I've been thinking about trainer-student systems for a while and how I could make my own for cheap since I really wanna teach a friend of mine how to fly RC planes. While "trainer-student system" is the correct literal translation of "Lehrer-Schüler System", I'm not sure if it's actually called that in english, so let me explain real quick: With the presented term I associate a system that consists of 2 transmitters of which one can override the control inputs of the other. However, as long as the trainer doesn't do anything the student is in control of the plane. But if the trainer needs to save the plane after the student fked up he can take control of the plane in a split second and level the plane out / do whatever needs to be done to prevent a crash. An idea of how to do that has been in my head for some time but i never had a good idea on how exactly to pull it off. That has changed this morning. Now we probably all know that our sticks are "read out" by potentiometers connected to the main PCBs of our transmitters with some wiring, unless they are PCB-mounted all-in-one parts like on a gaming controller. My idea was to use a bunch of relay switches to be able to switch between the sticks of the trainer's transmitter and those of the student's transmitter (which are linked together with a cable) at the push of a button. It would even be possible to do this for every axis individually in order to have the student learn what the effect of each axis is first. I'm willing to risk both of my transmitters to try this idea out since there really isn't a whole lot to go wrong and as an electronics technician everything else should be an easy repair for me. Let me know what u think of this idea. I'll post the results after trying it out and if more of u guys want the system I'll make a schematic of the wiring. Just be warned that relay switches may draw alot more power while they're on, I just don't know of any better way yet to switch between 2 sets of control sticks.