Copter crash in RTL mode

If FS_THR_ENABLE is enabled, it will FS when no R/C is detected.

If you have an R/C connected and the telemetry fails and you’re not in guided mode, the telemetry fail safe will not activate since there is an assumption that the R/C can be used to control the bird.

Here is the logic:

There is still an assumption that there is always an R/C, which may not be the case these days. There probably needs to be a discussion with the ardupilot team to flesh out all the edge conditions.