retractable landing gear automated

[o_lampe]

Hi Folks,
more and more frames come with retractable landing gears.
Instead of using a separate switch on the TX, it'd be nice to fold/unfold it automatically by baro/sonar/land-switch .
The SW would need a threshold ( say 5m above ground ) and maybe two variables for top/bottom servo angle.

What do you think?

[FengShuiDrone]

.

[o_lampe]

The point is to eliminate the need for a separate channel on the TX, regardless of the way your retracts work ( servo or servoless).