Hi, sorry if this is covered elsewhere - if it is I didn't find it!.

Using a Futaba 7c 24 MHz with an electric delta-type pusher model, take off from grass is on a wheeled dolly latched to the bottom of the plane by a staple and pin, which is released when airborne over a drop zone by switch B operating a servo on channel 7. The back of the dolly is very close to the prop, and any contact is likely to be destructive.

The system works well, but to improve safety I want to prevent the dolly being released while the motor is running, and the idea is to inhibit the switch (or operation of channel 7) unless the throttle stick is at zero. It seems a simple idea, but I can't seem to configure a P Mix to make it work. Maybe there's another way!

Any ideas? Thanks.

Alan