What just happened on short final?

Nov 12, 2026

Short final, stable approach to land, storms visible in the distance. Suddenly the airspeed indicator increases by 30 knots, followed by a drop of 60 knots. What just happened?

AAirspeed indicator failure

Wild swings in the airspeed indicator could indicate mechanical failure -- the view out the window suggests we rose suddenly and then sank, which is consistent with dramatic shear. Option C is the better answer ⛈️

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BEngine power fluctuating

On short final, a light single can't gain 30 knots in a few seconds even at full throttle. If you look at fuel flow, you can see the engine is close to idle as the airspeed increases up to 120. Couple this with the view out the window -- the plane is climbing. Option C is the better choice 🌬️

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CFlew into a microburst

You got it 👍

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DWake turbulence from a departing jet

Wake turbulence is a possibility, but it's usually accompanied by a rolling motion. Here, the plane stays wings level. Notice the storm activity in the area -- a more likely explanation is Option C 🌧️

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Pick an answer. You can try as many as you like.

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The explanation

C. Flew into a microburst

What the airspeed indicator showed

A microburst is a small, intense downdraft that hits the ground and spreads out in every direction. An airplane flying through one meets the outflow in three stages. First comes a headwind, which raises the indicated airspeed and lifts the airplane above its path. Next comes the downdraft. Last comes a tailwind, which takes the airspeed away again. The 30-knot gain followed by a 60-knot drop from the peak is that sequence: a 30-knot headwind that turned into a 30-knot tailwind, a 60-knot shear in a few seconds.

Why storms in the distance still matter

The AIM describes the downdraft as typically less than a mile across, with the outflow at the surface spreading out to about 2 1/2 miles. Downdrafts can reach 6,000 feet per minute, and the horizontal winds can reach 45 knots, which means a 90-knot shear from one side of the microburst to the other. A microburst gets stronger for about 5 minutes after it reaches the ground, and once one starts, more in the same area should be expected. They also come from weak-looking convective cells with little or no rain reaching the ground, not only from the storm itself.

What to do about it

The sudden airspeed gain is the warning. The natural reaction is to reduce power and lower the nose to get back on speed and on the glide path. That leaves the airplane low on power and nose low just as the tailwind and downdraft arrive, with little altitude to recover. Treat an unexpected gain near convective weather as the cue to go around with full power, and the best defense is to stay away from the storms in the first place.