Definition
The forward-facing edges of the wings and tail surfaces (horizontal stabilizer and vertical stabilizer/fin) that meet the oncoming airflow first in flight. These surfaces are critical airflow regions where ice accumulation most directly disrupts lift, control, and stability, and they are typically the primary areas protected by anti-icing or deicing systems.
Plain English
The front edges of the wings and tail — the parts that hit the air first as the airplane moves forward. Because air strikes them first, they are also the first places ice tends to build up, which is why most ice protection equipment is installed there.
Context Anchor
Seen in icing, anti-icing, and deicing discussions, especially when inspecting or operating equipment that protects the front edges of the wings and tail.
Why Pilots Care
Ice forming here changes the shape of the wing and tail, reducing lift and increasing drag until control may be lost.
Intuition Check
“Leading” does not mean the most important edge here. It means the edge that leads into the airflow—the front edge that meets the air first.
Example Sentence 1
Before departure, the pilot inspected the wing and tail leading edges for any frost or ice.
Example Sentence 2
During the preflight inspection the pilot checked the wing and tail leading edges for any accumulated ice.