So today, after 340 flights I lost my drone. Tried the new platinum propellors and when the wind picked up the drone just wouldn't accelerate forward. It drifted 1,300 metres at 5m/s backwards until I managed to get it under control over a farmers field and start to land. I'd sent it up to 168m to retain signal - it hovered and descended to 126m at which point it stopped descending and accelerated at 5-6m/s away from me. Last known position was 70m from where I started the landing but still at an altitude of 126m.

Any thoughts on what would have disengaged the auto-landing. It had around 29% battery - 5m50s remaining, what would have been its pre-programmed response? Would it have remained at 126m until it hit critical power and then descend? At the moment I'm looking at about 3sqm of muddy winters fields that it may have ended up in.

Upload the flight log (TXT file from your mobile device) to PhantomHelp using these instructions, provide a link to it here, and we may be able to shed some light on what happened and where to look for your lost Mavic.

DroneFlying Posted at 2017-11-12 13:49
Upload the flight log (TXT file from your mobile device) to PhantomHelp using these instructions, provide a link to it here, and we may be able to shed some light on what happened and where to look for your lost Mavic.

LogViewer/7I0R4C8D2UUH31S3ORHV/

Thanks so much guys.

Immediately before trying to descend I lost contact due to weak signal - hence this is on a fraction (51 seconds of about a 14min flight to date. I was actually located 1,300m NNW of this location at the time.

The intention had been to go straight up and down - but with a 15mph wind, the Mavic just drifted off backwards at 5-6m/s.

fans5465be23 Posted at 2017-11-12 14:40
LogViewer/7I0R4C8D2UUH31S3ORHV/

Thanks so much guys.

I don't really know why the landing stopped. My best guess would be that maybe it gets canceled if the Mavic moves a certain distance beyond the point over which landing was initiated, but again, that's just speculation.

What I do know is that its last reported location was here and that it was moving roughly southeast (around 141°) with the wind and that it was using up battery power pretty quickly. I'd estimate it had about another 3 minutes of flight time left before it reached the 10% critically low battery level, at which point it definitely would have landed.

Based on that, my best guess is that it would have started landing somewhere around here . . . but, it also would have initiated RTH shortly after the connection to the controller was lost (assuming you didn't set it to hover). Your home point location was almost (but not quite) in the opposite direction of the wind at around 332° from the last recorded location, so it likely would have started landing slightly west / northwest of that location I just mentioned. On the other hand, during the descent it would have continued to drift slightly more to the southeast.

The bottom line is that I'd suggest looking in the area around 50.94511355,-0.9609546 and search outward from there, particularly to the northwest. Good luck and please let us know how it turns out.

That's a pity to hear about the loss of the drone, have you sent an email to support.nl@dji.com and reported this case to them? If not, please sync your flight record and export the Flight Controller LOG Data and contact them and start a data analysis. We will try our best to help this out.

DroneFlying Posted at 2017-11-12 19:14
I don't really know why the landing stopped. My best guess would be that maybe it gets canceled if the Mavic moves a certain distance beyond the point over which landing was initiated, but again, that's just speculation.

What I do know is that its last reported location was here and that it was moving roughly southeast (around 141°) with the wind and that it was using up battery power pretty quickly. I'd estimate it had about another 3 minutes of flight time left before it reached the 10% critically low battery level, at which point it definitely would have landed.

Thank you so much for insight - super helpful and incredibly kind of you. Must admit I was pretty devastated yesterday and spent about 2 hours in the field until it was pitch black out.

I searched the original field parallel to your estimated point but I didn't cross over into the adjacent field so I'll start roughly along those co-ordinates.

I'm in touch with the farmer and am going to head back today for a last attempt - if I find anything I'll let you know. Thanks again guys.

DroneFlying Posted at 2017-11-12 19:14
I don't really know why the landing stopped. My best guess would be that maybe it gets canceled if the Mavic moves a certain distance beyond the point over which landing was initiated, but again, that's just speculation.

What I do know is that its last reported location was here and that it was moving roughly southeast (around 141°) with the wind and that it was using up battery power pretty quickly. I'd estimate it had about another 3 minutes of flight time left before it reached the 10% critically low battery level, at which point it definitely would have landed.

Some amazing news - after 67hrs lost in a field the local farmer found my drone!

The really interesting thing is that it was located in almost the exact spot I last had visual contact view from my phone - which was near the pond, about 250m from the spot where 'find my drone' indicates it was, about 400m from where the 'flight record' shows it flying off and a km from where both yours and my projections had it.

My only thought is that as you said, the RTH could have kicked in and it's just coincidence it came down where I was last looking.

Thanks again for all your help - after 48hrs in a bath of rice the drone seems to be working normally.

Great news !!  I agree with DroneFlying that your Mavic probably aborted autolanding due to the drone's inability to control it's movement.  It may have regained the ability at a lower altitude and made some headway back before battery exhaustion.  Still it would be very interesting to see the flight logs  from the Mavic  itself to understand how the Mavic analyzed the situation and responded - purely academic.   If you get a chance, please post the flight logs back to this thread.

fans5465be23 Posted at 2017-11-17 05:34
Some amazing news - after 67hrs lost in a field the local farmer found my drone!

The really interesting thing is that it was located in almost the exact spot I last had visual contact view from my phone - which was near the pond, about 250m from the spot where 'find my drone' indicates it was, about 400m from where the 'flight record' shows it flying off and a km from where both yours and my projections had it.

You're very welcome. I'm very glad you got it back and appreciate the update.