Plain English Meaning

The extra speed between a steady wind and its strongest gust. Pilots add some of that extra speed to their landing approach speed so the airplane stays controllable if a gust dies away suddenly.

Full Definition

The difference between the steady (sustained) wind speed and the peak gust speed reported in a wind observation. Pilots use this difference to add an airspeed increment to the normal approach speed when landing in gusty conditions, helping maintain controllability if the airplane suddenly loses headwind during a gust lull.

Context Anchor

Used during approach and landing planning when wind is reported with gusts, especially in turbulent air.