Today I really thought I've lost my Mavic for a moment
I was flying around above a valley (there were just trees and a river beneath), the drone was several hundreds of meters away from me so I didn't have eye contact but it was definally in my line of sight (the remote controller signal indicator gave me full bars). I was recording a video just like always.

At a certain point, the DJI GO app said that the aircraft is disconnected (the remote was not). I patiently wait a few seconds in order to trigger the automatic go to home procedure, without any luck. After a while I noticed on the lcd screen of the remote that I was correctly receiving telemetries, I saw the distance and the motors spinning velocity just fine. I immediately hit the return to home button, I got the response beeps from the remote, the message "going home" appeared and I saw the distance getting shorter and shorter. After a while I regained eyesight of the drone and I manually landed it, just as smooth as always. During and after all this time the app was still saying "Aircraft Disconnected".

This has already happened to me with a previous DJI GO app and firmware version. I experienced it while I was landing with a critically low battery, so I thought that it was due to that and didn't bother too much. I was recording a video that time too. Today was really frightening because the aircraft was far (but with a very clear line of sight for the remote) and the battery was over 50%.

This is a known issue? Anybody else experienced this?
I'm running the DJI GO app version 4.1.18 with a Samsung Galaxy S7 with Android 7.0. The aircraft has the newst firmware v01.04.0100
Is there anything useful I can provide to help you guys debug this?

P.S. I know that it's not safe to fly the aircraft without eye contact, but the area was really wide open and I think that there's no point in having a 4km range and tons of intelligent flight modes if you can't fly your drone more than a couple of hundreds meters away...

Yes this happened to me yesterday

I updated everything before I left home and drove 3 hours to some waterfalls I wanted to fly around.
There seemed to be trouble for the app connecting to the drone at first. This seemed to be "fixed" by turning off the drone and controller and then back on it connected. It wasn't really fixed though because within a minute of flying it disconnected. I could see the drone luckily but this was honestly the first time for me it has ever had to RTH where I could not regain control when it moved closer, it was actually disconnected.
Since the entire point of my roadtrip was to fly the drone I tried again nervously, but I got the same result again, within a minute or two the app said disconnected (except this time I quickly controlled the drone back manually before it lost signal from the controller and I grabbed it from the sky)

grozmo Posted at 2017-11-26 12:28
Yes this happened to me yesterday

You are using android or iOS? Were you shooting a video at the moment?

FrenchiVIII Posted at 2017-11-26 12:35
You are using android or iOS? Were you shooting a video at the moment?

I'm using a Google Pixel and I was shooting video

grozmo Posted at 2017-11-26 12:45
I'm using a Google Pixel and I was shooting video

I think this is app-related since the aircraft and the remote were doing fine, maybe it's an android issue? Something related to video caching? Can someone from DJI please answer?

Hi there, so the drone was able to be controlled very well while the app said aircraft disconnected, right? Just to verify, will it also happen at the very beginning of the flight and will it disappear when the drone flies back and near around the RC? Is there a transmission UI recording for this case? Would like to forward it to our engineers to check. Thanks.

grozmo Posted at 2017-11-26 12:28
Yes this happened to me yesterday

I updated everything before I left home and drove 3 hours to some waterfalls I wanted to fly around.

Grozmo, could you please help to confirm whether the app said disconnected or aircraft disconnected? They are kind of different. If the app showed disconnected, that meant the app hadn't connected to the RC, try to reconnect by rebooting the app or plugging the cable again.  If the app said the aircraft disconnected before the flight, you need to relink the drone and RC, if it happens during the flight, please try to adjust the antennas. See if it helps.
BTW, were you injured by catching the drone in the air? we don't suggest doing so, coz the damage by the props would be very hurt. Safety first.

Are you still using the original cable? I'd replace it for someone better.

DJI Thor Posted at 2017-11-27 00:07
Hi there, so the drone was able to be controlled very well while the app said aircraft disconnected, right? Just to verify, will it also happen at the very beginning of the flight and will it disappear when the drone flies back and near around the RC? Is there a transmission UI recording for this case? Would like to forward it to our engineers to check. Thanks.

Hi Thor,

1) it just happened twice, and always when the drone is airborn and I was recording a video.

2) as I said, when the app said it's disconnected in this likeliness, it won't re-connect without rebooting the aircraft and remote (never tried to reboot just the app thou). The first time it happened the aircraft was at 50m above my head so I don't really think this can be related to a weak signal. I would also like to say that sometimes I actually got the aircraft disconnected (for example because I flight it behind a hill when I was at a lower position), but in that occasions I regained the connection and video feed in the app as soon as the aircraft returned in sight during the automatically go home procedure.

3) what is this transmission UI recording? Where I can find it?

Thanks for your support

P.S. yes the rc was working fine as I could see telemetries, control the aircraft, initiate the return-to-home procedure etc

DJI Thor Posted at 2017-11-27 00:20
Grozmo, could you please help to confirm whether the app said disconnected or aircraft disconnected? They are kind of different. If the app showed disconnected, that meant the app hadn't connected to the RC, try to reconnect by rebooting the app or plugging the cable again.  If the app said the aircraft disconnected before the flight, you need to relink the drone and RC, if it happens during the flight, please try to adjust the antennas. See if it helps.
BTW, were you injured by catching the drone in the air? we don't suggest doing so, coz the damage by the props would be very hurt. Safety first.

The app disconnected.

I turned on the drone and controller, the app opened automatically but did not say "Go Fly" like usual. I turned off the drone and controller and then back on (without closing the app) and it then connected and said "Go Fly" so I went in. It seemed fine for a few moments but then the app disconnected again. I restarted the drone and controller once more and it stayed connected for a little longer this time so I started the drone and then launched, however within a minute the app once again disconnected - I was still able to control the drone  (my mistake I forgot I could cancel auto RTH in my panic). I tried again but again the app disconnected before I flew very far.

(I had to hand catch the first time because I launched from a large rock surrounded by cliffs so needed to land very precisely so I didn't trust RTH would be precise enough in the situation)

Bump...

I know that this I was able to escape with my mavic in one piece, but prevention is better than cure...

FrenchiVIII Posted at 2017-11-27 02:28
Hi Thor,

1) it just happened twice, and always when the drone is airborn and I was recording a video.

Hi, thanks for coming back.  After going through your case, please try to refresh the firmware and app, then try another place to test. Make sure that the RC signal is working stably, the signal bar is not blinking. The transmission recording means that you keep the transmission interface recording, thus we can grab the whole process of the app's changing.
See if it helps. And if the issue repeats, it would be nice if you could have a friend to record the app and RC for this case.

grozmo Posted at 2017-11-27 09:59
The app disconnected.

I turned on the drone and controller, the app opened automatically but did not say "Go Fly" like usual. I turned off the drone and controller and then back on (without closing the app) and it then connected and said "Go Fly" so I went in. It seemed fine for a few moments but then the app disconnected again. I restarted the drone and controller once more and it stayed connected for a little longer this time so I started the drone and then launched, however within a minute the app once again disconnected - I was still able to control the drone  (my mistake I forgot I could cancel auto RTH in my panic). I tried again but again the app disconnected before I flew very far.

Hi, please try to change another connecting cable or reinstall the app, also, sometimes changing another mobile device might also help a lot with troubleshooting.

DJI Thor Posted at 2017-12-1 03:52
Hi, thanks for coming back.  After going through your case, please try to refresh the firmware and app, then try another place to test. Make sure that the RC signal is working stably, the signal bar is not blinking. The transmission recording means that you keep the transmission interface recording, thus we can grab the whole process of the app's changing.
See if it helps. And if the issue repeats, it would be nice if you could have a friend to record the app and RC for this case.

thank you for your reply, well I can't say it's something that happens often since I got this problem twice out of 107 flights, so I don't think it would be easy to catch it unless I record every flight session but that would be annoying... But even if this doesn't happen so often, if it happens just once in the wrong moment (for example in case I'm low on battery or I need to avoid obstacles during RTH because I'm not in an open area) I could lose my drone

I'd like to clarify one more thing, when you are talking about transmission interface recording, is there a way within the app to record it or I have to make a friend take a video of the phone + RC?

FrenchiVIII Posted at 2017-12-4 11:46
thank you for your reply, well I can't say it's something that happens often since I got this problem twice out of 107 flights, so I don't think it would be easy to catch it unless I record every flight session but that would be annoying... But even if this doesn't happen so often, if it happens just once in the wrong moment (for example in case I'm low on battery or I need to avoid obstacles during RTH because I'm not in an open area) I could lose my drone

I'd like to clarify one more thing, when you are talking about transmission interface recording, is there a way within the app to record it or I have to make a friend take a video of the phone + RC?

It would be nicer if recording the procedure by another people, coz I can grasp more info like the RC status as well as the app's status. But if it is hard to do, you can also use an internal app to record the transmission. Appreciate your work. BTW, I found a tutorial for the antennas position for your reference.

This is not a new issue. Just search the topic pages for connect, connection, disconnect, or disconnected and you'll find dozens and dozens of threads on this. Most of them are just a few messages long but several are hundreds of messages long with lots of in depth discussion about everything that has been tried.

A small number of the threads are about RC-AC connection but most are about phone/tablet - RC connection. Several start out appearing to be about AC-RC connection but turn out to be phone/tablet - RC connection where the app says disconnected even though the RC is connected to the AC and the drone can be controlled.

Android 4.1.18 DJI GO4 app totally unreliable for video feed and app disconnect. Uninstall and replace with 4.1.15

Other app disconnect problems can be from overloaded/overheated phone/tablet cpu's, bad cables, poorly oriented antennas (antennas more likely to render AC RC problems but the app won't like it) ......
And of course app problems are very much related to which tablet/phone you are using and what else might be running on it. My old tablet marginally runs DJI GO4 and in the summer would reproducably bug out during the second battery flight, beginning with video lag, disconnect warnings (even though the RC MP control is still working fine) and app crashes. it works better now that it's cooler outside. The 4.1.18 version gets the tablet extremely hot with video lag right from the start. Each DJI GO4 app revision seems to be trying to do more computing and video processing, more than the phones can keep up with.

djiuser_larry Posted at 2017-12-11 22:09
Android 4.1.18 DJI GO4 app totally unreliable for video feed and app disconnect. Uninstall and replace with 4.1.15

Other disconnect problems can be from overloaded/overheated phone/tablet club's, bad cables, poorly oriented antennas ......

This is not an RC-AC connection issue but rather an app to RC connection issue. The RC is still connected to the AC and the AC can be controlled and telemetry shows up in the LCD screen on the controller.

It's happen with me, 4.1.18 is not good,4.1.15 is the most stable version for android but you don't have the pano feature.
Also on Spark isn't 4.1.18  good, i have lost telemetry and altitude wasn't correct. Almost lost Spark.
I hope that DJI fixed a stable version again with the pano feature. It's almost 14 days ago since a update version of 4.1.18 came out.

I have some update on the issue.
After a while without experiencing new issues, the las two days I experienced it two other times, with two different version of dji go (last on play store today and last on play store -1).

Like the other times, the app says "Aircraft Disconnected" (but still recognizes there's a remote plugged in), but I receive telemetries on RC LCD and I can control the aircraft. This time I tried to restart the app, to plug/unplug the usb camble with no avail. After landing, I powered off - then on the RC (without turning off the aircraft) and I finally re-established the video feed in the app. Not sure this is a good recovery action to do while flying...

As an additional info, yesterday I experienced the issue while the aircraft was in active tracking mode. Same story here, the app says "Aircraft disconnected" while on the RC LCD it was said that the aircraft was still in active tracking, and indeed it was as I could crearly see it following the subject. I just hit the pause button and then landed it manually.

I'm beginning to worry this is a RC issue, DJI have no clues yet? People are saying it's a common problem...

Are you using the side or bottom usb slot?
Try the cable that came with your phone, into the bottom slot and see if anything changes.
The supplied DJI cables are not of good quality.

I don't think the issue is the cable quality, since I've tried to unplug/re-plug without any effect while "rebooting" the RC worked. Seems more an issue of the app or the RC to me.

P.S. wasn't the other usb port dedicated to another purpose?

FrenchiVIII Posted at 2018-4-29 09:21
I don't think the issue is the cable quality, since I've tried to unplug/re-plug without any effect while "rebooting" the RC worked. Seems more an issue of the app or the RC to me.

P.S. wasn't the other usb port dedicated to another purpose?

For me I would get disconnects from my iPhone to RC all the time.  But the RC would ALWAYS have a connection to the AC.  The DJI GO 4 app would always show disconnected and only way to fix was unplug and plug back in cable.  Then another minute or so later would do again.  To find out it was my iPhone interfering with the RC.  After putting my iPhone in Airplane mode I never have that issue anymore.  So give that a try.  

Your issue is the cable. I have experienced this myself a lot. threw away the Cables that came from Dji and used my own, no issues for the last couple of months

grozmo Posted at 2017-11-26 12:28
Yes this happened to me yesterday

I updated everything before I left home and drove 3 hours to some waterfalls I wanted to fly around.

could you please tell me if you were using an android phone, smart phone or Ipad?  I am just curious thank you.

SparksBird Posted at 2018-4-29 09:27
For me I would get disconnects from my iPhone to RC all the time.  But the RC would ALWAYS have a connection to the AC.  The DJI GO 4 app would always show disconnected and only way to fix was unplug and plug back in cable.  Then another minute or so later would do again.  To find out it was my iPhone interfering with the RC.  After putting my iPhone in Airplane mode I never have that issue anymore.  So give that a try.

Thank you, today I just experienced the issue again, I've tried both to unplug and plug the cable and to swap the cable, but nothing worked.
I've found out that by rebooting the RC without unplugging or swapping anything, the app connects again to the aircraft (even without closing it while rebooting the RC!)

@DJI Thor I have some updates on this nasty issue...

I will summarise everything I've learned so far

Sometimes, can't  understand when and why, the app would say that the aircraft is disconnected, even if the RC is still correctly connected to it. The app would say that it's just the aircraft that is disconnected, like when I lose signal with RC, except that in this case the signal is very good (it also happened when the aircraft was a few meters away from me). It even happened once during active track mode, and while the app said - Aircraft disconnected - the Mavic kept following its subject (even on the RC screen it was shown ACTIVE-TRACK).

The following things won't restore the connection:

• restart the app
• unplug-replug the USB cable
• use another USB cable
  

The only thing that seems to work is to powering off and then on again the RC. In this case the app whould reconnect immediately, even if it wasn't closed after turning off the RC.
I hope you can fix this bug quickly because it can be bad to lose video feed in some situations... To turn off and then on the RC would trigger the automatic go-home procedure so it's not always the best option if the drone is flying on certain environments

Here is what I would do if you have not already tried.

Use the bottom port of your RC instead of the side.  Have to make sure side port is unplugged in if using bottom.  

Put your phone in airplane mode ensuring internet/wifi,bluetooth all turned off(This was my issue with RC disconnecting with my phone)

If this does not work do the below

Uninstall and reinstall DJI GO 4.  You will want to backup your videos in there if any

If this does not work then refresh your firmware of your RC and AC.  

If that does not work then roll back to a previous version firmware.

SparksBird Posted at 2018-5-12 15:32
Here is what I would do if you have not already tried.

Use the bottom port of your RC instead of the side.  Have to make sure side port is unplugged in if using bottom.  

apart from using the bottom USB I've done everything else. I don't think a firmware downgrade will be of use because I experienced the issue for the first time on 10/2017, and It's pretty rare. Today I flew three batteries and the issue didn't show up

@DJI-Thor I tried to get your attention on my last post but maybe I put a wrong tag, maybe this time it will work?