So today I went on a hike and brought my mini to record once I got up to the top. When I get there, I set the mini up, calibrated it, set its home point, and I take off. I get about 1000m away with no lag in the video, and no wind warnings, when in the top right corner- I get a brief 'sensor error' before the connection is lost and I get a "RC not connected to device". I wasn't worried because I know the mini has auto RTH. So I wait for about 10 minutes and its nowhere to be found. The RC never reconnects to the drone. I hike back down the mountain and go to the last place in the 'find my drone' and look all around the area for about a hour without finding it. I looked both in the trees, and a good radius around the last connection point. But nothing. I even hiked back up the mountain to where the drone's home point should have been and it wasn't there. After driving very gloomily back to my dorm, I checked my logs from my phone and found that there wasn't any .txt log files from today. I did find .dat log file and converted it to excel sheet, but it's just over the limit of being able to be attached to this thread. I sent in a ticket to DJI in hopes that I can get some questions answered. Any ideas you guys have would also be greatly appreciated!

See if my article helps including some links to very specific guides about the log files

https://m80stake.blogspot.com/20 ... fety-tips-from.html

Considering the environment I believe you pushed way too far your MM, but somehow I still think you have no fault in what happened afterwards. I experienced it myself and nothing that AC (aircraft) should have done happened to recover the connection. Mine did not RTH and there is no explanation that can stand to that... it was already clear of every obstacle in the return path, with more than 20 minutes of battery and with almost zero wind (chimney plumes almost dead straight).

You can upload the .dat file to an online host like G Drive or M OneDrive for sharing.

Please provide the .DAT via Dropbox or similar.

m80116 Posted at 1-21 03:04
Considering the environment I believe you pushed way too far your MM

I'd really like to know how you reached this conclusion.

@OP A bird strike seems like a plausible answer.

Ice_2k Posted at 1-21 05:45
I'd really like to know how you reached this conclusion.

@OP A bird strike seems like a plausible answer.

Ah I didn't even think about that. That seems likely

Alright I got the DAT file here on dropbox https://www.dropbox.com/s/1ewpdze9xrsq14d/20-01-20-02-10-28_FLY050.DAT?dl=0

looks to me like the Mavic Mini ran into the bridge. Is this where you were looking?

BudWalker Posted at 1-21 10:17
looks to me like the Mavic Mini ran into the bridge. Is this where you were looking?
[view_image]

Yes I did see that, that's where the dji fly app told me the last point was. But I wasn't near the ground. I was flying above the bridge- I'm not entirely sure how high- but I know I was high enough to clear the nearby trees

mtaft Posted at 1-21 10:22
Yes I did see that, that's where the dji fly app told me the last point was. But I wasn't near the ground. I was flying above the bridge- I'm not entirely sure how high- but I know I was high enough to clear the nearby trees

Looking at Google Earth it looks like the difference in height between the launch point and the ground of the road way next to the bridge is about 84 meters.But, the MM was 127 meters below the launch point. Maybe the MM crashed into the river below the bridge.

BudWalker Posted at 1-21 10:43
Looking at Google Earth it looks like the difference in height between the launch point and the ground of the road way next to the bridge is about 84 meters.But, the MM was 127 meters below the launch point. Maybe the MM crashed into the river below the bridge.
[view_image][Image]

Hmm, that's not good. So I might have ran into something I couldn't see from my phone and it fell into the water?

mtaft Posted at 1-21 10:54
Hmm, that's not good. So I might have ran into something I couldn't see from my phone and it fell into the water?

Most likely hit the bridge under structure. Either that or you managed to hit the water directly under the bridge.

BudWalker Posted at 1-21 10:58
Most likely hit the bridge under structure. Either that or you managed to hit the water directly under the bridge.

But I'm positive my last camera shot from my phone was me going over the bridge?

Sorry for you loose maybe you end up finding it, I hope so.
A Vifly Beacon seems like a no brainer to me at 15dollars, at least if is not under water, gives you more chance to find it.

Do you have the Video cache file from your phone ?

You did not loose the connection between the drone and the rc but between the phone and the rc! Thats what the warning says. Your drone die not Enter Auto rth until you 1. Shut Down your rc or 2. The battery got to Low.
Hope this might help
Cheers

Spark_Pilot_XxXx Posted at 1-21 12:42
You did not loose the connection between the drone and the rc but between the phone and the rc! Thats what the warning says. Your drone die not Enter Auto rth until you 1. Shut Down your rc or 2. The battery got to Low.
Hope this might help
Cheers

That's what I thought also. But what is the best plan when that happens and you have no LOS? I am thinking it may be best to press the RTH button or switch off the remote if you do not have sight of the drone and force the RTH. Or maybe do a major increase in altitude until you see it.

I will check your path later... bird strikes always begin with the drone being upset by the attack and you get video feedback evidence with it... not with a sudden dual transmission loss (down and uplink).

It's exactly what happened to me, and the reason is entirely DJI's fault. If the signal strength and warning information systems were reliable I'd still have my other Mini.

GaryDoug Posted at 1-21 19:22
That's what I thought also. But what is the best plan when that happens and you have no LOS? I am thinking it may be best to press the RTH button or switch off the remote if you do not have sight of the drone and force the RTH. Or maybe do a major increase in altitude until you see it.

In this case you should immediatly rth on the remote.

Hi, I am sorry to know about this unfortunate incident and thank you for sharing your informative insights on what happened. Rest assured that our DJI support team will do their best to assists you with regards to this matter. Thank you.

I am sorry I cannot participate to the analysis having no knowledge converting .DAT files to more commonly used .TXT
You may want to upload your .txt file to https://www.phantomhelp.com/LogViewer/Upload/ or https://app.airdata.com/flight/ for open consulting.