Definition
The lateral (left/right) guidance signal provided to an aircraft on final approach, indicating its alignment with the runway centerline. In Microwave Landing System (MLS) operations, approach azimuth guidance is transmitted from a ground station located beyond the stop end of the runway and defines a wide coverage sector through which the aircraft can intercept and track the final approach course.
Plain English
It's the signal that tells the aircraft whether it's lined up left or right of the runway as it comes in to land. It doesn't tell the pilot how high to be -- only how to stay on track side-to-side toward the runway.
Context Anchor
Seen in instrument approach discussions, especially when describing systems that guide an aircraft toward the runway for landing.
Derivation
Azimuth comes from the Arabic 'as-sumut,' meaning 'the directions' or 'the ways.' In navigation, azimuth refers to a horizontal direction or bearing. So 'approach azimuth guidance' literally means 'directional guidance during the approach' -- which is exactly what it provides: horizontal alignment toward the runway.
Why Pilots Care
Maintaining correct azimuth alignment prevents lateral deviations that could lead to an unstable approach or missed runway.
Grounding Statement
Picture the runway centerline extended outward into the sky; approach azimuth guidance helps you stay on that left-right line as you fly toward the runway.
Intuition Check
Approach does not just mean “getting closer” here; it means the instrument path flown toward landing. Azimuth guidance does not tell you height; it tells you left-right direction.
Example Sentence 1
After intercepting the approach azimuth guidance, the crew tracked the centerline inbound to the runway.
Example Sentence 2
During the RNAV approach the GPS provided continuous approach azimuth guidance through the final approach segment.