Definition
The general term for the act of changing from one phase of flight or flight condition to another, such as moving from cruise to approach, from VFR to IFR conditions, or from en route airspace to a terminal area. In ATC usage, transition also refers to a published procedure that connects an en route route structure to an instrument approach or departure procedure, or to a defined route segment used to enter or leave a terminal area.
Plain English
A change from one stage of flight to another, or a published path used to move between en route flying and an approach or departure.
Context Anchor
You may see this term in approach procedures, air traffic control instructions, training maneuvers, and discussions of changing from one part of a flight to the next.
Derivation
From Latin transire, meaning "to go across." The aviation use keeps that core idea: moving across from one phase, route, or condition into another.
Why Pilots Care
Allows pilots to follow a cleared path from airways into an approach without needing radar vectors, improving predictability and reducing workload.
Intuition Check
Do not read transition as just a casual change. In aviation, it usually means a specific move from one defined flight phase, condition, or procedure into another.
Example Sentence 1
Cleared direct BOACH, then the BOACH TRANSITION to the ILS Runway 19L approach.
Example Sentence 2
During preflight planning the pilot reviewed the available transitions for the destination airport's instrument approach.