So, I lost my Mavic today...

Where flying about 350m (around 1200 feet) from my controller when my DJI Go 4 app (Android) just crashed. I thought, “no worries, this has happened before” so I just restarted the app, but it would not connect. Seconds later the controller displayed “SYS WARNING + CHECK APP”. I had no live feed so I could not make up the directions to take it home. Lowered it down to 50 m (170 feet) to see if the controller responded. It did. Tried RTH but it just said “NO RTH” even though I had 17+ satellites in range. Jumped in my car and drove to the place. Before I reached it, I lost connection to the controller as well. Arrived and the drone was gone. The drone had about 40 % battery when I lost connection. There is no water nearby, only houses and trees. Have been searching now for four days, but starting to lose hope.

So, a couple of things I did before takeoff. I re-calibrated the compass because of trouble the day before. Made sure to do it outside on grass with no metal nearby except the controller and mobile attached. . I then proceeded to takeoff and had the drone in the air for about 10 minutes around my house, testing out flight control and making sure that the internal magnet was working as expected. I then landed the drone using RTH. Everything worked. Afther this I perfomed a precise takeoff function so that the Drone could easily return back home, before i proceeded to follow my fligt plan, resulting in the loss of connection and furthermore the Mavic.

So I have some thoughts about what could have caused this. Right before the problems started, I switched from Sport mode to GPS mode. The log file show that seconds later the Mavic experienced compass errors, and then I lost connection. The controller never said it entered ATTI mode, but I cannot conclude that this has not happened.

My questions to you is:

When I lost connection and the drone got compass error, could it have drifted with the wind? The battery as I said was at around 40% so the drone should have stayed in the air for some time.

OR could the drone started drifting and then reconnect with the satellites and try to return home? The drone was only 1200 feet from my home, and the Mavic would have had tailwind all the way home so could it be somewhere nearby my home? RTH where set to min. 50 m (170 f) and there is nothing near that height in my area.

Also, I am writing a letter to DJI Europe (this happened in Norway) wanting them to take responsibility for this. I believe that the drone had a software error resulting in the drone flying away. What do you guys think about this?

Link to the log file of the last flight.

https://drive.google.com/file/d/ ... kE/view?usp=sharing

fans571b6884 Posted at 2017-7-5 03:16
Link to the log file of the last flight.

https://drive.google.com/file/d/0Bz_uzPscqksxS2s4cHN0YlhLNkE/view?usp=sharing

Went ahed and postet the .txt file into the flighlog viewer.
http://www.phantomhelp.com/LogViewer/BWW07P4M68PQ6FODR4D5/

Same warning after last update. Also, having trouble with the vision sensors.

Sorry for your unfortunate incident.  I have just a few comments.  You indicated that you were able to use the RC to lower the altitude to 50 m.  I presume that was confirmed on the controller,  since the app was dead and you were out of visual contact. I also presume that you did not then raise the drone back to 100 m. (which might have given you a better chance to keep RC connection - but that may not have helped much).

The compass warnings are interesting.  While I'm not sure why that would happen at that altitude, the reported incidents involving compass errors have usually resulted in erratic flying behavior - i.e. flight system trying to resolve conflicting inputs from GPS and compass.

I've never seen the 'NO RTH' message - it's shown HOME was set.  But I imagine it could result from the conflicting inputs issue mentioned above.  It knew where home was, just couldn't figure out how to get there :-(

There may be some additional information in the RC "black box".  It can be retrieved via DJI Assistant and sent to DJI for interpretation (I'm under the impression that the file is enctypted.)  Try contacting support.   In the mean time, keep looking . Good luck!

Griffith Posted at 2017-7-5 06:23
Sorry for your unfortunate incident.  I have just a few comments.  You indicated that you were able to use the RC to lower the altitude to 50 m.  I presume that was confirmed on the controller,  since the app was dead and you were out of visual contact. I also presume that you did not then raise the drone back to 100 m. (which might have given you a better chance to keep RC connection - but that may not have helped much).

The compass warnings are interesting.  While I'm not sure why that would happen at that altitude, the reported incidents involving compass errors have usually resulted in erratic flying behavior - i.e. flight system trying to resolve conflicting inputs from GPS and compass.

Thank you for the helpful input and questions!
It is true that the controller was still connected during the disconnection from the app, and this I did confirmed by lowering the drones altitude and moving it a couple of meters. I could see the live feedback on the controller, except distance from home point.
As you said it could have helped to maintain the altitude of 100 meters, but I was worried it would make the drone harder to spot, or in case it would crash land.
I'm thinking maybe by going into the car that his where enough to completely disconnect the drone, who knows.
When NO RTH showed I felt that I did not have any cards left to play, so I went over to visually land the drone, but by that time it was gone...

Is there any change that DJI can get some more data about last location other than what my Flightdata log says? Or is that impossible because of lack of connection to remote?

fans571b6884 Posted at 2017-7-6 03:56
Is there any change that DJI can get some more data about last location other than what my Flightdata log says? Or is that impossible because of lack of connection to remote?

Maybe you didn't pick up correctly on my last comment.  The RC itself collects some information.  What information - I have no clue.  There is a way to extract it and send to DJI.  In the DJI Assistant program there's a selection where you can download "Black Box Data" .  Select and send to DJI. You might want to open a case with customer service and reference the case number.  

I re-calibrated the compass because of trouble the day before.

What sort of trouble did you encounter the day before? Can you also upload that flight log?

When I lost connection and the drone got compass error, could it have drifted with the wind?

It's possible, though I noticed that the compass error cleared up even before the app crashed, so it should have hovered in place and you should have been able to fly normally after that. And based on your comment about descending, it appears that you were still able to control the aircraft until the connection was lost.

The battery as I said was at around 40% so the drone should have stayed in the air for some time.
OR could the drone started drifting and then reconnect with the satellites and try to return home?


Either of those -- drifting or RTH -- is possible since we don't know anything about what occurred after the disconnect. I'd first search the path between its last known location (shown in the lost you posted) and the home point and then look in the direction in which the wind was blowing at that time starting from the Mavic's last known location.

What do you guys think about this?

I think you should open a case with DJI and hope for a warranty replacement, though I'm not confident you'll get one. They'll want you to synchronize the logs on your mobile device so that they can see the flight information that way. Good luck.

P.S. If you ever run into this problem again, it may be best to increase your altitude and try to fly it back "blind". The best way to do this is to rotate the aircraft until you find the heading that causes the distance shown on the controller to decrease at the fastest rate possible.

What sort of trouble did you encounter the day before? Can you also upload that flight log?
http://www.phantomhelp.com/LogViewer/7WYP3P6B27SF2ER2N4FU/

  

As you can see I encountered big problems the day before. Not sure the cause of problem, but I had VLOS so I was able to get it down, but the drone went on a flying rampage.

  

After recalibrating the day after, the Mavic worked flawlessly for a good 10 minutes.

  

  

"I think you should open a case with DJI and hope for a warranty replacement..."

  

Have done so and synchronized the log file with the DJI cloud. They said they would investigate the Flight Data.

  

I am certain in my case that this was not pilot error. I was aware of trouble the day before so after I recalibrated I test flown the drone and testing out the different controllers and function to see if the drone behaved normally.

  

  

P.S. If you ever run into this problem again, it may be best to increase your altitude and try to fly it back "blind". The best way to do this is to rotate the aircraft until you find the heading that causes the distance shown on the controller to decrease at the fastest rate possible.

  

Yeah, so this have saved me before but this time the distance meter on the controller showed only "--" after the warning messages appeared. All of the other flight instruments on the controller worked tho.

What's the temperature up there?

Griffith Posted at 2017-7-10 06:41
What's the temperature up there?

Around 10 to 25 Celsius at this time.

fans571b6884 Posted at 2017-7-11 04:34
Around 10 to 25 Celsius at this time.

I see what you mean about the problems with your previous flight and I'm starting to suspect that (as usual) BudWalker hit the nail on the head -- even though he hasn't weighed in on this particular case, at least not directly.

In short, my guess is that the compasses in your Mavic -- and maybe those of all Mavics -- aren't sufficiently reliable when used so far north. As BudWalker pointed out in another similar case recently, the compass readings by nature aren't as accurate as latitude increases, and in this case you were flying in an even higher latitude (69°) than that the pilot of the other thread who also experienced a problem (about 64°). It also makes sense that we'd start seeing these problems now given that with the warming weather there's probably a bit more flying going on in these areas compared to even just a month or two ago.

Of course this is all speculation on my part, but again it's based on insight from someone who's usually right about these things and I definitely think you need to pursue this as a warranty claim with DJI. If you could find the drone that obviously would help your case, but if the magnetometers weren't functioning effectively it's debatable whether I could provide any information that will be useful in locating it. Even so, I can't think of a better place to focus on than the path between your Mavic's last known location where it was hovering and the home point, though I'd definitely concentrate more on that last known location. I've attached an image from Google Maps that shows the approximate path, so you may want to try searching some more along that line, and especially around here (69.69531935, 29.99949349), and you might even consider offering a reward for its return.

Good luck and please let us know how this turns out.

DroneFlying Posted at 2017-7-11 05:34
I see what you mean about the problems with your previous flight and I'm starting to suspect that (as usual) BudWalker hit the nail on the head -- even though he hasn't weighed in on this particular case, at least not directly.

In short, my guess is that the compasses in your Mavic -- and maybe those of all Mavics -- aren't sufficiently reliable when used so far north. As BudWalker pointed out in another similar case recently, the compass readings by nature aren't as accurate as latitude increases, and in this case you were flying in an even higher latitude (69°) than that the pilot of the other thread who also experienced a problem (about 64°). It also makes sense that we'd start seeing these problems now given that with the warming weather there's probably a bit more flying going on in these areas compared to even just a month or two ago.

Hi again and thank you so much for the good response, that goes out to all of you! Nice to see people trying to help

I am indeed in contact with DJI and I have uploaded all of my data to their servers. They have asked me twice about video cache and both times I have told them that I have turned this feature off since it made my DJI Go 4 app (Android) crash constantly.
I am more and more sure of that this has to be some kind of software or instrument error, and not piloterror. I just hope that DJI will agree with me and maybe give me an explanation on what went wrong. The drone worked perfectly for over 10 minutes, and suddenly went heywire when I went from Sport to P-GPS Mode. Have seen several posts and suspicions around this particular subject.

On another note, went searching today as well. Looket from my homepoint (aka. my home) and backwards as this is where the wind was blowing this day. The drone could have climbed to the flight maximum alltitude of 105 meters after I lost connection. From there it could have flown in that alltitude untill it the batteries went out. There is nothing nearby that is even close to this alltitude, therefore it can't have crashed into any objects. Tthis make the search area even bigger...

Hoping for fast process with DJI so I can get back on my wings!
And again, thank you all for the help & support!

Same thing just happened to me (sys warning, check app, then app crash, followed by No Return Home warning) but luckily I was able to bring drone home after some tense moments of not being able to fly drone via visual RF flying due to total connection loss. I've had my Mavic Pro about 6 months and hadn't used much lately it the past 45-60 days (therefore no updates)...started it up,a couple days ago, udated it and went to fly and got all the above warnings (sys warning, check app, etc), with beief periods of no connection and inability to control drone each time I've flown it since updating.  Scary...seems to be clear software problem.  I'm fearful of flying mine right now as i worry I'll lose my expensive drone also.

Peter
Necedah, WI, USA

fans70bbfb49 Posted at 2017-9-9 08:45
Same thing just happened to me (sys warning, check app, then app crash, followed by No Return Home warning) but luckily I was able to bring drone home after some tense moments of not being able to fly drone via visual RF flying due to total connection loss. I've had my Mavic Pro about 6 months and hadn't used much lately it the past 45-60 days (therefore no updates)...started it up,a couple days ago, udated it and went to fly and got all the above warnings (sys warning, check app, etc), with beief periods of no connection and inability to control drone each time I've flown it since updating.  Scary...seems to be clear software problem.  I'm fearful of flying mine right now as i worry I'll lose my expensive drone also.

Peter

Add-on comment...I too was receiving intermittent compass errors when flying today and having the issues described.

Peter
Necedah, WI, USA

i cant make heads or tails of the situation myself.. to me it seems like something confused your mavic, maybe bad compass calibration or maybe soomething else interfering with compass/gyro/etc.   im sorry for the loss.   dji really really needs to work on stability of application and be more clear with certain errors and events.   

  this is one reason i have since switched back to iPad mini 2, the risk involved with using android is too high. i was constantly crashing the app out.  i have only a few times had "sys warning" display on my RC and that did crash my djigo4 app on my S8 and it wouldnt let me reopen it, just kept crashing. wasnt worth the risk, and it was worth me spending $140 i idnt have at the time on an iPad mini 2 32GB refurb.  but i recovered mine by  just using my controller status screen and raised my mavic up 250 feet (so above all trees and building) and turned and started flying my mavic in every direction until i saw the distance winding down rapidly then once i got it back in visual sight i landed her at my feet, the system error i had was related to my front facing vision sensors.. a dead bug in left side.  wiped it out and rebooted and no system error..

Similar happened to me. After updating to latest firmware on sight.
Was using GSP for mission mapping an area. The mission required battery change and efter swapping battery I resuméd the mission. Drone took of in the direction of last point to capture , but then passed the point to just vanish behind a forest hill. The live feed was still transmitting but was saying system warning , no signal etc . After 1,5km I managed to manually stop the drone and was able to fly home.

I havent had an issue with this before the firmware update. And doing resume mapping with other software worked fine. So me guessing its not any drone related errors just newly introduced bugs from latest firmware update.

ImHereToCrash Posted at 2017-9-9 10:38
i cant make heads or tails of the situation myself.. to me it seems like something confused your mavic, maybe bad compass calibration or maybe soomething else interfering with compass/gyro/etc.   im sorry for the loss.   dji really really needs to work on stability of application and be more clear with certain errors and events.   

  this is one reason i have since switched back to iPad mini 2, the risk involved with using android is too high. i was constantly crashing the app out.  i have only a few times had "sys warning" display on my RC and that did crash my djigo4 app on my S8 and it wouldnt let me reopen it, just kept crashing. wasnt worth the risk, and it was worth me spending $140 i idnt have at the time on an iPad mini 2 32GB refurb.  but i recovered mine by  just using my controller status screen and raised my mavic up 250 feet (so above all trees and building) and turned and started flying my mavic in every direction until i saw the distance winding down rapidly then once i got it back in visual sight i landed her at my feet, the system error i had was related to my front facing vision sensors.. a dead bug in left side.  wiped it out and rebooted and no system error..

Thank you for the comments.  Interesting in that I'm using a Samsung Galaxy S7 (Android).  Others with this problem, please list if you were using Android or Apple/IOS and what device...might help troubleshooting  this.

Thanks for your input!

iPad Air 2 , GSP latest firmware

fans70bbfb49 Posted at 2017-9-9 11:50
Thank you for the comments.  Interesting in that I'm using a Samsung Galaxy S7 (Android).  Others with this problem, please list if you were using Android or Apple/IOS and what device...might help troubleshooting  this.

Thanks for your input!

Were using a Nexus 6P with Android 7.0

Whoa, sorry to hear that.