Turning Goals Into Reality:Revolutionizing Air Transportation

Mobility

George L. Donohue

George Mason University

GEORGE MASON UNIVERSITY 2Source: BTS 1998

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Premise #1

• Air Transportation Hub and Spoke Systems– Network of Airport and Sector Queue’s– Approaching Max Capacity Today– Models Predict Higher Delays in 2010, even

with all planned new runways and new technology

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Hub and Spoke Network

Completely Connected Network = 2(N-1) Flights(eg., 50 Airports, 98 Flights)

Ref: J. Hansman, MIT

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Hyperbolic Growth in US Delay (>15min/1000 operations)

vs. Airport Capacity Fraction

0

20

40

60

80

100

0.00 0.20 0.40 0.60 0.80 1.00 1.20AIRPORT CAPACITY FRACTION

NUMBER DELAYS > 15 min. / 1000

AIRLINE REPORTEDDATA

Expon. (THEORY M/M/1QUEUE)

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Premise #2

• Avoiding Network Hubs Exacerbates Airspace Management Limitations– Small Aircraft Traffic Grows like N2 vs. 2N– Controller Cognitive Workload Limitations– Radio Frequency Spectrum Limitations

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Fully Connected Network

Completely Connected Network = N(N-1)(eg., 50 Airports, 2450 Flights)

Ref: J. Hansman, MIT

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Comparison of US and European Delay (min./flt.) vs. Airport Capacity Fraction

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16

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20

0.00 0.20 0.40 0.60 0.80 1.00

AIRPORT CAPACITY FRACTION

AVG. TOTAL DELAY (MIN)

EUROPEAN REPORTED DATA

US CODAS DATA

Expon. (M/M/1 THEORY)

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Backup

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Macro Capacity Model

• Cmax = 2 x C AR MAX S i (XGR)i

– C AS MAX K AK.

• AK = (A/CREQUEST – A/CACCEPT) / CAS MAX

• CAR MAX = 64 Arrivals/Hour

• CAS MAX = 120 Aircraft/Sector/Hour

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Aircraft Arrival Rate vs. Separation Distance

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40

50

60

70

80

0 1 2 3 4 5 6 7

DISTANCE ( NMi)

ARRIVALS / RW / HR

120 Knots

130 Knots

140 Knots

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Arrival Spacing is Critical to Capacity and Safety

SDF AIRCRAFT ARRIVAL DISTRIBUTION

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5

10

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20

25

0:30 1:00 1:30 2:00 2:30 3:00 3:30 4:00 4:30 5:00

ARRIVAL INTERVAL (Min.)

NUMBER AIRCRAFT ARRIVING

4:14Z - 5:53 Z(11/24/99)

WAKE VORTEXLIMIT

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16 US Airports in Northeast TriangleRepresenting 7.6 X 106 Operations/Yr

US NE TRIANGLE MCM ANALYSIS - 4 N.MI. SEPERATION (1997)

TOTAL OPS/YR M CM M AX PEAK OPS/HR CAPACITY PREDICTED REPORTED AIRPORT # R/W GATES G X FAA 1997 EST.@ 4 nmi. FAA 1997 FRACTION DELAY DELAY

CHICAGO (ORD) 7 173 0.97 0.5 892,665 217 159 0.73 11 24

ATLANTA(ATL) 4 180 1 0.7 785,854 179 140 0.78 14 32DETROIT(DTW) 5 99 0.99 0.4 547,350 127 98 0.77 13 8ST. LOUIS(STL) 5 86 0.92 0.4 528,746 118 94 0.80 16 31MINNEAPOLIS(MSP) 3 73 0.9 0.55 496,091 95 89 0.93 55 7CHARLOTTE (CLT) 3 62 0.86 0.7 473,800 116 85 0.73 11 6BOSTON(BOS) 5 88 0.95 0.36 473,127 109 84 0.77 14 25NEWARK(EWR) 3 92 0.97 0.47 461,500 88 82 0.94 64 58PITTSBURGH(PIT) 4 122 1 0.6 454,259 154 81 0.53 4 3PHILADELPHIA(PHL) 3 63 0.86 0.5 422,493 83 75 0.91 42 16

CINCINNATI(CVG) 3 120 1 0.7 413,579 134 74 0.55 5 12NEW YORK(JFK) 4 180 1 0.36 362,305 92 65 0.70 9 18LA GUARDIA(LGA) 2 60 0.92 0.55 348,854 65 62 0.96 101 49WASHINGTON DULLES(IAD) 3 78 1 0.67 337,383 129 60 0.47 4 6WASHINGTON REAGAN(DCA) 3 48 0.93 0.47 311,105 84 56 0.66 8 4CLEVELAND(CLE) 4 50 0.92 0.36 300,620 85 54 0.63 7 6

TOTAL 61 1574 7,609,731 1873 1359

AVERAGE 0.52 0.74 24 19MEDIAN 0.75 12 14STANDARD DEVIATION 0.15 28 17

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US Airport Runway Utilization16 Airports in NE Triangle

0

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30

40

50

60

70

0 2 4 6 8NUMBER OF RUNWAYS

( PEAK OPERATIONS/HOUR ) /R * X *

G

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16 European Airports Representing 4.3 X 106 Operations/Yr.

EUROPEAN MCM ANALYSIS - 4 NMI AND 6 NMI (1997)

Airport R/W Gates S G X PROJECTED MCM MAX PEAK OPS/HR CAPACITY PREDICTED REPORTED4nmi OPS/YR EST. @ 4 NMI 1997 FRACTION DELAY DELAY

IATA 1997 . 4 NMI 4 NMI ADM 1

Heathrow 3 172 0.5 1.00 0.71 428,600 136 77 56% 1 3Rheim/Main 3 145 0.5 1.00 0.76 389,600 146 70 48% 1 4

Charles De Gaulle 2 193 0.5 1.00 0.77 374,998 99 67 68% 2 4Schiphol 5 144 0.5 1.00 0.80 353,000 256 63 25% 0 7Orly 3 103 0.5 1.00 0.77 250,000 148 45 30% 0 3

Leonaro Da Vinci 3 72 0.5 1.00 0.77 245,757 148 44 30% 0 4Barajas 2 93 0.5 1.00 0.55 252,400 70 45 64% 2 5Gatwick 2 90 0.5 1.00 0.71 207,679 91 37 41% 1 4

Brussels National 3 107 0.5 1.00 0.66 277,006 127 49 39% 1 6Munich 2 83 0.5 1.00 0.77 255,948 99 46 46% 1 4Copenhagen 3 128 0.5 1.00 0.63 280,800 121 50 41% 1 2

Zurich 3 60 0.5 1.00 0.50 268,352 96 48 50% 1 5Dusseldorf 3 67 0.5 1.00 0.65 187,549 125 33 27% 0 6Linate 2 35 0.5 1.00 1.00 165,283 128 30 23% 0 5

Arlanda 2 264 0.5 1.00 1.00 255,000 128 46 36% 1 2Dublin 3 95 0.5 1.00 0.55 134,300 106 24 23% 0 2

TOTAL 44 1851 4,326,272 2022 773 . .

AVERAGE 0.73 40% 1 4.10MEDIAN 40% 1 3.91STANDARD DEVIATION 0.14 0.5 1.3

Note 1. Average Delay per Movement data from EUROCONTROL Annual Report 1998

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European Airports in Comparison

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European Airport Utilization16 Airports

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70

0 2 4 6 8

NUMBER OF RUNWAYS

( PEAK OPERATIONS / HOUR ) / R *X

* G

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Hyperbolic Growth in US Delay (min./flt.)

vs. Airport Capacity Fraction

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5

10

15

20

25

30

0.00 0.20 0.40 0.60 0.80 1.00 1.20

AIRPORT CAPACITY FRACTION

AVERAGE TOTAL DELAY (MIN)

CODAS DATA

Expon (THEORY M/M/1 QUEUE)

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Conclusions

• Air Transportation Systems can be Represented as a Network of FCFS Queue’s with a Loosely Coupled Central Flow Control

• The US is operating at a relatively High Airport Capacity Fraction with increasing Delay

• Europe is operating at a relatively Low Airport Capacity Fraction with sector workload producing high delays imposed through Central Flow Control

• Delays of 2 min per aircraft seem to be the minimum airspace induced delay independent of Airport Capacity