Hello!

Please, need help ASAP to try to recover my lost Mavic. Sent email to DJI but no answer yet.

On October 26 around 11:20 was flying my drone in waypoint mission when it started to drift away, next it switched to ATTI mode and app disconnected. RC showed error SYS [WARNING] and [CHECK APP] so I tried to reconnect DJI GO app on my Huawei P9(Android).
While reconnecting lost visual control of UAV but did not panic as was sure that will get back the view from camera and drone drifted in direction of open field where I could land it safely.
Unfortunately when I managed to reconnect app I could enter flight mode but it didn't show any image and there was message "controller error". Tried to restart RC and also reconnected USB which didn't help. So I was left in dark as RC didn't show distance to home nor it allowed RTH as it was still in ATTI mode and didn't switch back to GPS. At some point even tried to switch Sports mode back and forth to reset mode but it didn't help. To not lose direction I only used rudder up to keep it at previous altitude of 75m.
To my relief when battery level reached 15% it somehow waked up the drone and reset mode to GPS and I tried RTH again. To my surprise after a sec altitude according to RC quickly dropped to 25m and RC showed message LANDING to which I responded by increasing altitude back to around 60m as was afraid it may land in lake nearby and tried RTH again. Now RTH command worked, RC showed that it is now returning to home with distance to home 2km but then sharply disconnected. This was last info which freeze on RC and RC kept showing CONNECTING. It almost seems that drone crashed which is unlikely as at 60m altutude there are no obstacles or it may experienced a battery malfunction. Drone obviously didn't return to home point and is now lost.
Please check attached logs and help to find out which was last GPS coordinate when RTH was initiated and did it start RTH or it actually continued to land. Checked "lost my drone" menu in app but it shows only home position as last as it seems DJI GO app didn't actually reconnect.

Attaching logs but they are not complete. Also attaching RC blackbox but it seems doesn't contain GPS coordinates. Need help to calculate bearing as at least last distance to home point is known so if initiating RTH succeeded it should have adjusted yaw angle to home location. Also need to calculate how far it could go with 15% left and RTH initiated.


Logs from phone:
http://www.phantomhelp.com/LogViewer/7VUI4P2327O73EMUO4BM/
http://www.phantomhelp.com/LogViewer/3BA004IMYM3QZT2DKJR4/


Blackbox logs from RC -

https://files.fm/u/5d7ey5rc

Sorry for your loss! I know exactly how you feel! I also lost my first spark!
I hope that either you find it or DJI will replace it with a new one! Good luck!

Fly safely all
Alex

Hi oto,

Do you have another flightlog?  your second log ends with batt power 60%.
So hard to figure out what have happend after 60%....

cheers
JJB

It ends at 60% because DJI GO never properly reconnected and showed "controller error".

Seems only DJI can analyze black box from RC and it should contain data down to 15% of battery.

What distance could Mavic travel if RTH is initiated at 60m and remaining capacity of 15%? At which bat level it starts force landing for this altitude?
If I had another Mavic could do a test.

I wonder if it didnt show 15% on reconnect and that remaining 15% wasnt fully accurate and the battery died.

Oto Posted at 2018-10-31 05:30
It ends at 60% because DJI GO never properly reconnected and showed "controller error".

Seems only DJI can analyze black box from RC and it should contain data down to 15% of battery.

Hi Oto,

I always thought that only the drone has BlackBox data, not the RC.
With your 2 flightlogs it is not possible (for me) to make a calculated guess where your drone has landed/crashed.

cheers
JJB

JJBspark Posted at 2018-10-31 07:21
Hi Oto,

I always thought that only the drone has BlackBox data, not the RC.

RC does have blackbox but very limited.

Hi, We're sorry to know about your loss drone. I would recommend syncing your flight records on your DJI  Go 4 app and contact our support for further help. Please let us know if you need assistance. Kindly see the link below for your reference.

www.dji.com/support

As DJI Go 4 didn't reconnect correctly there is nothing more to sync as it doesn't sync the last log where I was preparing for launch but didn't lift off. I have known home point coordinates( lat=55.877296°,lon=26.566967) and blackbox from RC. Need to extract last bearing to home point from RC log and approximate distance it can go if RTH initiated with 15% battery left at altitude 60m considering that signal was lost after couple seconds when RTH was initiated.

Oto Posted at 11-1 08:07
As DJI Go 4 didn't reconnect correctly there is nothing more to sync as it doesn't sync the last log where I was preparing for launch but didn't lift off. I have known home point coordinates( lat=55.877296°,lon=26.566967) and blackbox from RC. Need to extract last bearing to home point from RC log and approximate distance it can go if RTH initiated with 15% battery left at altitude 60m considering that signal was lost after couple seconds when RTH was initiated.

You have our sincere apologies for the unfortunate experience with the drone. We strongly recommend you to contact the designated support assigned to your region/country and report about what happened. If the unit still within its warranty period, data analysis is required to check if this was due to a product malfunction. You may visit the link provided by DJI Tony  or you can have this phone number to call support during business hours.

I have sent an email trough support page(as chat is not working) but no answer. Will try a call.

Oto Posted at 11-1 10:57
I have sent an email trough support page(as chat is not working) but no answer. Will try a call.

The email response is usually a little slow, if you need an urgent support, please call our support. Please keep us updated if you need any further assistance. Thank you.

Thanks. Recieved my replacement Mavic after log investigation by data analyze team.
Housing was little bit dislocatedin transit or from factory but not a big deal pushed it together and recalibrated all sensors.

Oto Posted at 11-16 13:23
Thanks. Recieved my replacement Mavic after log investigation by data analyze team.
Housing was little bit dislocatedin transit or from factory but not a big deal pushed it together and recalibrated all sensors.

Glad to hear you received your replacement, Oto. If ever you need further help, just feel free to let us know. Hope you have safe flights!

Blast from past. Just installed DJI Pilot mission planner without connecting RC and for some reason it shows some last coordinates for lost Mavic even that I have had flights with new replacement one with DJI Go.

From where it got these coordinates?