It seems that once a landing failsafe sets in, the autopilot should not enter other modes, especially after landing! The following scenario unfolded about a week ago:
Takeoff manually in stabilize, go in loiter mode, battery failsafe incorrectly triggered (due to incorrect voltage readings), the copter comes down and lands; knowing that the battery is actually OK, I put it back in stabilize, then loiter then auto - the copter leaves on its mission, but it immediately starts to lose altitude (apparently still in land mode) while moving on the X and Y toward its waypoint. I get it back in stabilize mode and make a mini-crash-landing (my fault).
I don't think that the copter should be in landing mode and auto-mode at the same time. Please correct me if I am wrong, but I think that one mode switch should clear the previous one.
Replies
Mihai, that is exactly what happens. Switching to any mode clears the Land mode. It's impossible to be in two modes at once.
Based on what you've stated, my guess is your battery really was depleted (at least, it was when it came down the second time) and you crashed because it didn't have enough power to fly.