The throttle failsafe value does not fit the throttle range

What ArduPilot says:

• PreArm: Check FS_THR_VALUE

With the radio failsafe on, FS_THR_VALUE is the throttle pulse below which the link counts as lost. It must be at least 910 µs, and the calibrated bottom of the throttle stick (RC3_MIN with the default channel order) must be more than 10 µs above it. Otherwise pulling the throttle down would look like a lost link.

What to do, most likely first

1. The transmitter's lowest throttle is close to FS_THR_VALUE: 982 µs against the default 975, for example.

   CheckCompare RC3_MIN with FS_THR_VALUE plus 10.

   FixSet FS_THR_VALUE 20 to 40 µs under RC3_MIN, but not under 910. With a CRSF/ELRS or SBUS receiver the lost link is also signalled by the receiver itself.

2. The radio calibration was done with the throttle reversed or trimmed, so RC3_MIN is wrong.

   CheckWith the stick down, the throttle bar in the Radio Calibration screen should read RC3_MIN.

   FixCentre the trims, calibrate the radio again, then set FS_THR_VALUE as above.

3. FS_THR_VALUE was set below 910.

   FixRaise it to 910 or more, staying under RC3_MIN minus 10.

Parameters to look at

Where to do it:Setup & Tuning GuideFailsafe ExplainerSetup & Tuning Guide