Definition
A revised IFR clearance route issued to a flight before it departs, replacing the route originally filed in the flight plan. Air traffic control uses pre departure reroutes to adjust traffic flow, avoid weather, accommodate airspace restrictions, or balance sector workload before the aircraft is airborne.
Plain English
ATC has changed your route before you take off. The path you filed has been replaced with a new one, and you fly the new one instead.
Context Anchor
You may encounter this when receiving an amended clearance before taxi or takeoff, especially when weather, traffic volume, or airspace limits require a different route.
Why Pilots Care
Allows pilots to adjust their route early, reducing airborne delays and ensuring smoother integration into the national airspace system.
Intuition Check
Do not assume this is a route change made after you are already flying. In this term, the route is changed before takeoff and becomes part of the clearance you are expected to follow.
Example Sentence 1
Clearance delivery issued a pre departure reroute that took the flight south of the original track to avoid a line of thunderstorms.
Example Sentence 2
We accepted the pre departure reroute and updated the flight plan before starting engines.