While on a 3-mile final approach, a flight crew observes a rapidly increasing headwind component followed within seconds by a sudden strong tailwind and a significant unexpected sink rate. Which hazard is indicated, and what is the appropriate immediate crew response?
- AMountain wave activity; climb immediately to a higher cruise altitude
- BWake turbulence encounter; reduce power and turn away from the flight path
- CMicroburst wind shear; apply maximum available thrust and maintain a constant pitch attitude without configuration changes
- DA distant thunderstorm's gust front; continue the approach with no change in technique
Show answer & explanationAnswer & explanation
Correct answer: C. Microburst wind shear; apply maximum available thrust and maintain a constant pitch attitude without configuration changes
The described sequence—increasing headwind followed by an abrupt shift to tailwind with a strong downdraft—is the classic signature of a microburst. The recommended response is to apply maximum thrust immediately and maintain a constant pitch attitude (typically go-around attitude), avoiding flap or gear configuration changes until clear of the shear.
Why the other options are wrong
- A. Mountain wave is associated with terrain-induced turbulence at altitude, not final approach wind shear.
- B. Wake turbulence produces rolling/upset tendencies, not this headwind-to-tailwind shear pattern.
- D. Continuing the approach without change is dangerous; immediate escape action is required.
Microburst Wind Shear
A small-scale, intense downdraft that spreads out upon reaching the surface, producing a rapid headwind-to-tailwind shift and severe sink rate, extremely hazardous during takeoff and landing.
- Can produce airspeed changes of 30+ knots in seconds
- Associated with virga and thunderstorms, often unseen at the surface
- Escape maneuver: max thrust, maintain pitch, do not change configuration
Memory trick: Microburst = 'mini nuke' of downdraft — headwind then tailwind then you drop.