I have flaps setup on only 1 model, because it has fixed undercarriage I chose the Gear channel and switch but you can use any available channel, make sure the the channel you choose is assigned to the port you are using in System Setup/Channel Assign then go to the Next which is Channel Input Config and select the switch that you want to use I chose Gear but you can choose any available 3 position switch. At this point make sure the flaps are moving as required when the switch is up position Zero that the flaps are up, if not go to Servo Setup and reverse the channel you have chosen. After that go to System Setup/Digital Switch Setup and select the switch that you are using and adjust the % of throw that you need for the 3 positions. Mine is Pos 0:100% Pos 1:45% Pos 2:12% this can vary and those figures look wrong to me so I probably should reverse the Servo Direction but I'm not going to because it works OK. From here if you have a Gen 2 DX8 you can go ahead and setup Voice.