FAA Instrument Flight Instructor (FII)WeatherMedium
On final approach in gusty conditions, a pilot notices an increasing headwind followed by a sudden shift to a strong tailwind accompanied by a significant increase in sink rate. This is a classic indication of which hazardous phenomenon?
- AMicroburst
- BClear air turbulence
- CMountain wave activity
- DFrontal wind shear
Show answer & explanationAnswer & explanation
Correct answer: A. Microburst
A microburst produces a rapid change from increasing headwind (performance-increasing) to decreasing headwind or tailwind (performance-decreasing) along with a strong downdraft, causing significant loss of altitude and airspeed in a very short time—exactly the scenario described. This combination of rapid wind shift plus severe downdraft is the hallmark of microburst encounters near the surface.
Why the other options are wrong
- B. Clear air turbulence occurs at altitude, typically associated with jet streams, not low-level approach wind shifts.
- C. Mountain wave turbulence occurs downwind of mountains and doesn't typically cause this rapid headwind-to-tailwind shift on approach.
- D. Frontal wind shear is typically more gradual and less severe than the abrupt shift described in a microburst.
Microburst
A microburst is an intense, localized downdraft that produces a rapid change from headwind to tailwind and a severe increase in sink rate, posing extreme hazard during takeoff and landing.
- Short duration, typically 5 minutes or less
- Can produce wind shear exceeding 45 knots differential
- Most hazardous during takeoff and approach phases
Memory trick: Microburst 'Micro but Mighty'—short but violently reverses wind and sinks aircraft.