DJI Drone Help Forum

Almost lost my brand new Mavic Air

My first two batteries were in close proximity to me, felt pretty good about the drone. After charging everything up again, I went for my third battery’s flight (the next day) and wanted to do a quick tour. I flew down a small road, then back and near/beside a rural highway. Snapped a picture of the quarry and boom… Lost signal. I frantically ran around trying to find high ground, freaking out, and nothing… Just beeps and lost signal warning. I waited and waited, thinking I heard it several times and after about 3 minutes of panic, I could definitely hear it. Looked around… Nothing, then all if a sudden, it was directly above me and landing. The radio still beeping that it lost signal, even when it was 4 feet in front of me at eye level. Wondering if anyone can help me understand what happened? Why it lost signal and why it never regained it.

The end of the log is when it disconnected and it never regained communication until I removed the battery and restarted the controller as well.

In this situation, would it be wise to restart the controller to try and regain connection or would that make it worse?

Here’s my log:. https://www.phantomhelp.com/LogViewer/HG6HD9E2CRZ6CYYTXONL/

Thank you!

The TXT flight log doesn’t contain information that’ll help diagnose remote controller connection issues.

The DAT flight log on your mobile device might have some useful information. Please retrieve the DAT file like this and upload it here. If you’re not able to upload it here, you can upload it to a file sharing site (like Dropbox) and share the download link here.

Thank you!

I have uploaded the log here, please let me know if you cannot access it, or if it’s not the correct one. Thank you!

I was able to access your DAT flight log. The attached event log is the data I wanted to review. I don’t see any messages that appear to be related to the RC connectivity.

19-04-30-03-16-16_FLY024.log.txt (20.6 KB)

Is the firmware updated on your Mavic Air? If not, updating would be a good idea. It would rule out the idea that you might have stumbled upon an undocumented bug that was fixed in a newer firmware release.


When the remote controller disconnects from the aircraft, the light on the front of the remote controller will change from green to red. At that point, it won’t hurt anything to restart the remote controller. And if the remote controller doesn’t reconnect by the time the aircraft is in view, that would be the first thing I’d try.

Thanks for checking it out… That’s very unusual, and a little scary. Because the drone is brand new, it told me I need an update for the controller and drone. They were both updated the day prior, except the drone failed the update. It forced me to use DJI Assistant (after googling the error) which was successful. When I started up the drone the next day (the day of the connection loss), it said there was a geofence update and then quickly said firmware mismatch. It seemed to resume the failed firmware update from the day prior, even though it was already current (620 I believe). It finished, I rebooted both devices then had that flight now that the firmware check was happy.

In the DAT flight log you attached above, I can see you updated the GEO database here (29 seconds before taking off):

-29.451 : 6659 [L-GEO][update_nfz_app_db]update app db[1]|
-29.451 : 6659 [L-GEO][print_app_db][0] id:0 (0, 0) 10|
-29.443 : 6660 [L-GEO][sa_drone_storage_process][0]write flash @ 136110|
-29.341 : 6665 [L-GEO][fmu_api_handler_update_app_db]reset recv buf|
-29.341 : 6665 [L-GEO][fmu_api_handler_update_app_db]add buf 0 1|
-29.284 : 6668 [L-GEO][fmu_api_handler_update_app_db]>end of app db|

The aircraft was not restarted after that update was done.

I don’t see anything in the log that indicates a firmware update was installed on the remote controller. That doesn’t necessarily mean it didn’t happen though. I’m not sure what’s normally logged when a firmware update is installed.

Is it possible that you didn’t restart the remote controller and aircraft after installing the firmware update?

I’m 100% certain that I did reboot the drone after the firmware update because my wife and father in law were watching and I said sorry for taking so long, but maybe I mixed up the order that the updates occurred in and by not rebooting after the Geo update, it caused issues.

I’ll have to keep an eye on it and if any changes are made, I’ll reboot both units to be safe. I’m happy to know that I can reboot the controller and it “might” reconnect. I’m just so happy that it flew home as designed (in this case).

Thank you for your help, and if the is any other information or suggestions, I would be happy to know. Thank you!

Your log shows the remote controller connected to the aircraft three separate times before you took off. You can see that in the log here:

-143.327 : 951 [L-RC]rc_connect:0=>1

-92.459 : 3501 [L-RC]rc_connect:0=>1

-28.625 : 6701 [L-RC]rc_connect:0=>1


The log also shows your remote controller was powered on for 2.2 minutes before you installed the GEO update. Is it possible that you installed the firmware during that time and then rebooted the aircraft and kept the remote controller powered?

That’s certainly possible…I very possibly did not reboot the remote after the update, but I suspect that it would have lost connection to the drone upon reboot though. I know better now… Regardless of what happens, any changes/errors/updates and I reboot both pieces to avoid any risk.

Yes, the remote controller would have lost connection. That’s why I was thinking the two additional connections noted in the log were during the time you were installing the firmware and/or restarting the aircraft.

Going forward, make sure you always restart both the aircraft and remote controller after installing firmware on either. That way you’ll at least know a newly installed firmware update sans reboot was not the cause of the problem if this happens again.

after particular version djigo4 android, firmware updates could soft reboot devices. during win10pc asst2v1.2.4 firmware refresh rc 01.00.0000 the rc incessantly beeped progress 70% so i pressed the poweron and it ceased. asst2 informed nothing yet succeeded writing.
so no reboot of rc. it still gets turned off without flying.
both android djigo4v4.3.14 and asst2v1.2.4 soft reboot drone automatically of firmware writes. the giveaway is craft illumination color change plus its notorious multi-wakeup horn cries