What does assisted flight mean in tailsitter?

ArduCopter
1 
// handle VTOL modes
// the MultiCopter rate controller has already been run in an earlier call
// to motors_output() from quadplane.update(), unless we are in assisted flight
if (assisted_flight) {
hold_stabilize(SRV_Channels::get_output_scaled(SRV_Channel::k_throttle) * 0.01f);
motors_output(true);
} else {
motors_output(false);
}

This is part of codes in tailsitter.cpp, I want to know the meaning of assisted_flight and when it wil work.
Thanks!

2

Same as normal quadplanes,

https://ardupilot.org/plane/docs/quadplane-flying.html#assisted-fixed-wing-flight

Just it happens on tailsitters were often using the same actuators for both modes, in that case its just a switch of controllers from fixedwing to copter.