If wind is 25 knots from the left at 90° to the runway, what is the crosswind component?

If wind is 25 knots from the left at 90° to the runway, what is the crosswind component?

• A. 10 knots
• B. 50 knots
• C. 0 knots
• D. 25 knots

Answer: (D)

Crosswind component is found by looking at how the wind direction compares to the runway direction. It’s the part of the wind blowing perpendicular to the runway. Mathematically, it’s wind speed times the sine of the angle between the wind direction and the runway heading. If the wind is exactly perpendicular to the runway (from the left at 90°), that angle is 90°, and sin(90°) = 1, so the crosswind component equals the full wind speed. The headwind or tailwind component would be wind speed times cos(90°), and cos(90°) = 0, so there’s no headwind. So the crosswind component is 25 knots.

Crosswind component is found by looking at how the wind direction compares to the runway direction. It’s the part of the wind blowing perpendicular to the runway. Mathematically, it’s wind speed times the sine of the angle between the wind direction and the runway heading. If the wind is exactly perpendicular to the runway (from the left at 90°), that angle is 90°, and sin(90°) = 1, so the crosswind component equals the full wind speed. The headwind or tailwind component would be wind speed times cos(90°), and cos(90°) = 0, so there’s no headwind.

So the crosswind component is 25 knots.