Definition
The published angle, measured in degrees below horizontal, of the descent path used during the final segment of an instrument approach. It defines the rate at which the aircraft is intended to descend from the final approach fix to the runway threshold crossing height, and is used by VNAV systems to compute the descent path.
Plain English
It is how steeply the airplane is supposed to come down on the final part of an instrument approach, given as an angle below level flight. A typical value is around three degrees.
Context Anchor
Seen in instrument approach procedure planning, especially when using VNAV to build or check the vertical path before flying the approach.
Derivation
Vertical means up-and-down, and angle is the tilt measured from horizontal. Together they describe how far the descent path tilts down from level flight on the approach.
Why Pilots Care
It provides the guidance needed to descend at the proper rate while clearing obstacles and arriving at the correct altitude over the runway.
Analogy
It is like the slope of a ramp. A shallow ramp descends slowly over distance; a steeper ramp descends faster over the same distance.
Grounding Statement
Picture a straight, shallow line sloping down through the approach path toward the runway; the instrument approach vertical angle is the angle of that line.
Intuition Check
Do not read this as just any vertical angle the airplane happens to fly. In this context, it means the specific planned or published descent angle used for the instrument approach path.
Example Sentence 1
The chart showed an instrument approach vertical angle of 3.00 degrees, so we set up the VNAV to follow that path down to the runway.
Example Sentence 2
During the approach briefing the crew confirmed the instrument approach vertical angle would keep them on the required descent profile.