Definition
A published route between two airports that ATC prefers IFR flights to use, established to streamline traffic flow into, out of, and between busy terminal areas and to reduce controller workload. Preferred IFR routes are listed in the Chart Supplement and are typically expected to be filed in flight plans when applicable.
Plain English
A standard route between two airports that ATC would like you to fly. Filing it makes your clearance smoother because it matches what controllers are already planning to give you.
Context Anchor
Seen when planning or filing an IFR flight plan, reviewing published IFR route guidance, or receiving an IFR clearance that follows established high-altitude routing.
Derivation
Preferred comes from a Latin idea meaning “placed before” or “carried in front.” That helps here because, among several possible IFR routes, this route is placed ahead as the one normally wanted for traffic handling.
Why Pilots Care
Filing the preferred routing raises the likelihood that ATC will issue the clearance as requested and reduces the chance of last-minute reroutes.
Intuition Check
Preferred does not mean the route is simply a pilot’s favorite or always the shortest route. Here it means the route ATC or FAA guidance favors because it fits the traffic system; ATC can still assign a different route when needed.
Example Sentence 1
Before filing IFR from Chicago to Cleveland, she checked the Chart Supplement for a preferred IFR routing and used it in her flight plan.
Example Sentence 2
Using the preferred IFR routing kept the flight out of busy sectors and simplified handoffs.