You can set up the flight modes available on the transmitter by doing the following:
1 - Turn on your RC transmitter Connect the Pixhawk (or other flight controller) to the Mission Planner Go to the Initial Setup | Mandatory Hardware | Flight Modes screen
2 - Use the drop-down on each line to select the flight mode for that switch position.
3 - When finished press the Save Modes button.
But what do you do when the drop-down menu is blank, and has no option available?
What flight controller and firmware are you using.
I have just experienced this in Mission Planner but it was when I connected to a PixFalcon loaded with the PX4 flight stack, which Mission Planner does not read
I also want to thank you Joe, yours was the only post that solved this issue. I will throw this out, I could see the flight modes when using my Win 7 desktop, but not when using my Win 10 laptop. Not sure if that is part of the issue, but more info cant hurt.
For me,
Frame type set through parameter only , that is custom Frame Type i.e. FRAME_TYPE = 18 (BetaFlightXReversed), and this caused problem.
So to fix it, selected Frame Type from Mission Planner as Quad X and later changed to FRAME_TYPE = 18 (BetaFlightXReversed) in Parameter List