Definition
The published vertical descent angle, measured in degrees from horizontal, that an aircraft follows along the final approach segment of an instrument approach to the runway. On most RNAV (GPS) approaches with vertical guidance, the GPA is typically 3.00 degrees, though it can be steeper where terrain or obstacles require it.
Plain English
It is the angle of the descent path the aircraft flies down toward the runway on an instrument approach. A 3-degree glidepath angle means the aircraft is descending on a slope of 3 degrees below level flight.
Context Anchor
Seen on RNAV instrument approach charts, usually in the profile view for the final part of the approach.
Derivation
Glidepath comes from glide (a smooth, descending flight without thrust changes) and path (the route flown). The angle is simply how steeply that path slopes down. Knowing this helps the pilot picture a steady, shallow downhill line in the sky leading to the runway.
Why Pilots Care
It determines the exact descent rate needed to stay on the correct vertical path and clear obstacles safely.
Intuition Check
GPA does not mean school grade-point average here. On an RNAV approach chart, GPA means the descent angle to fly on final approach; it is not necessarily a radio beam like an ILS glideslope.
Example Sentence 1
The approach chart showed a glidepath angle of 3.00 degrees down to runway 27.
Example Sentence 2
Maintaining the proper pitch attitude keeps the aircraft on the required GPA during the final approach segment.