Hi all,

  

A few days ago I was flying my now lost mavic mini in the park.

  

It was a clear day, very low winds (not even a single strong wind warning throughout the flight) but I lost GPS and radio link and lost my drone

  

I couldn't find it after.

  

Here is the link to the flight log: https://app.airdata.com/share/QTHTfA

  
  

Flight description:

  

·         From 1:57.6 into the flight GPS Signal went down to only 10 satellites, Followed by a loss downlink data loss connection
this was at a distance of only 200m from home, with no obstructions between me and the drone.

  

·         At 2:51.8 the drone started autolanding, without RTH because of bad GPS reception, the area in which it was autolanding in is fenced so I tried to cancel the auto-landing and get back

  

·         At 3:14.7 I regained control. Canceled autolanding and regained altitude to start heading back home which was very difficult because of the bad control link reception

  

·         At 3:31.8 Drone went to attitude mode because of bad GPS reception, I continued trying to head back home but it was really hard because of the bad control and video link.

  

·         AT 4:52.5 I completely lost the control and video link, according to the log you can see the drone drifting off and finally performing auto landing, probably into the river

  
  

Post flight attempts to find the drone

  

the find my drone feature showed the mavic landed in the last position shown in the flight log. I first went to that location but couldn’t find the drone nor reconnect to it and get it to beep

  

I then went to the first location where the drone tried to auto land first (at 2:51) and couldn't find it nor reconnect there.

  
  

because I couldn’t reconnect I guess that sadly the drone probably autolanded into the river

  
  

My question is: what happened? could I have done anything different?

  

to me this looks like some sort of failure, does the DJI warranty cover this?

  

I'm pretty upset with the situation because I don't feel like I pushed the limits in this flight.

Thanks for any help and insights

Just before 2 minutes into the flight it looks like a hardware fault was causing your GPS sat numbers to fall.
From then on the numbers were up and down and GPS Health was zero, indicating that the flight controller recognised a problem with the GPS.

Without GPS and the ability to RTH, the drone started to autoland when signal was lost.
There is a rough GPS location in the data, but it's not certain that the drone actually landed there.
The approximate location was 32.09635   34.81417

This shows the flight data better:  https://www.phantomhelp.com/logviewer/BSJ78LRT63DX6ACKS00C/

Hi,

Sorry for your loss.

About the GPS data ; when i plot the last records of the autolanding then i see a straight line, not all random values for the LAT LON data.

So IMO your craft in ATTI because of low GPS sats and low to zero GPS reception, but i think the GPS position data was good * received but your MM thought they were bad!* if GPS data is not correct that the Distance to HP will show incorrect numbers, they look pretty normal to me.

Hope you find your MM just North of the river, see the GE map. Last postion already given by Labroides.

Interesting to see and know that if:

a) loosing RC contact and bad GPS at that time a MM will not RTH (cannot ofcourse) and perform an autolanding,
b) loosing RC contact while in flying in ATTI mode it will enter an autolanding as well.

cheers
JJB

Labroides Posted at 10-6 02:21
Just before 2 minutes into the flight it looks like a hardware fault was causing your GPS sat numbers to fall.
From then on the numbers were up and down and GPS Health was zero, indicating that the flight controller recognised a problem with the GPS.

Thanks for the answer, and for showing me the PhantoHelp interface

JJB* Posted at 10-6 06:20
Hi,

Sorry for your loss.

Thanks for the analysis
I went north of the river right after the signal loss, and indeed that's where the find my drone interface showed that the drone was suppose to be.
I Couldn't find it nor reconnect to it, which leads me to believe that it probably landed inside the river.
I went to the same last coordinate a day later to try and find it with no luck.
and when I was actually there it seems like the exact coordinates are in the river

Eladov Posted at 10-6 07:49
Thanks for the analysis
I went north of the river right after the signal loss, and indeed that's where the find my drone interface showed that the drone was suppose to be.
I Couldn't find it nor reconnect to it, which leads me to believe that it probably landed inside the river.

Oke, did you checked the top of the tree s as well?
Hard to tell from an old GE picture, bad luck that it probably has landed in the river   ;-(

cheers
JJB

Yes I've spent a few good hours there looking everywhere, including tree tops.

Sorry for the loss of the drone, I hope you manage to locate it

Eladov Posted at 10-6 08:02
Yes I've spent a few good hours there looking everywhere, including tree tops.

You have Care Refresh? If so, I'd probably find a way to drag that river (magnet fishing) maybe and if you find it by some miracle... you'll get a new one.  

Raydog9379 Posted at 10-6 11:46
You have Care Refresh? If so, I'd probably find a way to drag that river (magnet fishing) maybe and if you find it by some miracle... you'll get a new one.

Unfortunately not, care refresh wasn't available in my country at the time of purchase.
Also that river is horribly polluted with really steep banks so i don' really want to get too close to i

JJB* Posted at 10-6 06:20
Hi,

Sorry for your loss.

Interesting to see and know that if:
b) loosing RC contact while in flying in ATTI mode it will enter an autolanding as well.

If you are flying in atti mode because you've selected atti mode and GPS is available, on losing signal the drone would initiate RTH and come home.

It sort of looks like that it may have come down on one of those islands in the river (if those are indeed islands). Or this image shows it probably sitting on that bench ;-) Sorry, I couldn't help it. Also sorry for the Bad Luck.

Hello there Eladov. I am sorry to read and to know what happened to your DJI Mavic Mini and thank you for reaching out. Since this unfortunate incident happened and you have lost the said drone. I would recommend for you to contact our DJI Support Team at https://www.dji.com/support?site=brandsite&from=nav for further assistance. We have a team that will do there best to help you and give out the best resolution for the said issue. Again, I am sorry for your loss and thank you for your understanding.

Labroides Posted at 10-6 17:18
Interesting to see and know that if:
b) loosing RC contact while in flying in ATTI mode it will enter an autolanding as well.

Correct, but in my case the drone switches to ATTI mode automatically because of bad GPS health
so when the radio link was lost no RTH was made, only an auto-landing.

GaryDoug Posted at 10-6 18:57
It sort of looks like that it may have come down on one of those islands in the river (if those are indeed islands). Or this image shows it probably sitting on that bench ;-) Sorry, I couldn't help it. Also sorry for the Bad Luck.
[view_image]

in the picture it's actually the other side of the river, I also looked there but had no luck
I did sit down in that bench after searching tough.. haha..

DJI Stephen Posted at 10-6 22:28
Hello there Eladov. I am sorry to read and to know what happened to your DJI Mavic Mini and thank you for reaching out. Since this unfortunate incident happened and you have lost the said drone. I would recommend for you to contact our DJI Support Team at https://www.dji.com/support?site=brandsite&from=nav for further assistance. We have a team that will do there best to help you and give out the best resolution for the said issue. Again, I am sorry for your loss and thank you for your understanding.

Thanks, I'll send  the DJI support a message and hope for the best

Labroides Posted at 10-6 17:18
Interesting to see and know that if:
b) loosing RC contact while in flying in ATTI mode it will enter an autolanding as well.

Hi,

Thanks for the addition for other drones than a a MM.

You are correct for some models, but this thread was about a MM.
On Spark, MM, MA, MA2 the user cannot select ATTI manually.

cheers
JJB

JJB* Posted at 10-6 23:02
Hi,

Thanks for the addition for other drones than a a MM.

but this thread was about a MM.
On Spark, MM, MA, MA2 the user cannot select ATTI manually.
I understand that quite well.

What are you asking then?
It's quite simple, if GPS is available, on losing signal the drone will initiate RTH and come home.
if GPS is not available, on losing signal the drone will is unable to come home and will autoland.

Labroides Posted at 10-6 23:07
but this thread was about a MM.
On Spark, MM, MA, MA2 the user cannot select ATTI manually.
I understand that quite well.

if you understand that quite well than your posting in#12 was confusing for forum members with less knowledge. Well just my 2-cents.

uh? where did i ask anything?
Just made clear for others how a MM act in 2 different situations when loosing RC connection.

cheers
JJB

JJB* Posted at 10-6 23:13
if you understand that quite well than your posting in#12 was confusing for forum members with less knowledge. Well just my 2-cents.

uh? where did i ask anything?

uh? where did i ask anything?
Several posts ago in the post I replied to.
You asked:
Interesting to see and know that if:
a) loosing RC contact and bad GPS at that time a MM will not RTH (cannot ofcourse) and perform an autolanding,
b) loosing RC contact while in flying in ATTI mode it will enter an autolanding as well.
Point A was what had happened in the OP's case (so there was no need to ask), and I answered your question B clearly and accurately.

I can't understand what you are complaining about.
I guess it's a language misunderstanding.

Labroides Posted at 10-7 02:02
uh? where did i ask anything?
Several posts ago in the post I replied to.
You asked:

yes, must be my english....

My writing "Interesting to see and know...." is not a question, not even close  ;-)

Your answer to Point B is IMO confusing, as a MM cannot be switch manually to ATTI.
You wrote to this case "...flying in ATTI because you`ve selected atti mode...", has nothing to do with loosing RC contact with the RC while his MM was flying in ATTI due to errors, not because of his own manual not-possible-to-do choice....

I do not complain about anything, just explaining and make things clear to all readers.
In that we are alike, so keep up the good work.

cheers
JJB

JJB* Posted at 10-7 02:19
yes, must be my english....

My writing "Interesting to see and know...." is not a question, not even close  ;-)

You wrote to this case "...flying in ATTI because you`ve selected atti mode...", has nothing to do with loosing RC contact with the RC while his MM was flying in ATTI due to errors, not because of his own manual not-possible-to-do choice.
But quite a few flyers have modified their Mavics to have access to atti.
I gave those details to cover all the bases, not just the OP's Mini.

Eladov Posted at 10-6 22:55
Thanks, I'll send  the DJI support a message and hope for the best

Hi there Eladov. Thank you for the reply and for this information you have given. If you have any other concerns or inquiries with DJI. Please feel free to post it here at DJI Forum. We are here to help and assist you. Thank you.