Wind Shear and Microbursts
What wind shear is, where it lurks, and why a microburst is so dangerous on approach and departure.
Wind shear is a sudden change in wind speed or direction over a short distance, vertically or horizontally. Near the ground, on takeoff or approach, it can be deadly because there's little height to recover.
Where it hides
- Thunderstorms and their gust fronts (the classic source).
- Microbursts — small, intense columns of sinking air that spread out at the surface.
- Temperature inversions and low-level jets, often at night.
- Frontal zones and terrain/sea-breeze boundaries.
The microburst trap
Flying into a microburst on approach, you first meet a headwind (airspeed rises, you balloon above the path), then the downdraft, then a tailwind (airspeed falls, sink rate increases) — often just as you reach the ground. The instinct to reduce power during the initial gain is exactly wrong.
Response
- Recognise the cues — a "performance-decreasing" shear (rapid airspeed loss, high sink).
- Apply maximum available power, pitch to the go-around/escape attitude, and don't chase airspeed.
- Best of all, don't take off or land into a known or suspected microburst; delay or divert.
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*Reference and training only — not for navigation. Always consult the current AIM, FAR/AIM, your aircraft’s POH/AFM, official weather products and a certificated flight instructor.*