If crosswind component is 10 knots and you fly for 12 minutes, how many nautical miles off course would you be?

If crosswind component is 10 knots and you fly for 12 minutes, how many nautical miles off course would you be?

• A. 1 nautical mile
• B. 3 nautical miles
• C. 2 nautical miles
• D. 4 nautical miles

Answer: (C)

The idea is drift from a crosswind: how far you get pushed sideways depends on the wind speed perpendicular to your path multiplied by the time you’re exposed to it. A crosswind of 10 knots pushes you 10 nautical miles per hour sideways. 12 minutes is 0.2 hours, so the drift is 10 × 0.2 = 2 nautical miles. So you’d be about 2 nautical miles off course if you didn’t correct for it. The other options correspond to longer times: 1 NM would be drift over 6 minutes, 3 NM over 18 minutes, and 4 NM over 24 minutes.

The idea is drift from a crosswind: how far you get pushed sideways depends on the wind speed perpendicular to your path multiplied by the time you’re exposed to it. A crosswind of 10 knots pushes you 10 nautical miles per hour sideways. 12 minutes is 0.2 hours, so the drift is 10 × 0.2 = 2 nautical miles. So you’d be about 2 nautical miles off course if you didn’t correct for it. The other options correspond to longer times: 1 NM would be drift over 6 minutes, 3 NM over 18 minutes, and 4 NM over 24 minutes.