Nearly Lost Mavic Pro - Aircraft Disconnected. No RTH

gingercookie · Feb 8, 2017

I had a scary flight this morning. I was shooting an Indian Temple Statue in Malaysia. Half way through the flight, DJI GO 4 Apps said "Aircraft Disconnected", I couldn't see anything from my DJI GO 4 Apps.

I tried closed DJI GO 4 apps and reopened again, it couldn't connect to my Mavic Pro. I tried to look for the Mavic location but can't really judge where was it located since my concentration was on the screen taking the footage. Here is the map and the flight logs

"H" was the took off point, I tried to look at Yellow area to locate my Mavic, because I wasn't sure where was it located. I was in panic mode, still can't see it anywhere at the Yellow area. After a minute or so, I tried looked at other area where "T" was, then I saw a Mavic hover in the sky.

There were couple of Mavic and Phantom crafts around, not too sure was that mine. I tried move left and right on my RC stick, the movement seems like what I controlled, then i tried move toward me... and YES, that was my mavic. At that time DJI GO 4 apps still not working, status were still "Aircraft Disconnected". Besides, there were no RTH trigger on the Mavic too ;(

As you can see, the flight record ended at "T", in theory the Mavic was stuck there. Lucky I was able to identify my Mavic Pro and slowly brought it back to me.

When the Mavic was above me, I tried to power off the RC and power on again, I was able to connected to Mavic Pro on DJI GO 4 Apps again. I was thinking to power off/on the RC when I saw the Mavic from far, but worried it couldn't connect it back, since RC still have control. It was best to bring it back.

It was a scary experience. It's the same bad experience the guys had while shooting The Bund at ShangHai.

Refer to the picture below, I was controlling 2 meters away from the tent in red square. The LOS was clear between my RC to the aircraft, there were no tall building around.

Below is the footage.

The flight record data can be downloaded here.

I will log the problem with DJI Forum. See what do they say on this.

Lesson learnt. Always fly at your line of sight. Phew..

Cyberpower678 · Feb 8, 2017

The latest iOS version of the DJI app seems to have a bug where it disconnects from the controller quite arbitrarily. To fix it unplug the phone from the controller and plug it back in.

Sent from my iPhone using MavicPilots

gingercookie · Feb 8, 2017

Sorry that I forgot to mentioned DJI GO 4 apps on Android 7.0 Samsung S7 Edge

Tim the Nomad · Feb 8, 2017

Looking at the picture you posted, if there were that many people around when you were flying and at a rough estimate 20% were doing something on their mobile phone, you probably had an issue with electromagnetic interference. If there is a lot of radio traffic in the area then reception range is going to get restricted, I doubt its more complex than that.

Cyberpower678 · Feb 8, 2017

Tim the Nomad said:
Looking at the picture you posted, if there were that many people around when you were flying and at a rough estimate 20% were doing something on their mobile phone, you probably had an issue with electromagnetic interference. If there is a lot of radio traffic in the area then reception range is going to get restricted, I doubt its more complex than that.

Actually it sounds like his remote was still connected, but his app disconnected, cutting off the visual feed.

peros550 · Feb 9, 2017

Hi, if you could export craft's flight data and upload them on a public cloud service (i.e. Dropbox) I'm sure the experts here will provide detailed insight on what went wrong.

Sent from my iPhone using MavicPilots

gingercookie · Feb 9, 2017

Tim the Nomad said:
Looking at the picture you posted, if there were that many people around when you were flying and at a rough estimate 20% were doing something on their mobile phone, you probably had an issue with electromagnetic interference. If there is a lot of radio traffic in the area then reception range is going to get restricted, I doubt its more complex than that.

Referring to the red square at the bottom right, that were where I was controlling the Mavic, not much people around there.

Usually if there is electromagnetic interference, it will get a warning. There were no warning and DJI GO 4 apps just displayed "Aircraft Disconnected"

It was the apps couldn't feed the stream, but the RC still able to control the Mavic.

Thinking could is be the 2.4Ghz interference around

deltalimatango · Feb 9, 2017

Cyberpower678 said:
The latest iOS version of the DJI app seems to have a bug where it disconnects from the controller quite arbitrarily. To fix it unplug the phone from the controller and plug it back in.

Sent from my iPhone using MavicPilots

Haven't seen this reported, which isn't to say it doesn't happen but can you provide more info on this?

gingercookie · Feb 9, 2017

peros550 said:
Hi, if you could export craft's flight data and upload them on a public cloud service (i.e. Dropbox) I'm sure the experts here will provide detailed insight on what went wrong.

Sent from my iPhone using MavicPilots

Good idea, i added the flight record data.

Oyibo VFX · Feb 9, 2017

Don't fly over "devine areas" with powers we can't apprehend

Adventure is just bad planning

Andart · Feb 9, 2017

I'm no expert . But I fly Samsung 7 edge and also spoken to other android users , this has solved all disconnect issues but could be coincidence .
It's simply how your go4 app opens , when i used to have to open the app manually I got crash and disconnect issues .
After speaking to some one I un-installed app and reinstalled , the first time it connects it opens on its own and a tick box gives app permission to always open on its own . I must of missed this the first time .
So now I plug phone into RC then start drone and controler and the app opens on its own . Since this is never have a disconnect . Further proof to me is that I manually turn off app then open it myself and had a disconnect again , so for me and like I said I'm no expert and this could all be coincidence but when app auto opens I have no problems . Also I do not fly in airplane mode and I don't turn off background apps .
I'd appreciate more feed back to see if it is a reel answer so any experts please let me know also if anyone has disconnect issues please check if your app auto opens or you manually open it .
Obviously if there are people who's apps auto open and still get disconnect then It's just a coincidence

Sent from my SM-G935F using MavicPilots mobile app

gingercookie · Feb 9, 2017

Andart said:
I'm no expert . But I fly Samsung 7 edge and also spoken to other android users , this has solved all disconnect issues but could be coincidence .
It's simply how your go4 app opens , when i used to have to open the app manually I got crash and disconnect issues .
After speaking to some one I un-installed app and reinstalled , the first time it connects it opens on its own and a tick box gives app permission to always open on its own . I must of missed this the first time .
So now I plug phone into RC then start drone and controler and the app opens on its own . Since this is never have a disconnect . Further proof to me is that I manually turn off app then open it myself and had a disconnect again , so for me and like I said I'm no expert and this could all be coincidence but when app auto opens I have no problems . Also I do not fly in airplane mode and I don't turn off background apps .
I'd appreciate more feed back to see if it is a reel answer so any experts please let me know also if anyone has disconnect issues please check if your app auto opens or you manually open it .
Obviously if there are people who's apps auto open and still get disconnect then It's just a coincidence

Sent from my SM-G935F using MavicPilots mobile app

After you re-open the apps, are you able to connect to the Mavic? Mine was not able to, got to turn off/on RC only can connect to Mavic on DJI GO 4.

Piranha · Feb 9, 2017

Did you try to push RTH hardware button on your controller? I think if you still can control your Mavic by sticks, RTH button should work also

Andart · Feb 9, 2017

Gingercookie after reinstalling and getting app to auto open I have no problems , the time I turned off app the drone was landed and I just needed to do something , so I then had to manually open app so yes connected but then in flight it had a disconnect.
So now I only ever fly if app auto opens and never have trouble . Dose your app auto open or do you open it

Sent from my SM-G935F using MavicPilots mobile app

Logger · Feb 9, 2017

Next time you have..

DJI GO 4 Apps said "Aircraft Disconnected", I couldn't see anything from my DJI GO 4 Apps."

First thing to do is look up to the RC screen. If is does not also say SIGNAL LOST or CONNECTING chances are you still have full control and can simply fly it home using the RC alone. All the info you need is in the RC screen.

BTW make sure to close all other apps on your S7 edge before each flight. This is always the last thing I do on my S7 edge, prior to opening DJIGo4 and this step has served me well.

As Andart has suggested if you launch DJIGO4 by plugging in the USB cable and having it auto-launch it should work better with the S7 edge.

Had you simply pulled the USB lead out momentarily after DJIGO4 reported "loss of connection" and re plugged it I am betting DJIGo4 would have come back to life. This was effectively what you achieved when you recovered DJIGO4 by power cycling the RC. "When the Mavic was above me, I tried to power off the RC and power on again, I was able to connected to Mavic Pro on DJI GO 4 Apps again."

"Besides, there were no RTH trigger" Pressing the RTH button would have been a viable option.

Cyberpower678 · Feb 9, 2017

gingercookie said:
Referring to the red square at the bottom right, that were where I was controlling the Mavic, not much people around there.

Usually if there is electromagnetic interference, it will get a warning. There were no warning and DJI GO 4 apps just displayed "Aircraft Disconnected"

It was the apps couldn't feed the stream, but the RC still able to control the Mavic.

Thinking could is be the 2.4Ghz interference around

The phone is hardwired to the controller. This is definitely an app bug. I'm inclined to think that this affects android users too. Sometimes my app arbitrarily disconnects from the controller. The only way to fix it without turning the controller off is to unplug the device and and plug it back it. That should re-establish the connection.

AlanTheBeast · Feb 9, 2017

Cyberpower678 said:
The latest iOS version of the DJI app seems to have a bug where it disconnects from the controller quite arbitrarily. To fix it unplug the phone from the controller and plug it back in.

Which _specific_ version please? I updated my iOS GO the other day and want to know if it is potentially affected. (I have 4.0.3).

After plugging back in, does one need to re-start the app ("kick it out" and re-start)?

Cyberpower678 · Feb 9, 2017

AlanTheBeast said:
Which _specific_ version please? I updated my iOS GO the other day and want to know if it is potentially affected. (I have 4.0.3).

After plugging back in, does one need to re-start the app ("kick it out" and re-start)?

My issue happens on 4.0.3

gingercookie · Feb 9, 2017

Piranha said:
Did you try to push RTH hardware button on your controller? I think if you still can control your Mavic by sticks, RTH button should work also

I didn't hit the RTH button. I was thinking about it but once I found where the Mavic is, I didn't want to do that, because my another concern is how to stop RTH auto landing. I need to double check the manual whether can cancel via RTH button when the Mavic is RTH-ing

Andart said:
Gingercookie after reinstalling and getting app to auto open I have no problems , the time I turned off app the drone was landed and I just needed to do something , so I then had to manually open app so yes connected but then in flight it had a disconnect.
So now I only ever fly if app auto opens and never have trouble . Dose your app auto open or do you open it

Sent from my SM-G935F using MavicPilots mobile app

I don't have this problem, every time I power on the RC, the apps auto launch on my phone

I have not try to open it manually / DJI GO 4 App cannot auto launch.

Logger said:
Next time you have..

DJI GO 4 Apps said "Aircraft Disconnected", I couldn't see anything from my DJI GO 4 Apps."

First thing to do is look up to the RC screen. If is does not also say SIGNAL LOST or CONNECTING chances are you still have full control and can simply fly it home using the RC alone. All the info you need is in the RC screen.

BTW make sure to close all other apps on your S7 edge before each flight. This is always the last thing I do on my S7 edge, prior to opening DJIGo4 and this step has served me well.

As Andart has suggested if you launch DJIGO4 by plugging in the USB cable and having it auto-launch it should work better with the S7 edge.

Had you simply pulled the USB lead out momentarily after DJIGO4 reported "loss of connection" and re plugged it I am betting DJIGo4 would have come back to life. This was effectively what you achieved when you recovered DJIGO4 by power cycling the RC. "When the Mavic was above me, I tried to power off the RC and power on again, I was able to connected to Mavic Pro on DJI GO 4 Apps again."

"Besides, there were no RTH trigger" Pressing the RTH button would have been a viable option.

You are right, the first I look at was the RC screen. It's "ATTI GPS" status. So I knew it was still "controllable".

Before taking off any flight, I make sure my Wifi is Off, All Apps are closed.

I would like to try out "pulled the USB lead out" to test some scenario when this error happen again

I have few cases to try out at open space.

Cyberpower678 said:
The phone is hardwired to the controller. This is definitely an app bug. I'm inclined to think that this affects android users too. Sometimes my app arbitrarily disconnects from the controller. The only way to fix it without turning the controller off is to unplug the device and and plug it back it. That should re-establish the connection.

Yes, I will definitely try that out next time, instead of turning RC off/on. At least RC still established the connection to the Mavic. Take note on that.