Definition
An aircraft's collision with the ground or with terrain features such as hills, mountains, trees, or water. In wind shear discussions, terrain impact is the worst-case outcome when a sudden loss of airspeed or altitude near the surface leaves the pilot without time or performance to recover before striking the ground.
Plain English
The aircraft hits the ground or something on the ground, like a hill or trees. It is the crash itself, not the events leading up to it.
Context Anchor
Seen in low-level wind shear discussions, especially during takeoff and landing when the aircraft is close to the ground and has little height available to recover.
Derivation
Terrain comes from the Latin terra, meaning “earth” or “land.” Impact comes from a Latin word meaning “to strike against.” Together, the phrase points to the aircraft striking the earth or something on it.
Why Pilots Care
Terrain impact is the most immediate and severe outcome of unrecovered wind shear encounters, directly contributing to many low-altitude accidents; early recognition enables escape maneuvers.
Grounding Statement
Picture an airplane on final approach suddenly sinking below its normal path; if the sink continues close to the ground, the result can be terrain impact.
Intuition Check
Do not read terrain impact as just a hard landing. It means unintended contact with the ground, rising land, or a surface obstacle when the aircraft should still be safely flying or landing under control.
Example Sentence 1
A microburst encountered shortly after takeoff can cause a rapid loss of airspeed and altitude, leading to terrain impact if recovery is not initiated immediately.
Example Sentence 2
Training emphasizes that prompt power application and pitch adjustment can avert terrain impact even when wind shear occurs below 200 feet.