Pixhawk 2/PX4: FD_FAIL Flight Termination not working

Hi Everyone!

We have hade some issues with our Pixhawk 2 (PX4) and flight termination. We have set FD_FAIL_R and FD_FAIL_P to 60 (default) and enabled the flight termination circuit breaker (CBRK_FLITTERM = 0). When arming the vehicle and then tilting it even by 90° (either pitch or roll), flight termination is not activated, the motors continue to spin.

Flight termination itself is working in general, since, for testing, we have used flight termination as our RC Failsafe, and turning off the RC activates flight termination as expected.

Any ideas what we might be missing?
Thank you!


Hello @michael-borkowski ,
normally, if FD_FAIL_[RP] and FD_FAIL_[RP]_TTRI are set to their default values, you just need to disable the circuit breaker CBRK_FLITTERM like you did.
Could you provide a log file (http://logs.px4.io) showing that the exceeded tilt doesn’t trigger termination please?

(For reference, here is the relevant documentation: https://docs.px4.io/master/en/config/safety.html#failure_detector)

Hi @bresch,

Thanks, we will have a look and provide a log file as soon as possible.


Same test executed here. See https://github.com/PX4/Firmware/issues/13244
@bresch, Mathieu i have attached a flight log as well.

Answered here: https://github.com/PX4/Firmware/issues/13244#issuecomment-544851852

Short answer: this feature will be available in v1.10 or currently on master but not isn’t implemented in v1.9.2.