I have a flight with APM 2.6 today and AC3.2.1
I did fly aggressively forward and then backward and at that time when pushing from forward to backward I got my APM beep two long and two short beeps ( -- -- - -).
I cannot find Beep codes anywhere but looking into my logs I can see EKF_CHECK-2 followed by EKF_CHECK-0 (recovered ?) . I was flying in STabilize mode all the time.
I assume that if I would have been in loiter then some sort of failsafe would be triggered but since I was in STabilize nothing happened and I continued to fly without any interruptions.
I wonder if this is correct, should it beep even when in Stabilize mode?