AI Assisted
Definition
A height measurement expressed as the vertical distance between the aircraft and the terrain directly beneath it. AGL changes as the ground beneath the aircraft rises or falls, even when the aircraft maintains a constant altitude above sea level.
Plain English
Context Anchor
Seen in weather reports, traffic pattern altitudes, obstacle heights, and low-altitude flying discussions.
Why Pilots Care
Critical for terrain clearance, obstacle avoidance, and meeting minimum altitudes that are not referenced to sea level.
Intuition Check
AGL does not mean height above sea level. It means height above the ground or surface being referenced.
Example Sentence 1
The traffic pattern at this airport is flown at 1,000 feet AGL.
Example Sentence 2
The tower height was listed as 300 feet AGL on the sectional chart.