Historical Use of “Exempt by Time/Status” Parameter in GDPs

CDM MeetingJune 28, 2000

Background“Exempt by time/status” options in FSM

Exempt by statusIncludes all flights on the ground, irregardless

of departure time. Used for releasing traffic out of a ground stop into a GDP.

Exempt by time + X minutesExempts any flight with an ETD within X

minutes of the current ADL time.Default setting on GDP setup panel is X=45

Methodology1 year of data: 6/1/99 - 5/31/00Includes 826 GDPs over 25 airports for a

total of 1,953 GDP events“Exempt by” parameters categorized

into Status and Time+0 Time+15 to Time+35 Time+45 Time+60

Summary Results1,953 events:

Status or Time+0478 events - 24.5% frequency

Time+15 to Time+35120 events - 6.1% frequency

Time+451,329 events - 68% frequency

Time+6026 events - 1.3% frequency

Ground Stop MethodologyTo be considered out of a Ground Stop:

GS must end within 20 minutes of the GDP start.

GS must end because of GDP start, and flights released on EDCTs.

An exemption by status should only be applied to a revision of a GDP if a GS ends through a revision start, and flights released on EDCTs.

Ground Stop Summary Results

Status or Time+0 478 events Out of a GS

414 events - 86.61% frequencyOut of all events - 21.2% frequency

Not out of a GS64 events - 13.39% frequencyOut of all events - 3.28% frequency

Results by AirportExempt By Time Parameter by Airport

1

51

366

29 33

310

11

156

20

270

112

9 11 8

214 211

20

75

14 204 3 2 2 10%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

MCOLA

XSFO

SEA IAH

EWR

DTWAT

LJF

KLG

APHL

CVGDFW

CLE ORDBOS

PHXSTL

IAD

MSPCLT

DCABW

ILA

SMDW

Airport

Perc

ent

0

50

100

150

200

250

300

350

400

Time+60Time+45Time+15 to 35Status/Time + 0 out of a GSStatus/Time+0 not out of a GSNumber of GDPs

Results by AirportExempt By Time Parameter by Airport

366

310

270

214 211

156

112

75

5133 29

20 20 20 14 11 11 9 8 4 3 2 2 1 10%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

SFOEW

RLG

AORD

BOSAT

LPHL

STLLA

X IAH

SEAJF

KPHX

MSP IAD

DTWDFW

CVGCLE CLT

DCABW

ILA

SMCO

MDW

Airport

Perc

ent

0

50

100

150

200

250

300

350

400

Time+60Time+45Time+15 to 35Status/Time + 0 out of a GSStatus/Time+0 not out of a GSNumber of GDPs

Results By MonthExempt By Time Parameters by Month

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

6/199

9

7/199

9

8/199

9

9/199

9

10/19

99

11/19

99

12/19

99

1/200

0

2/200

0

3/200

0

4/200

0

5/200

0

Month

Perc

ent

Time+60Time+45Time+15 to 35 Status/Time+0 out of a GSStatus/Time + 0 not out of a GS