Wind Sailor is an in-game achievement in Run 3.
If you are using the Child, start on Box Storage Area, part 10, and as part 11 begins, jump. You will notice that the level keeps getting bigger at about the same rate as the Child is falling, meaning he can keep aloft until the level stops getting bigger. Just be sure to land somewhere, or the achievement won't count.
If you are using the Gentleman, try to enable your electromagnet when you're underneath a power cell, and use the power cells as a "bridge" to stay aloft for 10 seconds.
Here is a video using the Box Storage Area trick: