Definition
The first segment of a Standard Terminal Arrival (STAR) procedure, connecting an en route fix or airway to the common portion of the arrival route that leads toward the destination airport. Each STAR may have several published en route transitions, each beginning at a different fix and joining the main arrival path at a defined point.
Plain English
It is the part of an arrival procedure that links where you are coming from in cruise to the main arrival route into the airport. STARs usually offer several of these entry segments, and you fly the one that matches the direction you are arriving from.
Context Anchor
Seen on STAR charts when choosing or following the transition that matches the direction from which the aircraft is arriving.
Derivation
Transition' comes from the Latin transire, meaning 'to go across.' Here it describes the segment that carries the aircraft across from the en route structure into the arrival procedure.
Why Pilots Care
Allows seamless entry onto the arrival without radar vectors or holding, preserving fuel and reducing ATC workload.
Intuition Check
Do not read “transition” here as a general change in flight. A STAR en route transition is a specific published path on the arrival chart that connects the en route portion of the flight to the main STAR.
Example Sentence 1
Cleveland Center cleared us to descend via the BRUNO TWO arrival with the DJB en route transition, so we loaded that entry into the FMS before top of descent.
Example Sentence 2
ATC assigned the eastern STAR en route transition to keep arrivals sequenced away from weather.