How is groundspeed affected by wind, and how would you compute it for planning?

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Multiple Choice

How is groundspeed affected by wind, and how would you compute it for planning?

Groundspeed is how fast you move over the ground, and it’s found by combining what the aircraft is doing through the air with the movement of the air itself. To plan, you separate the wind into the part that acts along your intended track and the part that blows across it. The along-track component changes how quickly you progress along that route: a headwind slows you down, a tailwind speeds you up. So you take your true airspeed and adjust it by the wind component along the course: GS along the track = TAS + (wind speed × cos(angle between wind and course)). For planning, use this to find time to cover a distance: time = distance / GS along the track. If the wind is purely crosswind, the along-track component is zero, so the along-track groundspeed equals TAS, though the wind still affects drift and overall ground speed magnitude through vector addition. For example, with TAS 120 knots and a wind from 030 degrees at 20 knots on a 040-degree course, the along-track wind component is about 20 × cos(10°) ≈ 19.7 knots, giving a groundspeed along the track of roughly 140 knots.

Groundspeed is how fast you move over the ground, and it’s found by combining what the aircraft is doing through the air with the movement of the air itself. To plan, you separate the wind into the part that acts along your intended track and the part that blows across it. The along-track component changes how quickly you progress along that route: a headwind slows you down, a tailwind speeds you up. So you take your true airspeed and adjust it by the wind component along the course: GS along the track = TAS + (wind speed × cos(angle between wind and course)). For planning, use this to find time to cover a distance: time = distance / GS along the track. If the wind is purely crosswind, the along-track component is zero, so the along-track groundspeed equals TAS, though the wind still affects drift and overall ground speed magnitude through vector addition. For example, with TAS 120 knots and a wind from 030 degrees at 20 knots on a 040-degree course, the along-track wind component is about 20 × cos(10°) ≈ 19.7 knots, giving a groundspeed along the track of roughly 140 knots.

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