Historical Use of “Exempt by Time/Status” Parameter in GDPs CDM Meeting June 28, 2000

Background z“Exempt by time/status” options in FSM yExempt by status xIncludes all flights on the ground, irregardless of departure time. Used for releasing traffic out of a ground stop into a GDP. yExempt by time + X minutes xExempts any flight with an ETD within X minutes of the current ADL time. xDefault setting on GDP setup panel is X=45

Methodology z1 year of data: 6/1/99 - 5/31/00 zIncludes 826 GDPs over 25 airports for a total of 1,953 GDP events z“Exempt by” parameters categorized into yStatus and Time+0 yTime+15 to Time+35 yTime+45 yTime+60

Summary Results z1,953 events: yStatus or Time+0 x478 events % frequency yTime+15 to Time+35 x120 events - 6.1% frequency yTime+45 x1,329 events - 68% frequency yTime+60 x26 events - 1.3% frequency

Ground Stop Methodology zTo be considered out of a Ground Stop: yGS must end within 20 minutes of the GDP start. yGS must end because of GDP start, and flights released on EDCTs. yAn 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 zStatus or Time+0 y478 events yOut of a GS x414 events % frequency xOut of all events % frequency yNot out of a GS x64 events % frequency xOut of all events % frequency

Results by Airport

Results By Month