This behavior is excessively paranoid about clearing the flag so now it's extra sticky. You can only clear the is_crashed flag when:
- changing modes
- starting to execute a takeoff wp (if mission/index gets reset while still in auto)
- while in takeoff and throttle is suppressed it's held false
behavior that was removed:
- clear flag when starting to execute any nav cmd (reached next wp)
- if while crashed, you "start flying again" (non-sticky)
due to zero-ish vibration in SITL, the is_flying check thinks you're not flying, and this thinks you crashed. This is a SITL specific problem but it brings to light that *if* someone actually had a very low vibration aircraft we don't want to crash them. So, the vibe test has been removed for now. A better test is a variance on the accel