Vortex ring state — transcript

00:00:00.600 --> 00:00:04.440 Vortex ring state: when your drone sinks into its own downwash.

00:00:05.400 --> 00:00:10.819 In a hover, your props push air down and away. Tip vortices form,

00:00:10.819 --> 00:00:14.020 but the turbulent air stays below you.

00:00:14.370 --> 00:00:18.554 Descend fast and straight down, and you sink into that dirty air.

00:00:18.554 --> 00:00:23.879 Air flows up through the centre of the props, more vortices form, and lift is lost.

00:00:25.370 --> 00:00:28.753 It takes three things: a high rate of descent,

00:00:28.753 --> 00:00:33.431 a vertical descent with little forward speed, and power applied.

00:00:33.431 --> 00:00:36.237 A prop in autorotation can't enter it.

00:00:36.587 --> 00:00:41.786 And here's the trap. In vortex ring state, more throttle only makes it worse.

00:00:42.587 --> 00:00:45.713 First you'll see a wobble. Then large swings in pitch and roll,

00:00:45.713 --> 00:00:47.080 and a high rate of descent.

00:00:50.587 --> 00:00:55.348 To recover, pitch forward or roll sideways into clean air, upwind if you can.

00:00:55.348 --> 00:00:57.118 You'll need height to do it.

00:00:59.587 --> 00:01:05.578 Better still, avoid it. Descend slowly, keep moving as you descend, and go upwind,

00:01:05.578 --> 00:01:06.588 not downwind.

00:01:06.938 --> 00:01:10.700 Quick check. You're wobbling and sinking fast. What do you do?

00:01:11.338 --> 00:01:13.376 Fly into clean air. Not more throttle.