Definition
A barrier built on or near an airport to deflect or absorb the high-velocity exhaust (jet blast or propeller wash) from aircraft engines, protecting people, vehicles, structures, and other aircraft positioned behind a running engine.
Plain English
A solid wall, usually metal or concrete, placed behind aircraft parking or run-up areas to stop the powerful air blast from engines from blowing things over or causing damage.
Context Anchor
Seen on airport ramps, maintenance areas, engine test areas, and near taxiways where aircraft may use higher power close to other airport activity.
Derivation
Blast comes from Old English blæst meaning a strong gust or burst of air. Fence comes from the Latin defensa, a defense or guard. Together: a guard against a strong burst of air -- exactly what it does.
Why Pilots Care
Protects ground personnel, vehicles, other aircraft, and airport infrastructure from damage or injury caused by jet blast.
Intuition Check
A blast fence is not mainly a security fence or boundary marker. Its purpose is to redirect or reduce engine airflow and debris.
Example Sentence 1
After taxiing into position behind the blast fence, the pilot held short and waited for clearance to enter the runway.
Example Sentence 2
Ground crew stayed behind the blast fence while the aircraft performed an engine test.