Crosswind examples, worked

1. A 30 degree wind from the right

Wind 300° at 20 knots, runway 27 (270°).

• Angle = 300 − 270 → 30° (wind on the right).
• Crosswind = 20 × sin 30° = 20 × 0.5000 = 10.0 → 10 knots from the right.
• Headwind = 20 × cos 30° = 20 × 0.8660 = 17.3 → 17 knots of headwind.

2. The same angle from the left

Wind 240° at 20 knots, runway 27 (270°).

• Angle = 240 − 270 → -30° (wind on the left).
• Crosswind = 20 × sin -30° = 20 × -0.5000 = 10.0 → 10 knots from the left.
• Headwind = 20 × cos -30° = 20 × 0.8660 = 17.3 → 17 knots of headwind.

3. Wind straight down the runway

Wind 180° at 15 knots, runway 18 (180°).

• Angle = 180 − 180 → 0° (wind straight down the runway).
• Crosswind = 15 × sin 0° = 15 × 0.0000 = 0.0 → 0 knots.
• Headwind = 15 × cos 0° = 15 × 1.0000 = 15.0 → 15 knots of headwind.

4. Wind straight across the runway

Wind 090° at 15 knots, runway 36 (360°).

• Angle = 90 − 360 = -270, and adding 360 → 90° (wind on the right).
• Crosswind = 15 × sin 90° = 15 × 1.0000 = 15.0 → 15 knots from the right.
• Headwind = 15 × cos 90° = 15 × 0.0000 = 0.0 → 0 knots of headwind.

5. Wind straight from behind

Wind 270° at 12 knots, runway 09 (90°).

• Angle = 270 − 90 → 180° (wind from directly behind).
• Crosswind = 12 × sin 180° = 12 × 0.0000 = 0.0 → 0 knots.
• Tailwind = 12 × cos 180° = 12 × -1.0000 = -12.0 → 12 knots of tailwind.

6. A 50 degree wind

Wind 230° at 14 knots, runway 18 (180°).

• Angle = 230 − 180 → 50° (wind on the right).
• Crosswind = 14 × sin 50° = 14 × 0.7660 = 10.7 → 11 knots from the right.
• Headwind = 14 × cos 50° = 14 × 0.6428 = 9.0 → 9 knots of headwind.

7. An angle that wraps past north

Wind 010° at 16 knots, runway 33 (330°).

• Angle = 10 − 330 = -320, and adding 360 → 40° (wind on the right).
• Crosswind = 16 × sin 40° = 16 × 0.6428 = 10.3 → 10 knots from the right.
• Headwind = 16 × cos 40° = 16 × 0.7660 = 12.3 → 12 knots of headwind.

8. A gusty wind

Wind 300° at 18 knots, gusting to 26, runway 27 (270°).

• Angle = 300 − 270 → 30° (wind on the right).
• Crosswind = 18 × sin 30° = 18 × 0.5000 = 9.0 → 9 knots from the right.
• Headwind = 18 × cos 30° = 18 × 0.8660 = 15.6 → 16 knots of headwind.
• In the gust: crosswind = 26 × 0.5000 = 13.0 → 13 knots from the right; headwind = 26 × 0.8660 = 22.5 → 23 knots.

9. Which runway has the least crosswind?

Wind 300° at 18 knots. Run the sum for every runway heading, 01 to 36, and put those with a tailwind last. The first 3 are:

Runway 30 points into the wind. This ranks headings, not the runways at a particular airport.