The problem with a tailwind on the way out
Flying downwind is fast and cheap. The trouble starts on the way back: the drone moves through the air at its normal speed, but the air itself is moving towards you, so its speed over the ground drops. Many lost drones flew out with the wind and could not come back against it.
The formula
- Speed over the ground on the way home = drone speed − headwind.
- Time to get home = distance ÷ speed over the ground.
- Flight time left on landing = flight time left now − time to get home.
- Farthest turn-back point = (flight time left − reserve) × speed over the ground.
If the headwind is as fast as the drone, the speed over the ground is zero or negative: it cannot come home at all.
Worked example
You are 1.5 km away. The drone flies home at 36 km/h (10 m/s) and there is a 25 km/h headwind at your height. Speed over the ground: 36 − 25 = 11 km/h. Time home: 1.5 ÷ 11 × 60 ≈ 8.2 minutes. With 12 minutes of flight time left you land with about 3.8 minutes, just above a 3-minute reserve. With a 28 km/h headwind the same trip takes over 11 minutes and eats the reserve.
What the calculator does not know
- The battery does not drain evenly. Flying fast into the wind draws more current than hovering, so the minutes left on the screen shrink faster on the way back. Keep a generous reserve, especially in the cold.
- The wind is stronger higher up. A 15 km/h ground forecast can be 22–28 km/h at 120 m. Use the wind at altitude calculator for the headwind.
- Automatic Return-to-Home flies at a speed set in your drone's app and may climb to its RTH altitude first, into stronger wind. Check those settings in your drone's manual.
The safest habit is simple: fly the first leg into the wind, so the wind helps you home when the battery is lower.
Frequently asked questions
Can a drone fly back against strong wind?
Only if its speed through the air is clearly higher than the headwind. Its speed over the ground is its own speed minus the headwind; when that gets close to zero it takes a very long time, or never, to get home.
Should I fly into the wind first?
Yes. Flying the first leg upwind means the wind pushes you home on the second leg, when the battery is lower.
How much battery reserve should I keep?
Enough to land calmly after the trip home, and more in cold weather, because cold batteries lose capacity and voltage quickly. Start heading back no later than your drone's low-battery warning, and earlier when the wind is against you.