Definition
The segment of an instrument approach procedure between the initial approach fix (IAF) and the intermediate fix (IF) or the point where the aircraft is established on the intermediate course or final approach course. This is where the aircraft transitions from the en route or arrival phase toward the final approach by maneuvering, descending, and aligning with the approach course.
Plain English
The first part of an instrument approach. It begins where the published approach starts (the initial approach fix) and ends where the aircraft is lined up and ready to fly inbound on the intermediate part of the approach. Its job is to get the aircraft pointed roughly the right way and stepped down to a workable altitude.
Context Anchor
Seen on instrument approach charts and in instrument flying discussions, especially when identifying how to enter and fly a published approach.
Derivation
Initial means first, and a segment is one defined piece of a larger path. So the initial approach segment is simply the first piece of the approach — the part that starts the procedure.
Why Pilots Care
It sets the start of descent, speed reduction, and aircraft configuration for a stable approach.
Intuition Check
Do not read “initial” as simply the first time you turn toward the airport. Here it means a specific published section of an instrument approach that starts at a named starting fix.
Example Sentence 1
Once cleared for the approach, the pilot crossed the IAF and began the initial approach segment, descending toward the intermediate fix.
Example Sentence 2
The chart showed the initial approach segment with a 10-mile leg at 2,000 feet before reaching the intermediate fix.