Definition
The angle, measured in degrees, between the aircraft's heading and the bearing or course it is flying to intercept. A larger interception angle produces a faster join to the desired track; a smaller angle produces a more gradual join.
Plain English
How sharply you turn off your current path to cut across and join the line you want to be on. A bigger angle means you cross over to it faster; a smaller angle means you ease onto it.
Context Anchor
Used during instrument navigation when a pilot is turning toward a selected bearing or course before tracking along it.
Derivation
From Latin 'intercipere', meaning 'to seize between' or 'cut off in transit.' In navigation, you are 'cutting across' from where you are now to the line you want to be flying along. The angle describes how steeply you cut.
Why Pilots Care
The chosen angle controls how quickly and smoothly the aircraft captures the new course without overshooting.
Analogy
It is like merging onto a road. If you approach at a shallow angle, you blend in gradually; if you approach at a sharp angle, you reach the road quickly but may need a quicker correction.
Intuition Check
Do not confuse the interception angle with the bearing you will fly after joining the course. The interception angle is only the difference between your present heading and the line you are trying to reach.
Example Sentence 1
The instructor told the student to use a 30-degree interception angle to join the inbound radial.
Example Sentence 2
A 30-degree interception angle allowed a gentle turn onto the final approach course.