide

range of configurations and operating policies, so that our validation

exercises do cover most of today's busy airport scenarios, indicating

the model's usefulness in estimating throughputs at these facilities.

Still* caution must be exercised if the DELCAP model is to be applied

in other contexts, since validity has been established only in the

limited sense noted above.

DELCAP is now operating both at NBS on the UNIVAC 1108 computer and

on a CDC computer chosen by, and accessible to, the FAA. On both systems

it may be operated remotely from a teletype terminal, which allows the

analyst to use the model at his desk as "what-if" questions occur. The

model has been used as a tool by FAA analysts in establishing EPS's,

that is, traffic levels which a facility should be able to handle during

busy hours, under a particular configuration and operating policy, with

a given mix of aircraft types and a given arrival/departure ratio.

Calculations which formerly had to be performed by hand (by FAA analysts)

are now done by DELCAP, which, because it is inexpensive, quick and easy

to use, can help investigate a wider variety of configurations and

operating policies. Runs typically require 15 to 20 seconds to simulate

one day's traffic. This speed and flexibility allow the analyst to set

performance standards for conditions which occur less frequently as well

as for the normal situation, since a large number of alternatives can easily be tried.

- 2 -
1.2 The Validation Process

Once a nathematical r.odel has reached operational status, there

is a natural temptation to put it directly to practical use, skipping

over any substantial effort to verify that the model does in fact do

what it was designed to do. Such an omission, however, courts disaster,

since a model which has not been exercised on a variety of data (and

had its outputs compared with what is actually obser\'ed in the situation

being modeled) may contain unsuspected anomalies likely to exhibit themselves at embarrassing moments or (even v:orse) to remain undetected. To

guard responsibly against this, it is necessary to subject the model to a pre-use validation and preliminary sensitivity analysis.

Validation involves two types of analysis. The first is an independent assessment of the appropriateness of the structure and methods

used. A second element of validity checking is the comparison of model

outputs with what is actually observed in specific instances of the type

of situation being modeled. Comparison of model performance with that

of other models which are well-based and accepted, for cases to which both

apply, could also be part of this type of analysis. Absolute assurance

of validity for all possible future uses is, of course, impossible. Replication of reality for a few test cases can only insure that in these

particular examples, the model performs as it should, but if the test cases were chosen carefully to be representative of the spectrum of situations

to which the model is expected to be applied, then increased confidence in

model validity can be obtained.

Beyond the basic validity testing described above, some preliminary

sensitivity analyses should be conducted—to identify those parameters

having most critical (most sensitive) effect on model outputs, and to

ascertain the degree to which model outputs can be expected to vary vrith

input variations. Such sensitivity analyses should also help to determine

the limits beyond which application of the model is inappropriate.

1.3 Description of DELCAP

DELCAP is a simulation model, written in the SIMSCRIPT 1.5 computer

language, of the airport terminal area including terminal airside operations

and those ground operations occurring on the runway surface. DELCAP was designed to focus on operations in the terminal area and to measure

throughputs and delays associated with this subsegment of the whole Air

Traffic Control (ATC) System. Its output consists of throughput and delav

figures. Input includes traffic levels (or the explicit schedules of

traffic, or both), the mix and characteristics of aircraft types, the

separation rules which apply, the airport runway configuration and its runway

operating policies.

In accordance with the modeling philosophy under which DELCAP was

designed, in which ease of use is a major criterion, a FORTRAN' preprocessing

program has been written to allow users to provide inputs in a format less

- 3 -
rigid than that required by SIMSCRIPT programs and to provide a set of

nominal input values. The user specifies values for only those input

parameters which are to differ from their nominal values. As noted in

Appendix A, procedures for selection and values of these nominal inputs

have been changed to those most useful for the EPS program.

Figure 1.1 displays the terminal area as seen by the DELCAP model.

The aircraft denoted by capital letters are landings; those designated

by lower case letters are takeoffs. The landing and takeoff streams

are lettered in reverse order of their entrance to the model. (The

particular configuration and operating policy shown—a pair of intersecting runways, one handling only takeoffs, the other only landings

is illustrative and should not be taken as a model restriction. Runway

configuration is a model input ; as will be shown by the exercises reported

in Chapters 2 and 3, a wide variety of such configurations can be handled

by DELCAP.)

It is convenient to describe DELCAP 's treatment of landing and takeoff streams separately, since DELCAP is an event-oriented model (time is

incremented to the next "critical event," rather than stepped along at

preset intervals) ^r^d each critical event in an aircraft's path anticipates

the next one along that path. Landings enter the simulation at handoff to

tower approach control (A in Figure 1.1). The next critical point along a landing path is the outer marker. DELCAP requires that at least a preset

minimum time interval ensue between handoff and the landing's passage of

the outer marker. However, the presence of other aircraft in front of A

in the landing stream may necessitate that it be placed in a holding

pattern or that it fly a longer path to the outer marker, either of which

would require extra time. DELCAP does not model the actual route flown

by A, but this extra time requirement is imposed by the modeling device

of "tying up" the outer marker, i.e., prohibiting A from passing it,

until all those in front have done so.

B's final approach can be scheduled once the aircraft in front of B

(C in the figure) has passed the outer marker. B must remain separated

from C by the required amount (presently 3 miles if C is not a heavy

aircraft, 4 miles if both C and B are heavies and 5 miles if C is a heavy

but B is not) along the whole final approach path. DELCAP employs the

idealization of constant final approach speeds (dependent on aircraft type),

and so the acutal separation required between C and B when B crosses the

outer marker is either (if C is faster) the minimum required spacing between

these aircraft, or (if B is faster) a spacing such that when C touches down

B will be at the required minimum separation distance from the end of the

runway.* A landing leaves the simulation when it turns off the runway.

* Of course D cannot land as long as E is on the runway surface. That is,

in addition to the airborne separation requirements, runway occupancy time

also can affect the prescribed separation between D and E. DELCAP includes

the "tying up" effects of runway occupancy, though in practice, it is

usually the airborne separation which is critical.

_ 4 _
FIGURE 1.1

The Terminal Area as Seen by DELCAP

/

Pi w

o :s

>>

CO

O

4J

tLO

n o

(U -u oP 14-4 O

O T3

0) o

CO (U

4-1 14-1 CO 4J 00 -H J-l X CO 4J CO 4J

CO 4-1 CO

O «4-l U 4-4

0)

c

V-i CO

u >,

CO x: CO B o 15 CO C

>-i O 3

CU )-4 )-l 4-1 3 Cu O CO O.o

CJo

0) iH

CO CO

14-1 M CO 14-1 OJ CO 13

-U O >^ C

3 t-( >H CO ^14-1 O O 14-1 rH

CO 43 a T3 U Q W
Takeoffs enter the simulation about 15 minutes before scheduled

departure time. A minimum taxi time between gate and runway is

specified. Since in Figure 1.1, landing E has passed the runway intersection, takeoff c can be cleared to start its roll, if takeoff d had

sufficient separation from takeoff c; this presently is 2 minutes after

d lifts off if d is a heavy and c is not, and is a shorter, constant time

interval—approximated as 20 seconds after liftoff—for all other aircrafttype combinations.

Figure 1.2 is a flowchart of the simulation. The bottom box, "choose

next operation," represents the implementation of the runway operating

policy which determines the sequence of landings and takeoffs on each

runway. The two boxes referring to "maintain separation" are implemented

in the model by "tying up" critical points in the landing and takeoff paths:

the point at which a takeoff starts its roll, the outer marker, and the

point at which a landing touches down. A landing or takeoff can be scheduled

to take place when no critical point will be tied up wjien the aircraft

reaches it.

The DELCAP model has been designed to provide output of two quantities,

namely throughput (the number of operations handled by the facility per

time period) and delay. Application of DELCAP is envisaged under two

different scenarios. The first is one in which a realistic demand level

is stipulated and DELCAP output yields resulting delays and throughputs.

In the second scenario, DELCAP is run with high demand levels to estimate

the airport's maximum throughput ( capacity )

1.4 Validating DELCAP

Validation of maximum throughput estimates is reported below in

Chapter 2. Testing was concentrated on this case, since the main application

which this validation effort supports operates in the second scenario.

That application is the computation of EPS's, throughputs which are achievable

under heavy traffic conditions, for several of the nation's busiest airports

operating under a variety of possible configurations and operating policies.

Chapter 3 recounts an attempt, using currently available data, to

validate DELCAP 's delay output. This effort, which had to be abandoned for

the present because empirical delay figures for that portion of the ATC

system modeled by DELCAP were lacking, is reported here as an example of a model exercise, showing the model's versatility and ability to represent

actual traffic together with artificially generated traffic. The exercise

also illustrates the problems caused by multiple definitions of delay.

We do describe (at the end of the chapter) the data collection effort re- quired to support a delay-figure validation analysis.

In Chapter 2, validation exercises employed to test DELCAP under the

second scenario above are described in detail, and their results are

compared with values obtained from FAA's Air Traffic Service. These

tests were designed in consultation with R. Scott of FAA's System Research

- 6 -
FIGURE 1.2

Flowchart of the DELCAP Simulation

HANDOFF

TO

TOWER

FLY TO

OUTER

MARKER

SCHEDULE

THIS AIRCRAFT'S

FINAL APPROACH

MAINTAIN

SEPARATION OF

LATER LANDINGS

AND TAKEOFFS

IF LANDING

CALL IN ABOUT

15 MIN. BEFORE

DEPARTURE

SCHEDULE

THIS AIRCRAFT'S

DEPARTURE

MAINTAIN

SEPARATION OF

LATER LANDINGS

AND TAKEOFFS

A

TAKE OFF

(CLEAR TERMINAL

AREA)

CHOOSE

NEXT

OPERATION

IF TAKEOFF

- 7 -
and Development Service and R. Woods and R. Toblason of the Air Traffic

Service, to cover that set of configurations most representative of

those encountered at major U.S. terminals. Including a single runway,

two Intersecting runway configurations (differing In the placement

of the Intersection), a pair of close parallel runways, and a pair of

close parallels with a third runway crossing the pair. Wide parallels

were not Included since they can be modeled as two separate single

runways. A variety of operating policies were chosen to approximate

those used under different traffic situations: when landings balance

takeoff s, when landings predominate, and when takeoff s predominate.

This diversity also allows comparison of results, to evaluate the sen- sitivity of DELCAP throughputs to operating policy. The exercises

Included different mixes of aircraft types, focusing primarily on the

fraction of heavy aircraft in the mix since different, larger separations

are required behind heavies because of wake turbulence. Other model

inputs (such as aircraft characteristics or the length of the final

approach path) could also have been varied, but preliminary tests have

led us to believe that the three factors mentioned—configuration,

operating policy, and aircraft-type mix—are the ones most critically

affecting differences in throughput at major U.S. terminals.

Chapter 3 reports the results of an exercise of the model using

actual scheduled traffic data from LaGuardla Airport (LGA) for October

25, 1974, plus general aviation traffic generated in a stochastic

manner. Simulated delays were compared with the "real" delays experienced

by the scheduled aircraft—calculated as the difference between the

actual arrival or departure and the corresponding scheduled time. This

comparison proved on closer consideration to be improper, "real" delays

necessarily being much greater than the simulated ones because they

Include the effects of interruptions or slow-ups attributable to other

parts of the system (not in the LGA terminal area) and to other sources

such as equipment - or crew- Induced delays. Simulated delays did, however,

agree quite well with the delay level reported by the facility, and the

shapes of the distributions, "real" and simulated, were very similar.

Chapter 3 also contains a discussion of the data required to do a proper

delay-figure validation, and suggests methods of acquiring these data.

Chapter 4 contains a conclusion and summary of the report. Appendices

A through E document in detail the current version of the DELCAP model

and its preprocessor. Appendix A includes a discussion of changes made

to the model since its original documentation [1]. Flowcharts and

descriptions of all the simulation routines are included in Appendix B.

Appendix C lists the variables and arrays used in DELCAP, and Appendix D

gives user instructions for preparing preprocessor input. Listings of

both programs appear in Appendix E. Appendix F includes a description

of the LGA data, together with a discussion of problems encountered in

reconciling two data sources for the LGA input.

- 8 -
2. VALIDATION OF DELCAP THROUGHPUT ESTIMATES

2 . 1 General Description

This chapter documents runs of the DELCAP model designed to test

the validity of its throughput calculations under a variety of conditions.

The characteristics attributed during these runs to each of three aircraft

types —heavy aircraft (over 300,000 lbs. gross weight), small aircraft

(most single- and two-engine craft), and medium and larger craft (larger

piston aircraft and most jets) — are described in Table 2.1. These

values were obtained from data collected by the Air Traffic Service at

O'Hare International Airport (ORD).

Five different runway configurations, representative of those most

often encountered and described in greater detail below, were investigated:

a single runway, two runways intersecting so as to form a V, two runways

intersecting to form an X, a set of close parallels (3000 to A300 feet

apart), and a set of close parallels with a crossing runway. Configurations

involving wide parallels are not included in this analysis since the DELCAP

model treats wide parallels as two completely separate runways, and as a result, the maximum throughput of a pair of wide parallels is just the sum

of the throughputs available from them independently.

For each configuration, operating policies (displayed in Table 2.3)

were chosen as most reasonable for each of three arrival/departure mixes:

arrivals balancing departures, departures dominant, and arrivals dominant.

Each configuration and operating policy was investigated for three aircrafttype mixes, identified by the percentage of heavy aircraft in the mix and

described more fully in Table 2.2.

For each configuration, operating policy and aircraft-type mix, the

model was run to simulate 20 hours of traffic. The average hourly

throughputs (averaged over the sample of 20 hours) of landings, takeoff

s

and all operations were recorded for each runway and totaled for all

runways to permit comparisons among policies, type mixes and configurations.

In Section 2.2 the model's outputs for these cases are described, and

evaluated, including the testing of agreement with analytical models (where

available) and with ATC experience about how throughput depends on the

factors varied. In Section 2.3, the outputs are compared with FAA-supplied data.

2.2 Validation Output

2.2.1 SINGLE RUNWAY

it The single runway case has been studied extensively , and admits

analytical expressions for capacity. Two such expressions, one for

See for example [4], [5], and [6]. Similar formulas to those appearing

below appear in these publications, but are derived here again for

completeness.

- 9 -
TABLE 2.1

Aircraft Characteristics for Validation Runs

Type Type Speeds (Knots) Runway Occupancy (Sec)

Number Description Landing Liftoff Landing Takeoff^

1 Heavy A/C 124 120 55 33

2 Small A/C 119 90 40 27

3 Category Ill's 120 120 50 32

(Larger A/C)

' " TABLE 2.2

Three Aircraft-Type Mixes Used

MiJL_I - 5% Heavies Mix II - 15% Heavies Mix III - 50% Heavies

^ -^^^ Type % in Mix Il£e % in Mix

1 .5% . , ;

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a runway handling takeoffs only and the other for the same runway handling

landings only, are derived below. As will be seen, DELCAP outputs for

these single-runway situations conform closely (as they should) to these

theoretical formulas.

To calculate the expected value of the maximum throughput for a single runway handling takeoffs only, under the assumption of a continuous

stream of departures in which heavy aircraft appear randomly and constitute

a known fraction of all takeoffs, let

N = number of takeoffs per hour,

p = fraction of takeoffs which are heavies,

r = runway occupancy time (hrs.) for heavies,

A = average time (hrs.) between takeoffs for non-heavies

6 = average time (hrs.) between takeoffs of two successive heavies

(Note that separation rules require a non-heavy to

wait 2 minutes after a preceding heavy liftoff before

starting its roll.)

Then it follows that:

1. The time between takeoff of a heavy and that of a following non-heavy is r' = r + 2/60, the time between

takeoffs of heavies is 6, and the time between takeoff

of non-heavies is A.

2. A fraction p of aircraft following a heavy are heavies;

(1 - p) are non-heavies.

3. The expected number of hourly takeoffs by heavies is pN;

for non-heavies it is (l-p)N.

Thus the following equation (between numbers of hours) holds:

pN[p6 + (l-p)(r')] + (l-p)NA=l

or

N = l/[p^6+p(l-p)r' + (l-p)A].

For r = 33 seconds, A = 54 seconds, and 6 = 90 seconds for example,

the values in Table 2.1 yield

N = 3600/[-64p^+99p+54].

This is plotted as the upper curve in Figure 2.1. The two circled points,

at 20 and 30 percent heavies, give the results of actual DELCAP runs and

agree well with the corresponding values from the preceding formula.

Similarly, to calculate the expected throughput for a single runway

handling landings only, under the further assumption that landing speeds

for all aircraft types are equal, let

:' '' y",

- 12 -
FIGURE 2.1

Hourly Throughput for a Single Runway

Handling Only Takeoffs or Only Landings
N = number of landings per hour,

p = fraction of landings v;hlch are heavies,

s = the landing speed (In knots) for all aircraft types.

(Although landing speed does vary among aircraft types,

the figures In Table 2.1 Indicate that using one value

is not a great deviation from reality. More complicated

formulas can be derived for the case in which speed depends

on aircraft type.)

Then it follows (cf. the separation criteria given in section 1.3) that:

1. The time between the landings of two heavies is 4/s,

between a heavy and a following non-heavy is 5/s, and

between a non-heavy and a following aircraft is 3/s.

2. A fraction p of the aircraft follov/ing a heavy are heavies,

a fraction (1-p) are non-heavies.

3. The expected number of hourly landings by heavies Is pN;

for non-heavies it is (l-p)N.

Thus the following equation holds:

pN[p(4/s) + (1-p) (5/s)] + (l-p)N(3/s) = l

or

N = s/(3+2p-p^).

For s = 125 knots, for example,

N = 125/(3+2p-p^),

which is plotted on the lower curve in Figure 2.1. The four circled

points, output from the DELCAP simulation, agree very well with the

expected throughputs.

Analytical expressions can be and have been derived for more

complicated operating policies involving dual operations (both landings

and takeoffs),* but are much more complex since for some landing aircraft

the minimum allowable 'spacing can be determined by the separation from a preceding landing, rather than the separation from a takeoff occuring

between the two landings. In this case, the takeoff is in some sense a "free" contribution to throughput since it does not require an extra

interruption in the flow.

* See for example [6]

.

- 14 -
As part of our validation analysis, three operating policies for

a dual use single runway were run using DELCAP . The output from these

runs is displayed in Table 2.4. For time periods in which the nunibers

of arrivals and departures are approximately equal, the operating policy

chosen for the single runway seeks to alternate landings and takeoff s. During departure-dominant periods, landings are spaced far enough apart

to allow two takeoff s between each pair of landings. For arrival-dominant

periods, takeoff s are permitted only between every other pair of landings.

As can be seen by comparing Table 2.4 v/ith Figure 2.1, dual usage of

the single runway decreases the takeoff throughput greatly (by about a factor of two) . The reason is that landings require more time betv/een

operations and dual usage forces some takeoff s to wait for landings. On

the other hand, landing throughput is not as greatly degraded by interspersing takeoff s among the landings. Alternation of landings and takeoff

s

decreased landing throughput by at most 30% from the pure landing operation

and increased total throughput by 40-60%. This agrees well with operating

experience: in the absence of stringent takeof f-airspace restrictions,

takeoffs are rarely the limiting throughput factor. On the other hand,

spacing between landings is critical, and directions such as "maintain

speed" sometimes have to be given by controllers to arriving aircraft in

order to ensure that minimum spacing is attained.

Validation for the single-runway case was carried out because it is

often an important component of more complicated configurations. Wide

parallels may be regarded as two single runways in throughput calculations,

for instance. Also, some airports may be reduced to essentially the single

runway configuration during IFR weather or outages. Still, the primary

advantage of DELCAP lies in its applicability to more complex runway

situations for which analytic expressions are much more difficult to obtain

2.2.2 INTERSECTING RUNWAYS

Two different configurations consisting of a pair of intersecting

runways were investigated: one with the intersection 2000 feet from the

ends of each of the runways (representing the near- intersection or "V"

case) , the second with the intersection 4000 feet from the ends of each

runway (a configuration shaped like an "X").

During periods in which arrivals and departures are roughly balanced,

two different operating policies were chosen as reasonable: the first of

them alternates landings and takeoffs on both runways, while the second

reserves one runway for landings only and the other just for takeoffs.

(The second policy can result in lower capacity, but is easier for the

controller and probably more representative of actual practice.) For

departure-dominant periods, one of the runways handles takeoffs only,

with landings and takeoffs alternated on the other. Similarly, for

arrival-dominant periods, one runway is set aside for landings only,

while landings and takeoffs alternate on the other.

- 15 -
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- 16 -
Each inter secting-runway configuration was run both with and without

the requirement that operations on one runway be separated from those

on the other. In the less restrictive case, the only interaction imposed

was that a landing's touchdown or a takeoff 's start-of-roll on one runway

could not occur in the period between a landing or start-of-roll of an aircraft on the other runv/ay and the time that aircraft passed the intersection. In the other case, in addition to the preceding prohibition,

landings on one runway had to be separated by the required 3, 4 or 5 miles from landings on the other, and also by 2 miles from preceding

takeoff s on the other. Two separate tables are given for each of the

V and X intersection cases (see Tables 2.5-2.8), one including the second

separation requirement (described as "with interference") and one without.*

The interference requirement reduces throughput by 3 to 45 percent,

with the lower reduction occurring when takeoffs are allowed on only one runway (i.e., the middle two operating policies in the Tables). It is

probably very unusual for landings to be allovzed on both runways of an intersecting pair. In fact, the "landings on one, takeoffs on the other"

policy is the one most often employed in practice for an intersecting

pair, if the runv/ays are of comparable length. ^vTien one is longer than

the other, then segregation by aircraft type, rather than by operation,

is often employed, and something approaching the policy of alternating

operations might be achieved. In this case segregation by type (and thus

by landing speed) would tend to decrease actual interlanding separations

(by reducing gaps due to a slow plane following a faster one), resulting

in slightly higher throughputs than those given in Tables 2.5-2.8. With

interference, the maximum number of landings — which occurs for the near intersection for the policy allowing one runway to handle only landings

and the other only takeoffs, and occurs for the far intersection for the

policy allowing landings on both runways with takeoffs interspersed on one — Is actually about the same as the number of landings on the landingsonly runway alone (under the same policies) when there is no interference.

The difference between 5 and 50 percent heavies in the aircraft type

mix leads to a decrease of 6 to 24 percent in total throughput, with the

larger differences generally occurring for the policy having only landings

on one runway and only takeoffs on the other. To explain this, note that

with landings spaced at 5 miles (as for a non-heavy aircraft following a heavy), a takeoff can occur between the two landings without affecting

either. The pure-landing/pure-takeoff policy does not exploit this, so that the full brunt of the increased separation is felt. Policies

employing dual-use runways are in a better position to utilize these

extra spaces.

* Output for the "pure arrival, pure departure" case in Tables 2.5

through 2.9 differs from that reported in [2] because of an intervening model modification allowing policies which coordinate

operations on different runways.

- 17 -
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The location of the intersection, far rather than near, causes a greater reduction In takeoff throughput than In landing throughput.

This is to be expected, since runway occupancy time is not a critical

factor in interlandlng spacing, but plays a much greater role in

constraining takeoff s. The intersection's location, however, has much

less effect than does operating policy.

In summary, the simulated behavior of a pair of intersecting runways

is very much as one would expect from logic and real-world experience.

The throughput levels produced by DELCAP may be higher than those usually

observed because two of the four operating policies simulated allow

landings on both runways, a situation atypical in practice. Thus the

predicted throughputs for the pure-landing/pure-takeof f strategy perhaps

represent the most realistic estimates.

2.2.3 CLOSE PARALLELS

A parallel runway configuration was run under the restriction that

landings on one runway must be separated by 3, 4 or 5 miles from landings

on the other, and by 2 miles from preceding takeoff s on the other. (This

restriction presently applies to parallels whose center lines are separated

by 3000-4300 feet.) The results are given in Table 2.9.

During periods when the numbers of arrivals and departures are about

the same, the operating policies of choice are either to alternate landings

and takeoffs on both runways or to reserve one runway exclusively for

landings and the second just for takeoffs, alternating operations on the two.

When departures dominate, one runway is reserved exclusively for them, while

landings and takeoffs alternate on the other runway. For periods in which

arrivals predominate, one runway is restricted to landings only, while

landings and takeoffs alternate on the other.

Comparison with Table 2.6 shows that the performance of a pair of

close parallel runways very closely resembles that of a "V" intersection

with interference, and many of the remarks made for that earlier case also apply here. Since runway occupancy time is not a critical factor

in interlandlng spacing and since the required separations between landings

On the two runways are the same as for one runway, the maximiom landing

throughput for a set of parallels is not much larger than that for a single runway with two landings between each pair of takeoffs (see Table

2.4). Alternating landings and takeoffs on both runways yields about a 16

percent improvement over the single runway, gained presumably because

runway occupancy time has no effect on the other runway's operations.

When takeoffs predominate, landings are spaced far enough apart to

allow extra takeoffs on the other runway, and a comparison with Figure

2.1 shows that the number of takeoffs is at most 11 percent less than

a single runway handling only takeoffs. Coordinating operations on the

two runways, so that a landing on one alternates with a takeoff on the

- 22 -

other, results in a decrease of only 8 percent in total throughput but

an increase of 28 to 37 percent in the number of landings. In fact

the second policy, involving cooperating pure operations, suffers only

a 6 to 8 percent reduction in the number of landings from the number

operating on a single runway handling landings only. The addition of

the second of a close parallel pair of runways thus buys some additional

throughput, 16 to 34 percent for periods when the numbers of arrivals

and departures balance and 37 percent when departures dominate. During

arrival-dominated periods, however, only 9 percent increase in total

throughput is observed.

2.2.4 CLOSE PARALLELS WITH AN INTERSECTING RUNWAY

The runway configuration for these runs is pictured in Figure 2.2.

For time periods in which arrivals and departures are balanced, the

operating policy chosen reserves one of the parallel runways (1) for

takeoffs, the other parallel (2) for landings and alternates landings

and takeoffs on the crossing runway (3). For departure-dominant

periods one of the parallels (1) is reserved for takeoffs and landings

and takeoffs are alternated on the other two runways. For arrivaldominant periods one of the parallels (1) is reserved for landings,

and landings and takeoffs are alternated on the other two. These last

two policies are probably unrealistically complicated for a real control

situation, but have been simulated to show possible throughput advantages

from dual operations.

V FIGURE 2.2

Close Parallels with an Intersecting Runway
Tables 2.10 and 2.11 summarize the results of these runs. Separation requirements for aircraft on the two parallels are those

described in Section 2.2.3 for close parallels. For the runs reported

in Table 2.10, no interference requirements were put on the intersecting

runway, so that takeoff s and landings on it were restricted only by

runway occupancy on the other runways. This, of course, does not

represent the real requirement when all runways are operated under IFR

conditions, but may be more reflective of actual operating practice

if the crossing runway is used primarily for smaller VFR aircraft.

The runs reported in Table 2.11 had all interference restrictions in

force.

Without the interference requirement in effect, the third runway

increases landing throughput by 50 to 79 percent and takeoff throughput

by 13 to 33 percent over the levels reported in Table 2.9 for parallel

runways operated in the pure landing/pure takeoff mode. This increase

does not accrue when the interference requirement is in force, since

as noted earlier, that requirement means that maximum landing throughput

is effectively that of a single runway.

The three different operating policies chosen differ by 17 to 34

percent in landing throughput, but by a factor of almost 3 in takeoff

throughput, again demonstrating that meeting takeoff demand is less

difficult and less critical than meeting landing demand, a fact wellrecognized by controllers. This is shown even more dramatically by the

observation that the first and second policies displayed in Table 2.10

differ only in that the first one restricts runway 2 to landings only

(rather than dual use) , but the landing throughput is almost the same

in the two cases

.

2.2.5 ANALYSIS OF RESULTS

The preceding section described output from applications of the

DELCAP model to a variety of common runway configurations, demonstrating

the model's versatility and its ability to represent those airport

facilities for which further computerized throughput analysis is desired.

DELCAP has also been run on the Chicago O'Hare (ORD) configuration

depicted in Figure 2.3. In addition, the model is capable of handling

even more complex configurations than this, with many more runways and

more complicated interactions among them.

- 25 -
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- 27 -
FIGURE 2.3

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27R

27L

32L

In the analyses reported above, the model was also exercised under

different aircraft-type mixes and different arrival/departure ratios to

demonstrate Its ability to model these variations successfully. Changing

the fraction of heavy aircraft from 5 to 50 percent decreases landing

throughput (per runway per hour) by from 0 to 20 percent with an average

decrease of about 12 percent, representing from 0 to 8 landings per run- way and averaging about 4. Hourly takeoff throughput per runway is

decreased more severely - from 0 to 28 percent, averaging 12 percent

and representing a decrease of from 0 to 19 takeoff s (averaging 7).

As noted above, operating policy has almost as great an effect on throughput as does runway configuration. The Influence of policy, a critical factor in actual operations, is probably somewhat exaggerated

by the simulation when used to estimate maximum throughputs. In the

simulation, operating policy is rigidly imposed. Whereas in a real

situation a controller might run overflow takeoffs on a runway normally

handling landings only, or divert a landing to a runway generally

reserved for takeoffs, the simulation does not have this flexibility.

In practice, the controller's extra leeway should allow him to exceed

the capacity levels predicted by the model and therefore should allow

for contingencies unforeseen by model assumptions, such as more serious

bunching of arrivals and departures, or gaps caused by pilot decisions

over which the ATC system has little control. The comparative rigidity

of the DELCAP model's handling of operating policy should not seriously

affect its usefulness as a tool in establishing EPS's, if care is taken

in its application to ensure the most appropriate policy is chosen for

simulation.

- 28 -
The DELCAP simulation as now constituted assumes interlanding

spacings of exactly 3, 4 or 5 miles as well as fixed and constant

runway occupancy times, assumptions which are unrealistic. However,

since real separations and runway occupancies may be either less or greater than the nominal values, it is unclear in which direction or

to what extent these assumptions bias the resultant throughput values.

Although it would be a relatively simple matter to represent these

factors in a stochastic manner, it is not at all clear that much

additional accuracy in throughput calculations would be gained, particularly since results are averaged over a period of 20 hours.

Throughputs calculated by DELCAP vary with operating policy,

configuration and mix in the expected direction and agree quite well

in magnitude with observed levels. (A more complete demonstration of

this last point follows in the next section.) There are, however, a number of instances in which model outputs are higher than those actuallyattained at most installations. These involved the simulation of operating

policies more complex in their control requirements than the policies in

present use, so that empirical data with which to compare these outputs

are lacking. For example, it would be unusual for a pair of intersecting

or close parallel runways to be operated for any prolonged time with

landings on both, unless one runway handled primarily smaller aircraft

making visual approaches. This also holds true for the "parallels with

crossing runway" configuration; most airports with such a configuration

would use the parallels for landings and takeoffs (on separate runways)

of larger aircraft, with the crossing runway allocated to lighter aircraft

as required. The DELCAP throughputs reported above, therefore, in part

require demand levels and controller capabilities which are unlikely to

be sustained over long periods. More practical capacity levels are associated with those policies which reserve main runways for pure

operations and shorter crossing runways for mixed operations of lighter

aircraft.

2 . 3 Comparisons of Model Output With Available Data

Table 2.12 reports IFR throughput figures for a variety of runway

configurations at several airports, as computed by a theoretical

procedure now under development by the FAA Air Traffic Service, as estimated by staff at the facility, and finally, as found using a version

of the theoretical procedure devised by the FAA to account for local

variations. The figures vary from facility to facility for the same configuration because of differences in aircraft-type mix and in other

special characteristics such as air space restrictions (at JFK, for

example). Differences between the theoretical and the modified standard

values range from 4 to 19 percent and average 11 percent, so that one can regard as acceptable similar differences between these values and

those produced by the model.

- 29 -
TABLE 2.12

Throughput for Several Configurations at Selected Airports

Configuration

L.iass

Theoretical Facility Modified

O LdllUclI. UWide Parallels

• JFK IFR-Pure 74 70 71

MIA - Mixed 106 75 100

• ATL - Mixed 114 91 98

ORD - Mixed 104 90 92

Close Parallels

• JFK IFR-Pure 60 50 52

• PHL - Pure 68 52 57

4 R/W's ORD

2 Pure Approach

2 Pure Departure 152 135 137

* A "pure" operation is one handling only takeoff s or only landings.

Parallels operated in a pure policy have one runway only for

landings and a second for takeoffs only. "Mixed" operations refers

to a policy allowing both landings and takeoffs on a runway.

In comparing the figures in Table 2.12 with DELCAP outputs, we

have modified the latter to take into account the fact that takeoff

capacity is rarely restricted and that the numbers in Table 2.12 are those sustainable over an extended period of time during which

the total numbers of arrivals and departures are approximately equal.

Whenever simulated takeoffs substantially outnumber landings, the

maximum total throughput as calculated by DELCAP does not correspond

to such a sustainable situation, and a better approximation to

realistic total throughput is twice the calculated landing throughput.

Table 2.13 reports throughputs thus obtained from DELCAP for configurations

similar to those in Table 2.12. (Most of these numbers are taken

directly from tables in the previous sections.) Throughput for the

- 30 -
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- 31 -
TABLE 2.14

Comparison of FAA Theoretical Throughput Estimates With

Those Calculated By DELCAP

Configuration Theoretical DELCAP

Class

Wide Parallels

. JFK IFR-Pure

. MIA-Mixed

. ATL-Mixed

. ORD-Mixed

Close Parallels

. JFK IFR-Pure

. PHL-Pure

4 R/W's ORD

2 Pure Approach

2 Pure Departure

74 78

106

114

104

113

113

109

60

68

61

75

152 143

- 31a -
wide parallels with pure operations is calculated by adding the throughput for a single runway with only landings, to that for a single runway

with only takeoffs.* Throughput for wide parallels used in mixed operations

is calculated as twice the throughput for a single runway serving alternating

landings and takeoffs. Throughput for the ORD 4-parallels case pictured in

Figure 2.3 is estimated as the sum of throughputs for a near-intersection

("V") configuration and a far intersection pair of runways (both pairs

without interference) . The FAA theoretical values are compared with the DELCAP

Estimates for the appropriate aircraft type mixes in Table 2.14.

Differences in throughput among airports depend in part on the

aircraft-type mix. The mix at JFK contains approximately 43 percent

heavies, while that at the other airports is much lower. (At ORD, for

instance, there are about 16 percent heavies.) For most of the airports

of concern here, small aircraft account for a relatively small proportion

of traffic (except for PHL where they account for about 40 percent).

Therefore, for most airports the throughput figures are more like those

reported for 5 and 15 percent heavies.

In the case of wide parallels and pure operations, values in the

two tables agree quite well. Whereas the theoretical value of 74

operations per hour agrees exactly with the DELCAP value for 15 percent

heavies, the value of 65 from DELCAP for 50 percent heavies is more

appropriate since JFK has over 40 percent heavies. Linear interpolation (of 40 percent between 15 and 50 percent) yields about 68,

slightly lower than the final figure of 71 (surprisingly, since one would normally expect the model, requiring perfect controllability, to

estimate higher than actual values), but still within 5 or 6 percent

of the modified performance standard.

In the case of wide parallels under mixed operations, DELCAP

maximum throughput values vary from 105 for 50 percent heavies to 113

for 5 percent heavies, agreeing very well with the 104 to 114 theoretical

values for the three airports using this operating policy. The most

applicable DELCAP values are for the 5 to 15 percent heavies for these

three airports, meaning that DELCAP estimates are 5 to 7 operations

high for MIA (Miami International) and ORD (Chicago O'Hare International),

and one operation low for ATL (Atlanta), but still within 5 to 6 percent

of the theoretical values determined by the FAA.

DELCAP values agree very well with the theoretical values for close

parallels. The DELCAP throughput of 61 operations at 50 percent heavies

matches closely the theoretical value of 60 for JFK, which has a large

percent of heavies in its mix. The PHL theoretical value of 68 is

closely approximated by the DELCAP-computed value of 69.5 for 15 percent

heavies. In both cases the DELCAP values are slightly high (1 or 2 percent) but the fraction of heavies at PHL is probably closer to the

5 percent level, in which case the DELCAP figure is 10 percent high.

* The numbers in Table 2.13 for this case are obtained from runs not

included among those reported earlier.

- 32 -

Throughput calculated by DELCAP for the A-runway ORD case lies

between the modified standard and the theoretical value in Table 3.2.

Note that the DELCAP throughputs used for this analysis are those

without interference. (If values from runs with interference were

used, the DELCAP estimates would be somewhat lower.) Discussions

with FAA personnel familiar with the ORD operation indicate that the

two sets of parallels are treated almost as two independent sets of

intersecting runways. For the pure operating policy, takeoff s are cleared once a landing passes the intersection, and occur in such a way

that the two mile departure/arrival separation does not limit operations.

In this operating situation the "without interference" policy more

closely describes the actual situation and therefore is indeed the more

appropriate policy choice for comparison purposes.

The exercises described above have incorporated some preliminary

investigation of model throughput sensitivity to aircraft mix and to

runway operating policy. Throughput decreases, from 10 to 33 percent

(averaging about 16), as the percentage of heavy aircraft in the mix

increases from 5 to 50 percent. Of much greater effect on throughput

are two other factors: runway operating policy, and the interference

requirements. The latter are determined by ATC rules, but only apply

to IFR traffic. If some crossing runways are used primarily by \rFR

aircraft, or if many aircraft are able to turn off before an intersection,

then throughput obtained from DELCAP runs without interference rules in

effect would more closely represent the actual situation. As has been

noted above, care must be taken in defining the operating policy.

Throughput for a mix containing 5 percent heavies for wide parallels with

alternating operations on both runways is 113, while that for wide

parallels handling pure operations is 78. Depending on the actual

sequencing of operations on the two runways, almost any value between

these two extremes can be obtained. Therefore it is necessary to be very

careful in defining the operating policy to insure that the DELCAP runs model the particular situation desired, and it is strongly advisable

to try a variety of policies if there is any question as to which is

most applicable.

The DELCAP simulation as now constituted assumes interlanding spacings

of at least 3, 4 or 5 miles as well as fixed and constant runway occupancy

times, assumptions which are unrealistic. However, the validation

indicates that not much additional accuracy in throughput calculations

would be gained from (the very easy- to- implement step of) representing

these factors in a stochastic manner.

The exercises reported in this chapter have increased our confidence

in DELCAP 's validity for use as a tool in setting engineered performance

standards. In the cases discussed above, DELCAP 's throughputs agreed

very well with the theoretical values calculated, using a manual process,

by the FAA's Air Traffic Service. These theoretical values are the ones with which we would expect greatest agreement, since they are arrived at.

- 33 -
in the simplest cases, in much the same way as DELCAP simulates events.

It was hoped that the validated DELCAP would be able to take over this

calculation chore, thus avoiding time-consiiming and cumbersome hand

Operations. These validation exercises have established DELCAP 's ability

to handle that task. The differences between the theoretical and modified

standard values highlight the fact that DELCAP (or any model, for that

matter) is only a tool to aid in developing the standards. Other factors

not included specifically in the model, such as airport noise restrictions,

special approach or departure route requirements, ground configurations,

or unusual bunching of the traffic distribution, may further limit the

sustainable traffic levels, so that two facilities with the same traffic

mix, configuration and operating policy may not be able to sustain the same throughput levels even though the model would output them the same. Use of model outputs without careful scrutiny is never advised in any

application, but the validation results reported above indicate that

the outputs of the DELCAP model will fit well into the philosophy and

process already adopted by the FAA for setting engineered performance

standards

.
3. VALIDATION OF MODEL'S DELAY ESTIMATES

3.1 General Background

In the previous section we reported a successful effort establishing

the validation of DELCAP's throughput results. This section will document

an effort designed to aid in establishing the validity of DELCAP's delay

outputs. Because of problems in the definition of delay and in available

data, the approach reported below was unsuccessful. It is described here

to provide a further example of the operation of the DELCAP model, as well

as a "lesson" in how not to attempt validation of delay output.

Although the effort was unable to establish the validity of DELCAP

delay output, it did illustrate how the model can be run with a mixture of

scheduled traffic entered explicitly and general aviation traffic generated

in a Poisson manner. Whereas model-computed delays were not comparable

with actual recorded delay (measured using the difference between actual

and scheduled operation times) , the model-computed delay figures agree quite

well with facility estimates of the delays attributable to facility operations

on the day to which the data apply. In addition, the shapes of the delay

curves in these two cases as they vary during the day are very similar, with

peaks occurring at about the same times. This section ends with suggestions

for future delay validation efforts, which would involve the collection of

special data referring to that portion of delay attributable to air traffic

control procedures in the the terminal areas.

Problems associated with the definitions of capacity and delay are discussed for example in [4] . Intuitively, the definition of "delay"

seems clear — to retard, to slow down, to detain — but the crux of the

problem lies in the question — retard, slow down, detain relative to what?

Presumably there is a faster way to accomplish the activity in question,

and delay is experienced because of not being able to do it that way.

The commercial air passenger believes he is delayed only if he arrives

later than his scheduled arrival time. The pilot may perceive delay

whenever he has to wait in a queue on the ground or in a holding pattern.

The ATC system seeks to measure ATC delays, those resulting from ATC

procedures, but unfortunately it is difficult to separate them from those

resulting from schedule bunching. The ATC system does not count those

delays occurring on the ground because of airline procedures, including

those resulting from gate assignment problems or from crew or equipment

shortages. Path stretching procedures are not normally considered by the

ATC system to generate "delay" but may be so considered by others.

Thus each party of the air transport system has a different part of the

total delay in mind when speaking of delay. The approach to delay calculation

also matters, since whether delay occurs only during specific maneuvers or only because of a particular time difference (e.g. actual versus scheduled

arrival times) affects the way it should be measured and calculated. The

problems arising because of different definitions of delay are further com- plicated by the need to ascribe portions of delay to different parts of the

system. ATC delay must be separated from total delay and then be apportioned

to the facilities involved.

- 35 -
DELCAP is oriented exclusively to the effects of terminal-area ATC,

and the "controls" exercised over each aircraft are necessitated predominantly by the presence of other aircraft in the environment. Therefore,

the definition adopted for delay in DELCAP is the difference between the

time to execute a maneuver in the presence of other aircraft and a nominal value of the time to execute that maneuver with no other aircraft

involved. The DELCAP-computed delay includes only that portion of an aircraft's total delay occurring while under control of the terminal

facility being modeled. It includes delay caused by airside operations,

but not by ground operations, with the exception of those occurring on the runway surface. These restrictions ensure that DELCAP-computed delay

refers to only that part of the ATC system, the terminal area, for which

it is desired.

While this definition is a quite straightforward way to model delay,

is physically meaningful, and corresponds correctly to the "terminal-area

ATC" level of analysis for which DELCAP was commissioned, it does not

correspond to any current operational definition. Thus, in order to

validate DELCAP 's delay figures it will be necessary to mount a special

data collection effort. The characteristics of such an effort are described below in section 3.6.

It was recognized early in the DELCAP-delay validation work (and

indeed noted earlier when describing future work in [1]) that there would

be difficulties in comparing the data on delay available from the scheduled

and actual operation times with the delays measured by DELCAP. Despite

these anticipated problems, it was decided jointly with the FAA to continue

on and to learn as much as possible using these data, which were the

only ones available in time without a special data collection effort.

Even if the analysis of delay output showed inconsistencies, the exercise

would allow testing DELCAP in a mode discussed previously but not actually

run: mixing scheduled and stochastic types of traffic input.

In the past, DELCAP has been run on a variety of runway configurations

representing several of the nation's busiest airports, but each of these

efforts used traffic descriptions concocted from general knowledge of the

traffic levels expected at the facility. The exercise described below

uses actual traffic for LaGuardia Airport (LGA) for Friday, October 25, 1974.

The facility reported good weather conditions that day and "no delays" (i.e. no aircraft delayed more than 15 minutes) . This includes only delays

occurring while aircraft are in a holding pattern or a ground departure

queue. Other factors contributing to passenger-experienced longer trips,

such as path-stretching, alternate routing, airline gate delays, or equipment problems, are not included in such estimates. Some of these factors, in particular path-stretching, do contribute to the DELCAP-computed delay figures.

The LGA facility reports only delays occurring while the arriving or departing aircraft are under its control, specifically while they are in

the facility's holding pattern or queues.

- 36 -
LGA handled 939 operations, of which 715 were air carrier operations

and the rest were mainly general aviation, with a few non-scheduled

suburban carriers included. The runwav conf ieuration for LGA is deoicted

in Fieure 3.1.

22

4

FIGURE 3.1

Runway Configuration for LGA

Most of the time the airport is operated with landings on one of

the runways and takeoffs on the other, with runway-directions depending on wind direction. A more detailed description of the input data for the

DELCAP run of LGA is given below.

3.2 Traffic Input Data

Traffic data for LGA are available from two sources: scheduled

operations from the Official Airline Guide [3] and actual operations from

CATER* data. The Airline Guide schedule data were provided to us by

the FAA from a printout of the FAA's Airport Information Retrieval System

(AIRS) program, which extracted the data in a form convenient to use in

this effort. A sample of this data appears in Figure 3.2. Arrivals and

departures were listed separately, sorted by departure or arrival time.

Ten minutes had been subtracted from arrival time (added to departure time)

to allow for the difference between gate time and touchdown (start-of -roll)

.

The data include the flight identification, the operation time (touchdown

or start-of-roll) , the aircraft type, and additional data giving origi-

*CATER, Collection and Analysis of Terminal Records, has been instituted at

the three large New York airports (LaGuardia, Kennedy and Newark), and under

it data are relayed to Washington concerning each operation at any of the

airports as well as meteorological conditions.

- 37 -
FIGURE 3.2

Sample Schedule Data

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AAnnu 1

?

1 U'(3 J7P7 n]U3 7AU

h A n 1 n.^< 1 U M nnu3 7RW

1 Uh^ JDCP nnfS'- 70P

P7 Ofl i7? 1 U'i7 J73/ nnuQ ZDC

1 ufsn J7PS npn 1 7KC

1 upsn JDQ5 niun 7AU

F Anpu.-^< 1 M^n . JDQ? 7DC

FAOni IS'i 1 asi J7?7 ni 4R 7JX

AL nni4Q? 1 UFSP") JRl 1 70R

HAnnaun 1 ttfSQ J737 ni 09 70R

isnn A/c PI G/A u

A'-nripPR 1 Rn^ J7P7 ni fiR 70R

AAnm UP 1 'sns J7P7 0035 7DC

iiAnnuRfi 1 PS1 7 J7P7 npi > 7MP

AAnnp.'i 1 51 R J7PS OfiUR 7DC

A'vnn^'i^^ 1 5? ^ J7PS OIUl 7ME

DL noTiiQ 1 RPr JDOS nf)p6 ZPW

MA n n mu 1 SP3 jni 0 npi 3 7MA

1 5pf^ J7PS ni u'l 7AU

UAnnnna 1 S3'> J7P5 ni U5 7AU

F An 1 1 '")3R J7P7 0nfS3

r 'V'M /j'T 1 Ran JDOS n ' 1 /4 - 7RW

1 f=>U' J7P7 0115 70H

( 7n"ao^ 1 SU'. vJDQS noup 7DC

1 ui.n 1 pa 1 vJ7p7 mil 7ID

Ai nf'^pi 1 f^l47 Tf n • > u p 7DC

A/ ni i3i ip 1 "^UR J7PS 0 1 UH 7AU

FAniiTun 1 S'.n JDQS nppo 7MA

F AO' 1 np 1 n JD9S 0151 7TL

FAnpu/i< 1 fS' n JDPS nil'.:) 7DC

rjAO'iupR 1 s'.n J7PS 0 7DC

FAO' 6(1 1 psso J7P7 npp<s 7Mlt

- 38 -
nating (or terminating) air route control center and flieht time. Flieht

id's with the symbol < as final character belong to Eastern Airline's

shuttle flights and may represent several actual aircraft for each flight

because of extra sections. Aircraft types represented in the example

in Figure 3.2 include Fokker Friendship Turbo-prop F-227 (TFH7) , Boeing

727 and Stretch 727 (J727 and J72S) , Douglas DC9 and Stretch DC9 (JDC9 and

JD9S), Boeing 737 (J737) , BAG 111 (JBll) , Douglas DCIO (JDIO) , and the

Convair 580 Turbo-prop (TCJ5) . All of these, with the exception of the

DCIO (a heavy aircraft), are "category 3" aircraft types.

A sample of the CATER data on actual flight operations at LGA appears

in Figure 3.3. These data are taken from flight strips and transmitted

daily via teletype from New York to Washington. Touchdown and start-of-roll

times are recorded for all operations at the three New York airports (LGA)

,

JFK and EWR) . Data recorded include the date and time of each operation,

the flight identification, the aircraft type, the user category (Air carrier.

General aviation, or Suburban) , arrival or departure designator, IFR or VFR

distinction, the runway on which the operation occurred, and gate departure

time for takeoffs. In addition to these traffic data, the CATER printout

also indicates operating policy and changes in policy as well as weather

conditions (primarily visibility range and wind direction and speed)

.

The traffic recorded in the CATER data includes helicopter operations,

designated by aircraft type HELD and an H associated with the user type

(AH is air carrier helicopter, for example) , but only fixed-wing operations

were included in the simulation input.

Input from the two sources, scheduled operations and actual operations,

was matched and discrepancies noted. The discrepancies and efforts to

reconcile them are discussed in greater detail in Appendix F, which also

contains a listing of the actual traffic input to the model.

3.3 Delay Analysis of the Input Data

For each of the 702 flights for which the data contained both a scheduled operation (landing or takeoff) time and an actual operation time,

"delay" was computed as the difference between the two times. Figure 3.4

records for each hour the number of aircraft whose delay fell into each

delay category (5-minute intervals ranging from no-delay to over one hour's delay). In addition to the hourly delay profile for all aircraft.

Figure 3.4 also contains separate profiles for landings and takeoffs. In

each case 26-27 precent of all operations are delayed more than 30 minutes

and 8-9 percent are delayed over an hour. Since the facility reported

good weather with "no delays", these long delays must be the result of

problems occuring elsewhere in the air traffic control system. This

indicates the difficulties, to be described below, in attempting to use

this delay profile for validating DELCAP-computed delays. DELCAP models

only the LGA terminal area, and can thus estimate only that subtotal within

the total delay which occurs within that terminal area. The delays reported

in Figure 3 .4, representing the difference between the actual and scheduled

operation times, include many delay factors not attributable to conditions

in the LGA terminal area. Even departures from LGA can be delayed by late

arrival of equipment from elsewhere.

- 39 -
FIGURE 3 .

3

. - . Sample of Actual Traffic Data

L6A DAILY

DATE 10/25/74 LIST OF OPERATIONS PAQE 07

DTQ/OP FLT/ID A/C CT AD IV RMY DTK REM ARKS /WEATHER /COMMENTS

251442-EAI53 DC9 A 0 I 13 1437

25i444-PI4 B737 A A I 22

25I444-AA593 B727 A D I 13 1433

251446-AA442 B727 A A I 22

251447-NYl HELO AH 0 V ///

251448-TW570 DC9 A A I 22

251450-EA1031 DC9 A A I 22

25I452-EA892 B727 A A I 22

251453-AA272 B727 A A I 22

251453 -EA543 DC9 A D I 13 1449

251455-NC50 DC9 A A I 22

25i455.AA389 B727 A D I 13 1450

25i456-NV200 B727 A A I 22

251456-N57129 AC€ G D I 13 1451

251458-TW72 B727 A A I 22

251458-TW323 B727 A 0 I 13 1454

25i459-AA412 B727 A A I 22

251500-N503T BAll 6 D I 13 1455

251500-N20SL BE55 6 A I 22

251502-EAt430 DC9 A A I 22

251503-S0713 DC9 A D I 13 1457

25I504-EA150 B727 A A I 22

251505-EA1441 DC9 A 0 I 13 1503

251506.NY2 HELO AH A V ///

25I506-UA840 B737 A A I 22

25l508-UA9n B727 A 0 I 13 1504

251508 -PI72 B737 A A I 22

251510-UA4«9 B737 A 0 I 13 1507

251510-AA298 B727 A A I 22

251511.NY2 HELO AH 0 V ///

251512-M1500C CJ23 G A I 22

251513*N3253Q C402 G D I 13 1505

251513-AL492 BAll A A I 22

251515«TW1I5 B727 A D I 13 1507

251516.AA257 B727 A 0 I 13 1511

2M516-UA450 B727 A A I 22

2Si5l7-AA413 B727 A 0 I 13 1511

251518.AA433 B727 A 0 I 13 1511

251519-EA1040 DC9 A D I 13 1509

2^i521-AA221 B727 A A I 22

251522-N8000U N2€5 6 0 I 13 1519

2^1523 4)L1904 F227 A 0 I 13 1520

251526-TV314 B727 A A I 22

- 40 -
_1

c

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r^^icccocccccco— <\jccoc^ — r-ccif a

ir

cr^ojocNjooooooo-HtOCNjoocMo—inr-rv!:*- —i

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in

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o«-ecctoccocc^f^p.K(rr^r'^^ccrc in

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- 42 -
cL o^l/C3cr^cccu"•-^^c^^lrccu"^ri: ^

t- cvi'"/^ (\.cvcv.^f\,-^(\jc\i-4<\ifv-cv ir c »^

af^ccccc— cccccccccc^cocKtr h

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If) IT

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IT

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D -4

- 43 -
Long delays are reported in hours 22 to 24 and 1 to 3 (or 2100 to 300

GMT, which is 5-11 p.m. local time), with about two thirds of the departures

and 52 percent of the arrivals scheduled for that period delayed more

than half an hour. About 46 percent of all scheduled flights are delayed

by more than 15 minutes. On the other hand about 15 percent of the operations were early: 11 percent of the departures and 20 percent of the arrivals

Since no scheduled air carrier can depart early, presumably the early

departures occur in the data because of the adjustment of gate time to

roll time. Since this adjustment involved a single time increment added

to gate time, whereas actual taxiing time depends on gate and taxiway

location, actual time may vary from the single nominal value by several

minutes. This could cause an aircraft to be listed as departing early if

that aircraft actually required less taxiing time than the nominal figure.

3.4 DELCAP Input

In addition to the scheduled traffic input to DELCAP shown in Appendix F, general aviation traffic was also included. Table 3.1 displays the

hourly general aviation traffic levels actually maintained on October 25.

Scheduled traffic was supplied to the model directly as an exogenous* input

through the exogenous event routine XGEN, while a representation of general

aviation traffic was generated randomly by event routine GEN according to

Poisson distributions with the hourly operation rates from Table 3.1 as means. All general aviation traffic was assumed to be aircraft type 2

(light aircraft)

.

The runway configuration for LGA is shown in Figure 3.1. Figure 3.5

gives the preprocessor output resulting from the LGA input. "Runway 1" is

runway 04, "runway 2" is runway 13, "runway 3" is runway 22, and "runway 4"

is runway 31. The initial operating policy allows landings and takeoffs to

alternate on runway 3 (22) . Changes in policy are input exogenously through

exogenous event routine CHGOP. The operating policies used during the run are given in Table 3.2. The change at 1920 — from alternating on 3 and

2 to alternating on 3 and 4 — involves a direction change (runway 2 to

runway 4), as does the change at 0250 from 3 and 4 to 1.

*SIMSCRIPT simulations have two ways of initiating events, exogenously

and endogenously . Endogenous events are those initiated by other events

in the program while exogenous events are initiated by user-supplied input

data. In DELCAP, flights may be generated by either of these mechanisms:

stochastically by event GEN which schedules the arrival to the system of

the next flight after the previous stochastically-generated one has arrived,

or externally by XGEN in which the user inputs the system arrival time of

each flight and the characteristics of that flight.

- 44 -
TABLE 3.1

LGA General Aviation Traffic Levels By Hour

Hour Landings Takeoff

s

Total

1 4 4 8

2 3 3 6

3 2 7 9 4 3 2 5

5 15 4 19

6 2 12 14

7 0 0 0

8 0 0 0

9 0 0 0

10 0 0 0

11 2 2 4

12 7 5 12

13 10 S 18

14 7 12 19

15 S 9 17

16 3 7 10

17 4 6 10

7 A

19 4 9 13

20 7 6 13

21 9 15 14

22 7 6 13

23 7 12 19

24 6 7 13

- 45 -
FIGURE 3.5

Preprocessor Output

THIS SIMULATION RUNS FPOM 7.00 TO "'.00

AIRCRAFT PESCRIPTTOM

TYPE SPEEDS (KNOTS) PIJNWAY OCCUPAMCY (Sf^COMOS)

LANDING LIFTOFF LANDING TAREOPF

1 I2t|. 120. S5. 3"^.

2 tlQ. OO. t|0. 27.

3 120. 120. "SO. 32.

TRAFFIC DESCRIPTION

TYPE LANDING TAKFOF^

MIX MIX.

1 0. 0.

2 100. ion,

3 0. 0,

- 46 -
FIGURE 3.5

Preprocessor Output (Cont'd)

AIRPORT CONFIGURATION

NUMBFR OP RUNWAYS - ^ RUNWAY 1 ( ^ ) - NC POLICY PROVIDED/ MOT ilSf^D INITIALLY

RUNWAY 2 ( 13 ) - MO POLICY opOVIDt^n/ MOT Mc;ED iMlTlfiLLv

RUNWAY 3 ( ?? ) - nUAL iiSE» ALTEPN^TTNC oPiiCJ ^TIO^IS

RUNWAY 4 (31 ) - NO POLICY PPOVIDFD/ '^'OT IJ^FD INITIALLY

RUNWAYS ^ ANP 13 INTE^SFCT AT A POImT 4900. FFFT '^RO^' TmF

END OF Pii:;'.jAY I* AND lO^O, FEET FoO" THE FNP OF RUNWAY 13

RUNWAYS h Ar.'D 31 I^JTEo<^ECT AT A POI^T U900. t^P"FT «^P0" THF

END OF RM.^WAY U AN'O 59^0. '^Ef^T FpO^' THr cnh qf RmnWAY 31

RUNWAYS 13 ANP 2? Ir.TERSc^CT AT A POT^!T lO^^O. PrrT "^RO^' THr

END OF RU.NWAY 13 AMQ 2100, FEET FnQv THF ENP OF RUNWAY

RUNWAYS 22 AtJC 31 IMTEPSFCT AT A P^InT 2100. F^rT FRO^' T^r

END OF PM jWAY 22 A^ = 0 59'^0. FEFT FpOm THf FN^^ OF RUNWAY 31

RUNWAYS 4 AND 13 ARE SE''-'

I

-DEPfn^emt

SIVULTANFOUS arrivals are oROHlBlTrr

RUrJWAYS ^ A^.'C 31 APE SF»^ I -DEPFNnENT

SIMULTANEOUS ARRIVALS APE PROHIBITED

RUNWAYS 1^ AND 2? ARE SE^ I-DEPFNnENT

SI'^ULTANFuMS ARRIVALS Ade P^OHlBlTrn

RUNWAYS 22 AN'D 31 A^e SE'^' I -DEPFN'^ENT

SIMULTANEOUS ARRIVALS ARE PROHIBITED

- 47 -
FIGURE 3.5

Preprocessor Output (Cont'd)

FRACTION OF LANDI^!GS OF E^CH TYPE ON FACH dijNWAY

RUNWAY 1 ( t+ ) 2 (13 ) 3 (?2 ) TYPE

^ (31 )

1

2

3

.onoo

.0000

.0000

.0000

.0000

.0000

i.nooo

1 .0000

1,0000

.0000

.0000

,0000

FRACTION OF TAKEOFFS OF EACH TYPE ON FACH oijNWAY

RUNrtAY 1(1 ) 2 (13 ) 3 (22 ) TYPE

I* (31 )

12

3

.0000

.0000

.0000

,0000

.onoo

,0000

1,0000

1,0000

1,0000

,0000

,0000

,0000

- 48 -
TABLE 3.2

Operating Policies for LGA, by Hour

Time Policy

0400-1025 Alternate landings and takeoffs

on runway 3(22).

1025-1920 Alternate a landing on 3(22)

with a takeoff on 2(13).

1920-0250 Alternate a landing on 3(22)

with a takeoff on 4(31).

0250-0400 Alternate landings and takeoffs

on 1(04).

- 49 -
Standard aircraft-type data as shown in Figure 3.5 were used, with

type 1 being heavy jets, type 2 being light aircraft, and type 3 being

category 3 aircraft, i.e. medium size jets and large propeller aircraft.

3.5 DELCAP Output

Summary output from the DELCAP run of the LGA data is shown in

Figure 3.6. Since the general aviation traffic was entered stochastically,

it is not surprising that the DELCAP traffic total (934) is slightly lower,

by about 0.5%, than the actual total (939). Each average hourly throughput

figure is obtained by dividing total throughput for that runway and operation

type by the time within the hour during which the runway accepts that operation. If the time period is not a busy one or if it includes a long time

during which no operations occur, the average hourly throughput may differ

greatly from that for a typical hour with more traffic. The average

hourly delay is computed similarly, by dividing the sum of the delays

suffered by all aircraft of the appropriate operation type on the runway

in question by the time period over which that runway accepts that operation.

The delay is thus the hourly average of all the aircraft delays for aircraft that landed (or started to roll) in the time period in question.

(Delay is recorded at touchdown or start of roll, so that a delay which

actually occurred before a change of policy may be recorded after the

change.

)

The DELCAP delay profile is given in Figure 3.7. This also is

standard DELCAP output whenever the delay output option is selected. Only

66 aircraft, about 7 percent of all operations, had delays of more than

fifteen minutes, which agrees fairly well with the facility estimate of

"no delay" (since the facility records only delays of more than fifteen

minutes) . Over half of all operations (57 percent) suffered less than

5 minutes delay. Peak delays occurred during hours 15 (10-11 a.m.) and

22 (5-6 p.m.), which agrees well with the peak traffic hours of 14 and 23.

Regarding LGA as it is operated during busy periods as a pair of V-shaped

intersecting runways, operated with landings on one and takeoffs on the

other, the capacity of the airport should be about 75 operations per

hour (from Table 2.5). Thus the highest traffic input (69 operations in an hour) is less than the airport capacity, but some delay results nonetheless, since the times at which aircraft desire service are bunched

instead of being evenly spaced. For instance, 42 percent (8 out of 22)

of the departures in hour 1 are scheduled to depart at exactly 0000,

clearly a situation making delay inevitable. Arrivals to the terminal area are not as bunched as departures, and even when several have the same scheduled arrival time, their prior processing by the air traffic control

system tends to space them apart more than the schedule would indicate.

This may explain in part why average takeoff delay per aircraft in Figure 3.6

is greater than the average landing delay, even when the number of landings

exceeds the number of takeoffs.

- 50 -
FIGURE 3.6

DELCAP Summary Output

HOURLY THROUGHPUT

HOUR RUNtvY Landings takeoffs total

p 1 U n \i 2 U r

r\n 3 U , 1 U

H 0 0 0

-i 11 U u n oc. U (' riU

nu

A 0

1

J. n n n c n n

•X n n n

0 r-J

1 • J X1X n U n p n p p

3 1 1

/I nu

ftu nu

1X n nI / n

c. nU <^ V

o 1 U

H U 0 u

1 U f U

2 0

-> — 33

"X 1 J> 1

r\ o 1

fi U U

i nu !J nU od

riU t "7

*/ 1 o 1 !

llH u

i. D

1X n r\L n p n 35

»

c. O p x

llH ur.L U

Ir 1X U c U

U c Z O "X c J o 21 0 ? 1 0 v.- n

1 7 1 0 0 0

2 0 30 30

3 24 0

0 0 0

1- 1 0 c 0

2 0 2f. ?6

3 27 n ?1

0 n 0

1 0 0 0

2 0 21 ?1

3 21 r 21

0 r 0

'^-'OiiRl V pri AY PFP /^irrPr'i-T

0 • 0 • n

,

0 • 0 • n

.

0 • 0 • . 0 • 0 • n

.

0 • 0 • n

.

U • 0 • n • n

U • u • n

.

u • u • n u • u • o' 1 . n n U . nu • nij •

'

'

.

n n n nu • n > • n nu -• 'J n

.

u • n nU • '1 . u • C ll C 1 1

1' . 11 » 'i 0 • 0 • 0 • n • 0 • 4 . ^

D • U n • 0 . 0 • 0 . U • n • M . 0 • 1 I . H 1 1 . R

ll p n •ll c

"1 . u • n 0 nu • 1 r • U IPJr.''n

1 o r\U .1 o U • 'J • n' ' •

r\ n • ' 1 • 0 • 3 • ? n • ^ . ?

0 • 0 • 0 • n • 0 • 3.0 3.0

2.4 0 • p , a 0. 0. 0.

0. n,' n. 0. P.

6

1.7 0. 1 .7

0. n.

0. 0. 0.

0. 1 .4 J .'I 3.5 n. 3.5

0. 0. 0.

- 51 -
FIGURE 3.6 . DELCAP Summary Output (Cont'd)

1 0 n n 0. 0. 'I. 2 0 15 15 0. 2.5 2.S

T•J 31 G 31 5.6 0 • 5 .

5

0 m 14 1^.7 1^.7

1 0 0 - 0 0 . 2 0 f) 0 0 . 0 . 0 . 3 31 31 n

.

u . 0 37 37 0. 13.5 13,5

1 .0, 0 0 0. 0

.

0 . 2 0 c 0 0. 0, 0.

3 38 3P 9.1 0. 9, 1 ^ 0

• 38 0. 17.

Q

17,

Q

1 0 c> 0 0. 0, 0.

2 b c 0 0. 0. 0.

3 35 0 35 2.° n.

0 , 36 0. Q.2

1 0 0 0

.

0. 0

.

2 0 r 0 0. 0.. 0.

3 30 70 0. 2.5

0 3? 32 u. 5.0 5.0

1 0 0 0 0. 0. 0.

2 6 0 0 0. 0. 0.

3 37 n 37 5.U n. 5.^^

0 ?A ?n 0. 6.1 6.1

1 0 0 0 0. 0. 0.

2 0 n 0 0. 0. 0.

3 23 0 23 1.2 0. 1.2

.0 la IB 0. 7.0 7.0

1 .? .0 0 0 0. n. n.

2 i 0 0 0. 0. 0.

3 1 1 c 11 0,0 0. 0 .

0

0 9 9 0 . 2.9

1 ' i

. ; 7 0.1 0. 0.1

2 Q c 0 0. 0. 0.

3 ,0 0 0 0. 0. 0.

0 0 0 0. 0. 0.

1 ,1. 1 0. 0. n. 2 0 0 e 0. p. n.

3 13 19 Q.P 0. O.o.

0 0 0 0. 0. n.

1

^ P 0 0 0. 0. 0.

2 0 0 0 0. 0. 0.

3 3 7 1 0 0. 0.1 0.1

U o 0 0. 0. n.

0 n 0 0. 0. n. 2 Q (.1 c 0. 0. 0.

3 0 \ 1 0. 0. 0.

0 ri 0 0. 0. 0.

Fif'AL RAfslDoM NUVBEo SEFD 3n230Sl36602

- 52 -
FIGURE 3.6

DELCAP Summary Output (Cont'd)

SU'/MARY REPORT FOR THIS RU"

TOTAL THROUGHPUT

RUN,- AY OPEP'^TOMS PE^FOR 'En

LANDINGS TAKEOP^FS TQtAL

1 6 2 8

2 0 251 ?S1

3 ^^54 9 463

4 0 21? 212

TOtAL 460 474 934

AVFRAGr HOURLY THROUG^^di ij

RUlM.AY OPERATlOf.'S PEPFOR^fd

landtmgs TAKE0FF5 TOTAL

1 0.2 0.1 0.3

2 0. 10.5 10.5

3 18.9 • 0.4 19.3

4 0. fl.B 8.0

TOTAL 19.2 19.7 33.9

AVERA&r HOURLY DELAY

RUN .AY DEi V^Y (MT^JUTFS)

LANDINGS TAi'EOFFS TOTAL

1 0.0 0. CO

2 0. 60.6 60.6

3 72.6 0.0 72.6

4 0. O0.4 90.4

TOtAL 72.6 ISl.O ^>23,6

- 53 -
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- 54 -
Table 3.3 gives a detailed trace of the various events in the

operation of several aircraft. During this time period, landings on runway 3(22) were alternated with takeoff s on runway 2(13) whenever

possible. An option in the DELCAP model has been developed which prints

out the times of various events in a slightly different format, arranged

by time of occurrence rather than flight, and with an internal flight

identification number instead of the actual flight number. In Table 3.3

we have arbitrarily assigned the general aviation flights tail numbers

NOOOl to N0005 for convenience. Figure 3.8 displays the same output

(with two additional flights at the end) directly as it comes from the

computer. It should be noted that in the computer output flight identification numbers may be repeated after an aircraft lands or takes off,

although at any one time the number refers to only one aircraft.* Examples

are flight ID's 18199 and 18203 in Figure 3.8. It will also be noted that

because of roundoff procedures the times at which fliehts enter the

simulation mav be printed, as for instance, 15.09.59 rather than 15.10.00.

These detailed printouts can be used to aid in evaluating the delays

given by the DELCAP delay profile as well as to ascertain how the model

actually treats the various operations. Such analysis of the internal

procedures of the model is itself a valuable step in establishing model

validation.

One comparison of the distribution of "total delay" as actually

occurring (from Figure 3.4) with DELCAP-com.puted delay (from Figure 3.7)

is given graphically in Figure 3.9, which shows the cumulative frequency

distribution for the two sets of "delay" figures. Only a quarter of

actual operations experience either no delay or delays of less than 5

minutes, while well over half (57 percent) of the simulated operations

fall into this category'. All simulated aircraft experience less than

25 minutes delay while only 68 percent of the actual operations do so. Thus there is very little agreement between simulated and actual delays.

This discrepancy can mean one of two things: either the model does

not correctly model delay and is erroneous, or else the data are inappropriate for this particular analysis. Even before the simulation was run,

analysis of the input data delay profile in Figure 3.4 indicated difficulties in using the actual versus schedule operation time data as a basis for terminal delay estimates. The LGA tower facility had reported

"no delays" on a day in which over one quarter of the operations were

actually delayed more than half an hour, with 8 to 9 percent delayed more

than an hour. Clearly this is possible only if the delays occurred elsewhere. The 59 operations delayed over an hour would certainly have com- plained about incurring such delays at a facility having no problems

with runways, weather or unusually high traffic levels, lending further

credibility to the suijposition that most of this delay did not occur at LGA.

*This is done for efficient computer storage of flight information.

- 55 -
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- 56 -
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- 58 -
The long delays occur late in the day and landing delay peaks before

takeoff delay, leading one to speculate that the takeoff delays are caused in part by delayed arrivals of an aircraft needed for a later

departure. Arrival delay, computed as scheduled minus actual arrival time,

clearly includes all delays occurring during the whole flight, whether

caused by air traffic control (ATC) factors or something else (equipment

malfunction, for example) . Takeoff delay will not contain ATC delays

from other sectors for this flight, but may be affected by delays to an earlier flight using the same aircraft, and may also include (non-ATC)

delays due to equipment, crew and gate problems. Thus even before the

simulation was run, there was doubt as to the likelihood of any agreement

of the actual delays with the simulation output delays, which represent

ATC delays only in the LGA terminal area. Once the simulation output

became available, these fears were realized as displayed in Figure 3.9.

Although the delay profiles were quite different, their "shapes"

appear similar; that is, as delay varies over the day the actual and

the DELCAP-computed delays peak or fall at the same times. To test this

hypothesis, i.e. that the distributions have the same general shape, the

number of flights actually delayed excessively in each hour are compared in

Table 3.4 with the corresponding number of flights with excessive modelcomputed delays. For the actual delay data excessive delay is taken to

mean more than 15 minutes; for the simulated flights delays of 5 minutes

or more were considered excessive since few flights were delayed in DELCAP by

more than 15 minutes. Observations in the two columns were ranked separately,

and these rankings compared by hour using the Spearman rank correlation

coefficient,* whose value was .725, significant at the .001 level. This

means that the probability of getting such agreement of two rankings by

chance alone is less than .001. Clearly some correlation between the two

distributions is to be expected since they both depend on the same traffic input, but the level of significance is high enough to indicate

greater agreement than one would expect from this fact alone.

Although, as the discussion above indicates, the LGA exercise has

shown the inadequacy of the particular data base used, it has been included

in this report because that type of data base is the one most often

suggested for delay validation and the one most obvious to those not

directly involved in modeling. Elucidation of the problems associated

with this approach will perhaps aid others involved in similar efforts by

providing a concrete example of the difficulties. Since the "scheduled

versus actual operation time" data base is inadequate to validate the

DELCAP delay calculations, we will include below a description of a data

base, together with directions for its collection, which we believe would

*For a further explanation of this statistic and its use see Sidney Siegel,

Nonparametric Statistics for the Behavioral Sciences , McGraw-Hill, New York,

1956, pp. 202-213.

- 59 -
TABLE 3.4

Number of Flights Delayed Excessively in Each Hour

' - ' " NUMBER NUMBER

HOUR ACTUALLY DELAYED DELAYED IN DELCAP

1" /^' 47 25

2 :/ , 20

'. 3 ^ . 18 . ' 1

' .4 , . - ... 1 0

5 -

-

" 4

' 6-1 0

0

7 0 0

. "

'

,

; ' 1 0

9 0 0

10 0 0

11 0 0

12 -

' 0 12

13 3 28

14 16 50

15 " V 15 33

16 3 13

17 .-.^-.v. 11

18 7 5

19 7 6

20 11 30

21 20 57

22 'Z: 34 68

23 c 37 31

24- „ y.,-;;,.^ 44 17

- 60 -
be adequate for that task. The Internal trace output can be used to

better understand the internal operation of DELCAP, and thus acts as a beginning delay validation, but in the absence of the type of data base

described below the validity of delays calculated by DELCAP is not yet

demonstrated. It should be remembered, however, that DELCAP throughput

output has been validated for use in setting engineered performance standards by the exercises reported above in Section 2.

3.6 Data Required for DELCAP Delay Validation

The delay measured by the DELCAP model includes (as intended) only

that delay incurred by an aircraft in the terminal area being modeled, and

incurred because of separations required between aircraft. The delay is

calculated as the difference between the minimum time for an aircraft to

execute the maneuver in question (fly from handoff to the outer marker,

make its final approach, land, and exit the runway — or request clearance,

exit from the gate, taxi to the departure runway, start its roll and liftoff)

and the time it actually takes in the presence of other aircraft.

Instead of scheduled arrival and departure times, the model needs

actual handoff and departure-request times. Using these will overcome

the problem of including delays occurring elsewhere, by capturing just

that portion of a flight arising within the terminal area in question. The

actual handoff times will spread out the arrivals from the artificially

bunched scheduled arrival times, thus reflecting the effect of the ATC

system in smoothing out schedule bunching. The use of gate-departure

request time will avoid contaminating the analysis with the results of

late equipment arrivals, equipment problems and other non-ATC-caused

delay factors causing late departure requests.

The actual handoff and gate request times could be obtained by stationing people in the tower and monitoring the appropriate positions, recording

the times and flight numbers. It would also be necessary to record actual

touchdown and start-of-roll times for each flight. These data could be

obtained in a similar manner from the tower in good weather, if the tower

is situated so that the runway is visible. Monitoring the appropriate

approach or departure position would provide the flight ID, but visual

recording of touchdown and start-of-roll time would be required. These

data could in principle be obtained as part of some other airport data

collection effort.

Such data would allow an analysis of terminal-area ATC-specific delays,

and comparison of the delays output by the model with actual delay of the

type the outputs are supposed to represent. (However, one major risk of

discrepancy remains. Path-stretching procedures may be used by facilities

without the additional flying time contributing to facility-computed delay,

while that time would contribute to DELCAP-calculated delays. We emphasize

again the necessity for comparisons based on the same definition and measure

of "delay".)

- 61 -
The analysis would focus on the comparison of DELCAP delays with

delays calculated as the difference between the actual operation time

(handoff to touchdown, or departure-request to roll) and a minimum

time for that operation. Ideally, this input data set would allow a flight-by-flight comparison (using DELCAP 's detailed trace procedure) of

actual and simulated events. In addition, comparison of delay profiles

could be used to assess overall performance. It is this latter that is

most critical for future application of the model, and discrepancies in

individual flight behavior are less important than is absence of overall

bias or other systemiatic errors.

If DELCAP-computed delays are to be used in further analyses of the

ATC system, there seems no choice but to evaluate these delay outputs using

data obtained in the manner outlined above. Such a procedure is not

necessary for further use of the model's throughput values, since the

exercises reported in Section 2 have demonstrated the validity of that

output for use in the engineered performance standard program.

- 62 -
4. CONCLUSIONS

The DELCAP simulation model is an existing analysis tool which has

proven useful in aiding the setting of engineered performance standards.

It has been operated both on the UNIVAC 1108 at NBS and on a CDC computer

chosen by the FAA, and has been run both by its designers at NBS and by

FAA personnel.

We have reported in Section 2 the results of a validation of DELCAPproduced throughput levels for use in FAA's EPS program. This analysis

included an examination of DELCAP outputs for five different configurations

(a single runway, two pairs of intersecting runways with different placements of the intersection, a pair of close parallel runways, and close

parallels with a crossing runway) representative of the configurations

most commonly found at major terminals*, and for three or four operating

policies for each configuration. The tests included three arrival/departure

mixes, and the operating policies were chosen to apply to the appropriate

mixes. Each configuration and policy was run on each of three different

aircraft-type mixes, distinguished primarily by the fraction of heavy

aircraft in the mix and ranging from 5 percent to 50 percent heavies.

Comparison of the model results with FAA-computed values at 5 airports,

covering 7 conf iguration/policy combinationsj was carried out. The DELCAP

values were within 5 to 6 percent of the FAA-computed values in all cases but one, and were within 10 percent in that case. Thus the DELCAP model

has been accepted as a good substitute for the manual procedure developed

by the FAA, and because of its ease of use and flexibility, it can extend

and enhance the FAA's analyses in the program.

The LGA exercise reported in Section 3 demonstrated the model's

ability to simulate actual scheduled traffic together with randomly generated general aviation traffic and to measure delays from these operations.

Inasmuch as the data presently available are insufficient to isolate delay

occurring in the portion of the ATC system DELCAP was designed to model, we are unable to validate DELCAP ' s delay outputs without a further data

collection effort. Such an effort, involving collection in a terminal

area of handoff and request-to-depart times as well as actual operation

times, is described in Section 3. The "delay validation" exercise has

highlighted the importance of insuring that definitions of delay are the

same, since there are many different definitions of this complex concept.

Although DELCAP 's delay values could not be validated because of these

data problems, model output agreed well with facility estimations of delay

and the time distributions of delay (actual versus DELCAP) were similar.

These results give a preliminary indication that DELCAP-computed delays

may indeed be useful for analyses, an indication which can only be checked

by further efforts.

The exercises reported in Section 2 indicate that the DELCAP model

is most sensitive to operating policies. Since different operating policies

are optimal for different arrival/departure ratios, this factor also

greatly affects model output. The model is also quite sensitive to runway

*We note again that wide parallels are effectively two independent single

runways

.
configuration, particularly to the number and the independence (or interdependence) of the runways, but the location of an intersection and the

difference between close parallels and an intersecting pair of runways

have only minor effect on throughput. Aircraft-type mix has less effect

on throughput than do operating policy and major configuration differences,

but it is still an important factor. Separations, too, have an effect

on the throughput, but reduction of all separations to three miles or less (for a dual-use single runway) has less effect than one might expect.

(Despite the reduction in minimum inter-landing separation, landing aircraft must be separated by more than three miles in order for takeoffs

to occur between landings.) Other factors affecting sensitivity include

approach speeds and runway occupancy times, but for the ranges occurring

at the busier airports, the model is less sensitive to these than to the

other factors given above.

DELCAP is a tool whose usefulness and validity have been demonstrated

for application in the Engineered Performance Standards Program. It

may also be useful for other analyses, but care should be exercised

that the model is appropriate and that the validations like those described

in this report be performed and include the types of scenarios to be

represented for that application. In order to use the delay figures output

by DELCAP, further validation — requiring a special data collection

effort such as that suggested in Section 3.6 — will be necessary. Preliminary indications from the LGA exercise reported above, suggest that

such an effort would be successful.

64 -
5 . REFERENCES

1. Judith Gilsinn, with E.H. Short, W.A. Steele, D. Klavan, A Simulation

Model for Estimating Airport Terminal Area Throughputs and Delays , NBS

Report Number 10592, FAA Report Number FAA-RD 71-9, May 1971.

2. Judith F. Gilsinn, Validation of Maximum Airport Throughput Levels

Estimated by the DELCAP Simulation Model , NBS Report Number NBS-IR 75-638,

FAA Report Number FAA-RD 75-66, January 1975.

3. Official Airline Guide, North American Edition , Reuben H. Donnelly

Corporation, Oak Brook, Illinois 60521.

4. Analysis of a Capacity Concept for Runway and Final-Approach Path

Airspace , NBS Report Number 10111, FAA Report Number RD-69-47, November

1969.

5. A.J. Goldman and W.A. Steele with W.A. Horn, Continued Analysis of

a Capacity Concept for Runway and Final-Approach Path Airspace , NBS Report

Number 10589, April 1971.

6. W.A. Horn, Extension of a Capacity Concept to Dual-Use Runways and

Multi-Runway Configurations , NBS Report Number 10593, 1971.

7. A.J. Goldman, A Capacity Concept for Runway and Final Approach Path

Airspace , Navigation IJ, pp. 253-259, 1970.

8. A. Blumstein, The Operations Capacity of a Runway used for Landings and

Takeof f

s

, in Proc. Second Inter. Conf. on Operational Research, J. Banbury

and J. Maitland (ed.), John Wiley and Sons, pp. 657-672, 1961.

9. R.M. Harris, Models for Runway Capacity Analysis, MITRE Corporation

Technical Report Number MTR 4102, October 1969.

- 65 -
APPENDIX A

CHANGES AND ADDITIONS TO DELCAP

During the course of the validation effort reported in this document,

modifications were made to DELCAP and its preprocessor in several areas:

output, separation criteria, random number generator, operating policies,

changes in operating policy, and standard preprocessor inputs. Several

criteria were used in deciding which of a number of plausible changes

should be implemented, and first among these was the preservation of the

DELCAP design philosophy, that the model should remain easy and inexpensive to operate. A second factor was the benefit expected to accrue and

the priority of need for that change in the Engineered Performance Standards Program. The changes chosen for implementation are described below.

A.l Modifications in Output

DELCAP is expected to operate under two scenarios: one to compute

airport maximum throughput ( capacity) and the second to compute delay

resulting from a particular demand profile. Since delay output would

be meaningless under the first scenario, the user now has the option

of suppressing delay output for runs under this scenario. Current

output formats have been modified so that the number of characters

per line is less than 72, permitting output to fit on most terminals.

Output now consists of actual throughputs and average delay per

aircraft for each hour, separately for landings, takeoffs and total

operations, separately by runway. Summary statistics at the end of a run provide for each runway — separately for landings, takeoffs and

total operations — the total throughput for the run, average hourly

throughput, average total hourly delay, and the delay profile. Illustrative

preprocessor and simulation outputs are shown in Figures A.l and A. 2.

In addition to throughput and delay information, DELCAP prints the

final random number seed for use in subsequent runs. (See below for a more complete description of the random number generation process.)

Average hourly statistics (throughput or delay) are computed for

each runway based on the time period within that hour during which the

runway operating policy handles the operation in question. It should be

noted that when periods of low traffic levels are averaged with busy periods,

average throughput levels may appear much lower than customary throughput

levels. In this case, hourly throughputs may be more appropriate and the

user may wish to compute (off-line) separate average throughput levels for

different time periods. The delay profile appears at the end of simulation

output whenever delay output is called for. The profile shows the number

of aircraft in each delay interval for each hour of the day. Delay is

recorded for each landing at touchdown and for each takeoff at start

of roll, so that the delay recorded to aircraft in a particular hour may

include delays occurring in a previous hour. The figures thus describe

- 66 -
FIGURE A.l

Sample Preprocessor Output

THIS SIMULATION RUNS FROM 2.00 TO 22.00

AIRCRAFT DESCRIPTION

TYPE SPEEDS (KNOTS) RUNWAY OCCUPANCY (SECONDS)

LANDING LIFTOFF LANDING TAKEOFF

1 12t+. 120. 55. 3^.

2 119. 90. t|0. 27.

3 120. 120. 50. 32.

TRAFFIC DESCRIPTION

TYPE LANDING TAKEOFF

MIX MIX

1 5. 5.

2 17. 17.

3 78. 78.

AIRPORT CONFIGURATION

NUMBER OF RUNWAYS = 2

RUNWAY 1 (15 ) - OPERATED WITH RUNWAYS 2

OPERATION SEQUENCE

DEPART ON 1 ARRIVE UN 2

RUNWAY 2 (18 ) - OPERATED WITH RUNWAYS 1 OPERATION SEOUENCE

DEPART ON 1 ARRIVE ON 2

RUNWAYS 15 AND 18. INTERSECT AT A POINT 2000. FEET FROM THE

END OF RUNWAY 15 AND 2000. EEET FROM THE END OF RUNWAY 18 .

RUNWAYS lb AND 18 ARE SEMI-nEP'ErjDENT

SIMULTANEOUS ARRIV'\LS ARE PROHIRITEH

- 67 -
FIGURE A.l

Sample Preprocessor Output (Cont'd)

FHACTION or LANDINGS OF EACH TYPE ON EACH PUNWAY

TYPE

1

PUN.AY 1 (15 ) 2 (1« )

5

'f^ooo l.OOOO

3

-f^oo^ i.oono

-OOf^O l.OOOG

FRACTION OF TAKEOFFS OF EACH TYPE ON EACH pUNWAY

TYPE

^^UNl.AY 1 (15 , p (IP ,

I

i-OOO^ .0000

3 }-0000 .0000 ^ 1-^000 .0000

- 68 ~
FIGURE A.

2

Sample Simulation Output

Q' IT HOURLY D FLAY PER AlRCf AF

HOI IR Rl Ifji. AY TAKEOTFS TOT AL AL 1

3 0 36 36 0 . 3,9 3.9

2 37 n 37 D , 3,4

(| 1 0 30 30 0 . A , q. P .4

30 0 P , 4 n

.

' t 2.4

c:•J X 0 3*^ 0 . 5 . 4 ^.4

2 37 37 U , Q 0

^ 4,9

1 0 30 30 0 . 14.6 14,6

2 3C 0 3 0 2 . 5 2 ,

5

7f 1 P 2R 2 A 0

.

2^^ . 5 P9,5

2 29 29 3 .

7

• 3 ,

7

6 1 C 37 37 0 . 4U , 6 ^4 , 6

2 36 n 36 4 , Q ^ . 4 , Q

9 1 C 3^^ 35 0 . 41.2 41,2

2 35 0 35 7 . 0 n

.

7, Q

10 1 0 37 37 0 . 33 .

1

33, 1 37 0 37 6 . 1 n , 6 . 1

1 1 X X 1 0 29 2" 0

.

2"' . 2 P7 . P

t— 26 0 — • " 0- *

^ • 12 1 0 31 31 0 , 41,9 41,8

2 31 0 31 . 0 P , 4,0

1 3 1 C 37 37 0 . 4"^, 3 ^7 . 3

37 0 37 1 . ? 1 . 2

1 u X 0 37 ^7 4 u . S 4U . R

37 1 37 2 n . Q n , ? P , 9

1 ^ 1X 0 36 36 0 ^ "^^ . 6 c 37 0 37 26 . t 26 .

1X 0 3*^ ^ R ^ 0 t u 2 37 0 37 X * ' n

.

17 i 0 3Q 3° n , 34,5 ^4 , 5

39 0 30 IQ . Q 0 , 1 °.9

le 1 (J 31 31 n

.

2U,2 P4.2

2 31 0 31 13.4 0 , 1^.4

1 y 1 0 34 34 n , 36w 'J .• 1X ^6 . 1 2 3** 0 34 7 . q n

.

-> • 7 . Q

20 1 0 36 36 n

.

2'^ . 6 20,6

2 36 0 36 12 i 1 P . 12,1

21 1 0 3''. 3B 0 . A , 2 « . 2

2 38 0 3 ^ 15.1 . • 15.1 t • X 22 1 0 33 33 2,7 2,7

2 36 0 36 17.^ 0. 17.6

FINAL RANDOM NUMBER SEF^ 36057554Pn52

- 69 -
FIGURE A.

2

Sample Simulation Output (Cont'd)

SUMMAKY REPORT FOR THIS RUN

TOTAL THROUGHPUT

RUNWAY OPERATIONS PERjFOPMED

LANDINGS TAKFOFFB TOTAL

1 0 690 690

2 690 ^ 0 6^0

TOTAJ- 6^0 . 690 1380

AVERAr-^E HOURLY THROUGHPUT . /

RUilWAY OPERATIONS PERFORMED

LANDIMGS TAKEOFFS TOTAL

1 0. 34.5 3t+.5

TOTAL 34.5 3U.5 69.

AVERAGE HOURLY DELAY

'

RUIWAY DELAY (MIMUTES)

LANDIMGS TAKEOFFS TOTAL

1 0. '^'-16.4 9«+6.U

2 374.4 0. 374,4

TOTAL 374.4 o(+6.4 1320.8

- 70 -
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- 71 -
the delay experienced by operations occurring (touching down or starting

roll) in the stated hour, not the delay actually experienced that hour

or the delay experienced by aircraft scheduled to land or take off that hour.

A. 2 Changes in Separation Criteria

With the advent of heavy aircraft (greater than 300,000 lbs.

gross weight) , wake turbulence problems have led to the imposition of

separation rules requiring 5 mile separation for all non-heavy aircraft landing following a heavy, and 4 mile separation for a heavy

following a heavy. All other aircraft combinations must be separated

by 3 miles. Any non-heavy taking off behind a heavy must wait for

two minutes after the heavy lifts off. Other takeoff separations are approximated in DELCAP by requiring that the second aircraft wait 20

seconds after the first lifts off. This eliminates all references

to whether aircraft diverge or not and all necessity for treating

departure paths. Other landing and takeoff separations may be input

if it is so desired, but the revised DELCAP allows separation to depend

only on the types of aircraft involved.

A. 3 Improved Random Number Generator

Early test runs of DELCAP indicated that the random number generator

available in the SIMSCRIPT system did not produce a sequence of

numbers which were statistically "random" to a satisfactory degree.

This has been remedied with the inclusion of a random number generator

obtained from the NBS Statistical Engineering Laboratory. This generator

requires a starting value (referred to as the "seed") , which is modified

each time a random number is calculated. The final seed is printed out

by DELCAP and can be used to start other runs. The sequence of random

numbers produced depends entirely on the seed, so that runs can be

replicated by using the same seed and on the other hand different

traffic samples can be obtained by using different seeds. The seed is

input and output as a 12 digit octal number.

A. 4 Modifications in Operating Policy

The initial version of DELCAP allowed 4 different operating policies:

landings only, takeoffs only, mixed operations where landings take

precedence, and mixed operations in which landings and takeoffs alternate.

To allow a more flexible sequencing procedure DELCAP was modified to

let the user input the desired operation sequence. The user may provide any sequence of operations (of length up to 20) , and this sequence

will be repeated for the duration of the run.

- 72 -
In the earlier versions of the DELCAP model, operating policies were

strategies for operating a single runway only. In the course of the "throughput validation" effort, it became evident [2] that allowing independent

sequencing and generation of aircraft on close parallels or intersecting

runways unduly favored takeoff s over landings, since the average minimum

time between takeoffs is less than that between landings. This led to un- realistically high takeoff throughputs and also to a degradation of the

landing throughput, because of the interference by takeoff s with the landings.

In discussing these problems with knowledgeable authorities at the FAA,

it became clear that in most control situations a pair of close parallels

or intersecting runways would be operated cooperatively, with a sequence

of operations applying to the pair. The most common example involves

either parallels or intersecting runways, operated with one of the pair

reserved exclusively for landings and the second for takeoff s. During

periods when the number of desired arrivals and departures are approximately

equal and traffic is heavy, landings will be spaced far enough apart to

allow a takeoff to occur in between successive landings. In practice

this means landings are spaced only slightly further apart than the minimum.

Takeoffs will be alternated with landings by clearing an aircraft for

takeoff as soon as the previous landing has passed the intersection (when

the runways intersect) or as soon as the landing touches down (for close

parallels). To accommodate a higher volume of takeoffs than landings,

landings are spaced far enough apart that two (or more) takeoffs could occur between successive landings.

The DELCAP model has been modified to accommodate such policies.

(See Appendix B for a description of the new version of event NXTOP,

in which the bulk of the modifications occur.) In earlier DELCAP versions,

a policy was specified for each runwav by indicating the operation sequence

for that runway. The modified version now requires that the user specify

the number of the policy applicable to that runway. Then he must specify

separately the policy itself in the form of two sequences, the first giving

the operation sequence and the second giving the associated runway sequence.

Therefore the i-th entry in the first sequence is the i-th operation and the

i-th entry in the second sequence is the runway on which that operation is

to occur. The number of operating policies provided may not equal the

number of runways; it may be less if one policy applies to several runways;

it may be more if policies are changed during the course of a run.

An example of the four policies used in the LaGuardia run reported

in Section 3 is given in Table A.l. Policies 1 and 4 use only one runway,

on which operations are alternated. Policies 2 and 3 both use two singleoperation runways, with an operation on one alternating with an operation

on the second. For instance for policy 3, takeoffs (operation 1) on runway 4

alternate with landings (operations) on runway 3.

- 73 -
TABLE A.l

Sample Operating Policies

POLICY

NUMBER

SEQUENCE

OPERATIONS AND

OF

RUNWAYS

1 1

3

2

3

2 1

2

2

3

3 1 2

3

4 1

1

2

1

With the inclusion of this additional flexibility of operating

policy, the user is now required to specify completely the set of policies,

for any run, including the trivial sequence of operations having a single 1

for takeoff s only or a single 2 for landings only, together with the

runway sequence whether or not only one runway is involved. This additional

input requirement is a comparatively small price to pay for the extra

flexibility and realism conferred by the more general operating policy

approach. The preprocessor checks that the policy, specified in its input

as applying to a given runway, can properly apply to it. It will not

check, however, that another policy also affects this runway, since this

may happen when policies change. Neither will it check that policy changes

(after the initial policies) correctly apply to the runway they are associated

with. This latter check is not made because the preprocessor does not

have among its inputs the policy changes associated with each runway,

since such changes are treated by the simulation as exogenous events.* Care

must therefore be exercised by the user to ensure consistency for his

input policies and policy changes initiated during a run.

*The alternative is to complicate the simulation itself by adding con- sistency checking to the simulation code.

- 74 -
A. 5 Changing Operating Policy During a Computer Run

In earlier versions of the DELCAP simulation, operating policies

specified at the start of the run for each runway remained in force throughout the entire run. This approach was unacceptable for the LaGuardia

exercise described in Section 3, since the operating policy in force

changed several times during the day, and it was desired to include the

effects of such changes on aircraft delay.

The main difficulty in incorporating the ability to change operating

policy during a run lay in deciding how best to represent such changes.

They can be classified into 3 categories:

1. use a runway surface not now being used,

2. change the sequence of operations on a runway now being used,

3. change the direction of operation of a runway now being used.

Any combination of these can also occur as a policy change.

In the first two cases little additional delay results from the change,

unless it must be made so suddenly that established queues must be moved.

It is assumed by the model that changes are not of this sudden type.

Operations will occur on a new runway as soon as the first operation

designated for that runway can take place under proper separation rules.

Policy shifts involving sequence changes (including those from pure operations — of landings or takeoff s only — to mixed operations, or the reverse) are allowed to occur as soon as the last of the operations waiting (in

queues) at the time the change is called-for has occurred. This is done

to avoid difficulties arising because a policy may affect more than one

runway. In practice, since operations are generated some time before their

occurrence (touchdown or roll) on the runway, this extra time period

required before effecting a policy change results in very little delay.

Additional delay does occur, however, for case 3 above. Whenever the

runway whose direction is changed previously handled takeoff s, and is to

handle landings after the direction change (it may or may not handle

landings before and/or takeoffs after), it will be necessary to clear the

takeoff queue before effecting the policy change, and also to allow additional

time for the last takeoff to clear the final approach path before the first

landing under the new policy can even start its approach. Since any runwaydirection change may require moving queues around and establishing new

approach patterns, an arbitrary time delay is required before initiation

of a policy change whenever a change of runway direction is involved, and the

model thus requires a fixed (input) time period between the last operation

under the old policy and the first under the new.

Each policy change necessitates also that the distribution of traffic

by runway be changed to agree with the new operating policies. (The

program does not check that the two agree, so the user must be careful

in providing input.) Policy change is handled by the DELCAP model as an exogenous event CHGOP, which reads the new policy number for each runway

and the new traffic distribution by runway. The user must also specify

for each runway whether or not the new policy involves a direction change

on that runway. All policies themselves are input at the beginning of the

- 75 -
run, rather than with each change, and the user is responsible for consistency here also. Policy change is accomplished in CHGOP, whenever the

policy change can occur immediately. In cases which require a delay,

either to clear operations waiting or previously scheduled for the runway,

or to effect a change of direction, the policy change occurs in CDIR.

Descriptions of these routines are given in Appendix B, and input formats

for the data required for a policy change appear in Appendix D.

- A. 6 New Preprocessor Standard Values

The preprocessor program has been designed to provide standard input

values for each of six input categories. The user may elect to provide

his own input or to accept the standard values, and indicate this decision

by an option (non-blank characters if the standard is to be used, blanks

for user provided values) on the preprocessor parameter card, the second

preprocessor input card (see Appendix D for its format) . Whereas the

original version of the preprocessor was designed to have an input tape

with standard input for several major airports, this tape is no longer

referred to in the program and standard input is now provided internally

through the use of the DATA statement.

Standard input for data group 1, aircraft type data, is shown at the

top of the Sample Preprocessor Output in Figure A.l. The three standard

aircraft types are:

1. heavy aircraft

2. light (piston) aircraft

3. other aircraft: larger piston aircraft and most jets.

The standard input for data group 2, aircraft type mix, appears below the

aircraft type characteristics in Figure A.l. Standard input for data

group 3, the departure and arrival rates, is set at 200 takeoffs per hour

and 100 landings per hour, values which would saturate IFR operations at

any large airport. These values are thus appropriate for throughput

runs but not delay runs. To obtain realistic delay estimates, the user must supply realistic traffic levels.

Standard separations, data group 4, are those now required by FAA

rules: 3 miles behind a non-heavy, A miles for a heavy behind a heavy,

and 5 miles for a non-heavy behind a heavy for landings; and for takeoffs 20

seconds more than the runway occupancy time behind a non-heavy, 2 minutes

for a heavy behind a heavy, and 2 minutes plus the runway occupancy time

for a non-heavy behind a heavy. (The takeoff time separations are approximations involving several constraining rules.) Standard input for data

group 5, the runway and operating policy data, specifies a single runway

operated with landings and takeoffs alternated. The distance to the outer

marker is 5 miles and the times to fly from handoff to the outer marker are

10, 13, and 10 minutes for the three aircraft types respectively. The

standard input data for data group 6, the distribution of runway usage,

have all aircraft using the single runway.

- 76 -
The changes described above have enhanced model capability and allowed

it to reflect more accurately the sitatuion being simulated, without

changing the basic philosophy of the DELCAP model. DELCAP was designed

to be limited in scope to the calculation of airport runway throughput and

the delays caused by terminal airside traffic. The design concentrated

particularly on enabling the user to describe those elements of the terminal

area which have primary impact on capacity and delay, without requiring

him to provide excessive detail in input data. To ensure that DELCAP

remains an easily used, convenient planning tool, candidate changes have

all been examined against these criteria and only those meeting them have

been implemented.

- 77 -
APPENDIX B

DESCRIPTIONS AND FLOWCHARTS OF SIMULATION EVENTS

Figure B.l gives a general "flowchart" of the DELCAP simulation

model routines. The word "flowchart" is somewhat of a misnomer in the

context of a SIMSCRIPT model. The diagram indicates which event routines occur as a result of which other routines, but it does not give the order

in which they are actually executed, since this is chronological.

Events GEN and EXGEN create flights , which are the units that move

through the various events in the model. EXGEN is an exogenous event which

occurs at times designated for the arrival into the system of specific

flights. GEN creates flights in a stochastic manner. Stochastically

generated flights are assigned an aircraft type and a landing or takeoff

runway by the two functions PTYPE and PRWAY. Flights are constantly

entering the system while other events are happening. GEN schedules the

next occurrence of itself according to a Poisson process, while the next

specific flight (if any are left) for EXGEN is always available. The event

NXTOP finds the next operation (landing or takeoff) which is to occur

on a particular runway. It is scheduled in one of two cases: (1) if the

queue is empty when the current flight is filed in it, or (2) when the current

flight has either begun to fly the final approach path to land or has left

its gate to take off. Condition (1) is detected in GEN or EXGEN, and

condition (2) in LAND or TOFF. NXTOP then schedules the next LAND or TOFF at the time the runway and/or final-approach path is free, as determined

by the function FREER. Since there is a time gap between NXTOP and TOFF

or LAND during which landings or takeoff s on other runways may have created

new tieups for "this" runway, LAND and TOFF again determine the first time

the runway is free (from FREER). Then the flight may land or depart, which

in the DELCAP model implies tying up the appropriate points for a period

of time sufficient to maintain the required separations. LAND or TOFF then

reschedules NXTOP, and the cycle continues. When a tieup is no longer in

force, the routine FTIEUP destroys it.

Several routines do not appear in this list, since they do not affect

each flight. The BEGIN event (see Figure B.2) starts the simulation,

and schedules the event ENDS which prints the simulation output and stops

execution. The routine CHOUR (see Figure B.3) updates the current hour

for output of delay and throughput, and reschedules GEN for the Poisson

parameter for the new hour. The routine PRINT records the delay and

throughput information at touchdown for landings, and at start-of-roll for

takeoff s.

The exogenous event CHGOP reads the characteristics of a new policy

and initiates the changeover if that can occur immediately. Otherwise CHGOP

or NXTOP initiates CDIR when the changeover should occur. CDIR also handles

the change of direction of a runway. The following sections will Include

descriptions of the events in Figure B.l, as well as CHGOP and CDIR.

- 78 -
TOFF

^ EXGEN

-<- NXTOP

V

FREER

FTIUP

GEN

PTYPE

ho

PRWAY

LAND

FIGURE B.l

Flowchart of the DELCAP Simulation Routines

- 79 -
FOR EACH OPERATION 0

>

SCHEDULE GEN

FOR (j)

NO

SCHEDULE ENDS

AT TEND

SCHEDULE CHOUR

AT TIME + 1

FIGURE B.2

Flowchart of Event BEGIN

- 80 -
YES

NO

1

:

IHOUR = 1

/

RESCHEI

EACH GE^

NEW LA>

)ULE

? FOR

IBDA

FIGURE B.3

Flowchart of Event CHOUR

- 81 -
B.l Event EXGEN

This event creates exogenously-determined flights provided by the user.

It, or the stochastic generation process or both, may be used for a particular run. When inputting the information for the routine EXGEN, the user must supply for each flight: the hour, minute, and second of entrance

into the system, whether this flight is a takeoff or a landing, the runway

used for takeoff or landing, and the aircraft type. The SIMSCRIPT system

programs read these flights one at a time at the proper simulated time.

Therefore, there is no limit on the total number of flights as long as the

number simultaneously active (including both those generated by EXGEN

and those produced by GEN) is sufficiently small to fit in core. (For a simulation run with 20 runways, 100 aircraft types, and 10 departure paths,

there could be about 6,000 flights active at any given time. This, which

is permitted in the present model, is far beyond the capacity of any

existing airport to handle.)

Figure B.4 provides a flowchart for the EXGEN event routine. For a landing, the array TIN stores the time the current flight could (in the

absence of other traffic) first cross the outer marker after flying from

its handoff point. A takeoff 's flight plan becomes active about 13 to 15

minutes before its scheduled departure. In the model this time period is

divided into two segments, so that takeoffs are scheduled about the same

time before start of roll as landings are before touchdown. The first of

these time segments (about 10 minutes) , which may be thought of as representing the time between when the flight plan becomes active and when the

aircraft is cleared to leave its gate, is added to the current time and

stored in TIN. (The second segment, about 5 minutes, may be thought of

as representing a time interval between when the aircraft is ready to leave

its gate and when it could start its roll down the runway; it will be

described in greater detail in the section on the TOFF routine.)

After calculating the appropriate TIN, the EXGEN routine files the

newly generated flight into the appropriate queue. There are two queues

for each runway, one for landing aircraft, the other for takeoffs. The

queues are organized in a first-in-first-out manner. This means there is no sequencing by aircraft type; when a slow aircraft precedes a faster one,

the latter is not permitted to overtake the former, even if it could reach

the outer marker first without thereby delaying the slower plane.

Each flight must remain in the queue until its TIN. Filing flights

into the queue about 10 minutes before they could actually cross the

outer marker or leave a gate provides a means for identifying the aircraft

type of the flight that follows the current flight. This allows calculation

of the proper tieup time to ensure that two aircraft remain separated by

the required distance. This distance depends on the speeds of both aircraft

involved, and so cannot be calculated until the type of the second plane

has been determined.

- 82 -
TIN(FLT) =

TIME + CALIN

o

_:L.

CREATE FLT;

READ OPERATION,

RUNWAY, TYPE

TAKEOFF

o

NO

0

LANDING

YES

T FILE FLT

IN Q

TIN (FLT) =

TIME + FLYOM

K)

SCHEDULE

NXTOP AT

TIN (FLT)

FIGURE B.4

Flowchart of Event EXGEN

- 83 -
If the queue was empty before the present flight was added to it, the

NXTOP routine is scheduled to occur at TIN, which is the first instant

when this flight could be removed from its queue. The NXTOP routine,

which schedules the next operation (landing or takeoff) for a particular

runway, thus occurs in one of two circumstances: either (1) a landing

or takeoff has just occurred, or (2) the runway has been idle but there

is now a new flight available for it. Case (1) will be described later in

conjunction with the NXTOP, LAND and TOFF routines. In case (2), which is

detected in the EXGEN routine, the appropriate queue will have been empty

before the flight was filed in it. Therefore the NXTOP routine is scheduled

for when the flight is first available to land or take off. However, an earlier NXTOP may have been scheduled in LAND or TOFF, since the other

queue may not be empty. In this situation, NXTOP is scheduled, but when

it occurs the next operation will already be defined (NEXT ^ 0) and the

NXTOP routine will be terminated. This means that NXTOP may be scheduled

more often than necessary. The programming alternative was the codine of a much more complicated set of tests to ensure that NXTOP is scheduled only

when necessary. This did not seem warranted, in view of the lack of computerstorage problems and the logical simplicity of the current test.

B.2 Event GEN

This event generates flights in a Poisson manner. Landings and takeoff

s

are generated separately, from two different sets of Poisson parameters.

This routine is first scheduled by the BEGIN routine. BEGIN schedules

two gen's, one to create a landing flight and one to create a takeoff. From

then on, the GEN routine schedules the next occurrence of itself. Therefore, within GEN we wish to sample from the Poisson distribution to reschedule

GEN for the next entry ("arrival") of another aircraft into the simulated

system.

The procedure used in the computer for sampling from a distribution

is based on the fact that the range of any cumulative distribution is

uniformly distributed over the interval [0,1]. In the case here, we have

assumed Poisson generation, so the probability of an arrival in a time

period of length dt is ydt (plus comparatively infinitesimal terms) , where

y is the expected number of arrivals per unit of time. Then the probability

q(T) that the next arrival will occur in at most T units of time is

q(T) = prob (t <_ T) = 1 - e"^"^.

Since q is a cumulative distribution, its range is uniformly distributed

over the interval [0,1]. We therefore employ a standard computer subroutine

to choose a random number R from this uniform distribution, and then find

the T for which q(T) = R, namely

T = -A In (1-R)

where X = 1/y. The next instance of GEN is scheduled to occur in T time

units. (Note that our time unit for the simulation is the hour, so X is

- 84 -
the reciprocal of the number of arrivals per hour.) Input to the simulation contains two sets of values for X for each hour of the day, one

for landings and one for takeoff s. As noted earlier, on the hour, each

hour, the next GENs, one for a landing and one for a takeoff, are rescheduled

according to the X for the appropriate hour.

In the event EXGEN, the type and the runway are provided as part

of the input. In the stochastic version GEN, however, these three items

are obtained by sampling from the appropriate distributions. The simulation

is provided (by the preprocessor) with the cumulative distributions of

(1) type of aircraft, one for landings and one for departures, and (2)

runway use by each type of aircraft for landings and also for departures.

The two functions PTYPE and PRWAY perform the sampling processes.

Figure B.5 provides a flowchart of the GEN routine. After rescheduling

the GEN routine for the next landing or next departure (depending on the

current operation) , and sampling to obtain a type and runway for the current

flight, the remainder of the routine is the same as for the EXGEN routine.

The appropriate value of TIN is calculated, the flight is filed in its

proper queue, and if the queue was empty before this flight was filed in

it then the NXTOP routine is scheduled at TIN.

B.3 Event NXTOP

This event finds the next operation, landing or takeoff, which will

be scheduled to occur on a runway. Figure B.6 is a flowchart of this

routine. Because of the new more sophisticated operating policies to be

simulated, this routine has required significant changes from the original

version of DELCAP. A search is made, starting with the next position

(stored in LAST) in the policy sequence applying to this runway, for the

first flight which can be scheduled immediately under this policy. If no flight can occur immediately, the search continues through the policy

to determine the flight which will be available soonest, and LAND or TOFF

is scheduled for that flight. In addition to determining the next operation

to be scheduled under the policy, the N'XTOP routine also recognizes when

a change in policy, which is not initiated by CHGOP , must occur. If the

next flight to be scheduled is the last flight in the queue at the time

the policy change was requested in CHGOP (i.e. if the current flight

FLT = QF(k,i)), then the QF ' s for the other runway, operation combinations

for this policy are checked. If all QF's are zero, the policy changeover

is scheduled to occur when the current flight either starts its approach

or leaves its gate. This is accomplished by scheduling CDIR at the (same)

time for which the LAND or TOFF routine was scheduled.

- 85 -
©

SCHEDULE NEXT

GEN AT

riME-X-ln(l-RANDM)

TIN(FLT) = TIME + CALIN

TAKEOFF

i

CREATE FLT;

GET TYPE, AND

RUNWAY

LANDING

YES

TIN (FLT) = TIME + FLYOM

o

SCHEDULE

NXTOP AT

TIN (FLT)

FIGURE B.5

Flowchart of Event GEN

- 86 _
NO

V

YES

SCHEDULE

TOFF

o

KRW = POLICY FOR RUNWAY K

NO

YES

FOR EACH INDEX IN POLICY

K, I = NEXT RUNWAY AND

OPERATION FOR POLICY KRW

FIND FIRST FLT IN Q(K,I)

NO

INDEX OF BEST POLICY IS IMIN

=1 =2

YES YES

NO

SCHEDULE

LAND

CREATE CDIE

FOR EACH RUNWAY!

IN POLICY KRW

NO

FIGURE B.6

Flowchart of Event NXTOP

- 87 -
The NXTOP routine is scheduled in one of two Instances: (1) the

LAND or TOFF routine has occurred, or (2) a queue was empty and a new

flight has just been filed. In the second instance, NXTOP is scheduled

for the time TIN at which the flight could first be scheduled. However,

since the other queue for the runway need not be empty or a LAND or TOFF

routine could just have occurred, another NXTOP may already be scheduled

for this runway. To avoid error because of having several NXTOPs scheduled

at once, an array NEXT with an entry for each runway has been introduced.

Originally it is zeroed. When a next operation for a runway has been

found by NXTOP, NEXT is set equal to 1 (for a takeoff) or 2 (for a landing).

Then NEXT is zeroed in the LAND or TOFF routine. Therefore NEXT is nonzero precisely when a LAND or TOFF is scheduled but has not yet occurred.

NXTOP proceeds to find a next operation for a runway only if NEXT for that

runway is zero. This condition is tested at the beginning of NXTOP, and

if NEXT is non-zero NXTOP is immediately terminated.

B.4 Function FREER

This function finds the earliest time a particular flight can land

or take off without violating the separation rules. FREER is first called

in NXTOP, to find the time at which the LAND or TOFF routine should be

scheduled

.

There may be a gap between the time the NXTOP routine occurs and the

time LAND or TOFF occurs, during which other flights might add new tieups

which require postponement of the operation in question. Therefore FREER

is called again from LAND or TOFF, to determine when the landing or takeoff

may actually occur. Figure B.7 contains a flowchart of the function FREER.

The left-hand side refers to landings, the upper right-hand side to takeoffs

and the lower portion of the chart to both. T is the maximum of TIN and the

current time, used to single out for examination only those tieups affecting

the current flight. The array TR is created to contain the time (TMAX)

each tieup affecting the flight will no longer be in force, and J is a count

of the number of entries in TR.

For landings, both the set of tieups (OMTI) associated with the outer

marker and the set (THTI) associated with the runway threshold are examined.

The time of tieups in THTI is translated to the outer marker by subtracting

off the amount of time it takes the current flight to fly from the outer

marker to the runway threshold; this reflects the fact that the runway

threshold need only be free as the current flight gets there, not before.

For takeoffs, only the set of tieups (ERTI) associated with the end of the

runway are examined. The time of these is translated to the gate by subtracting off TDMIN, since takeoffs are scheduled before they leave their

gates to taxi to the runway.

If there are no tieups affecting the current flight (i.e. J = 0), FREER

is set equal to T. If only one tieup affects the current flight (i.e., J = 1)

,

then TR (1) will contain the time at which that tieup will no longer impede

the start of the landing or takeoff procedure, and so FREER is set equal to

- 88 -
o

T = max(tihe, TIN(FLT))

STORE ALL TIEUPS

IN OMTI WITH

TMAX > T

IN TR

LANDING

STORE ALL TIEUPS

IN THTI WITH

TMAX-DOM/VLAND > T

IN TR

TAKEOFF

STORE ALL TIEUPS

IN ERTI WITH

TMAX-TDMIN > T

IN TR

/

FREER = T

FIGURE B.7

Flowchart of Function FREER

- 89 -
it. If several tieups affect the current flight, FREER is set equal to

the maximum of the TR's.

It should be clear from the previous description that this routine

does not attempt to fit a flight in between two others, even if the gap

between the two is wide enough. To do so would require a great deal more

coding. The crux of the difficulty is how wide a gap is "wide enough".

The tieups occurring as a result of the inserted flight must not affect

any previously scheduled flight. This means that all the tieups which

LAND or TOFF would create must be examined to see if they would interfere

with a landing or takeoff already scheduled or in progress. This is similar

to performing the whole of the LAND or TOFF routine, and involves the

additional burden of identifying the flight which is being interfered with.

(It is no longer just the first in a queue.) Therefore the simpler procedure,

of waiting until the last tieup is no longer in force, was used in the

DELCAP simulation.

One further difficulty can arise when a slow landing follows (i.e.

lands later than) a fast takeoff. NXTOP is called as soon as the takeoff

leaves its gate. The landing therefore is not permitted to cross the

outer marker before then, since FREER is at least T which in turn is at

least the current time of NXTOP. However, if the landing is slow enough

it could in principle be scheduled earlier, and the takeoff would still

be able to precede it while maintaining the required separation. Therefore,

although the sequence of operations on the runway must be a takeoff followed

by a landing, the sequence of routines should really be LAND followed by

TOFF. This difficulty has not been resolved, but in sample debugging runs

it occurred only about 2 to 3% of the time, and added only about 30 seconds

extra delay at each occurrence. Therefore it does not seem to affect the

DELCAP results by a significant amount.

B.5 Event LAND

The primary purpose of both the LAND and TOFF routines is to tie up

the appropriate points in order to ensure that following flights remain

properly separated from the current landing or takeoff. Figure B.8 is a flowchart of LAND. LAND removes the first flight from the landing queue

for the appropriate runway. Then it calls FREER to find when the runway

and final approach path are first free so that this flight may cross the

outer marker.

The separation rules which apply to a landing, and their implementation,

are discussed below:

(1) No two aircraft may occupy the same runway at the same time.

This rule is implemented by tying up the runway threshold (for landings)

or the end of the runway (for takeoffs) for the time the current landing

will occupy the runway.

(2) Two landings must be separated by a minimum distance (called

SEPLL, in DELCAP) and depending on the two aircraft types involved. We

assume a constant nominal final-approach speed, depending on aircraft type.

Therefore, the point at which two landings are closest while always main-

- 90 -
REMOVE FIRST FIT FROM Q

TIE UP ERTI AND THTI FOR ROTL

TIE UP OMTI OR THTI TO

MAINTAIN SEPLL

TIE UP ERTI

TO MAINTAIN SEPTL

YES

) \f

YES

FOR EACH INTERFERENCE WITH

ANOTHER RUNWAY KK

> NO V>

SCHEDULE

NXTOP —K

AT T

=1

TIE UP OMTI (KK)

OR THTI (KK)

TO MAINTAIN

SEPLL

FIGURE B .

8

Flowchart of the Event LAND

= 6 V /

TIE UP OMTI (KK) TIE UP ERTI (KK)

TO MAINTAIN FOR INTERSECTING

SEPTL RUNWAY

- 91 -
taining the required separation depends on the relative speeds of the

two planes. If the first (of aircraft type i) is faster, they will be

closest when the first crosses the outer marker. In this case the outer

marker is tied up for the time it will take the second (of aircraft type j)

to fly SEPLL (i,j). If the second is faster, the two planes will be closest

when the first just touches down. In this case the runway threshold is

tied up from touchdown of the first until that time plus the time for the

second to fly SEPLL (i,j).

(3) A landing must be separated from a preceding takeoff by a required

distance (called SEPTL in DELCAP) . The standard present value for SEPTL

is 2 miles. As noted above, the final-approach speed is treated as constant

Under the assumption of a single constant acceleration for a takeoff on

the ground and in the vicinity of the airport, the distance the landing must

be from the takeoff when the latter starts its roll is

SEPTL + 0.5 v^ • ROTT/S,

where v is the speed of the landing, S is the liftoff speed of the takeoff,

and ROTT is the runway occupancy time for the takeoff. (This formula

is derived in Appendix F of [4].) The end of the runway is therefore

tied up from the time the landing passes this point until touchdown time.

Tying up a point is accomplished in the simulation by creating a temporary entity called a TIEUP, with attributes TMIN, the time the tieup

goes into force, and TMAX, the time the tieup is no longer in force. The

TIEUPs are filed in one of the sets OMTI, THTI, or ERTI, which are scanned

in FREER to decide when the runway and final approach path airspace are free

Once the TIEUP is no longer in force, it is removed by the FTIUP routine

which is scheduled in LAND as the TIEUP is created.

In addition to tying up points on the same runway, points on interfering runways must be tied up. Two arrays RPT and TPT control these interferences in the DELCAP simulation. For each runway and interference,

RPT contains the runway being interfered with, and TPT contains the

type of interference. There are six types of interference:

1 Landings on one runway must be separated from landings on the

other runway by SEPLL, depending on the aircraft types involved.

2 Landings on the one runway must be separated from preceding

takeoffs on the other runway in the same manner as that described

in (3) above.

3 Takeoffs on the one runway must be separated from following

landings on the other as described in (3) above.

4 Takeoffs on the one runway must be separated from takeoffs

on the other runway by the same separation as takeoffs on the same runway.

5 Takeoffs on the two runways are separated by the times in the

array SEP2.

6 The two runways intersect.

- 92 -
Types 1, 2, and 6 apply to landings. Tieups for interference

types 1 and 2 are computed in a manner similar to (2) and (3) above.

For intersecting runways, a takeoff or landing on another runway may not

be on the runway between the time the current landing touches down and

the time it passes the intersection or turns off, whichever occurs first.

The time for an aircraft to travel from touchdown to an intersection a distance D from the end of the runway is

(1/A) (-V + v2 + 2AD)

where v is the landing speed and A is the acceleration of the landing.

We assume A is constant, so

A = (v^ - v)/ROTL < 0,

where vj^ is the turnoff speed of the landing, v is the final approach

speed, and ROTL is the runway occupancy time. This formula is derived in

Appendix G of l4].

The RPT and TPT lists are scanred, and appropriate tieups are initiated to maintain required separation between the current landing

and operations on other runways. As each tieup is created, it is filed

into the set for the point being tied up. At this same time, an FTIUP

is scheduled to destroy the tieup once it is no longer in force.

Once all the necessary tieups have been created, the LAND routine sets

NEXT = 0 and schedules NXTOP for the time the current landing crosses

the outer marker. Then the delay to this flight is calculated as the

difference between the time it crosses the outer marker, and TIN (which

is the first time it could cross the outer marker were there no other

aircraft present) . The PRINT routine is scheduled at the touchdown time

for this landing. PRINT adds the delay to this flight to the total delay,

and increments the number of landings for the correct hour. Since all

tieups to maintain separation from this landing have been created and

since the delay for this flight has been calculated, the flight is no longer needed, so it is destroyed. This completes our description of

the landing routine. The takeoff routine performs similar tasks related to

takeoffs.

B.6 Event TOFF

Figure B.9 is a flowchart of the TOFF routine. Much of it is similar

to the LAND subroutine. The first flight is removed from the landing

queue and FREER is called to ascertain the first time the flight can

taxi to takeoff. Tieups are created to maintain separation, both on the same runway and on others where there is interference. NXTOP is scheduled

for the time specified by FREER, the delay is calculated, and the flight

is destroyed. Thus the overall structure of TOFF is similar to that of

LAND.

- 93 -
REMOVE FIRST FLT FL FROM Q

T = FREER

TIE UP THTI AND ERTI FOR ROTT

TIE UP ERTI TO MAINTAIN SEPTT

TIE UP THTI TO

MAINTAIN SEPTL

TIE UP THTI TO

MAINTAIN SEPTL

SCHEDULE

NXTOP

AT T

FOR EACH INTERFERENCE

WITH ANOTHER RUNWAY KK

=4,5 =6

TIE UP ERTI TO

MAINTAIN SEPTT

OR SEP

2

TIE UP ERTI AND

THTI FOR

INTERSECTING RUNWAY

/

^

SCHEDULE NXTOP AT T

FIGURE B.9

Flowchart of Event TOFF

- 94 -
Takeoffs, however, are special in one way. They enter the system

several minutes before scheduled takeoff and the TOFF routine occurs

later still before takeoff. The reason for this early scheduling of

takeoffs can best be described here, in the context of the TOFF routine.

Takeoffs are scheduled early so that their scheduling can be compatible

with that of landings. Landings need to be scheduled before touchdown,

since they must be properly separated from other operations along the

whole of the final approach path. If takeoffs were scheduled only at

start-of-roll , a following landing could be scheduled no earlier than

that start-of-roll. In other words, the following landing could not cross the outer marker until the preceding takeoff had started its roll.

It would greatly complicate the model if landings and takeoffs for one runway were scheduled in an order different from that in which they occur

in LAND and TOFF. By scheduling takeoffs early, landings and takeoffs

can be treated in the same manner. As noted above, there is still a residual

difficulty when a very slow landing follows a fast takeoff, but for the

most part, scheduling takeoffs early permits proper sequencing and

scheduling on a dual-use runway.

One may still ask, "Why generate takeoffs so early?" It is necessary

to generate takeoffs at least 3 to 5 minutes (depending on the separation

rules) before they are scheduled by TOFF. When calculating the tieup

duration needed to maintain separation from following aircraft, it is

necessary to know the type of the following aircraft. Therefore takeoffs

have to be generated as far ahead (in time) of scheduling in TOFF as the

greatest time separation required between aircraft.

The careful reader may wish to inquire whether this procedure is

indeed not too artificial. We note in response that these time intervals

can be interpreted in terms of real events. The time between flight generation and scheduling of TOFF may be thought of as the minimum time ahead

of departure at which a flight plan can be filed. Such a minimum time is

in fact required at the more congested airports, and as more terminals

become congested this practice will become more widespread. Also, with the

addition of computer processing of flight plans, a minimum filing time is

quite likely. The time between scheduling and start-of-roll may be thought

of as the time for the aircraft to leave its gate, taxi to the runway,

and complete final checkout. In the model, queuing for takeoff would

then occur before leaving the gate, although at most terminals gate space

is limited and there are parking ramps for waiting. This is another

instance of a situation in which we are interested in the length of a time

interval but not in where the aircraft is during that interval. We would

be interested in where the aircraft actually is only if this were to affect

whether the aircraft could turn onto the runway when the runway is free.

The DELCAP model does not include any ground operations, and therefore,

the delay figures do not include delays incurred during ground operations.

Future model modifications might address this additional source of delay.

- 95 -
To return to our discussion of the TOFF routine, we will now describe

the separation rules applying to a takeoff, and their implementation.

(1) No two aircraft may simultaneously occupy the same runway.

This rule is implemented in the same manner as it was in LAND. The runway

threshold and the end of the runway are tied up from start-of-roll to

liftoff.

(2) Separation between departing aircraft depends on the types

of aircraft involved, since under current rules extra time is required

for aircraft departing behind a heavy, and this time is less if the following

aircraft is also a heavy than if it is not. Separation times are stored

in the array SEPTT, which is a two-dimensional array depending on the

aircraft types involved.

(3) A takeoff must be separated from a succeeding landing. The process

here in TOFF is similar to that described for separation (3) of LAND.

The runway threshold is tied up from start of roll until that time plus

(1/S)(SEPTL + 0.5 v^ ROTT/S)

where v is the landing speed, S is the liftoff speed of the takeoff, and

ROTT is the runway occupancy time of the takeoff.

Each tieup created is filed in the appropriate set ERTI, for the

end of the runway, or THTI for the runway threshold. Along with each

tieup, the routine FTIUP is scheduled for when the tieup is no longer in

force.

TOFF also ties up points on interfering runways in order to ensure

that the required separation from the current takeoff is maintained. Of

the six types of interference listed in the description of the LAND routine,

four pertain to takeoff s:

3. Takeoff s on one runway must be separated from following landings

on the other runway.

4. Takeoff s on one runway must be separated from takeoff s on the

other runway by the same time as takeoff s on the same runway.

5. Takeoffs on the two runways must be separated by the times in the

array SEP2.

6. The two runways intersect.

Tieups for types 3 and 4 for different runways are computed in the same manner as separations (3) and (2) above for one runway. Tieups

for type 5 are computed in a manner similar to that of separation (2) above,

except that a second array SEP2 is used instead of SEPTT. SEP2 contains

time separations required between aircraft on different runways. Type 6

is handled for takeoff s in the same manner as for landings. The threshold

and end of the second runway are tied up from the time the takeoff starts

its roll until it has passed the intersection.

The remainder of the takeoff routine is the same as the landing routine.

NXTOP and PRINT are scheduled, delay is calculated, and the flight is destroyed.

- 96 -
B.7 Event FTIUP

This event destroys a tieup as soon as it is no longer in force.

A flow chart appears as Figure B.IO. These "erasures" free computer

storage for new flights and tieups, and make searching the sets in FREER

easier. Since the sets OMTI, THTI, and ERTI are ordered by TMAX (the time

the tieup is no longer in force) , FTIUP only needs to remove and destroy

the first tieup in the appropriate set.

B.8 Event CHGOP

This event, whose flowchart appears as Figure B.ll, reads the new

policy to be used for each runway together with the new runway usage,

distributions, and initiates policy changeovers whenever the changeover

can occur immediately. The array QF(k,i) indicates for each runway and

operation the status of the runway for changing policy. CHGOP sets up

QF so that QF = 0 if either the queue for that runway and operation is

empty or if the runway was not used under the previous set of policies.

If, on the other hand, the runway was previously used and has aircraft in

its queue, QF for that runway and operation is set equal to the last flight

in that queue.

The old policy for a runway is stored in the array INDX and the new

policy in TNDX. Changing the policy consists of replacing INDX with

TNDX and setting TNDX to be zero. The change can occur only when all the

QF's for all runway/operation combinations in the policy are zero. However,

if the policy change involves a change in direction of a runway, it cannot

be initiated immediately, and in this case the routine CDIR which handles

runway direction changes is scheduled at the current time. If any QF's are non-zero then the policy change is initiated by NXTOP, which detects

when the next aircraft scheduled is the flight stored in QF, and calls

CDIR to initiate the policy change.

B.9 Event CDIR

Figure B.12 is a flowchart of event CDIR. This event also initiates

policy changes, and can be scheduled either from CHGOP or NXTOP. It

first tests if a runway-direction change is involved in the policy change.

If that is so, the changeover must be deferred for a time (AFIN(k)). To

accomplish this, CDIR is rescheduled after a lapse of AFIN, and CHGD is

zeroed so that when CDIR is next entered the change will not be further

deferred. When CHGD is zero, CDIR changes INDX to be TNDX and zeroes

TNDX, thus actuating the changeover.

- 97 -
=1 \/

-4-

REMOVE FIRST

TIEUP FROM

OMTI

PT

= 2 ^

REMOVE FIRST

TIEUP FROM

THTI

DESTROY

TIEUP

N/

=3

REMOVE FIRST

TIEUP FROM

ERTI

FIGURE B.IO

Flowchart of Event FTIUP

- 98 -
READ

TNDX, CHGD,

CRWYT

UPDATE TIM FOR EACH RUNWAY

RUNWAY K

ZERO QF's

^ .

)—

SET OF = LO FOR EACH

OPERATION IN POLICY INDEX (K)

FIGURE B.ll

Flowchart of Event CHGOP

- 99 -
NO

RESCHEDULE CDIR

AT TIME + AFIN,

AND SET CHGD = 0

UPDATE INDX TO BE

TNDX FOR ALL

RUNWAYS AFFECTED

BY THIS POLICY,

AND ZERO TNDX

FIGURE B. 12

Flowchart of Event CDIR

100 -
APPENDIX C

MODEL ELEMENTS: ROUTINES, VARIABLES

AND ARRAYS, ENTITIES, AND SETS

This appendix is divided into two parts. The first lists each of the

model's routines, corresponding to events and functions, and provides a phrase describing what each does. The second section lists the names and

descriptions of variables used in the model. The variables are listed under

the SIMSCRIPT headings of: entities, arrays, attributes of event notices,

temporary entities, attributes of temporary entities, and sets.

C . 1 Routines

Exogenous Events

1. BEGIN - starts the simulation

2. EXGEN - creates explicitly generated flights

3. CHGOP - initiates an operating policy change

Endogenous Events

1. GEN - creates flights in a Poisson manner

2. NTTOP - finds the next operation (landing or takeoff) for a runway

3. LAND - creates tieups resulting from a landing

4. TOFF - creates tieups resulting from a takeoff

5. FTILT - destroys tieups no longer in force

6. ENDS - prints final output

7. CHOUR - updates current hour

8. PRINT - records delay and throughput

9. CDIR - accomplishes policy changes, taking into account runwaydirection changes

Functions

1. PTYPE - picks an aircraft type

2. PRWAY - picks a runway

3. FREER - finds the first time the current operation can proceed

C.2 Variables

Entities

1. 0 - operation (1) takeoff, (2) landing

2 . RW - runway

3. TYP - aircraft type

4. DX - operating policy

5. H - hour

6. SLOT - positions for printing the delay profile

- 101 -
Variables and Arrays

1. LAMBD(O) - Poisson distribution parameter, the average time (in

hours) between operations

2. OPER(RW) - operational procedure

(1) takeoffs only

(2) landings only

(3) dual use, alternate operations

(4) dual use, landings take precedence

(5) dual use, operation sequence user-provided

(6) more than one runway operated together, operation/ runway

sequence user-provided

3. DOM(RW) - distance from the outer marker to the runway threshold

4. NPT(RW) - greater than zero if the runway RW interferes with others

5. FLYOM(TYP) - time to fly from handoff to the outer marker

6. SQRW(DX, NSQRW(DX)) - sequence of runways used for policy DX

7. VLAND(TYP) - landing speed

8. VTOFF(TYP) - liftoff speed

9. ROTL(TYP) - runway occupancy time on landing

10. ROTT(TYP) - runway occupancy time on takeoff

11. VTAXI - turnoff speed for landings

12. DAFIX - distance from departure/arrival fix to the runway threshold

13. SEPLL(TYP. ,TYP.) - interlanding separation required between a TYP,

aircraft and ~'a following TYP. aircraft

14. SEPTL - separation required between a takeoff and following landing

15. CALIN - minimum time between the generation of a takeoff and

clearance to leave its gate

16. CTYPE (0, TYPE) - cumulative distribution of aircraft mix

17. CRWYT(RW, TYP) - cumulative distribution of runway use for takeoff

18. CRWYL(RW, TYP) - cumulative distribution of runway use for landing

19. SQOP(DX, NSQOP(DX)) - operation sequence for policy DX

20. NEXT(DX) - is 0 if the next operation has not been scheduled, nonzero otherwise

21. LAST(DX) - index of latest operation used in the sequence for policy DX

22. DINT(RW., RW.) - distance from the end of RW. to its intersection

with RW.

23. TPT(RW,-'nTPT(RW)) - type of tieup caused by an operation on runway RW

(1) to maintain interlanding separation

(2) to maintain a landing separated from a preceding departure

(3) to maintain a departure separated from a following landing

(4) to maintain departure separation between completely dependent

runways using the separations in SEPTT

(5) to maintain departure separation on semi-dependent runways

using the separations in SEP2

(6) to maintain separation on intersecting runways

24. RPT(RW, NRPT(RW)) - runway tied up as a result of an operation on RW.

No lie that RPT and TPT together describe the interference between

runways; RPT tells which runway is interfered with and TPT tells how.

25. TDMIN(RW) - minimum time between a takeoffs leaving its gate and

starting its roll

26. SEPTT(TYP;£, TYPj) - minimum time separation between a takeoff of

type TYP^ and a following takeoff of TYPj

- 102 -
27. SEP2(TYPi, TYPj) - similar to SEPTT for a takeoff on one runway

following a takeoff on another runway

28. IHOUR - current hour

29. NARR(H) - number of landings generated

30. NDEP(H) - number of takeoff s generated

31. NLAND(H) - number of landings performed

32. NTOFF(H) - number of takeoff s performed

33. DELT(H) - total takeoff delay

34. DELL(H) - total landing delay

35. TBEG - time the accounting for delay starts

36. TEND - time the simulation ends

37. GENN(O) - the identity of the GEN currently scheduled for operation 0

38. TDRW(RW,0) - total delay for operation type 0 on runway RW

39. HDRW(RW,0) - hourly delay for operation type 0 on runway RW

40. TNRW(RW,0) - total number of operations of type 0 on runway RW

41. HNRW(RW,0) - hourly number of operations of type 0 on runway RW

42. INITR - random number seed

43. CAP - is 0 for only throughput printout, 1 for both delay and throughput

44. INDX(RW) - policy used for runway RW

45. TNDX(RW) - policy RW will use as soon as the changeover can be effected

46. CHGD(RW) - is 1 if the new policy for RW involved a change in direction

from the previous policy, 0 if not

47. AFIN(RW) - the time required for a runway direction change

48. QF(RW,0) - used when a policy is being changed; is 0 if this runway

can accept a new policy, and otherwise is the last FLT, in the queue

for operation 0 on runway RW, which is to occur before the policy

change

49. NDLAY(H,SLOT) - the number of aircraft in hour H delayed between

SL0T*(INC-2) and SL0T*(INC-1) minutes. (The last position contains

all delayed over (NSL0T-2)*INC minutes, and the first position all

occurring early or on time.)

50. INC - interval-length for the delay profile

51. IDT (SLOT) - daily totals of NDLAY

52. DTIM - time of latest policy change

53. TIM(RW,0) - length of time period during which runway RW handled

operation 0.

Attributes of Event Notices

1. RWAY - runway

2. OP - operation

3. PT - point tied up

(1) outer marker

(2) runway threshold

(3) end of the runway

4. DLAY - delay for the current flight

Temporary Entities

1. FLT - flight

2. TIEUP

- 103 -
Attributes of Temporary Entities

1. TYPE(FLT) - aircraft type

2. TIN(FLT) - first time FLT can cross outer marker or leave its gate

3. TMIN(TIEUP) - beginning of tieup interval

4. TMAX(TIEUP) - end of tieup interval

Sets

1.

2.

3.

4.

Q(RW,0) - landing and takeoff queues

OMTI(RW) - tieups in force at the outer marker

THTI(RW) - tieups in force at the runway threshold

ERTI(RW) - tieups in force at the end of the runway

c

- 104 -
APPENDIX D

REVISED INPUT FORMATS

D. 1 Revised Preprocessor Input Formats

Card

No.

Column

Nos. Variable

No. Decimal

Places

FORTRAN

Format

1 1-7 TBEG - beginning of

simulation

2 F7.2

8-14 TEND - end of simulation 2 F7.2

2 1-18 INPUT (1 - 6) , 3 columns _ 6A3

19 print indicator

(0 = throughput,

1 = both delay and

throughput)

— 11

20 - 31 random number seed - 012

GROUP I

one per

type

1-3 number of type ( < 10) 0 13

4-10 aver, landing speed (knots) 2 F7.2

11 - 17 aver, takeoff speed (knots) 2 F7.2

18 - 24 aver, runway occupancy

time - landing - (seconds)

2 F7.2

25 - 31 aver, runway occupancy

time - takeoff - (seconds)

2 F7.2

//types + 1 end-of-f ile

//types + 2 1-7 aver, turn-off speed,

all types

2 F7.2

- 105 -
Card

No.

Column

Nos

.

Variable

No. Decimal

Places

FORTRAN

Format

GROUP II

1 6 per

type

decimal fraction of takeoff mix, of each type

H

2 same dec. frac. of landing mix

of each type

4 12F6.4

GROUP III

u J. hour off per hour

1 12F6 .

1

3,4 same # planes landing per

hour

1 12F6.1

GROUP IV

1 1-7 required separation

between an arrival and

a departure (naut. mi.)

2 F7.2

2 through

NTYPxNTYP

10

7 per

type

pair

required separation

between landing

aircraft (naut. mi)

2 10F7.2

next

NTYPxNTYP

10

7 per

type

pair

required separation

between takeoffs on the same runway (min .

)

2 10F7.2

next

NTYPxNTYP

10

7 per

type

pair

required separation

between takeoffs on different runways (min.)

2 10F7.2

GROUP V

one per

runway

1-2 number of runways

(1 - 9)

0 12

3-6 heading of runway 0 14

7-8 left/right designation A2

9-12 policy to be used

by this runway

0 14

- 106 -
Card

No.

Column

Nos

.

Variable

No. Decimal

Places

FORTRAN

Format

13-19 distance to outer marker

(naut. miles)

2 F7.2

#rw+l end-of-file

two per

policy

1-3

4-6

policy number

operation code: 1-takeoffs

only, 2-landings only,

3-both, alternating

4-both, landings preferred

5-both, sequence provided

6-both, sequence provided

for several runways

0

0

13

13

7-9 number of operations

in sequence

0 13

3 per

operation

in sequence

operation sequence 0 2013

(second card

of policy

pair)

1-3

4-9

policy number

blank

0 13

3 per

operation

in sequence

runway on which operation

is to occur

0 2013

2*policies + 1

end-of-f ile

one per

runway

7 per

type

time, in minutes, for

each type to fly from

handoff to outer marker

2 10F7.2

one per

intersection

1-2 first runway number 0 12

3-4 second runway number 0 12

- 107 -
Card

Nos • ColumnNos • V Cl J_ d^d U A~\Z No. Decimal

1 r* ^ c FORTRAN

r u xTuici u

"I 5-12 distance from end of

j-±irbL s\n LO j-iit.cr&ec t. ion

(feet)

0 F8.0

L3 - 20 distance from end of

second RW to intersection (feet)

0 F8.0

//interone per

interference

1-2

end-of-f ile

first runway 0 12

3-4 second runway 0 12

5-6 interference code:

1 - simultaneous

are permitted, given

divergence, but arr/arr

is prohibited, 2 - all

prohibited.

0 12

# interferences +1 end-of-f ile

GROUP VI

one per

type

6 per

JL Llilwciy

decimal fraction of all

LdivcU J- J- o Oi. Lypc wlliCn Uoc

each runway, followed by

decimal fraction of

all landings of type which

use each runway

4 12F6.4

- 108 -
D. 2 Revised Input Formats for Exogenous Events

D.2.1 FLIGHT GENERATION

CARD

NO. COLUMNS CONTAIN

1 3 the number 2

6 - 7 the hour the flight enters

the system

9-10 the minute of that hour

11 - 12 the second of that minute

13 - 14 1 if flight is a takeoff,

2 if a landing

15 - 16 the runway to be used by

this flight

17 - 18 the aircraft type for this

flight

- 109 -
D.2.2 POLICY CHANGE

CARD

NO. COLUMNS CONTAIN

1 3. the number 3

b - / the hour the policy change

is to be initiated

9-10 the minute of that hour

11-12 the second of that minute

for each

runway

3-4 new policy number to be used

5-6 1 if the runway direction is

changed, 0 otherwise

for each

runway

and type

5-11

(4 decimal places)

CRWYT

12-18 :

' CRWYL

- 110 -
APPENDIX E

PROGRAM LISTINGS

E. 1 Listing of the Preprocessor

C THI'^- p;T^r;f<A -I IS A ouTPi^nrLSrop '.^mIcm Pfftnc; T^l THE PATA A^ID

C PUT^ IT T".J^' pr^OPr^ FOP-' F^r^ IJ^:!^ BY THF STM"I.ATIOM PROGPAM,

PAPA'^F. T^P ^ , kJYPr 1 n , KSf"'^ = ?^ , K0 = ? » TPTr o n r K MHX = 20

INTF'^Fo OPEPCK'^TVY) r j ( c n » i/ TPT ) » TPT ( KP'-' » K TO"^ ) »

1 Snop(KMpx»KSEO) »So'^V, ( 'DV t K TF ^ ) »P''(KP''') » IMnx(KPW)

REAL LA iRn(K0f?4)

nir^FriS'^O'! DO"(KP''.') » "f-'T C^'Pi' ) » F| y^'M K TyP » k pk. ) » \/LANO ( K TYP ) r ROTL ( K'J'Y^

)

1 » Vy^FF (^TYP) »ROTT(KTyp) , ^yyPF ( k ^ . KTYP ) » P^WYT ( KT YP » KRW ) n..A5T(KRU') , CJ!"'/'YL(KTYPrKRV,') r'SOO^fK'^'- ) » P T MT ( / P W » 1^' ) »Tf)pi)T(R) » TD^^ T N ( K W ) » ^SFP?(KTYn,KTyp) r S'^^:PTT ( KTYp , i/ TYP ) f I MFR ( KPW » i^t^

I. ) »CALIN(KPW) rMdOO) r

'4 I^:F^,n{KP,v) r TLO(Kf^'-. ) » AFT^'(l^^W)

r,x;/rf ^ST^" SFPLL TYP» i^Typ)

C

C T-)F'"-»T:- in flPF TI^.'FS OF nrGT"Nir.'^- AMH FM^ CF SIW'ILATION

C c'XA"PL~''^ r'T F^P VT'^NirMT '^Mn 17,30 FO^ '^.'^O P.M.

C

•"^FA ^ ( 5 r 7n«^> ) TRFT. r Jf-^' IP 705 FOi^'^-AT (1 nF7.?)

/R T TF ( » SPO ) TPFO r TP' ;n 500 r-QP'-AT ( 1 THIS S P-ML A T j O' I Rijt"- FPOM»tr^,p,» TO»F6,'5///)

TBF r,r A TMT ( T'^FG) + (TPrc-A TnT ( TPpr. ) ) /G*^ . TEf IP = A T 'T ( TFf IP) + ( TFMn-A TK|j(TFr,ir) ) /6n . IF (TP- ^-.GT,'^. ) GO TP 1 THF crT' + . TFri'"rT.^',^ + ?'u

1 IF ( TF' -'.tr."!"!- pr.) Tr'-'n = TrMn4-4 . IBF ^rT . IMP! 'Pr ••on ( jorr, , ) + 1 ;,'HrTFN')-T'^-''~r, + .^Q

IF (^!H.LT.2'-^) ^0 "^0 ^ 11 = 1

GO TO 'I 2 II = T^^O•)?

IFf:;>=TP ")! Jjrvof ( Jf^r iPf ) -H

IF (JJ.LT.TT) 'IP^JvJ

C

C INPMT(T) - LFAVE ' L'-r'K T"^ T'^H p/^ta GROUP or SMPPLIFI RY USE^

C AriYTHTMG '^'L'^F 'TLL CAU^r ppoGDA^' TO SUPPLY STANfOARD DATA

C ^AT'N G''~'^"PS APE - n nii'PE^ fl^'P '^ESCP IPTTO^J op Alt'CPAFT TYPES

C ^) 'ijv OF ATPCAFT TYFFS

C ^) L/\>'-.IMr A^iO TA/FOFF OATFS» PY HOUR

C ) SF '">/" P A"^^or oFOHIRF^''Fr.'TC

- Ill -
5) DFSCRIPTICM OF /MR^ORT AND ITS OPFRATIOM

6) FRACTION 01^ TYPFS HSlMr; EACH RUNWAY AND

"^PARTIIRF PATH

TCAP - FLAG MSFD TO CONTROL PRI^!TIN^^ OF opLAY OUTPUT

(0 - ONLY THr^oiiGHPUTf 1 = BOTH TMROI'GHPUT AND DELAY)

XMITR - TfUTTAL RAri^^o^ MMMRPR SFFD (1?? OCTAL DIGITS)

HEAP (S»73n) ( IMPUT f T ) » T-l r(=>) r TCVPr TN'ITR

FORf'iAT (6A"^»I1»01P)

* I^!PUT ")ATA GROUP 1 .,

r'JYPF - MllWRFP 0^ TVPES

VT0FF(7) - TAKEOFF ^.Ppf^n qF TYPF I, IN KmoTc;

VLAfir-d) - LAfiQlMG ^.^FE^ QP TYPi^ If IN K^'OT<^.

ROTI (I) - RUNWAY OCCUPANCY TIME ovj l.ANDTMGS PQR TYPE I» IN SECONOS

ROTT(I) - SA"iE FOP TAKEOC^FS

VTAXI - AVFi^AGF TMPriOFF FpEFD FOR ALL TYPES

IF ( T'JPDT ( 1) .EO. • • ) GO TO

STAr'PAf?n TYPE iriPUT: TYPE 1 - mfAV^ AIRCRAFT

TYHE ? - S'^ALL PROP ATRCRAPT

TYPE - CATEGORY ors

^ATA FnO'" VALUFS OnTATNt^O AT JFK

HATA UTY"F/"^/vTAYT/pr) , /

JAT'^ C/L'^N'MI) rVTOF^(T) f^OTI ( T )» POTT ( T )» 1 = 1 » ) /

GO T^. 1 T <FA'^(S» 7?Sri^''!r-6)'lTYPFrVLANO(MTYnF) , VTOFT ( MTYPE ) »

1 '^OTL(NTYPE) »POTT(NTYPE)

5 P"ORf-AT{ T3»4C^7,?)

',0 TO '

,

, ^ . , h i.-LA^'('.» 7nr- ) VTAXI " ' '

'

i'O 7 Itrl M jTYPE

("OTL ( I) rPOTL ( I ) /3G"r , 7 ^0TT(I)=PnTT(I)/3fnr'.

+ INPUT ">ATA GROUP ? *

^: + )(t* + *r + >tr<c* + + + *:t:* + ** + ^r +

PTYPFdfl) - THE FP'^OTIo^• OF TOT'vL TAKEOFFS VHICH ARE OF TYPr I PTYPfC-^rl) - SAFE F^P LANDI^'OS

IF( Tf;P')T(P) .EO. » )G0 TO IS

STAMn/>on TYPF MIY - A V IP"S r 1 7-^ S^ALLr 7R«»^ CAT^^GORY 3»S

J ATA ( C^TYPE ( I » J) » J=1 f 3) » 1 = 1 »?) /. 05» 1 .0 » .0S» .??» 1 .0/

GO TO ^•"! 5 00 16 T=l

i<r An(5f7in) fPTYPF(T,J) »Jzl»MTYP^>

-112 -
no FnP'^/>T ( i?F6 , 4

)

If COMTINjF

no ?G j=^r^TYPr

?n PTYP- ( T » J) =^TYP!^ ( T , J-1 ) +ojYr r ( J , I) IF ( T'T ( ( ^TYP'- ( T r NT Y-r) + . ^ ^ ) * 1 P

-

. ) . : r . 1 n p ) JOTTp ( ^; , p 0 0 ) T 80r FOr"'*T{' A7'jr"( - r^n^ ' ^ T L f' T T

- 0^^ ,*.Ll. ^yorr: c^Q OPpP T T 0\i » I ? » 1» ( 1 -L V,"^ r.'r, r p-TA^-'PFF) ^'OT <^U'' TO '^^T » ) 2 5 COiiTiriMF

c

C * ir;pijT '^'iTA r^POUP 3 *

LA"'^^! ( 1 » T ) - A\/FPA ITH HOIJR OF THE

LA'-'^'5n (

.-> , I ) -

IF(T'ipi:T(^) 0. • ' ) TO

^.Tl'r^F A.^'D ACJRP'^L f^ATFf"- A^"^ ?0P A^- iO ]_Po PEP HOMO

n;pc;prcTT VLY (FO-^ ' '*^F T*' C'PrCTTY f^ii'JS)

"^0 ^1 Tr1,P4

LA'-'-n (1 • I )ri ./PC 0 . LA-'^^(?» I )=1 ./If 0.

51 COf.Tir.M?:

no in u 35 IF ( . r^' ) G^ TO ^7

JO 3*^, I-t»?

PEA-^ChrTPn) (LA'vi|-n( T , J) , jriT , jj)

7?n FOP^'AT f 12F6. 1 ) CO ^6 .1:^1 r?'i

.

" IF (LAM'^n ( ] , J) ,i_r. .

) '-O -^^1

LA-'-^ ( T r J) -1 . /LA V ( J , J)

00 TO

3'-j1 LAT-r ( t , J) rQ.QOQ

3 A CO^'TTM'!^

CO TC- i-^ 37 ^0 3^ Tri,?

-'EAr;(r,, 7pp ) l\p.y'P->{ i , j) , j- l^^/.jo , ^ a ) , f|J\Mor>( y , ,) ^ j--, ^^p)

^0 3n jrl,pu

IF(LAV' I » J) .LF. ^ . ) GO to ^-'j

L A-^'f-r { T , J ) z t . /L ^ U T f J ) GO TO ^, 371 LA^-^^( T ,.j)rT,qq9

33 COr TTii ip r\^C + * + + +

C irnnj '^ATA GROUP *

c

c

C SEPIJ- - '^A?'\'^ SF D-i^-'TTO'' R'^'^M^crn prru/trrM AT^C^^FT Of" SA*-^F PATH

C SE'^T!. - c;rp/^n Tjor , f^r'^lllptrn prJW^^^! a L/iMrjjM/:; /^/(^ ^fvjH ft A/C

C T/^i^I'ir OF^ rroov THf^ «^A'--P^ RLi"vAY

C ALL CTGTA-''C'='S APt t-, ''AityjrAl ••'TLE'^.

- 113 -
C SEP? - TI'T SEPARATION' c^EOi'IPFTr BE"^K'EFM AIPCRAf^T DEPARTING ON

C niprrprrjT Pll^^WAYS

C

'40 IF(T"Pi'T('i) .FQ. MGO TO 'J'=^

C

C STA'inA'^^ SEPAPATTOK f'prMjjRrMflViTc;

fj —

SFPTL^:?.

00 4! jrl,MTYPr

SF^IJ . ( 1 » .!) ::S. '

. TiO "1 T-'^f^^TYPF

^\ sEPLi ( I » = : • .^.. .T • - SEr^l L ( 13^^ "^0 l^iC T = l»MTYPr

r:0 1 -I'l .1=1 »' 'TYPF

SFPTT ( T , J) roi) . / ,-^.f-,nn . +pott ( t ) I'fO :;EPo ( 1 , ,1) z^^oTT ( I ) '^0 ]'i il J='^,'iyYpr

11(1 SFPTT( 1 , j)z:p,/,';,r ,+^>rT-]-( 1 ) SEPTT (1,3 ) zP./bC

.

TO ''>'^ 'JO '<EA'. (OfTns) orr^TL

;rEA''^ ( (0^r>L[ ( I , J) , izl rr'TYpr) , jrl ,'ITYPF)

pFAn C-.^Tfi^-,) ( Cj^rJjilfJ) rlrl ,^lTYPF) ,J=l,rTYnp)

r:EAn (q,7n^) ( ( ^rp? ( j , j ) , i : i , rnYn- ) , jr i , kityhp )

r ^ If'Pijx '"^rTA ("-ROUP ^. * . ,

C

r . C W \F i J ) - TAf !^r,•^•)7 'ir or <^lirjl.'/\Y I IL-MT) - fr):i pACAiin PMMWAYC, TNE I PFT ^-P pTghT PFSinNATION

C ^OP rXA'Pl!^, IP P:)r ;AY P IS U r IH!-An(p)r^1 AMP TLR(P)='^

C TM?:)Y(T) - ';'!';^FP np: JH"^ opFPATT^'^ P'^LTCY TO PE MSFO ON C5)I^'WAY T C OPPfMj) - '-^ori-.-M j-r^ CPPP FOr^ POLICY MiriRF^^ .i C SQOP(Jr') - SFOljr:;r^ qp OPPpaTIO'-S ^op POLICY J (1 = TAl^FOFF*

C p - L^^'O. THE FFOMFrjcr is orpFftTPn OVER AMO OVrp,

C ^S')OP'( J) - MUV'PFP or OPi^P AT TON'S TN ^OLTCY J

C SQ'^'-'{JfK) - TMF PM\''AY 'IPor! WHirM TMF K-T(< oppp/MlON IN POLICY J

C IS TO '^CCUP.

C^PES A"r 1- TA.KrrrFS nt|LY, p- lANPINRS ONLY

C 3-.ni|A|_ M^F, '\LT^PNATTMG OpFpATIOMS

C 'i-nii/\L MSE, I ANHT'sK^c TAi'P" PRFCFDENCF

0 nO:V(T) - riSTAflCF rr. oi*TPR ''APKi"^ F^-P piiMWAY I C !^'LYOM( T f D- TIMp r I" vi'MiTF^f PP" A TYPP I A /C TO FLY FROM HANnO*^F

C TP Oi'TFP »'APKEP OF PUT. '-'AY J

C jI';T(I,J) - PiSTA'^iCr FPOm E^'O OF RU'iwAY T TO ITS I ^ITFRSFCT I ON

C "'ITM r-ll' WAY Jr TN FP^T

C TfiTFP(T»j) - if.iTF:.'P!^PEP!CF CPPF r^r^ ^UMWAYS T AMP J

C COr)FP ^PE 1- I A^ir^TMr;s o^| T ArjP j TNTFRFFRF ANO

C ;r ''UST '^F SPPAPATPn, nijT S I WULT ANFO' is

C . . ^ T/\KFPPFS ARP PEP'^TTTEO IF THEY DIV/FRGP".

C '>- '•'0 ST^'i IL"^AMF'>"S OPEP'^TTONS PPRMITTFP

C IF Mt-TTMpp, CO'^PLt^T"^ r 'PEPFNnPfiPE IS ASSUMFO.

- 114 -
?P JF(IMPiJT(5) .FO. ' ')'^0 TO ^5

r' ^ ^ — — —

C ST/\'.nAr-^ r-.ATA IS TOP 51 'GL^^ ^ll^""'^Y '•'ITH /^LTF'^'i^TTMG OPE^ATIOmS

C

PATA rj^?=-V] /T'-<F/"'f> (n/]S/!IR(M/?^ /^Dco f i) /^/ro'-l ( 1 ) /5. /

1 {'"LYOK J» 1 ) » J=l r ^ ) / l'^ . , 1^ . » ] . /DIMT { 1 , 1 ) / n . / JMJFR ( I , 1) / O ./

P f :p / C>/(C.OOP( 1»I) ,^- \ »?,Q*0/( SQR". ( 1 » T ) , 1 = 1 r ] 0) /1» 1 »e*n/

3 L'^^T(M/l/Tr-i>(:)/l /^-'^x/i /

GO '-^~"> 55

551 RE/*:.! (~f '^,5»'rr:D=S'^P) I » TwF/i- ( I ) » tlp f t ) , jr'^x f T ) , '^n^' ( X ) 73"=^ FOR'-.^K TPf lU»AP»T'-i»^7.P)

;RV r' lP • + 1

b52 30 553 iri^^Mf.X

LA5T(I)-l

553 OP^T'(I)-'^

554 PEAP (^r6l5»'^r!" = '=>'^7) y , QPfo (

^ - y ) ,

* > j m , ( qooP ( : » I ) » I = I

» "ilD

)

'jS0OP{ ny)=MTn

615 crop ^ AT (2313)

PEA^ (5r6l6) (SO" (^X» T ) , Irl ,r T^O

616 FO^'VT (ox»20I31

IF (Mpx.GT. M^T'X ) •rY3f'"^Y

SO TO c.5i^ 557 pO '^56 i^-if'iP'A

I=I"PX (K)

IF (I.^Q.O) f^O TO 5^6

IF (OPf^"^. (I) .GT.O) or TO ^56

•RITF (<^.»'=^nO) I»K

590 roRr-/T r n .;AR^JIri'^ - no "olKY P^^^^I^-FP T p y » , 1 5 , 2X »

» FOP RUM'^-'A

1 Y » T ) 556 C0!'TIM-^

PO Tt:l,^!R^'

PEA^^ ( ^ # 70^.) ( PLYOv (.Jf T ) , jrl , -TYP^)

PO "^6 . izl , NIP Pl lT( I r.J)=0.

I;.-T^r- ( T ,,J) r-,

56 CO' TIf.

57 PEAn(«^, , -71^ ,rK|r-57i ) I , J, - TfgT ( T , J) pDI'ij ( J, T ) 71C-, F0Q'",7 (oTp,orq,i; ) GO TO n7

571 RE'^D(5»^?n»^^iOz57^) I r J » T "TF^ (I » J ) 70 0 FOf^-.! T ( I't I ? ) GO TO S71

572 PO 1 = 1 no 5P J=l»^tTYPF

5R FLYOv(j,I)=FLY0^'{J» T)/^'^.

no 5'^ jrlfN^v.'

59 Pir'T ( I » J) =nTMT ( I , J) /^0 7^,

00 6G T = lf^iPW

^0 60 jrir^!RV

iFdNiTFod, J) .rrj.r, T-^ 60

T'JTF" (J, T ) ZT^'TFP ( T , J)

60 CONTI*-

no 1 = 1 »'!^--'

00 '^ ' J=l » 'l-^W

- - 115 -
IF( IMTFR{ T f J) .EO.n)r.o TO fiO

Il^IMDXd)

11=4

IF (Il.^JF.n) II=OPFP(ii)

J1=IN0Y(J)

IF (Jl.Mcr.n) jjropro(ji)

IF ( TI.LT.?,Of<. JJ.LT.?) GO TO 6^. K=K + ] ^PTdrOrj

TPTd »K )=1

65 IF ( T I .ro.2.0R. JJ.r-,.?) go to 7n

PPT(T»K)=J

TPT { T rK ) -4

IF{ inTF^. ( T » J) .FO. 1 ) TPT ( T f K ) - 5

70 IF (II.^o.p.op.JJ.F^.l) r^O ^0 7'=-

RPJ ( T r'O =J

TPT(T»(')r3

75 IF ( TI .r-^. 1 ,0R. jj.Fo,2) r^O ^0 fin

,PPT ( T rK )=J

TPT(Tr:/)r2

an coNTiNiir

DO ^5 J=:1 » IFC^TT'^Tf T» J) .LF.O. )'^-0 TO 85

K::K + 1 PPT (I » =J

TPT(I»^^)=h

NPT(I)-'<

K = K + 1 no Qf- vrKfKTn>T

PPT( I f !.) -n • • ^ TPT(T»!^)-n

86 COr:TIf.,i!- '

^ CO''TTK>u^

C

C * INPUT OATA GROUP ^ *

Cc

~

C PRWYT^dfvJ) - THE i^PACTI^M or ALL TA'^FOFF': OF TYPF T A/C

C /;HICM ijS"^ pUMa'AY J

C PF?i»^YL ( T , J) - THF SA"F FOD LA^!nIMr;S

110 IFd- 'PUT .FO. MnO TO 115

C STAf'HAr^n PLjr^iv/AY USAG^ hA*^ ALL /"Ti^CRAFT ODFRATIOMS OM RUMWAY 1

DATA (pr^^'YT( T r 1 ) d = 1 r :^ ) /3* 1 . / ( n^'-'Yt d » 1 ) d= l r3)/3*l./

GO TO t'lS

115 no 1?0 J= If "'TYPE

120 PFAP ( 5r 71 0 ) (PPWYT ( Jf ^ ) ,

-[ = 1 » ^'RlW) » (PR'/YI. ( J» I ) dzl »NRW)

:jO ^22 1 = 1 f MPW

Il = T!'DYd)

- 116 -
Ilru

IF (Il.^-T.o) IT=Of^^^(in

DO 1?2 J=l»-iTYPE

IF (PR • YT( Jf T ) .GT. ^ . flN^. TI . ) WRTJE (f=>»8"^'^) J»I

830 FOP'"AT{» '"A-'lI'lG - Tt-iE°^ IS a p^<;ITTVE PC^ORA^ILITY THAT ^ Jy^E* * llP.r' AI-^CpAFT 'ILL ^AK^ OFF FOC" /I » • "^tJMWAY t

, IP ,

f

, WHICH HAMOL'^S

? L'\L:ni"GS O^ILY ' ) IF (PRwYL ( J» I ) .GT. n . AN^ . II 1 ) WPTTF (f»qun) j,i

Alto FOP^^AT( VfAf^'oiNJG - T^JFP- IS A posuTVE pdORAOh tTY THAT A TYPE'r

I12f' AIPCPAFT AflLL LAMH ON » / 1 ? v ,

f Ri )mwa Y , I ? , , WHICH HArJDLFq TA'^E

''OFFS 0^)LY)

IP? COMTIM"^

1 24 1 IF ('IR.A .E0.1) SO TO 1'+^

^0 130 T = lr\'TYPE

no 1?5 .J-?_r\R\;:

PRV'YL ( I f J ) r'^PW YL ( T » . '-l ) +^RWVL ( I , J

)

PR.jYT( T f J)=PRIVYT( I r J-1 ) +oq^.ivj{ j ,,))

IF ( r'T( {pp',vYL( I »NP''' ) + . 01 ) *i 0*^ . ) .r-;'^. IP'^ ) '.'PTTF (^» "in ) i 810 FORf'AT(» 'vA'^MiriG - "^POHARILTTIFf; OF A aipCPAFT LA^oin^

lOM ALL PiJf'WAYS no (!0T SU»' T*^ Or^FM

IF(iv'T( (PPWYT( i»rin./ ) +,ni)*ion. ) .r!f^, ino ) wrttf (6»8?n) i 820 FOP'/'TC' WAP'II^'G - ^PORA^ILTTirS OF A TYDr»fT2»' AIRCRAFT TA^'IMG

lOFF FR'^-^ ALL RUnw^Yv DO NQT sU*-^ tq omE')

130 COMTir'ilF

145 'JO 150 r = i»i?o

15n rj(I) = I no PS m »^|R'.•

TDf^MC T ) r (no^/" ( I ) /v'LAr-'n ( 1) ) *PTYPr(2, i ) AFP' ( I) =Tn^'pi ( I ) +POTT { 1 ) *PTVPF (1,1)

no QS .jr?,MTYP'^

TDVr'( T ) r (nO^^{ I ) /VLANnC J) ) f PTY^F(2f J)-P'^Yor (p , j-i ) )+TnMpj( J ) 95 AFIN( I ) rTD^TMC i)+r>nTT( J) *PT^DF( 1 , J)

no ICC 1 = 1 r 'PW

CALP; ( T ) 3FLY0M ( I f 1 ) *PTYPr

(

p » 1

)

PO 100 J=?»NTYPE

ino CALI' : ( I) ^FLYOf' (I» J) * ( PTY^E ( P » J

)

-pTYPE ( ? f J-D )+CALIM(I)

C

C * /.RITE ST"'^iLA,TIO^! Ti^UT *

C ******+*****************

c XINCr5.

L=0

vzP.

.'iRIT"^ i'upoq)

:iP9 FOPV'XT (

' 1* » QX »' » » a y » -^0 ' » '4Y » M

aRITF(v»P0O)'J{1)

'•;KlTf^( P00)N(?) »\tPVv'RITF(.,',on0)N(3) r^TYPE

'•.PITC {^'1»q00) M('+)»*^'nX

•,VPIT'^ ('W 900)N(5)

WRITE (-'»920) M((=>) r"^:ny»^!('^) » (OP<^R(T) »I = 1 rVMPX)

WRITE("»^30)M{7) »MP 'rMC?) » (nOM{ T ) » 1 = 1 ,MP'J)

wRITE("''»92n)N(8) »Mpw,M(p) , (r PT( T ) » 1 = 1 »^JP''')

no 155 T = lr'|PV/

IF(f!PT(T) .EO.0lf!PT{ I)=l

155 CO'^ TIM!!'^

•RITF(^f f^40)'i(Q) »|TVDp,M(3) ,'jRi. ,M(2) , ( (PLYOMf J, I) , T = l ,MPW) r

- 117 -
lJ=i»F'TYPF)

".'RITF CUO^f)) M( 10) ,MMnY,N(" ) > ( ( ';QP'^' ( K » T ) ^ ! = 1 »KSFQ) »NSQOP(K) r 1 K-it'^my)

RTTFC ^r930)M(ll) ,NTYPFrM(?5) r (Vl ANDd) r T = l r^•TYpr)

WRITF('i»^30)M(l,?) »NTYP'^»M(3) » (VTopRf I) »T=:l»MTYPF)

VvRIT!^( /ir^30)'l(l3) f ^iTYP'^»^l ( 3) » (POTL(t) ,irl ,mtypf)

V'RITFC lr03n)'j(it|) r!lTYPr,M(^) , (POTT(T) rl = i rriTYPF)

.vRITF( lrQin)N( 15) rV^/^XT

IVRIT''"('^»910)M{16) »M{P)

l-'RITc- CrOUS) M( 17) f MTYPFr^'(3) r YPr , M { 3 ) t I (^FPLL{ I » J) » J-1 rNTYPF) »

I T = l r iTVpc::)

v RT TF {

' r Ql 0 ) N ( 1 q ) , F^PtL

.'PTTC ( -^o-^o) M( IQ) r 'P'^'•'»^'(P) r ( rALTM( I) » 1 = 1 »MRW)

'RIT^( ' (.?{) ,M(,o) ,.)(!) ,r;TYPi^»[Jf ') r ( fPTYPF( T» J) » J=l»'^JTYPr) » II = 1 »'^)

"(RITF (-.1, QUO ) M { ?1) , 'iTYpr f M ( 3) »MPW , tH '*) r ( (PPWVT ( T » J ) » J=l »MRW) » 11-1, iTY^-'^)

;PlTr ( Q/tO )

f

I ( 22 ) »' i'^YPC-»f ! ( 3) » MPW,',N) ( P) , ( (DpwYL ( T r J) » J=l »MRW) » 11 = 1 »'!TY"F)

•RITr ( ',0^,0) ^^(P^.) »"'NnX»N(a) r ( (^QOP(K»T) » 1 = 1 »KSFO) rNSQOP(K) ,

1 Kri , ,r IPX ) - 'aRTTP C'.^q^:)) ri(;34) f ,tj( 1 ) f '-^^iDXrriCU)

WRIT^ (",^pn) ^J(P5) »^'Mnv»N(fi ) » (I 'VSK T) r T = ] »MMDX)

:''RITr( ',Qi+^)M(^6) f ^'^Jl•'r^'(0) , r'RW r M ( 2 ) » ( ( HlMT ( T » J) rvJ=l»MRW) »I = 1»NPW)

WRlTF('»9S0)r|(27) r

1 1 ( P fi ) r ^• ( ? ) »r!RW,M(?) rM(P) rM(l)

'JRITF (''%Q60) N(20) »MRi-',r!(?) r ( (0PT(T,J) » J=1,KTPT) » NIPT ( I ) »T = 1»NPW)

.iRTTf (''r"6')) 'i(^n) pMRWf^i(?) » { (TPT(T»J) »J=1»KTPT) »NPT(I) »I = l»MRW)

v.'RIT^" ( ) M

( 'D r NPW, M ( P ) r (TP^'TNtC I ) r 1 = 1

»^!t''•') WRITF {"rQ'4 0) t!{ ^^) ,NTYP'^,N(7) rMTYPFrM(?) » ( (SEPTKTr J) » J=lfNTYPE) p 1 T = W!TYPF)

A'R T rr ( ^,Q'SO)M( 33) .38) »M( 1 ) »M(?'i) ,M(^)

V'RIT^("r910)M(39) rT^^FG

'RITF ( 1r 9S0 ) ^| (UO ) » N ( 4S) r M ( 1 ) »^-!RV' »N ( ?)

,vRITP (-,qiO)M(46) rTFr-n

,'.RITP'CW^^i40)M(a7) » N ( ? ) »

f

' ( 1 ) » N ( ?a ) r N ( ) r ( ri Ir J) r J= 1 T = 1 r P ) ViR I T" ( » f^P 0 ) ; 1 ( i^F. ) » T '-*OUP

yRITF C't^^^O) ^^C+f^) »^'TY^r,M(3) »'"TYPr»M(3) » ( ( SPPP ( I » J ) » J=l r NTYPE ) »

1 I = lr'^YPF)

A'RITF ( f Q''50 ) N ( SO ) rM(l) r^fp) ,M(1)

ifiRITF ( ^ r ^^5 0 ) N(51 ) rM(P) f M^W»M(p) ,M(p) »M(1)

v;RTTr »95S) ^1 ( ) f INT TP

'-..'RTTr (

' » no o

)

M(Sh) r TCA^

^^;rit^- { »^;^(t) ^) ( S7 ) r MR''.' (P) r (I-^'nXd) tT-^ rMP'Al)

WRITF »95n) I ! ( 5P ) , N!(co) rM( 1 ) f'^'P O'K?)

»Cj3D) ^! ( ^SO ) r \'R'.'' t M ( P ) » ( AFTfi ( T ) » 1 = 1 »r!r?w)

/:RIT^- (^ »9'^vO ) ^•(61

)

» ( fsi ) ,^'D^,',^|(p) ,M(P) 1)

'''R1T~ ('^ f 900 ) M ( 6P

)

( I'l)

v/RITt- » Q5 3 ) ! 1 ( 83 ) .f|(A3) f M(P) ^^'(24) »M(S) »M( 1<+) »M(6?)

-JRTTT (

' »9n) M ( ) ^ VI^'C

•".'RITF (••• » ^50 ) M ( 6^) Fr'( A"-.) fM(l) »^'(14) »N(6P)

WRITF » 91 0 ) r'(66) r T P, F '^ WRTT^^ t c^o ) M(^,7) r^'(^7) f N ( P ) » MP A/ r ^' ( P ) » ( P ) » N ( 1)

wRITF

(

' f nyn ) 'RIT*^ ( Q.SO ) ^! ( 1 ) r L »l. 90 0 FOR"'/'-"'^ ( T 'i»SX» ' 0 p »

;

^39)

0 -O^-'-'AT {IU,S/,M r Tf,, TU rp-'x ^ Pf^ ( IP ) ' / f PO TP) ) 930 FOl-''"/' T ( I '4 » ^ ^ » ' 1 ^ • » T f, , T u , 27V , » i < 13 . 4 ) / f 1 QFo , a ) )

- 118 -
9k0 FOR^ 'iTC T'ir5y» P • f ^^^^ » i^TU , 5Y » » R F » i IX »

• 1. ? ( n i . u ) / ( 1 ?Ff, , U ) ) 9^5 FOR^'AK TUrSVf »?. P ' » 1 6 , 3 Ta , ^ Y , P F » 1 1 X r

• 1 n f n? . '4 ) / ( 1 OF? . U ) ) 95n FOP'\M ( ^T^l r I? r 7»»T5r^T4)

955 FOR^'/^T (T4»5X»»0 P • » 37y » C0 1 ? ) • / ( 01 ) ) 960 FOR-^'-^T (T'4»5Xr».'> » 16 f I'4 » 1 " X » ^ » BX r

• ?>n ( I P ) / ( ?>0 T ? » 30X » T2 ) ) 97n FOPvAT { »

)

9Pn For^-.'AT ( T^r Ta» T-^)

C

C * PR I : IT ^'iM DFSCPIPTTO^ ' *

C

'.'RITr (f^» 505)

50S FOP^"^'T(//?nx»ATPr^M^T r^r^'^CRTPTTOMV/l X»TvpEM5y»SPFFD5 (KN0T^)»6Y

] »Ri'^V'A / OCC'IPAr CY. (SFCO^'nS) • /] 8Y»LAMniMr. 4X» liftoff 6X»LANDIMG» 6V

ptjAi/rori^'//)

00 160 T-l » ^iTYPr

RROTL = '-'0TL(T )*3h0r,

.

PR0TT-^?'^TT(I)*^60G.

'•/RTTF (-^f 51 n ) T rVLA'O ( J ) , >/T0Fr( I ) » PPOTl. » OP^TT

eir- FO!-* 'n( ' 1XT?» i5v'"t'.,or"'YFU.o» lOYFM-.nrgvFu.n)

160 CCJTirhj-

. RITr(f,,Sl 1 ) 5 3 1 F0Pvv'\T(//5X» TRAFFIC nr<;r o j pT t of ' • //IX TYPF » 5X LANOING t+X TAKFOFF

1 / 1 P Y ^

' I Y M X

' " " I X • / /

)

A^PTYPr r o, 1 ) *3 no,

RrPTYP? ( 1 r 1 ) *inO

.

'.•'RTTF(Af515)M(l)

515 FOR^^M ( '^X 1 2 r P ( TX^'i . 0 ) / ) no 165 T = P»[!TYPF

A=("TY^'f^(P» T )-PTYP^(P» T-1 ) )*ino,

p=(PTYnr ( 1 , T )-PTYr-r( 1 » T-1 ) ) +1 on.

V'RTT^^ ( A, Si 5) T»A»R

16S CO'iTlNU'"

•RTTF(6»5??)

5P0 FOR"AT ( I/'' I'^PQ^T ^O'-'F I m !R AT T Ori ) ,.PTTr(.-,»'^P5)MPW

5P5 FOPf"^T(///« MU^^PF'^ '^F PU^JWA^t; r»T?)

no 190 T = l

» MPv;

I I=T"DX ( T

)

IF (IT. ^0.0) ^-0 T^^ 166

jzOPFRdT)

GO TO ( 170 H 75» » 1 '^'=>» 1 «^6» 1 ^6) ».l 170 '/RITF(6»530) I r iMF'-iPf I ) r TI.R ( T ) 530 FOP'^aTC OPU'-''/MY» T-^r • (TP»'iP»») - TAKEOF^^S 0MLY»)

GO TO I'^O

175 .JRITr(^,rS35) I»IHP''\n(T) ,t| p(T)

535 FOP-'^'iTC OP'i'].JAY» IP» » ('T^»AP»») - LA^|D.TM^S OMLY»)

GO TO

IPC i.'RITr(^,, ^'10) I , IMF^n ( T ) , TLR( ) 540 FOP-'AT{ nPilM''AY» IPr ' (I^rA-'rM - D'lAL l'5F, ALTERNATING 0PERATI0^'5

] ) GO TO

185 /.RTTt^C^-.fS'^S) I » THr'\n( T) , T| p{T)

5i4S f^or.'"AT( IRMMWAY* IP» ' ( • T P r »

' ) - Di'AL l'«~F, LA^•^T^IGS TAKE PRP"CFDF^N

ICE')

00 TO 1 '^'^ i^^o ;;i(!=';s )0P( T :

)

- 119 -
DO 189 J=1»NIN

JJ=SQOP( II r J)

GO TO ( 1B7» IRB) fJJ

1'87 SQOPdIr J) = »nEPAPT»

GO TO nQ

136 SQ0P(IT » J)=' ARRIVF*

189 CONTir'DP"

IF (OPP'^dT) .GT.S) -^o T'^ 191

WPITP {^,f'^^e>) I » Iiir/^n( T ) , 11.^7 ( I ) » (SQOP( I , J) , jri ,MTM)

5^^6 FORfiAT ( 'nP.iMif'AY' » ('»IP»A2»») - nu/^l. -IJ«;P » OPFRATIOM 5E0MENCF

1- '/(Sv, 10( A6r IX) )

)

GO TO 1 "^n , 19] 11^=0

;}0 1 » "IM

IF C^.O'^ ( 1 I » J) .FO. T) GO TO

IF (('I' .f"r;,0) GO TO lo;^

no 1 pp J:i~]

19? IF {<^,Ofv':'( II , J) .FO.:^ '( JJ) ) GO TC 19'+

193 'ii'''=rji''+i

RW('iT.'1)-S0PA'( ITf J)

194 COMTINi'F

IF (Nl-i.GT,0) r.O TO 19<^

^JPTTF ('^»SM6) IrlHFAn(T) »ILr (I) . (S0OP(I»J) »jrl,MTM)

GO T<^ 196 /JRITF (h»5'+7) I » ThF/^ o ( t ) , IL^^ ( I) » ( RW ( J) » J^l » MTM)

547 FOR^^AT ( nP!J^'lA^AY # I?» Crl^rAPrO - OPFPAim i/'TTH RUNWA YS r 1. 0 12

)

•/RITF {,Sr5'^'^) (SO(M^(IIrJ) rS'^PWdTr J) rJ=l»MIM)

548 FOR'"iAT (» OPFI^ATJOM '^FOUFNC'^ Z"^. ( 1 X r AfS » » OM»,T:?))

(^0 198 jrl f'llN

IF (S0OP( 1 1 f J) .FO. • /\RRTvr» ) SOOP(IIfJ)=?

196 IF (SGO'M 1 1 f J) .FO. "-TPAPT' ) c;oOP ( 1 1 » J ) = 1 CO TC I'^O

lfS6 wPTTF i^-fTAn) I r T^-^nn ( T ) , IL^^ ( I

)

549 FOf">'AT ( O^ti'lvvAY* » TP, » ( , I , /! P » ) - NO noLTTY PROVTOFD/ NOT U5FP

1 INITIALLY*

)

190 CONiT JMi ir , .. , ; . 00 1 ^5 T:=1 f'lRV

00 195 J=If-iPW

TF(nTf!T( T» J) ,L£,0. )G0 To IQ-^

A=niMT( T » J)*6G7fS.

B=:nT'\|T ( Jr I ) *<^076.

'•'RITF(f,»55? ) IHFAn( 1) ,IL^(1) , jy^Fi^niJ) , IL^ ^ J) » a , THFAn( I ) » TLR ( T ) »R»

1 IHFAO( J) f ILR( J)

SSn FORMAT(//»0^UriWAY'^' T3» A?r » ^'D T r A p. » IMTFP'^ECT AT A POTNT»r7.0»

1» FFt^T "^^POM THFV FJID PP Ri 'MW AY » I :^ , A? r • ANn»F7,0r» FFET FROM THF

?END OF RUNWAY I 3 r A? ,

• ,

)

19B CO'.iTiriMF

DO Pl"^ Trl r TI

JJ=T+1

DO ?\b l=JJ»MR>/

IF(IMTF(MI»J) .<^O.r-.AMn.TMFA'^(T) .lE.TtlFAnf J) )r,o TO ?15

L^Jf'TFi^ ( I » J)+l

IF( T'-'E'\''( I ) .MF. INF AP( J) ) ^0 Pn

GO TO(500,?O5»P10) H.

20 n ''RITt-(Gr S'^S) THFAP ( I ) » IL'^ ( T ) » THF/^n( J) , ILP ( J)

S?5 FO'^^ /^T ( / ORUN'^/AYS* T ^ » AP» » A' 'O » T

•« » Ap » » ARt^ IMnrprMpp|,jj PflRALLFLS

i/» S T V! I", T/" Mr-r)li^> or^p<". TIOMS ^^F PFR,VTTTFn»)

- 120 -
GO TO ^IS

205 WRlTE(^»^6n ) TrFAH ( T ) » T ( T ) » T h ip; n ( J ) , I L P ( J

)

reo FOrT'^T (/» DPUM/.'AYS' I?» A?» ' A'n»n»A?r» AR"" SFMI-OFPENOFNT PARALLELS

1 -•/ ^T'njLTANFOUS .^PRIVALS APT oROHIRITro*)

GO TO 215

210 ;RTTr(^,Sf,^) THFAHC T ) » Tl."^ ( I ) » TMr/^n( J1 , TLP f J)

565 F0»' AT( ^'Of?:)M'vAYS' T^»A?» ' '\ ^ n » I » A P » APf^ Df^PEMDFMT PAR*LLEL'=; -/

It ,>;n SI'^' M.T ArjFOUS OPFRATTO^'"^ Ar>r pppMUTrr)')

00 TO c: IS

211 GO T0(?15»21 ^f?!."?) »!_ 212 ,;RTTF(-»'570) THEAn( I ) , ilp f I) . TMF j) , ILP ( J)

570 P'OF''AT(/»0Pijr!i^AYS' T^f A2» » A' 'n « j ' , A2 » APf^ SP''I-nFprMDFMT -/ SI^^U

1 LT/^' I'^C )^ ARRIVALS A .T P^AHT^! TTF'^ ) GO T^ 2!^

?1?> mRIT:^('-, »S75) IHFAP(T) »TLR(I) »THFAn(J) rTLP(J)

^75 F0P''AT( /nP'jMoVAYS' I''»AP» AMn»i-»,A2r» APr r)rDp;iMr)EMT -/ NO SI^''ULT

lftKjFO"S ^PFRATIOfiS At^F PFt^M I TTFT' • ) 215 COfiTir;*:^

PO 'iP2 I = lr'lTYPE

J= MPl-

'fOl c'-R^'Yl ( T f J) rr^-'RvYL ( T » J) -P"'''YL( T » J-1 ) PR''iYT( T , .J)rORv. YT( T » J

) -PPWYT ( T » J-1 ) J=J-1

IF ( J.^-T. 1 ) 00 T^ 'K 1 402 COrTJNJ^

'.VRIT^ (f r'lUn)

i^;|0 pr)R^'AT (! FRACTIO" !.'^N^T^lGS ^'F ^^ACH TYPE 0^' EACH PUMWAY*///)

wRTJr- (^,,t|Sn) { Jr TMc-,rn( J) » I!_P ( J) , J=1 »NR''')

aSP FOP^'^T ( 7X » ' PIJN'wAY ' » "^X » 7 ( II » » (

• » 1 2 » A2 »» ) • r o Y ) ) •'RITF (0»c.c;|)

451 FOP 'U C^y* 'TYPF'/)

[)0 '^0 3 i::i »'iTYPF . WPTT^ ("»45P) I r (PV 'YL ( T » J) » J^l »"RW)

452 FOP'^'^T ( 3/ » I2r 3X»7( 1 OX ^-'S.a) ) •4r.3 COI 'T I N'J^

A'RIT^ (0»'u53)

453 FQP'^AT ('0'///)

/'RITF (6fM54)

454 ^OP'^'iT (0 FRACTI0:J OF TAKf^Pi^FS OF PACH "^Ypr qm FACH RUMWAY*///)

.vRITf^ (6»45n) ( Jf TH'-An( J) » Tl R ( J) . J=1 rMPW)

WRTTP (0»951)

404 I^lrNTYPF

vRITF (r)r452) If (OR-YT(I»J) r J=l»f'RW)

4Ct^ COMTINIJF

STOP

END

- 121 -
E.2 Listing of the DELCAP Simulation

+N GFN 4 RWAY 31 ? I 10 F

-N MXTOP'+ . N OP 3P ? I ?RW F

^-N LAriD 3TYP p

TOFF u any r COIR . ^l PT '^ I SH r

+r: FTIUP^ T TYPF 1 I fnOPFR 1 T +r TMTU nL/\Y f+ F 1 P

+ T cri T u T TJM •? P 1

1 T + J TTFl.iPU 9FL Yn"»i 0 p

J Tf-"TM T T T f A p 1 1 \/L ^'•10 1 r

+ 1 ?VT'^'~F 1 c + 1 3P0"ri 1 P

1 P

T SO I 1 "^VTA Yl 0 r + 0 r

4- 1 TSFF*' L C> p

+ 1 PSf^^TL 0 c

1- 1 r PQCTYi^E ? P

+ CR»/"'YT '5 + P F

T p(4 Mpyj 1 T + 1 T + r

'57FC pi T + T oqr?pT T + ».riTpT T + 1 r

+ ^PSFP^T p r

+ 1 T + 1 T *5^ILAMD 1 T ^f>MTOFF 1 T + «7nfI T 1 F

f 1 r

+ 0 F + T PQMT t 3 T '1 OFO'^"'" I \ T T SOMT T a TX. 1 y + T1 PTHT T 3 TX

/I ppTWTT 1 T T1 CTUT T

71 1 ~ f J. T

i

fi"^! TMTT 1

1 T

1

4. T np-p T T T

1 /iZiCrpQT * M- T r r. ' i

1

I T

4. T1 r P T T ii T

1

'* " L r 1 i

1

! T

1'T ') f P r

+ a PI HOI IR 0 T + fi ac;pn'5 p r + nr.FMM 1 T •"ITPP''' p r

0 r

Q 2 F PTYPFI

PRWAYI

FREERF

OVTTl RTMAX L

THTTl RTMAX L

FRTIl RTMAX L

- 122 -
+

CT T ' Oil T

I o T + T 1

' K 1 + ^ ^ C A ^ P T +

c "7 J

' : Y 1 T +

c Q T • "-\ y 1 T

4 +

+ J 4 ^ 3 N P L Y P T ++ 1 T

j + ^1 A P T T ' ^ 0

^ 7 T T r

r\/rr i-|-c;

cry~(r>-; f ^ ) CH'~-OP( 3)

r 'XT'^P

LA •'1

FT r

CHO

PRT'iT

OTP

- 123 -
00 TO 1» FO^ EACH n T

STOf-T I Tt! OP(OFfi)

STOPF "^f T'l GEf IN ( I ) . CALL "•'Mn(+*IMITRf *P)

LFT T = TT'-^F-LA^'nn( i , t hoi IP ) * ^ LOO (1 .-r?)

CAUSE "jFM at T

LOon

cpf'AT^ Ef-ins

CAUSE 'Uns AT TF'!'^

CHEAT" CHOI IP - CAUSE CHOUR AT TIMF+1.

IF Cf\^ GT 0» GO TO ;? iAiPTTE TAPE (S i FOpVAT ( 1 rS?0 » 'H^HPLV TMOOl IGH^^UT » 1/» 'rlQij^ RUNWAY' »S^f M.A^iDP'GS T^KEOFFS TOTAL'/)

[<FT! 'P' I WPTTF 0'! TAPE b

FOPf'AT ( 1 »S2G » UOMRl Y TH'^OUGnnUT r SO »' HOURLY DELAY PFR AIRCRAFT*

l/« HO'ip "U^'K'AY» »St-,» iLAMDT^^-S T'VKF^FFS TOTAL* rS5r

ofLAr'PTNOS TAKEOFES ALL*/)

RFTt iP ! ENP i;>-oTri

- 124 -
C ASSIG-'S ATTPI?UTrS Tq Tme^^.

C OP(GEM) IS 1- TA'^E'^'^F » QP P-L/^^'DlMf;

STORE OP (GEM) iNj I C GF^ EvC H-nMLES ITSE! F ocrup acaTI AFTi^p a TT^"'^ TMTFRVAL

C OE'^^^!';T'^'G or: TI'.F i^/»TF (^F C^FRaTTON,

CALL 'jn ( +*TNITR » ) CA'ISE '^^E^' \J TP^F-i. AMf^'^ ( I » THOl'R > Al.OG( 1 .-R)

CPFAT- cr|_T

LET IT-PTYHEd)

STORE TT IN TYPF(Fl T)

LFT K = "P -.'AY ( I r IT)

GO TO ( 1 » ^) » I C Tr'(FLT) TS ThF Ti^E FLIGHT T5 M/AIL'\PLF TO pEGIN FIMAL

C DFSCE-,T (For? LA^!nT^:ns) ^R TO [^rr^i^\ TAXITMG RUNWAY(F0R TAK'EOFF)

C CAL^M TS A TIV'F I. AT- PiTROnMrEP Ttl TAKFOi^FS* CORRFFPONOTNG TO

C FLYHv - THF TT« r r\ LA^!nING TAKi^F TO FLY FR^m

C HAMPOrp T*^ THE OHT^R ''"APKE'^.

1 L^T TI•J{FLT)=TI^^f^ + CALT^'(K)

GO TO

?. LFT TT'i(FLT)=TI^'!E + FLYO*'( I"^rK)

3 IF 0(i^»l) IS r*OT P"f'PTY» Gf^ TO a CREATE f'YTO"^

LFT R Y (

' lYTCP)

CAUSE "XTOP AT TI'KFLT)

C 0('<fl) - IS THE O'l^l'E ^F P^A^|^S WATTING TO TAKE0FF(I = 1)»

C LA^:0(I = ^) •">^ RlJ'iWAY ^,

4 FILE FLT IN Q(K»I)

RETHP'l

Er;E G^M

EYOGE 'OUS EVENT EX^-'^N

C EXG!^r; GENERATES t^^f^-LICTT 0-PAPTMRES ANH ARRIVALS

SAV"^ EVENT CARD

CRFAT^ ri^T

RE AO T»KrIT

FO^'^AT C^I?)

STOPF IT l-i TYPE{FLT)

GO TO (If?) fl

1 LET Tl '(f^LT)=:Tr^'^ + rALI^'(K)

GO TO

? LET TT"{FL"^)=TIMr + ri_YO '( ITrK)

3 IF r.(t/»I) IS ^OT -^'^PTYf GO TO <l CRraT^^ MyTQP

LFT P ; '\Y(NXTOP)=»^

CANSE ^'VTO" AT tt'KFlT)

4 FILF eLT II 0(K , T

)

RET'JP'-'

- 125 -
C PTYPF CHOOSES r-h^ /VTPCPAcx TYPF FOP FACM FLT^HT ACCOROIfMG TO

C - CTYPE - THF Cnr^JLATTVF niSTQiru itiq-^' OF fl/C TYPFS IN THF MIX,

CALL '^!n( + + ir)TTR»*P)

DO TO 1 » FOP EACM TYP ,1 IF " IF CTYPE(I»J)» GO TO r> ; 1 LOOP

2 LFT pj-^nf-.j v RFT')^^' ^ . "^"'^ ^^'f^ PTYPF • /' , • : ^

F'l'iCTi"'' ! A Y ( T ) C PR' .'^Y ^'iroS^S A (>')"WAV coR p/^CM FLIGHT /^CCOPPT^|0 TO

C Cf'-YL - TMF CUvilLATTVF n i c;tr i r i it i qm OF PPWYLCSFF PREPROCESSOR ), or

C CP'^'YT - SAMr- AS CP'-YL FOR TAKFnrpS.

CAI L ^"n(**Tf,j-rR^*o)

no TO FOR FACH J

GO TO { 1 r ?.) » I 1 IF R L^ C^,vYT(rv'» J) r GO TO " GO TO ^

2. IF P i .F CP ••^YL(r'> J) F GO TO 'J 3 LOr^Ft| LFT P'^•'/^Y=J

RF T' IR' !

^ •:

'

phi'-* pr? /AY • ,1 ; ;

- 126 -
C MXTOP -^f^Cln^S WHICH OP[PATTO^l WTLL <;rHFni)LFO NEXT

C 0^' FAC'I PU^'^-'AY.

STC^F '>•'.' /5 <( 'iXT^P) T^' K DFSTPOY riYTOP

LFT KR..'=ri^X(K)

IF i^^y ; FG Of PFTiJP"

IF ^'F <T ( K^'-.' ) f'F ij» PFTMPM

IF tii/'^r (yo'i) r,j n<=,r>.0P{i<O',^i) t LFT LA^T ( K P*'' ) = 1 jf nPr-'{KP") ^0 ^» LFT LAS"^(KP''')=1

LFT I T=LA5T(KPv'')

LET IF' 'Or II

LFT X

' irgqoQQq

LFT r^^'irP.

1 LFT K:rSOP''' (!^f< W» I I ) LFT IrS'^0^{KPWf IT ) pyp, FTr?<-^T # F0<"^ ^f^C'i ^LT I'l 0(K.»T)»Tr rmNT, r.Q TO ?

c-jjoPF CLT If: r L^T TrF^Ff~'MK f I rF)

IF TTmCF) L' Tr ^.0 TO 3

IF T '^T T'l^'f GO TO ?

LPT T-^'irT

LFT I I^'l-IT

STORE ^ ri "fir

?. LFT IT=IT + 1 IF II '~.T MSO0P(K^''') »L^T Ilrl

IF TI -!F I^M'^f TO 1 GO TO t 3 LFT I -iNrn

LFT T-"-T

Sjr>oF c T^i "t;r

4 IF T'lT"! Fv) n, f-'iTTmr,

LKT Ir^-'^OPfi^R'-'f Tv.1' ) LFT KrS^cj,./(i<PWf I"T^ ) GO TO (S»6) f T 5 Cr?r,,flTF TOFF

5TORF 1^ P' PvAY(TO'"P)

CAiJSF TOFF AT T'-u, GO TO 7

^ CRFATF LAMP

STOrJC •< IN ^'\AY(LA^'n)

CAHSF L'^^i-? at Tt^m

7 LFT L^ST ( KP'O ^I'-nN

LFT K;FVT(K^'-;)=IMTfi

IF Tn:-X(K) ~Q Or RtrjUPM

LFT K'- •' = T^nX ( K ) IF \ -IF ^F(K»I)# PFTiir^ri

LFT ryr(^fl)-[]

LFT f,'T-.'r'!S0Op(KP 'M

- 127 -
DC TO TOP ) (nl ') LET I~^,00P ( '<r f J)

L'T K rS'^P'," ('^Pw'» J)

IF OFC^'fl) MF n» orTDPM

IF *':R . ]f GO TO o DO TO 'W FOP 1 ) C^iP ^') IF K in {[^ri) , r;r, to i q

V. l.QOp

9 l_FT •'r:"''P'''+

LFT I9v,' ( r-'R' ) rK

10 LOOP

LFT TrT'.M'+.OciOl

DO TO n » fOP ! = (!)( '^^P <)

STC^E Tr?w(T) Pi Y ( C^^ I R ) CAll^F C^IP '^T T

11 LOOP

RtT' IP' 1 ENP 'j<Top->

- 128 -
FREER CALCHLATES Tlt fI^ST TTvr AT WHICM Ft TGHT FLT CAV- PERFORM

OPFf'ATTOr' I or; Rmkj .aY »^ aTTMOUT VI'^LATTMr; qrpflPATTON RULES.

DIf^E^iSIO^• T»(;>5)

LET JrO

LTT TrTT'E

IF T:-;(rLT) r,T T» L ~T ' = TP'(FLT^

LET -'rT^^'EC^LT)

LET F^-rprT

IF ^ ?» ^^0 TO i+ IF -pTie^) IS E'-^PTY, prjut^^i

EPTT(K) TS ^HE SF'T OF 'TIEMPS' "^0^ THE "^Mn OF THE RUNWAY K,

A TIE''^ IS A TIWE IMTf"^VAL OUPTmg vhICH Mn TAKEOFF MAY OCCUPY

THE E':D OF THE RU J-/iY to x "TFRrfrRrMr r poqw OTHER AIRCRAFT.

I_FT T^=" '=TO.'T'.' (

)

TO'-'IfJ TS A Ti:/E L^''-^ iMT'^onuCED TiJTO Th^" SCHEDULE OF A TAKEOFF

C0O^ES^0r!^I^JG TO T^^^ TT'"F TT J^^E?^ A LANDIM^ TO FLY FROM THE

OUTER •APKEf' TO T^MCHPOWN. IT '-'AY pE LOOSELY THOUGHT OF AS

T/*xir'<^ Ti'-"^.

DO "^0 ?»FOP EACH TTEUP TN ^RTK^^)

in T"^-TvAy (TIEU") -TE*'

THE E :! OF THE TTT'in, r^^^ Tji/r ,jhE-' THr p'jn qF THE RUNWAY

BECON'ES P3-E» IS ^IS^l.^rE^ RACK'-iAROS TO GI\'f^ THE TIME WHEN

THr TuKfOFF ^..AY s-^E'^lN t^XI.

IF TT LS T f GO TO 3

LTT Jrj+1

LET T'?( !)=TT

LOOP

on TQ lO

IF rvTr(K) IS F''PTv» GO T^ « 0»'TT THE SET '''^ TI»^iiPS FOP TmE oiiTE^^ VAPKER.

UO TO ^.f FOP EAC*- TTFUP I\' ON'TT(K)

LET T-^ = T--A V (TTEU^)

IF TT L.S T f GO TO ^

L'^T J= '+1

LET T"-(J)=TT

LOnp

IF THTT(K) TS E"-^Tv, G" T-^ 1?

LET T:-'-f-0 '(K ) /VLA' n(v)

THTI 'S THE SET OF Tli^Uns TuE THRFSmOL^ OF THE RUNWAY.

TO FOR EACH TipiiP IM THTTfK)

jjinF5,jr>Lr- TIEUP5 APE '"TSPL^CE" nACi^'; AP"^*^ TO GTVf^ THE TT^^E THAT

ji^r L\T'T;'- -"flY POES TrJF 0''TFf? ''^AR'^ER.

LET TT-T"^X {TI?^UP) -Trv

IE Tj I c; T f GO T':^ o

L'^T J- 1+1 L-T T = (J)=-^T

LOOP

IF J QFT\}o>^

Lf-T F---p = Tn(i)

IF J ] , Tl *P-. ppr-rp Tc; ^rj rG'.'^L TO Tur r-K]n nr jur L'^-Trc^j TTEUP^ WHE^' THEPE

tir> LO'"'"EP '"iMY iMTrnrFi^^f 'CE.

DO TO .^1 » FOP JJ= (!){.!)

IP TP( JJ) OT FPEE-S L^T FP^^R-TP(JJ)

LOOP

RETI IR . Er F'^'~E^

- 129 -
L/^^'D C^i^ATES ALL THC^ 'TiEijoc;! v/i-aCM

RFSI'LT FPOM AM AI'"vrRAP"T LAMOTMr^.

STORE :?V'AY(LArin) K IF 0(Kr?) TS MOT l-""PTV» TO <^ WRITE Of] TAPE ft TT^'Ff^^

FQP'^AT { .'^.T TIME' r^V^.r^.a^S^r M_/»NnTriG Olipur FOR RUNWAY » 13 »

1 • IS EMPTY'

)

STOP

FIT. TME L/\'JnT;iG T^. RF SCMrpijl ro » /^nh <^T0PF ITS ATTPIPDTES.

RE'-^OVr FIRST FLT PPOM 0 ( K

» '>

)

STonp PI T If I n

LET fvrTYPE (FL)

LET V = VLA^|n(w)

LET T r FREP:«(Kr'^»PL)

LET T^rT + no'/i(K) /V

TIP" UP THRESFiOLH T'-i LAMPPir f^jPrRfirj FRo^« TOiJCHnOWN TIME UMTJL

AFTER t^'ir.iWAY OCCUPANCY Tivr HA<^ EL'VPSED.

CRFATr TIF' IP LET T 'TU(TTFUP)=T^

LET T 'AY (TTruP)=Tn + RoTL (M)

FILE TIEUP ir; THTKK)

CREATE FTTMP

STORE I'f Rl-w\Y(FT lUP)

ST^RE ? in PT(FTrJ^)

CAUSE '^Ti'jn AT Tr/; a > ( T I ^np ) TIF UP EMO CF RUM'^'AY TO dfp/\PTTmG /\IRCRAFT rpo'fi TOUCHDOWN UNTIL

AFTER ^Ur.'WAY OCCUPAMCY TI''F H/"-*^ ELAPSFO.

CPEATF TIEUP

LET T'''IM( TIEUP )-Tn

LFT T' -AX (TIEUP) =T'^ + ROTL ('^)

FILF T^EUP Tu ERTI(K)

CPFAT!" FTIUP

c;TnRE D PWAY C^TjiiP)

STonp ^ jM PT(FTTUp)

CAUSF ^TTUP AT T^Av(TTc-Mp)

Flf'O THi^ FOLLOWP'G PLA^T lh> TF"^ LAN^IMG OUFUF

AND STORE ITS ATTRJ"UTFC.

Finn PTRSTf FOR EACH FLT IM 0(t'»2)rIF MOME» GO TO 11

STORE FLT lU F

LET w —TYPE(F) •

. < LET S-VLAUDC^f'')

C»FATF A TIEUP WHICH 'A'TLL MAINTAIN PPOPFR RADAR SEPARATION

t^ETWEE'' A^RTVIMG ATRCPAFT, . QPfr\jr TIEUP

IF S G^ V» 00 TO ?f' IF THt- LAU'lING SPE^P OF THF PLA-^'E "ETNG SCHEDULED* IS GREATER

THAT; THAT OF THE t^OLL0'"'TNG pLA^"^» TIE UP THF OUTER MARKER FROM

THE TT^'- THF FIRST PL/*'"^ p/^SSE*^ THE OUTFR markER UNTIL

TUP TT'^- IT TAKES THE Srco^'n T^ FLY THF SEPARATION DISTANCE

HAS EL'A^SEO,

LFT T iTM(TTFUP) =r

LE"^ T AY (TTf^UP)-T + '^FPLL (M»"^^)/S

FIL'~ TIEUP T|; OMTKi^)

(-pf « jt: CTiMp

CjY^or 1/ If I RWA Y ( f^^Ti IP )

- 130 -
C-'^HS*:'. '^'TJl'^ AT "r"A-MTT'""P)

GO TO 1 1 C IF TH' L/'!".!^'^- Snf-rn r)r J'^J- roL I O'aTmG PI.A'JF IS Gf5CATFP» TIF IJf^ C THF Ti -^-SHOLP F^->"' Tnt 'C--'D^"M OF T\-\c FTP*^T ll^'TTL THE TIME IT jnK^S

C THF Fr-oiin TO FLY ^^'F ^rp i\r f^j ir^' ^Tc;TA^'^P" MAS FLAPSED.

LFT T' TM(TT^UP) - L^T T - A Y ( TTFyt^) =T^ + FFD1J. (M,MM) /c;

Ftl."^ TTT| ip Tr, TMTT (K ) CPFATf^ FTHiP

STQPE ^ I^J PWAY(FTIUP)

STOPE ? IN PT(FTli.ic)

CA'iSF FTI'JP AT T^^Ay(TI^"P)

C CP'~AT!^ i\ TIFijP V'^TC!-I '"'ILL "A jr'TAlM proPfp SFpA"ATIOM RFTWEEM

C T!-!TS I 'VlOlr.r, AMP A TAKFopF OM THE SAMF ^^l^)WAY,

11 FI^-'D FIRSTr FOR PACH Fl.T In; Q(K,1)» IF MONF, GO TO ?

CPFATF TIFUP

LFT T--'\X(TTFiiP)=TO

STO^F Ti J PI p

LFT rTYPP"(F)

LFT S-''TOFF{i^'''M

L"T T •T'l(TTFUP)rT+(^0""(i^)-(SFpT| >,s*V**P/S*f'OTT(MM) ) )/v

ini Fli.r- TIFUP If! fPT HK

)

CPr ^T"" f^T II IP STO'^F IM RWAY(F^TUP)

STor^F ^ i:i f^TCFTINP)

CAUSE cr-rjiin T"^v(TTf^"p)

2 IF ^'PTCK) FO Q» '"^^ TO 10

r NOW CPFATF TTFUPS OTHE^ PUr"'"iY5» IF SUC^ I^•TERFEPE^'CE EXISTS.

DO TO '^.»F0'^ J=( 1 ) ("PTdM ) CPt^AT- TlPi'F

C IS THF PilMWAY AFFcrCTFn.

LFT '<''~^i'J{KfJ)

C IT IS TUF; TYPC^ 0^ Tjnip TT' PF rr:'EATFD.

C TT^UP TYPF'^ Ir ?» ^MD AP^l.Y To LAMDIN^S.

LET iT^TFTC^fJ)

G'^ TO { T » 4 » A , ^, , 8 » ) » I T

C CRf^AT^ A TIFUP TO ^'AINiTMN T^iTFP-Aop i VAL. SFPAP^TI0N.

? FlUn FIPSTr FOR FACU FLT I^' 0(K>^»?)» IF M0UF» GO TO 6

STO'^E ^LT lU F

LET iV,MrTY^F(F)

LFT S = VLANn (rv.M)

IF S V» no TO 3P5

LET T:'ri(TIFUP)zT

LP-T T'W (TIFUP) =T^-FEPLL(M»^'»M

LFT jjrl

GO TO -y 325 Lf^T T"I'J(TTFUP)=Tn

LFT T^AX(TTEUP)="rn + SFPLLCi»"'^0/S

LET

GO TO 7

C CPFAT^ A TIFUf^ TO "AI^'TAIN OEP/aRP SEPADATTOn.

4 LET T '^X(TI^UP)=TO

f+?F Fpin FTPST » FOP EACH "^L T T^i 0(KKrl)f TP Nf^ME GO TO 6

c^jrpr n T P! F

LET v,rTYn'^(F)

L^T Srv'ToEF(^•^')

Lc-y T^ ^I'KTTFUP) -T+ ( '"Or ' ( ) - ( SEPTL+ . V** ^ /S*f'0TT ( ) ) ) /V

- 131 -
if 50 LET Jj::3

GO TO 7

C TIF UP TfiE END OF /^r^ ImTER'^FCTTmg ni.if^wAY To TAKEOFFS ANH LAMDTN<^S

C UNTIL AFTER THE LA\'PIUr, D^c;c;pc JHE iMTc^PSFrTTOM.

^ LET T~'^^' (TIEUf) -Tn

LET Ar ( VTAXI-V) /KOTL(^')

LET TE'>'=.5*A*R0TL( **? + V*POTL ('")

C IF TH^ L/^MDIMG WTLL NOT RP'/^CH TmE T MTEPSFCTTON » C TIF UP U^'TTL TI-IE L'^.h^DlM'^ T'idms oFF.

IF TF^ LF ^ir.T (K rKi^ ) r S'^ To 51

LET P- + ? .*f:*?A* >J f^K)

LET TMP=Tr)+(-V + SnRT{R) ) /A

GO TC

51 LET T'i^=T^+ROTL('*'i)

.52 LET T^ ^.y (TTEUP)=TUP V FIL^~ TTFUP Tfl THTI (KK)

CPEAT^ !="TT')P ' STORE '<K T^l RWAY(FTTUP)

STOPF -5 r.* PT(FTT'I^)

CAUSE FTTUP AT TMfiY(TTn)P)

CREATF TIEUP -

LET T''IN( TTFUP )=TP

LET Ti/W (TIEUP )=TUn , LE^ J.J=3

GO TC 7 ^ , G DESTROY Tin IP GO TO •

. . 7 GO TP (70 1 ,702»70^) f JJ ; - 7P1 FII F TI^UP lU OMTI(KK)

GO TO 7n<-. 70? FTLE TTrriip Tfi TMTTfi^K) . GO T(, 7ns

70^ FII..r TT^UP IN E^TTfKK) - ' -

• 70^ CREATE EriUP ' '

' STORE ^^K Tr' RWAY (FTTU")

STOFr J J I J PKPTI'JP)

CAUSE f^TIU" AT T^^AV(TI^"P) - ; i-^

ft LOOP ' ' '

' 10 CRFAT^ NX TOP

STOPE r? RwAY(NyTOp) .' L^T KK=n;nY(K

)

LET NEXT ( ) =0

CAU'SE MXTOP AT T

C PTE^' IS THE DELAY i^oNf iTEorp py T^-TS LANPTMG.

LET OTE''-(T-TIN(FL.) )+G0.

IF TD LS T'^EGfGO T^ 50

CREAT^^ PPINT

C STORE PAT A TO Ri^CORPFp T TOUCHDOWN.

STO-E ^TF^^ IN OLA Y (PRTfiT)

STORE '< IN "WAY(pRTr!T)

STO'^E ^ If'! OP(PRIf!T)

CA'IS'^ ^ojuj AT T^

50 PESTpoY CLT CALLEI) FL

LET L " ST (K'O =LAST ( K ) + 1 PESTP .^Y I VjP

RETi'P '

- 132 -
TOFF Cd^aTFS TH>^ Ttfijdq p^rr i ij^ t

t

'13 rpQM a^rcpAFT TAKING OFF.

STOWF '^'V/* Y (TOFF ) I^^ K

nr^TRov TOFc^

IF 0(K»1) IS E'Pjy , Gf^ TO

Firr^ T'.KFOFF TO SCH^nUL'^H /^^n STORF TTS ATTRlRUTES.

PEMOVF Fir>ST FLT Fro.'/ 0(K»1)

STORF FLT TN FL

LFT M=TYPF(FL)

LFT V-^''rOFF{M)

LFT TzF^FER (K > 1 »'"L)

LFT Tn-T+TT'rJ{K

)

Tir thF f^U'i.vAY TO T^^t'O^cr^ AMD LANOIMOS FQR DURATION OF THE

Riid.vAY OCCi Jf^A'jCY TT^'F.

CPrAT- TTc-iin

LET T- T'l(TTFUf^)=T'^

L^T T /'X(TT^UP)=T^ + O0TT(M)

FIL- TIEIIP IM T(^TT(i/)

Cpc-ATF FTT'IP

ST^RE IN R'.^'AY ( FTTijP ) STOf?E ^ I'! PT(FTHJP)

CAUSE f^TH'P AT T^'AV (TTFl'P)

CPFAT'^ TIEi.if^

LET TviM(TTFUD)rTn

LET T '/\ Y { TjruP) =TO + RO"rT ( M)

Ftl TT-i iP TM ERTT (K

)

STOPF I'l R V/JY (t^TlUP)

STORE 3 P! c^TtFTTiiD)

CAUSE f^TTUP AT TV A Y ( TT-i IP)

FlKf' pTPc,T» FOR EACH Fl.T IN 0 ( » 1 ) » IF f'OMF» GO TO 2

STORE !^LT IM F

LET M^-rTYPFCF)

TIE IjJ the p:M0 of the r^'irj'-'AY jn THE ''JE^T jai/eOFF LONG E'^IOUGW

TP, ^AI'iT/^I^' IMTFP-^'^PA'^TURE SEPARATION!. THIS PEPENDS QM THF

TYPES OP T'|t^ TWO AJPC^^^T.

CPE'^T^^ TI^Dp

LET T- r!(TTFUP)=Tn

LFT T- 'iY ( TIFUP) rTH + QE'^TT (v, VM)

FILF jir\,o Tfi EPTIfK)

Qivr/'Tc- FTI'in

cjopp ;/ TM pi.(/\Y(t^TIUP)

STORE ^ Tf' nT(ETINP)

CAMSe: cttIIJ'^ at T'^^v (Tirnp)

FT''' FT'^STf FOR F/\rM clT P 0(K»2)» IF mONF» GO TO 5

STopp -LT ri F

LFT SrVLAMndYPEC^) ) CREATE A TIEUP TO •AT^jT/^p| nfP/i\9R SEPAPATTOfj.

create; TIEUP

LET T'-'T'I(TIEI)P)=TP

LET T ''^X ( TIEUP) =T^'+ (SFPTL+. '^*S**2/V*R0TT{v!) >/c,

FILf" TTFiin ir' THTKK)

CPEATE FTIUP

^jonr 1/ IV Rv'AY (FTTijp)

STOPL R r' "T(FTT'ir,)

CA"'SE -TTUP AT T- 'Av ( TI^' !p)

IF 'lpr{\n ^0 r» IfS

- 133 -
C CRFATF TIE'iPS OF OTHEP pU'^IVAYS "S RFQUTPFD. n TO !4»F0o J=( 1 ) (ripKK) ) CRFATF TIFIJP

C KK - r?S'MV.'AY AFFFCTFH

LET KK=RPT(KrJ)

C IT - TYPF TIFUP

C TYPF5 5f U» 5r A^i^ 6 fPPLY TO TAKF^FF^^.

LFT IT::TPT(KrJ)

GO T0( 1 ?» 6»ftrH» 1 0) r TT

C C^PAT'^ A TI^UP TO "'AT^'T^Ini npoorR nrp/APP «;'^PAR ATTON

FlfO FTPSTfFOP F'\.CH FLT IM 0(KK»2)» IF MONFrGO TO 12

STORE FLT TM F

LFT M ^rTYPF (F)

LFT S-\/LP'''\^(m)

LFT T a'HTTEUP)=Tn

LET J.irP

LET T"AX(TTrUP)="fn+(SFr^TL+.'=i*S**2/V*R0TT{M) )/c;

GO TO 1

P, FI'T FTt^STfFOR EACH FL"r I^' OCKi^^l), IF mO^P* GO TO 1?

STOPE "^LT r-l F

. LET Vf'rTYPECF)

C C»EATr n TTFUP jo .iATMT.«r>' PPOPt^R TrjTFP-DEP/^RTMPF SFPAPATIOm,

LET T-T^'(TIFUP)-T^

C IF THt" PI]^!'^'AYS A^'"^ PFP^^rjOEMT » D^E THE SA^E FEPARATION A5 FOR ONE

C RUr;".'AYf I.^. THOS- IN TME F'^PTT ARpAY.

LFT T 'l'^.v (TIFUP) =Tn + EFPTT (M, VM)

C IF THE RtJ^lWAYS rtl L^w SV^ULTANEOMS orPAPTURFS WHFM THEY DIVERGE*

C USE THE SEPAPATToriS IM THE SEP? ARRAY.

IF IT El 5»LET T"*' Av ( TI^^'IP ) =Tn + qrp2 ( m , M'^'l) LET Jjr^

GO TC 1 C TIE UP THE EMP OP 'TER'"^CTTMG pUNWAY To aLL OPERATIONS UNTIL

C THF TAKEOFF PASSES THF TrjTrpc;f-r:TIOM.

10 LET T "T; !(TTruP)=Tn .- '^ LET A rv/ROTT(M)

LET Tr''ir.5*A + R0TT('')* + ? + V*^0TTCO

r IF THF TAKFOFF I^ irpopne tfe^pE "EACHTNG THE TriTERSECTIONr

C TIP UP ONLY ur'TII. "IRPOPNF.

IF TE • LF nirncK go to bi

Lf^T 3rV* + 2 + P.*A*nir:T(K f KK)

LET TMf^rTOf (-v + SOPT(R) )/A

GO TO

51 LET TMHrTD + ROTT (^") ' ! 52 LET T '/^v (TIFUP) =TU^ v

. , FILE TIEUP IN THTI(KK>

CREATE FTIUP

. STOPE KK IN R'"MY (FTIUP)

STORE ? IN PT(FTTUP)

CAljSE FTIUP AT T"^Av(TTEi'P)

CREATE T I El IP LFT T'-r!(TTEUP) =T"^

LET T ^'^Y( TIEUP )=TUP

; LFT J.J=^

GO TO 1 ^

. IP DFFTp.iY TIFHP

GO TO m

1^ GO TO ( 1 'J r 1^1 r 13? ) » .IJ 131 FIL^ TT'NP TM THTI(KK)

- 134 -
G'J TO 13"^^

SToPr jj T-; pT(FTT''P)

CfiUSF fTlUc^ AT T -Av f Ty^iJP)

15 CP'^/iT'I ^;XTOP

STORE K T^i R'A'AY ( "VTOP)

LET K'( = If'")X(K)

LFT riE^T(KK)=0

C/^'iSE 'XTOP AT T

C OTP-* - THE npLAY r;CUP'^,ED -Y T^TS TAKEOf^F

LET DTE"=(T^-T^^Ufl(K )-TifHc^L) )*aO.

I"^ TP LS T^FG»C-0 T-i 50

CDTATr apTiT

C STOP!^ '^^.TA TO r-E f^'^CQC^'^Fn 'iT T^r TT"F T^r T^i/FOf^F TURNS

C O'- TO T'|c PDriA'AY,

STORE "TFM ir. DL^'Y(Dpp T)

STORE K IN RWAY (f^^f ^'T)

STnn)F 1 iM OP (PPT IT)

CAUSE oaJ^:T TH

50 DESTROY pLT CALLF^ Fl

LET LAST ( K^^ ) =LAST ( ) +1

RETI.'R'

16 WOIT^ Of T/ipr f,, T-[vr, k

FOP'-'AT (' AT Tivp ,r2,u,S2» T.'^K't^OFF OU^' 'F roR RUfiWA Y • r T 3 f S2 » 1 IS ^"PTY*

)

STOP

-135 -
-

. .. ENnOG;--' lOLiS FV'Frj ^^TTlIP

C FTT'JP PFMOVFS TIF'JP^ FPr^^ ^hfip SE^f, AM^ nFc;TROYS THFM WHEN

C SP'^'JLMET; TIME PASS!^*^, THE ENH-LTMIT OF THE TIEUP,

STO^E ^'''AY(t^TIUP) I'^' K

STOPF PT(FTXUP) T^i J

DESTROY FT I'. IP GO T0( 10»?0» 30) fj

10 REMOVE f^IRST TIEti^ ^ROv O'^^KK)

GO TO 'JO 20 RFK^nVF i^IPST TIEUP '^PO'^^ TH^KK)

TO 'iO

7>{) R^'^OM^ PIRST TIE' IP FRO^^ ERTT(K)

tin PFSTR'-Y T I flip

RFTDR ' Erin FTI'JP -,

ENOOG'^'-'OUS FVFr'T f'RTMT

C PRir'T Rf-'CORDS P'vT''. ON ^^C^ FLIGHT AT TMF ttmf IT ACTUALLY

C TP"CHFS now' J OP TU^MS To THF RU^'WAY* AS THE CASE MAY BE.

STORE RH'^^Y (PRTMT) iri K STOPE nLAY(PRlMT) TM n STORE OP (PR I NT) t OESTRoY PRINT '

' LET HOPW ( K » I) rhO^'v' ( K r I ) -i-D LET Hrr'W(K»I)=^lN!>l"/(K,T)+l

C NTOFF ANR NLANP jHF TOTAL '^"I'^B'^R OF TaKFOFFS AND LANDINGS

C DIlPTr'O THIS HOUR.

C DELT ANO DELL ACCU^MtLA t^:: TotaL OELAV om TAKFqFFS AND

C LAMorj-^S F3Y HOUR.

LET I^rn/INC + l . IP ID ^-T NSLOTr LFT lOrMSL^T

^ IF TP L^ Of LET inn

LET r^LAY( IHOUPf I0)=rjnLAY(TH0l)r5f ID)+1

GO 'rO ( lOr^O) » I 10 LET NT0EF(IH0UR)=N'TOFF(IH0liP)+1

LET 0'-LT{ IH0'JR)='U^LT( IHOUR)+n

RETUi^f!

?0 LET ML'\NI1( IHOUR)=NLANn( IH0I)R) + 1 LET OFLL( IH0LIR)=0ELL (IHnUR)+n

RETHP'i

- 136 -
EnoOGI^'OUS EVFMT CHOIJP

LFT HOUP=IHOUR + 1 IF IHC:)R GT riH» LFT tmo!|r = i LET TrTTN"F+l.

IF T LF TENPf CAHSF CHOIjr r^j j

DO TO W FOP EAC'-l I STORE '^^FMNd) IN GFM

CANCEL GEN

CALL R'r'(**INITPf*P)

CAUSE ^'^M AT Tp^'^-L'^MRn(I»TH0LiP)*AL0G(3 .-R)

1 LOOP

IF TI'.'F LE Tf^EG» PFTiJPf!

LET IirlHOUR-l

DO TO f+r FOR FACl-l RW K

LFT NO^SzHrPW (K , 1 ) +HNP'--' (K f ^)

DO TO FOP EACH 0 I LET T^'R\"'(K » I ) =TMPW (K » I) +HNPW(K » T ) 12 LOOP

IF CA'^ GT Or GC TO 1 1 IF K ^T If GO TO ?r: ^JRITE T'\PE 6» IT rK »"^'RW(K »?) »HNC>W(K» 1 ) »MOPS

FOrv^AT ( I'4f T6»5'+»

GO TO

20 WRITE 0"! TAi^r 6» K»MNRWfK»2) »HMRW(Kf n »MOPS

,FG^"Ar (S4 » l6rS'+» 31^)

GO TO ?'> 11 LFT Tn-L=n.

DO TO F^R FACM n i LET T: ( K » T ) rTOR.v { K , T ) -t-H^PW ( K » T ) LET T^crLi:TnFL + Hn^'-'{KrT)

2 LOOP

LET PlrU^!P.J(Kf 1)

IF Bl '^T 0. r GO TO 5

LFT nirO.

GO TO 6

5 LET Dl^HHRw (K » 3 ) /PI

6 LET eP::MrjP'«'(K rp)

IE GT 0,, GO TO 7

LET DO-O,

GO TO M

7 LET 0P-wnRu/(Kr2)

8 LET B'.-"IOPS

IF '^3 GT 0 . , GO TO 9

LET E3=n.

GO TO in

9 LET D3=TnEL/P3

10 IF K '^T 1» GO TO 21

WRITE 0"! TAPE 6» I T » K » HMRW ( , ? ) , HNRW ( K » 1 ) » MORS » ^2 r Dl » D3

FOPvlAT ( T'4» I6rSU»3I9»S3r3D7. 1 ) GO TO 2^

21 WRITE ON TAf^E 6» K » nnr w ( K » 2 ) , HN^W ( K » 1 ) r MOPS » 02 » Dl » D3

FOR'.^AT (S'4» T6»Si^» 3I9»S3»3n"^. 1

)

22 DO TO 3» FOR EACM 0 I LET HORWCK^Dro.

LET Hv.'P'MK» I)=0

3 LOOP

U LOOP

RE"^')R '

- 137 -
C THIS E^'FMT RFAHS THE Nr-'W nprRA^ING POLTCY AMD PMNWAY PREFEP^NCES AND

C IMTTIATES THR CWANGEOVrR.

DO TO 1 » !^0f? EACH K READ TMnx(K) i»CI-!Gn{i^)

FOP^'^AT (S?.*^1?J

1 LO^P

DO TO ^» FO^ EACH f>W K DO TO ^ r t^Oi? FACI ' TYP J

RTAO roi.'YT( J»K) fTP'. YL(.J»K) ^ FOP'IA"^ (S4».?n?,u)

2 LOOP

3 LOOP

IF Tir^ LT TnEr-» r.o jn S(+

LET T=TT^'E-nTIv

DO TO POF^ EATH RVi 1^ LFT Kf^ .'-INnX (K ) IF KR V LE 0» GO rn LFT r T"=fJSOOP ( K P'-/

)

LFT n-0

00 TO SI , FOP J=( ! ) (NlIN)

LET K,K-SORx/(KPl'v » J)

IF KK ME K » GO TO "--1 LET I r-500P(KRl- f J)

IF II EO If LFT 11 = 1

' IF II Fo LPT T'>-^ .

• S3 LOOP ,

^ T i n , r;o TO SP

LET TT'Mk » D^TinC^ » 1 )+T

52 IF IP "0 n , 00 TO

LET TT '(K »p)-TIv(KrP)+T

53 LOnn

LET r«T^-' = Tl''T

5t+ or, TO O^r POP. EACH i^W K LFT or f K r 1) =0

LET GF(K»5)ro

LFT i:-X\:'^<(K)

IF T I 0 , 00 TO ^-^ LET Ml lr^:s^OP( T I ) /' '

.

' DO TO r^-^f FOR J=(n(NM)

LET KK=SO^'V{ I T f J)

IF KK , 00 TO

LET I-S^nP(ll,j)

IFO(i^»T) IS EMPTY, GO TO f.? LET Gr(K»I)=LO(Kf I)

fo? LOOP

63 LOOP 'N. J :^'-p.h.' ^ -

- 138 -
00 TO ^C"^' r^rv. q y

70 LFT ^ rT :->X(K)

IF i<P rr, o , jr, 1 Q n ir optro (KP .-) i_r c^, PO TO. -f7 LFT ;jT ••-riS')'^p(Ko , ) 00 TO 7Pf FOP T={ 1 ) (^'i-i)

Lf^T K*- rS'vP (KP'A r I

)

DO TO "'I* FOn FACH tj

IF QF(KK,IT) MP r>, GO TO mo

71 L00r»

12 LOOD

73 IF rM-.^{¥^ r,T p, QQ

7t+ LFT I';^Y{K)rTf;'"

LFT T '^Y(i/)rn

30 TO 110

?0 CPF.ATr Cri'^

STnpr 1/ J-. Dii AY (C iT^:'

)

CAM'~>E '"HID -sj jT -r 100 LOOP

PFT'JPt

Ff.r Ci- nop

Fr'nOGFMOUS FVF' T C^Tp

'JI'''F^,sTO^' TP'.-'(?.i)

STO'-?E -^'-/AY (C:>ir^ ) I K IF C^, - -A (K ) ro C r 0-^ TO 1 CAHSF rnip A J TI C+ r.Fn](K)

LFT Cm~0(K)=:C

RFTllR'

1 •Jr'^>TROY CD in

LFT - rT^"" i< (

)

IF ' ""C PFTi!^''

Lf^T v'> -1

i_-T I

"' ( n ri-^ IF jt^^ ^ ( - ) LF u» oo TO e L^T ;. .z-!S-ion(Kr>..')

no TO '\ * FOQ Tr ( 1 ) (firj)

L-'T wr;^rSr,o ..; (KF'- » T ) IP* "P • -r. J» 00 TO 7

OO TO -"f FO^ J= ( 1 ) { ^'P'-') I!^ KK "o TP ( J ) , nr^ JO ;^ 2 LCOO

3 LFT -'z-v^ + ! LFT 1-5 '•('. ^5' ')=KK

14 LOOn

6 DO TO For, k k r ( l ) ( vp ) LFT KrlR-MK'^)

LFT I ;-^X(K)=Tr-'r-X (K ) LFT T',^X(K)-0

WFT' T-^*' K 'O C I''

- 139 -
WRTTF on TAPE 6f P^TTP

FORM/iT (0»//*CFTMM Q/*^!DO^' MUMPER SEFn »oi2)

LFT TrTlMF-nilM

UO TO '~^^^f FOR F/\CH PW

LFT (^'^jwrlNHX (K)

IF KRw LF Of GO TO ^^3 LFT ! ir '=MSOOP (KRw ) LFT 1 1-0

LFT I--0

DO ^0 Sir F^l.' J=( n (^;T^')

LF'T K^-'^Z/.p {K^i\' r J) ^F |r /K, "F X t GO T^"; "^1 LFT lTTSOOP(KR-i» J)

IF IT "0 1 r LFT 11=1

IF II ^0 ?, LFT K 51 LOOP

IF 11 FO Of GO TO F2

L^T TT(^^ » l)=TtM(i<f n+T

5?. IF 12 ^0 0» GO TO ^.-^ , . , LFT TT '(K»^)=TrMK,^)+T

53 - LOOP

WRITE O'-'' T^f^F 6

FOP-'AT ( » ISF'^'^WAi^Y ^FPOOT Fon TMTS '^MN»//)

Wf<ITF 0^! TAPE b

FOP'FAT (FS» 'TOTAL T HROi ir.HP' 'T //

1 S-"^f 'i^ '^".AY» 'ont^p^TToMc pcproR-'"^n /Tl q , • L AflDlNGS TAKEOFFS'r

2 F4» 'TOTAL'/)

LFT Fl.-vmr.o . .

• LFT vTOFFrn '

' DO TO I » FOP FAC'-i - K . i

• Lcj 'v'-!r^r'/ii_/rrip + j(ir?v'(k »2) '

^ LFT MTOFF = fiTOFF + TMr?w(/» 1)

LET r.lor>SrT^!r^'v(K»?)-4-TMPw'(K» 1 ) WRTTF on TrtHfT 5, K»Tr>JP'''(K»P) »T^i•?W('^»l) fMOPS

FOP'iAT (^10 » n r S'-J » ^1 1 n)

1 LOOP ^

• ,

'^^^ LPT ^'O'^Sr^M.IND+^^TOFF '

rt'PITF on T'yPF f^f ^"L /\ f )'^ #

^ 'TOT » t 'OPS

FO^?f''AT (S'^'r 'TOTAL •»3T10///) /

'v'JPTTF O'l TAPE 6

FO'^'^AT (S^)* ' AVERAOr HOijRLY Tmroi •GH'^i IT //

1 Ef-^f '-^"ffA'AY' ,SPr 'O^'^RATTOMf; PEPt^OR' iFO ' 1 9 » L AMO T MG5 TAKFOFF^W

2 SU» 'TOTAL'/)

LP"T TMorjrf in-TPEO

Lp;T TL^M't^O. ^ LET TroFE::0.

DO TO FOR EAC'^ "^l"' K LET Tl-TN:"''/(Kf 3 ) LFT jr'^rFzTTOFF + TI

IE TT 'C^fl) GT O.Or GC TO -7 LFT Tiro.

GO TO ; / • 7 Lf^T TirTi /TTi'CKf 1 ) 8 L^^T T-^rTri'-'-^Kf?)

LET TF. '^'f -TLA^U +T''

- 140 -
GO TO 1^

LET TP=T?/TTM (Kr?)

LFT T-Tl+T?

v'JRITF: Oft TAPF f^f i^fTprTlfT

FOPMAT » T 1 »Sf » ^np. 1

)

LOOP

LFT T=(TLA'i'^ + TTO'^- ) /THP

LF'T TL'\rJD=TLANP/T^n

LFT TTOrprTTOFf^/TM^

WPTTE O:,' TAPr f,, TL ^JO , TTOf-'^ » T

FCP -^A T (sn, » TOTAL • »Sl » "^^8. 1 ///)

IF CA'"^ I.E Ir GO TO 1+ WPTTE 0 1 TrtPF 6

prc-AT (<^5# AVFPAi-^cr HOIIPLY RFLAVt//

1 SA» ''^UfWi^' f S! 1 » 'nELAY (^'TMliTPS) »/SIQf 'L/^^'DTNGS TAKFOFFS » S4 r ^ ^TCT'VL'/)

LET OLV^inro.

LET DTC^Pr^.

DO TO FOP FAC^' K LET Tl=T^O'V(K » 1

)

LFT ^yTr>FF='^TOPF + Tl

IF TI i(K» 1) GT O.Or GO TQ M

LET 'ti =0.

GO TO 1?

LET T1 -Tl/TTM(K f 1 ) LET iP-Jn^'iKt?)

LET ^l.,'\^!n='^LA^!D+T?

IF Tr'(K»^>) GT O.'^f GO TO 13

L^T TP=n.

GO TO

LET T?-Tp/TT:"(K » ?)

LET T::"^1+'^?

wPTTE or; T'^PF 6» <'f'^?»Tl,T

FOP''- AT (^10rTl»SUr^Oft.l)

LOOP

LET T= (^L A-JO+nTOPr) /TH^^

LET DL'\'^'Oi:nLANn/THr<

LET DTorF=r)T0FF/THi3

WPJTE ''! T'iPE Gr ^1. AMOrnTOFFrT

FOP^AT ( SO r TOTAL » f^^l r ?^na, 1 ///)

DO TO Of FOP FACf^ ^- I DO TO 5f FOP EACH SLOT J

LET I^T(J) = TnT(J)+r'PLAY(I»J)

LOOP

LOOP

CALL -tGUT

STOP

- 141 -
a ct c

L.>

c

c

vC

I IT

If!

IT

ic

•c

ir

I u3

o

C

ir3

IC

<I

c C

d1 >- IT *

ro

er LO cu 1 u c *

»- K

<r C

>- ro < 1ir

ii. (V c

I ir

(_ 0

1 UJ o

L. c. >

t

_lUJ C>: *

L 1 c? 0"

L. a

ir « •—1

1 c

r

L_

4* S 7

Xa

c.

li.

• UL •

c

I X c >

• o • _J _J

• • ^ • _J _( >- _j r _)

CL >-

cr u > * c

• • • • • m • • • • •

'-^ _ ."^ w. C U C- rO U.' " f J 1—1 r- _i J- a' — c c c 0 0- 0 a c

~> O

r

<j KT t— -J * t o C »- X u r, t— a: LL LL

V
APPENDIX F

PROCESSING THE LGA TRAFFIC INPUT DATA

In Chapter 2 of this report we discussed a run of DELCAP using

traffic schedule data from [3] together with actual runway-use information

from the CATER data. These two data sources were matched, and the discrepancies noted were resolved to the extent possible. Figure F.l records

those errors, inconsistencies and mismatches which were found but could

not be reconciled.

Three flights identified as TWPCK were listed among those scheduled,

but were rejected because their flight identification numbers had

incorrect form (correct form is two alphabetic characters followed by

3 or 4 numeric characters) . We were unable to discover anything further

about the identity of these flights, although it is speculated that

they are TWA pilot check flights.

Three flights had a discrepancy between a scheduled aircraft type

and the type actually used. Two Eastern flights scheduled for heavy

aircraft actually used category 3 aircraft, and one Air New England

flight scheduled for a light aircraft actually used a category 3. In

all three cases, the actual type used was input to the model.

A total of 43 flights were not matched. Of this total, 24 are National flights which were scheduled but did not occur because of a strike by National employees. This left unexplained a total of six

scheduled flights which did not actually occur, and 13 flights which

occurred but were not among the list of those scheduled, amounting altogether to an error in less than 3 percent of all the scheduled flights.

A list of all flights, arrival/departure designator, aircraft type,

runway used, scheduled and actual operation time is given in Figure F.2

at the end of this appendix in order of actual operation time. All times are in Greenwich Mean Time (GMT) , and since local time on October 25th was Eastern Daylight Time, one can obtain local time from GMT by subtracting

4 hours.

Several other problems in reconciling the two data sets were encountered and overcome. The schedule data, being computer output, had a fixed format: 7-character flight ID, two leading alphabetic characters,

followed by a zero and 4 trailing numerics. The CATER data listed the

flight ID with no extra zeroes between the alphabetic airline identifier

and the numeric flight code. In addition, airline identifiers for

suburban carriers are not the same in the two sources. For instance Air

New England is ANE in the CATER data and NE in the schedule data.

Command Airways is CMD in CATER and DD in the other, and Catskill Airways

is CSK in CATER and KF in the schedule data.

-143 -
FIGURE F.l

Inconsistencies in Two Data Sources

AIRCPAFT rVpr: iNConSISTEMCV. SCHP-:nU! En TY^^E I^' PAorMTHrsF<;.

( A0'+1'+ . U1 7 A ^(1)

MEl^tfd 1 3^^ n EAoOll u 3(1) 1,3

73;> SCH^UULE; QPEflATions '^Fv.- OF Ht.^h 30 i-.rtjp m^j N'ATCHm

- 144 -
Inconsistencies in Two Data Sources (Cont'd)

IN T.iF L "..TA

1^ 3

^ AHbll ion I IA0605 inn

^ An612 ^1^

.AObOe (+1?

J0729

A060a ^^ roouoi 1125 1

V,

1305 n NA0n55 1-^13 !\ •;A005h 1355 n IA0092 lUl? .^

AO It+M' 1523 ] 1535 _^ ALn621 154? 1

/ iAn4?>b 155'^ -y

,Ani4i 15^0 1 ''AOOPS* 165^

• c 1 '+'+6 17. ,5 n

IAHOOd 18U7

L0677 lfit+5 J ( / A04n!j l^l'S r ,A00^1 l^^o fi 1 AO 12 9 2nis

!A0146 2123 A A009<4 2l5n r.

1

• 6 0 1 f| b 223n n

•

CRObOl 22^45

'Aonq3 2300 r. I

!A009u 2350 '\ 1

IN THE r^jtrp

r I'^'^f.i 2*+ A 2 31

C''2Aon 43 A 2 31

A A235n 1 52 n 3 31

2U3 D 3 31

FA?U35 r 0^4 E-.71 21 1 1 32 n 3 13

UAnf?03 1206 n 3 13

EaOI 22 1 3no n 3 13

U 172 18 1U37 A 3 22

T,j032'^ 1 ^^^^3 n 3 13

Ea7"»23 1716 A 22

NIFn«^7U 22a8 A 3 22

MF2^72 ?"^5i+ n 3 31

- 145 -
Another difference between the two sets concerns the designation

of the Eastern Air Shuttle flights. Each such flight appeared in the

schedule data once with the symbol < as the final character in the ID.

It appears in the CATER data as many times as there were sections of the

flight. There were different numbering schemes in use for the shuttle

flights in the two data bases, which required further hand reconciliation.

All of these discrepancies were identified and standard formats decided

upon, using the two-letter airline code from the schedule data and a four-digit, right-justified numeric flight code. Additional sections

of the air shuttle were included as scheduled when they actually occurred.

Differing shuttle numbering schemes were eliminated by an arbitrary choice

of one coherent scheme. The result of these efforts is the list of 702

flights in Figure F.2. ^

- 146 -
FIGURE F.Z

LGA Scheduled Flights Input to DELCAP

detailf:o FLK,nT OilTPi IT FLT Uj A/n TYr^E

T w 0 H A 5

D 3

AAOt+?'+ A 3

AL07^3 u AA0s'-2 A

AL07S7 L' 3

UA0'4P2 A 3

EAODru 0

0

AA0pQ6 A

UAO.^32 A 3

EAlS^

u EA2h22 A

AA0;JPR U 3

D 3

J

A 3

PlO(jS3 0 3

A 3

AA043n A Tw0b?3 u

EAOb'^ 1 J 3

A AO ill D 3

AAO^'U /\ 3

ALO ,01 D

» EA1;333 J 3

EA2i 51 ij 3

EAll?3 i\ 3

UAO A 3

EA2i'2 J 3

A 3

A 3

EAO ^"^7 D 3

AA027.-3 A

S0071

9

J

UA0 7'-^6 A 3

AA0:::'5n A 3

AL0 7'^9 U

Nrt02'tl 3

DLl2^B A 3

Aa02^9 ^ AlO'iO^s A 3

T.vOisl u 3

FA2S]

A 3

UA0 4.'>(|. A

AAO 7

EAl I?/) A 3

^1 2?5''> 0

225-^ 1 2^ 23U0 1 •i 221'» 2

^2 223M 3

^1 233'

5 2 2^0^^

31 2:^1^ 6

"^1 230^ Q

22 2:^0'^ Q

2^2^ 1 n

^ 1

fi 1

12 12

31 2^3- 1 2

31 2^4'^ 1 u 3 . 1 6

•5

^ 2"^5o 1 fS 31 233'" 17

2 ^ 2'^5'^ 17

? . 23i+-' 18

^1 27b^ 1^

^1 225^ ^0

3 , 2?(+- ?2

2- 23U'^ -53 ^1 234S -^a 31

31 n 2f^. 2^ -56

r>p 235-^ 27

^1 2"' 27

22 233^ ^9

22 2"»5l 50

31 ^1

2? 232' 32

^3 33

2;' 234-'

o 22i+f^

3^^

3 1 2^2^ 38

2"'u^ ^Q

r>

e 235^ 3Q

'4 0

? . ^\

235^

^1 233"

2 '4 6)

- 147 -
J 1 n7

A

A 0 p o 7 J 1 UP

A yi 0 1

->

U 1 22 2"« TV 0 1 1 Vt ^ i. O U r\ t A 3 2 "

>\ ' 1 A ii n p li ti M " ^ •^ n '-r A i '

t\A

A 0^ S. 1 /*1 S r\ 22 0 MA M D'J 11 ^ u"t S7

EAl 1 ^1

A 22

TWO VtO

A P2 100

AAOs'^h

A 22 3^ 101

AAOqfl I u 31 r\ 101 A A U 1 n 6 A 3 22 201 -« 102

EAl f^J

A • . -^- j.? 

"> ? 1 OA

EAl?)'+3

J 3 ^ 1 1 1

'^'^ AmOs( 2 A : i 3 • _ (_ lop

EA2 1

1\ 1 (j '"3 » 1 1 u ^ 10" A - -^3 1 1 'J 110

AAO.^al ij -.3 1 1 ro EAOShS 0 . - -^1 234'^ 1 1 

P 1 0 1 ) 2 £4 A 2 ' ?l 1 1 

ALO14SI

J 31 1 1 3

Ea00S2A ' 22 235"^ 113

DLOp 1 A 3' 22 p/i 1 1 u NCOoSP, 3 ''2 11^

EA0i);.\'3

A 22

r 31 117

UAO ,5(i7

D .:-3- 1 1 1 " AAO ')22 A 3 ? 11^

AA0.^r^2

A 3 ri 5'^ I'^O E A 1 1 U 

A 3 1 t+r 121

AAO^Sl l) 3 1 20 121 A A 0 2 i n A

^- ^ i3. 22 2"^ 122

DLl 2

""^

u 3 T 1 1 0 ^ 1 ^3

AA 0 

' )

i_y

.': .3 1 PU

EA2S'^1 ^\ 3 o^- 1 AAOo. *0 j "1 LJ ' ''.".3 X 1 - ' J 127 E /* 0 1 n n A - • 3, 2'i 1P7 1jaO,^ 1 A 3 P - 51 1 2^ A A 0 1 ^ P MA - -x DLOy n 0 u h4..:,3 20 1 30 T W 0 P ^ h 3 p , 2 3U ^ l'^3

FA2-,'^2A 3 ' 2 1 3*^ 1 3S

TW

O I A 

A 3 2 > 1 0 1 1"^6

AAO'-^nO

A 3 22 1 U'* 1 3n A 3 1 U Ian

AAO ^1 1 LJ ^ 1 1 U 0 A AOS'iS 3 1 U2

EAO(ir,e

A 3 22 1'4 2 A 2 ^1 232-^ 1M3

ALn':^u7

A 3 ^2 5'^ 143

TW0^';6 i\ 3 I'iS

FA2S'i 1 A 3 ^2 1 1^'^ lUfS - 148 -
E • ' ' ) 1 n

M ? _ 1 r- 1 /I

T

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A rtn 7 1 A " f_ i j

-I 1 2 - 1 /I ri

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trA 1 /i 1 1 U ' t M " / O M 0 T c; 0 J. ^ ^ A J s 'J A

•3 i Sb

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AL0o7>i

A 12r 1 S7 A 12"' ISA A 1 2^ A 2 M

EAO^ 1 

u I 1 C' ^ POP A 1 V ' P (^1 0 0 ^ A 1 3 ^ 2 n (J.

A i\n c: (1 \ y c. 0 n^ b

AM

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CA ? U (I

AA I-J ^2 ^ r, 2')^

DTn . 1 iJ

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DTn ' , K i 'J ( 1 ) c A

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A -*O 3 U I T 1 1 n 1 U " 0 1 c Ln

A .'in r:n

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L'^ ' 1 o ij Ti 4 4 -\ f— 0 ^ t A "J4 ^ 1 \ ^ + ?1 ^ 3 t 1 A A f 1 ' 1 / 1 O AA

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A 0 £4. ^ 1 i E A u 1+ ^,2 M 4 1^

EAO4I 

A ''2 44P

FA041 5 A P? 44"^ A ^2 4K'> - 149 -
A /'i 0 1 1 ( L

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A 02 3 1 r 702 c A p 1 r, 1 K i^'- 1- 'A 1 3 1 1 uo ins r A 1 a f 1 ' D 1 3 11 0 n U 07 A A u i '1 f"! IJ 1 3 1 1 0^1 X JL 1 X A A n ( 1 1 1 "< 1 1 u 3 1 3 A. ' V 1111

nlUL i-1 u 1' KJ 1 7 1 110"". 1113 ^ /\ U q. V nIJ 1 < t , / 1114 A A " *+ i u 1 J u 1116 A M U M- / i ^ u 1117 C A 0 1 Q U 1 1 1 n 1119 J 1 3 X11?" J c 

HPS

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USCOMM-NBS-DC 160 -