Triple Tree Hit - A Record?

[tom29928]

My Mavic Air 2 crashed itself into an oak tree three times in a flurry yesterday. I have a lot of experience with my Mavic Air, but the Air 2 is new and I may need to read the manual. The flight log is attached, and the video is here

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I was observing an alligator in my backyard, and I was about 25 feet from the drone. I got my first battery low (7 minutes remaining, I think) warning on my phone/controller, and started a simple return of the drone toward where I was standing. A large oak tree overhangs much of the area, with 10 feet or more of clearance under it. As the drone approached me, it suddenly flew straight up on its own, into the tree branches, fell out, and repeated twice more before it came to rest on the ground. I pushed every button I could find during this phase, but the drone stayed on self-control (unresponsive to the controller).

My guess is that its default settings triggered a RTH and the drone was proceeding to its prescribed altitude. Its landing point was less than 50 feet away, behind me. The only real damage was the gimbal, which was destroyed, and the drone will be going to Care Refresh.

So, I will be studying the Air 2 manual, but it would help to know what happened. Thanks!

 

[boblui]

Yes, RTH was triggered at 1065 seconds into the flight. As the triggering reason was low battery, a message with 10 sec count down like this should have popped up on the FLY app asking if you want to proceed or cancel RTH.



Apparently no cancellation was done so RTH commenced and the craft ascended to the pre-defined RTH height on it's own. Full throttle-down has been applied repetitively afterwards but the craft did not respond.

Then you managed to cancel RTH after the craft hit the tree twice but RTH was re-activated after 2 seconds, probably because the RTH button on the controller was pressed again. The craft then ascended again and hit the tree for the last time.


Just recently another member lost his drone because RTH due to low battery kicked in unexpectedly : uncommanded , unwanted rth and crash into stream.

That was a cute alligator BTW. Your MA2 must be the strangest prey it has ever seen.

 

[itsneedtokno]

Pressing (maybe holding) the pause button should have stopped everything.

 

[tom29928]

Many thanks to boblui and others.

After reading the MA2 manual and many other posts, I think I know the basics of what went wrong in this incident.

The entire flight was simple. The drone was never more than 50 feet from the takeoff point (properly mapped), never more than 25 feet from me, and never more than 10 feet AGL. I was observing and recording an alligator in a pond. I was monitoring my minutes remaining on my controller/phone. With about 7 minutes remaining, I started to bring it back to the takeoff point. Less than a minute into the return, it triggered a low battery RTH and took over control.

I now understand that unlike my MA, my MA2 does not have a user-set low battery warning. The MA2 uses its own algorithm.

My flight area (Hilton Head Island) has a very dense tree canopy at around 100 ft, and my flights are nature observations below the treetops. Most likely, any RTH trigger will lead to disaster. It's unlikely that the MA2 will be able to get to 150 ft AGL without hitting a tree on the way up, and the takeoff point has a pretty small vertical window for the descent. When I get the MA2 back from Care Refresh I'll try some experiments in safe areas.

So, I think the MA2 would do exactly the same thing again under the same circumstances, and I don't a way to disable the RTH, to accurately predict the RTH, or to quickly and safely abort the RTH after it starts.

It did not affect this incident, but I also learned about similar issues in flights where GPS is lost, particularly in hilly areas. There seems to be conditions where the MA2 will impose an altitude limit in flight that can prevent a safe return flight.

My first Care Refresh has also been a learning experience, that I could share in a different thread if there's interest.

Thanks to all.

 

[itsneedtokno]

So, I think the MA2 would do exactly the same thing again under the same circumstances, and I don't a way to disable the RTH, to accurately predict the RTH, or to quickly and safely abort the RTH after it starts.

There is NOT a way to disable RTH at 10% but at 30% you can press the on screen cancel button.

Also, pressing the battery icon DOES in fact give you an EXACT time until RTH. (exact in DJI terms)

Pressing the pause button SHOULD stop RTH altogether. Until you reach 10%, then it will land (not RTH... land), but holding the up stick will stop or slow descent.

 

[lowellton]

Thanks for sharing this. I need to test this 10% battery on my MM. keep safe