Departure Time Changes

AIM ¶ 5-1-13 — Departure Time Changes

AIM 5-1-13 explains how to keep your IFR flight plan active when departure is delayed 2+ hours. Notify ATC, FSS, or your flight plan provider.

In Plain English

AIM 5-1-13 explains what happens to a filed flight plan when your departure is delayed. To keep ARTCC computers from being overloaded with stale proposals, most centers automatically delete proposed flight plans that haven't been activated within about 2 hours of the filed departure time or Expect Departure Clearance Time (EDCT).

Why this matters operationally:

If your plan gets purged, you'll have to refile — potentially delaying your release further, especially in busy airspace.
If you know your actual departure will slip 2 hours or more beyond your filed time, you should notify ATC of a new proposed departure time.
ATC controllers are often too busy on frequency to accept these revisions by radio.
The recommended method is to pass the revision through a flight plan service provider (e.g., Leidos) or a Flight Service Station (FSS).

This is a recommended practice in the AIM, not a regulatory requirement, but following it prevents avoidable delays at the gate or run-up area.

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AIM Source Text

FAA AIM ¶ 5-1-13

To prevent computer saturation in the en route environment, parameters have been established to delete proposed departure flight plans which have not been activated. Most centers have this parameter set so as to delete these flight plans a minimum of 2 hours after the proposed departure time or Expect Departure Clearance Time (EDCT). To ensure that a flight plan remains active, pilots whose actual departure time will be delayed 2 hours or more beyond their filed departure time, are requested to notify ATC of their new proposed departure time. Due to traffic saturation, ATC personnel frequently will be unable to accept these revisions via radio. It is recommended that you forward these revisions to a flight plan service provider or FSS.

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Oral Exam Questions a DPE Might Ask

Q1How long after your proposed departure time will ATC typically delete an unactivated IFR flight plan?

Per AIM 5-1-13, most centers set the parameter to delete proposed flight plans a minimum of 2 hours after the proposed departure time or EDCT to prevent computer saturation in the en route environment.

Q2If your departure will be delayed more than 2 hours, what action does the AIM recommend?

Per AIM 5-1-13, pilots are requested to notify ATC of their new proposed departure time to keep the flight plan active.

Q3What is the preferred way to pass a revised proposed departure time to ATC, and why?

Per AIM 5-1-13, because traffic saturation often prevents ATC from accepting these revisions via radio, it is recommended that pilots forward revisions through a flight plan service provider or an FSS.

Related Paragraphs in Chapter 5

¶ 5-1-1

Preflight Preparation

¶ 5-1-10

IFR High Altitude Destinations

¶ 5-1-11

International Flight Operations

¶ 5-1-12

Flight Plan Changes

¶ 5-1-14

Closing VFR Flight Plans

¶ 5-1-15