Definition
The segment of an instrument approach procedure between the initial approach fix and the intermediate fix, or between the initial approach fix and the point where the aircraft is established on the intermediate course or final approach course.
Plain English
The first leg of an instrument approach. It begins where the aircraft leaves the en route structure at a published starting point, and ends once the aircraft is lined up to begin the next part of the approach.
Context Anchor
Seen on instrument approach charts and in instrument procedure descriptions, especially when identifying where an aircraft enters the approach and how it gets lined up for the later part of the procedure.
Derivation
Initial means 'first,' from the Latin initialis meaning 'beginning.' This is literally the first segment of the approach.
Why Pilots Care
This segment positions the aircraft at the correct altitude and track so it can safely transition into the intermediate and final approach phases without losing alignment or altitude awareness.
Intuition Check
Do not read “initial” as just a casual word meaning “early.” Here it names a specific published part of an instrument approach procedure. Do not read “segment” as any random stretch of flight. Here it means a defined portion of the procedure with a specific start and end point.
Example Sentence 1
After crossing the initial approach fix, the crew began the descent prescribed for the initial approach segment.
Example Sentence 2
During the initial approach segment the crew maintained the assigned track while descending toward the intermediate fix.