A microburst encounter poses a serious threat to aircraft during takeoff or landing because it produces which type of wind shear?

• A. Only vertical wind shear
• B. Only horizontal wind shear
• C. Both vertical and horizontal wind shear
• D. No wind shear

Answer: (C)

A microburst creates both vertical and horizontal wind shear because it involves a strong downdraft that reaches the surface and then spreads outward as a gust front. The vertical shear comes from how wind speed and direction change rapidly with height inside the downburst—the air at lower levels can differ dramatically from just above the downdraft. The horizontal shear comes from the outward spreading gust front, which causes a sharp change in wind speed and direction across the runway as the outflow passes by. On takeoff or landing, aircraft are close to the ground with high lift demands and limited time to react, so these sudden, multi-directional wind changes can dramatically affect airspeed and control, making microbursts a serious hazard.