Copter could not figure out it has landed; weird throttle bumping; could not disarm

Hi all,

I experienced confusing landing behavior after an otherwise successful flight.

It was on the ground safely but would not disarm. it was in LAND mode. My attempts at manual disarm (throttle down-left all the way) did nothing. the copter just sat there, periodically throttling up, but not enough to get off the ground. At some point i switched modes back to loiter, to try and switch it back to land to see if that would help. at some point the drone finally tipped over and it finally knew it crashed and finally disarmed. no damage fortunately.

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It probably had to do with the fact Vibration Failsafe triggered Vibration Compensation well before the Land attempt and this was active while you were trying to disarm. The Attitude Controller changes condition and can do funny things.

Despite it;s name this isn’t necessarily cause by high vibration, it can be triggered by a general bad positional estimate. GPS glitch could have done it in this case.