Throttle doesnt respond

[quads500]

I have Crius AIOP using with multiwii 2.2. Calibrated and set pids. It hovers, goes up and down, pitch and roll  normally.

But there is a strange behaviour. When I am descending from 30m to down, I push the throttle to hold in hover about 10m but even if I give full throttle it doesnt stop.  It slows down but it doesnt hover, sometimes hits the ground. Any idea why throttle doesnt respond?

[PaulJC]

Complete vertical descent?

[quads500]

When doing small moves its ok. But when descendin fast, it doesnt stops even I give full throttle.

[PaulJC]

Vortex ring state by the sounds of things... Happens a lot in pre vertical descent with multi';s...

Essentially, the helicopter descends into its own downwash. When the condition arises, increasing the rotor power merely feeds the vortex motion without generating additional lift

[quads500]

Is there a solution?

[PaulJC]

Movement, don';t descent completely vertically

[quads500]

Can barometer help for altitude hold in this situation?

[PaulJC]

No, no amount of electronics can deft the rules of physics

A barometer will just apply more power no different to how you have, the end result would be the same just with you having even less control of it...

[quads500]

Thank you Paul, for your interest and fast reply. 

[PaulJC]

No problems, just zig-zag your way down or fly in one direction, it doesn';t have to be fast, it just has to be enough to disturb that pattern of airflow

[philtrum]

have you got a video of it happening ?

Cheers
Phil

[quads500]

Yes, I was experimenting gopro. (on board)