When in the failsafe setup screen, there are two checkbox's one is labeled:

"throttle failsafe"

       the other is labeled

"throttle failsafe action"

By default "throttle failsafe" was unchecked, and 'throttle failsafe action" was checked.

I set up failsafe for my Radio, so that channel three goes below 975 if the transmitter is turned off.

I want that condition to trigger RTL.  

I don't understand the labels, how are they to be used? I would also like to have a switch on the Transmitter like my landing gear switch to trigger RTL.  

Not knowing what I am doing, I have checked the "throttle fail safe" hoping that is correct, but what the heck is "throttle failsafe action" ???