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Couldn't shut down motors in RTH mode with hand grab

dacarter

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So I had a weird malfunction/user error? this weekend. I was camping with some friends and flying the Mav quite a bit. At one point, I'm in the camp site flying slow under some trees and it went into RTH mode due to low battery. I saw it start to go up to RTH altitude and I stopped it with the left stick since there were trees above it. I walked over and thought I'd grab it and shut it down, but after I grabbed it, holding the left stick down would not shut down the motors. They reved really high and I started getting max RPM warnings or something like that. Eventually, with a crowd of people watching, the only thing I could think to do was set down the controller and reach over the top with my other hand and remove the battery, which worked but was a bit scary... Any idea why this happened? I'm on the the 400 FW.
 
I guess it would be better to cancel RTH here, as I'd imagine the mavic isn't in landing logic at that point in the RTH process so you can't "land" it - maybe that's wrong, but one way to find out would be to let the same happen over a safe landing area and just hold stick down to see if it will land on the ground in the same circumstances.

Interested to find out for sure what the cause was though, as I also hand catch sometimes so if this is a special case where it should be avoided I'd like to know.
 
Did you disable downward VPS sensors ? Any time I have had them enabled the Mav will rev her rotors if she detects your hands. Hand catching is quite simple if you disable down VPS just before catching. In GPS mode anyways..
 
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So I had a weird malfunction/user error? this weekend. I was camping with some friends and flying the Mav quite a bit. At one point, I'm in the camp site flying slow under some trees and it went into RTH mode due to low battery. I saw it start to go up to RTH altitude and I stopped it with the left stick since there were trees above it. I walked over and thought I'd grab it and shut it down, but after I grabbed it, holding the left stick down would not shut down the motors. They reved really high and I started getting max RPM warnings or something like that. Eventually, with a crowd of people watching, the only thing I could think to do was set down the controller and reach over the top with my other hand and remove the battery, which worked but was a bit scary... Any idea why this happened? I'm on the the 400 FW.
What Draezn said, the sensors will detect your hand and try to get out of there. Normal but very scary behavior.
 
Did you disable downward VPS sensors ? Any time I have had them enabled the Mav will rev her rotors if she detects your hands. Hand catching is quite simple if you disable down VPS just before catching. In GPS mode anyways..
It's only Landing Protection needs turning off, not VPS.
Not sure what happened in OP case, RTH isn't cancelled by doing anything with left stick though.
 
So I had a weird malfunction/user error? this weekend. I was camping with some friends and flying the Mav quite a bit. At one point, I'm in the camp site flying slow under some trees and it went into RTH mode due to low battery. I saw it start to go up to RTH altitude and I stopped it with the left stick since there were trees above it. I walked over and thought I'd grab it and shut it down, but after I grabbed it, holding the left stick down would not shut down the motors. They reved really high and I started getting max RPM warnings or something like that. Eventually, with a crowd of people watching, the only thing I could think to do was set down the controller and reach over the top with my other hand and remove the battery, which worked but was a bit scary... Any idea why this happened? I'm on the the 400 FW.
To shut off motors both sticks have to be down and in.
Hard to do with one hand.
 
Yes, I know about the VPS sensors and how it tries to get away when you grab it, but normally if you hold the left stick down, it will eventually give up and shut down the motors. I had obstacle detection off, but VPS I think was on, because it would raise up when I put my hand under it. Not sure what else I could have done, except maybe hold the left stick down to keep it from going up into the trees, then try to fly it out to an open area.
 
Wait a moment, when you grabbed the Mavic did you had the stick all the way down and it didn't stopped the motors? Very strange.....
 
Wait a moment, when you grabbed the Mavic did you had the stick all the way down and it didn't stopped the motors? Very strange.....
Yes that's what leads me to believe that maybe when RTH is active you can't hand catch in the normal way because the aircraft is not able to "land" unless either it autolands at the end of the RTH maneuver, or the RTH is cancelled.
 
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I think @BorisTheSpider is probably correct about the Mavic not being in landing logic and therefore not shutting the motors down.

I presume you didn't try the Pause or RTH buttons to cancel the RTH. Perhaps you could try the expirement @BorisTheSpider suggested and let us know what happens.
 
I did not try to cancel RTH or hit the pause button. I will try to remember those options next time it happens though. Once I grabbed it, it would have been hard to do much with the controller or ipad screen, but could probably have hit the pause button.
 
Left stick down and in.
If just down motors won't cut out.
With Landing Protection on it will initially try to rise and will throttle up but if you hold it firmly and pull left stick down and in it should cut out.
The two stick manoeuvre is basically an emergency immediate cutout.
If I do a return to home I generally cancel it as it comes closer then steer toward me and position it facing away at just over shoulder height. That way your hand is below the rotors.
What you could have done is hit pause when it was close and then this gives you time to work out what to do.Bit hard when battery warning sounds are going though, but you still have some flying time left.
 
I'd be fascinated to know how you extracted the battery while the blades were spinning.
 
I'd be fascinated to know how you extracted the battery while the blades were spinning.
I just checked and with my thumb and finger on the battery release buttons there's about 1" clearance to the blades, so not that hard to do.
 
Definitely cancel RTH first. Actually, first set RTH to "hover" when you're in the woods. Nice move with the battery. Ballsy.
 
The belly sensors is doing its avoidance job. When it detected your hand, it tried to avoid your hand by going higher.
In future, just open your palm. Move your palm under the belly of the mavic and the mavic will raise up a little. Now keep your hand still and pull the left stick down and it should smoothly land in your palm.
 
The belly sensors is doing its avoidance job. When it detected your hand, it tried to avoid your hand by going higher.
In future, just open your palm. Move your palm under the belly of the mavic and the mavic will raise up a little. Now keep your hand still and pull the left stick down and it should smoothly land in your palm.

Yikes. Sounds like a potential disaster there.

I'd suggest that you bring it to a hover below shoulder height and simply grab it from underneath while pulling the stick down. It revs for a few seconds and then shuts itself down.

But waterworks for you.
 
Yikes. Sounds like a potential disaster there.

I'd suggest that you bring it to a hover below shoulder height and simply grab it from underneath while pulling the stick down. It revs for a few seconds and then shuts itself down.

But waterworks for you.
Palm landing is graceful and more predictable. It also makes the grannies wet when they see it in action.
 
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