I fly with DX-18 ,, the easiest way to do it is to assign the servo for the steering to its own channel and then go into your mixing and mix that Servo with the rudder, rudder being the master, assign that mix to the gear switch, highlight the block for the gear down position, that way the steering will only work when the gear is down when you retract the gear the steering servo will not be mixed in so it will not move. I also assign the trim for the nose wheel servo to one of my right tab, that way I can trim the nose wheel individual of the rudder. If you are still confused or have questions feel free to p.m. me or email me [email protected],, and I will walk you through the setup step by step this is the setup I use on all of my Jets and it works perfect.