Definition
The flight of a military aircraft maintaining a constant Above Ground Level (AGL) altitude above the terrain or the highest obstruction. The altitude of the aircraft will constantly change with the varying terrain and/or obstruction.
Plain English
Flying a military aircraft so that it stays the same height above the ground at all times. As hills, ridges, or obstacles rise and fall, the aircraft climbs and descends with them, keeping a steady distance above whatever is directly below.
Context Anchor
Seen in ATC and flight planning discussions involving low-level military operations.
Derivation
The aircraft 'follows' the terrain — its flight path traces the shape of the ground below rather than holding a fixed altitude above sea level.
Why Pilots Care
Allows safe low-level flight over varied topography while preserving terrain clearance and reducing detection risk in military or special-mission contexts.
Analogy
It is like driving over rolling hills while keeping the car the same distance above the road surface, rather than trying to stay at one height above sea level.
Intuition Check
Terrain following does not mean simply looking outside and avoiding hills. It means intentionally flying a path that stays at a selected height above the ground as the ground rises and falls.
Example Sentence 1
The military flight was conducting terrain following along the published low-level route, holding 500 feet AGL across the ridges.
Example Sentence 2
During the low-level route, the aircraft used terrain following mode to stay below radar coverage while matching the valley floor.