These instructions explain how to set up a Spektrum DX7 transmitter for 6 different flight modes, using just the 3 position Flaps switch (in combination with the Rudder switch). This way you'll use just one channel for the flight modes and leave the Gear and Aux2 channel open ...

(note that you have to use…

This is how it worked for my DX7,

I use various switch combinations of the FLAPS and the GEAR switch which will give you 6 modes;

(note that you have to use the DX7 in "airplane mode", not in "heli mode" to fly a…