Terminal Airspace Traffic Complexity

Fedja NetjasovUniversity of Belgrade

Faculty of Traffic and Transport EngineeringDivision of Airports and Air Traffic Safety

.

Why Terminal Airspace?

• Terminal airspace (TMA) represents transitional airspace between airports and ATC sectors;

• The TMA contains a high concentration of arrival trajectories converging on the airport as well as departure trajectories diverging from the airport.

Why Complexity?

• Mix of aircraft types resulting in different separation rules;

• Aircraft traverse the TMA at a broad range of speeds.

Definition of Complexity

• complexity presents a measure of quantity as well as quality of the interactions between the aircraft which are to be controlled (managed) by one air traffic controller.

Concept of Complexity

airlinecosts

airport andsector trafficcomplexity

traffic

situation

noise level and air pollution

influenceon

quality ofpassengers

service

controller workload

Basic assumptions

Complexity depends on two groups of factors:

• static factors: TMA geometry;

• dynamic factors: traffic demand characteristics, distribution of traffic in TMA, etc.

Causes of Complexity (1)

In the case of arrival, traffic complexity could be generated because of:

• existence of traffic on trajectories (C’ARR);

• potential catching-up situations (C’’ARR);

• potential conflict at trajectory merging points

(C’’’ARR) ;

• demand exceeding trajectory capacity (C’’’’ARR)

Ts

1

34

2

Ts

1

34

21

34

21

34

2

Tr

Tr

Catching-up situation

Conflict at trajectory merging point

Causes of Complexity (2)

In the case of departure, traffic complexity could be generated because of:

• existence of traffic on trajectories (C’DEP);

• potential catching-up situations (C’’DEP);

Index of Complexity

The concept of measuring complexity is based on a no-dimensional variable named “Index of complexity”. It is assumed that the Index of traffic complexity (C) consists of two components:

• Index of static complexity (Cs ) and

• Index of dynamic complexity (Cd ).

Index of Static Complexity - Cs

Depends on airspace geometry, i.e. number of trajectories and their length, number of runways, number of entry and exit points, etc.

Nm1)Nm(P

d)kn(d)mn(

C2

mn

1i

kn

1j

DEPj

ARRi

s

Index of Dynamic Complexity - Cd

Presents the sum of two elements:

• Index of dinamic complexity in case of arrival traffic - Cd

ARR and

• Index of dinamic complexity in case of departure traffic - Cd

DEP

Index of Dynamic Complexity in case of arrival traffic - Cd

ARR

Presents the sum of four elements:

CdARR = CARR

’ + CARR’’ + CARR

’’’ + CARR’’’’

ARR

ARR

p

Pp

maxp

)t(D

1r faf

rfaf

Pp

maxppp

)t(A

1s

spp

pARR N

TTT

)t(zN)t(N)t(gT

TT)t(y)t(N

)t(B)t(C

C’ C’’ C’’’C’’’’

Index of Dynamic Complexity in case of departure traffic - Cd

DEP

Presents the sum of two elements:

CdDEP = CDEP

’ + CDEP’’

DEP

DEP

r

Rr

maxr

R

)t(A

1s

srr

rDEP N

TTT

)t(y)t(N

)t(B)t(C

C’ C’’

Index of Complexity (rèsumè)

DEP

DEP

r

ARR

ARR

p

Rr

maxr

R

)t(A

1s

srr

r

Pp

maxp

)t(D

1r faf

rfaf

Pp

maxppp

)t(A

1s

spp

p

mn

1i

kn

1j

DEPj

ARRi

DEPARRsds

N

TTT

)t(y)t(N

)t(B

N

TTT

)t(zN)t(N)t(gT

TT)t(y)t(N

)t(B

P

d)kn(d)mn(

)t(C)t(C)t(C)t(C)t(C)t(C

Experiments (1)

Characteristics:

• TMA contains two arrival and two

departure trajectories (generic case);

• hypothetical traffic;

• simulation of traffic in TMA

Experiments (2)

• Changes in the number of trajectories in the TMA - the purpose of which is to determine what influence changes in the number of trajectories have on the value of the Index of complexity; and

• Changes of traffic volume - the purpose of which is to determine what influence change in traffic volume has on the value of the Index of complexity.

Changes in the number of trajectories in the TMA (1)

01

23

456

78

91011

1213

1415

1

121

241

361

481

601

721

841

961

1081

1201

1321

1441

1561

1681

1801

1921

2041

2161

2281

2401

2521

2641

2761

2881

3001

3121

3241

3361

3481

3601

Time (sec)

Num

ber

of a

ircr

aft

C(t)

0

1

2

3

4

5

6

7

8

9

10

1

115

229

343

457

571

685

799

913

1027

1141

1255

1369

1483

1597

1711

1825

1939

2053

2167

2281

2395

2509

2623

2737

2851

2965

3079

3193

3307

3421

3535

T ime (sec)

Inde

x of

com

plex

ity2

C(t)

0

1

2

3

4

5

6

7

8

9

10

1

116

231

346

461

576

691

806

921

1036

1151

1266

1381

1496

1611

1726

1841

1956

2071

2186

2301

2416

2531

2646

2761

2876

2991

3106

3221

3336

3451

3566

T ime (sec)In

dex

of c

ompl

exit

y3

C(t)

0

1

2

3

4

5

6

7

8

9

10

1

128

255

382

509

636

763

890

1017

1144

1271

1398

1525

1652

1779

1906

2033

2160

2287

2414

2541

2668

2795

2922

3049

3176

3303

3430

3557

Time (sec)

Inde

x of

com

plex

ity

4

24 op/h

Changes in the number of trajectories in the TMA (2)

0

1

2

3

4

5

6

7

8

9

10

1

134

267

400

533

666

799

932

1065

1198

1331

1464

1597

1730

1863

1996

2129

2262

2395

2528

2661

2794

2927

3060

3193

3326

3459

3592

Duration (sec)

Inde

x of

com

plex

ity

twothreefour

≈ 800 ≈ 2100 ≈ 3200

Changes of traffic volume (1) N1(t) + N2(t)

0

12

34

5

67

89

10

1112

1314

15

1

114

227

340

453

566

679

792

905

1018

1131

1244

1357

1470

1583

1696

1809

1922

2035

2148

2261

2374

2487

2600

2713

2826

2939

3052

3165

3278

3391

3504

T ime (sec)

Num

ber

of a

ircr

aft

C(t)

0

1

2

3

4

5

6

7

8

9

10

1

115

229

343

457

571

685

799

913

1027

1141

1255

1369

1483

1597

1711

1825

1939

2053

2167

2281

2395

2509

2623

2737

2851

2965

3079

3193

3307

3421

3535

T ime (sec)

Inde

x of

com

plex

ity

18

N1(t) + N2(t)

0123456789

101112131415

1

115

229

343

457

571

685

799

913

1027

1141

1255

1369

1483

1597

1711

1825

1939

2053

2167

2281

2395

2509

2623

2737

2851

2965

3079

3193

3307

3421

3535

T ime (sec)

Num

ber

of a

ircr

aft

C(t)

0123456789

101112131415

1

115

229

343

457

571

685

799

913

1027

1141

1255

1369

1483

1597

1711

1825

1939

2053

2167

2281

2395

2509

2623

2737

2851

2965

3079

3193

3307

3421

3535

T ime (sec)

Inde

x of

com

plex

ity

24

N1(t) + N2(t)

0123456789

101112131415

1

120

239

358

477

596

715

834

953

1072

1191

1310

1429

1548

1667

1786

1905

2024

2143

2262

2381

2500

2619

2738

2857

2976

3095

3214

3333

3452

3571

T ime (sec)

Num

ber

of a

ircr

aft

C(t)

0

1

2

3

4

5

6

7

8

9

101

117

233

349

465

581

697

813

929

1045

1161

1277

1393

1509

1625

1741

1857

1973

2089

2205

2321

2437

2553

2669

2785

2901

3017

3133

3249

3365

3481

3597

T ime (sec)

Inde

x of

com

plex

ity

30

Changes of traffic volume (2)

0

1

2

3

4

5

6

7

8

9

10

1

155

309

463

617

771

925

1079

1233

1387

1541

1695

1849

2003

2157

2311

2465

2619

2773

2927

3081

3235

3389

3543

Duration (sec)

Inde

x of

com

plex

ity

18 aircraft

24 aircraft

30 aircraft

≈ 130 ≈ 700 ≈ 2400

The main result of this research is the development of a model for the Index of complexity, of general use.

This model could be used:

• for evaluation of current and novel organisational solutions for the TMA containing one single runway airport, or

• for estimation of effects of implementing new arrival and departure trajectories, on traffic in a TMA.

Conclusion

• Consideration of irregular situations such as

missed-approaches;

• Consideration of influences of the meteorological

situation on traffic;

• Analysis of traffic complexity for airports

with multiple runways;

• Usage of weight factors;

• Consideration of heterogeneous aircraft fleet, etc.

Further research

University of Belgrade Faculty of Transport and Traffic Engineering

Department of Air TransportDivision of Airports and Air Traffic Safety

http://apatc.sf.bg.ac.yu Vojvode Stepe 305, 11000 Belgrade

Serbia and Montenegrotel: +381 11 3091 352fax: + 381 11 466 294

Thank you for

your attention