Lost Drone on RTH due to RC loss

[pvidamaster]

Hi ! It was in my second flight today, when I engaged RTH. The drone was in GoHome-Mode 1180 ft away from the homepoint, at 325 ft height when I lost RC communication. RTH was set to "auto-land", it worked on the previous flight, but did not happen here. I never saw the drone again. Battery was at 37 %, GPS OK with 17 Satellites...

We searched for 2 hrs without success. Curious is, that from home, when checking the "find drone" on the app it shows the drone lost far away from the lost signal point. Unfortunately as the flight was on the cliffs of an island, far out on the water.

Can anyone get more out of the log files and/or confirm that this maybe a technical problem under warranty and how to process with DJI ?

Regards Robert

 

[pixl]

Here's a link to your log: DJI Flight Log Viewer - PhantomHelp.com

others will chime in...I'll take a look

 

[pixl]

Hmmm... I'm not seeing an obvious problem, and I even looked at the terrain on Google maps...nothing appears to have obstructed your path. Battery was well within parameters. From where I sit, you weren't doing anything wrong -- unless I've overlooked something. Perhaps @lisadoc or @sar104 can chime in...

 

[sar104]

Interesting case. It was making reasonable progress back against a significant headwind, and then the log just stops - no warning, no unusual readings and excellent signal strength until a weak signal warning at 838.3 s just before it disconnects.

How long did you leave the RC on afterwards to see if it would reconnect?

 

[pixl]

Even with a disconnect it should have continued home since RTH was engaged.

 

[BigAl07]

Even with a disconnect it should have continued home since RTH was engaged.

"RTH was set to "auto-land" so that's part of the problem.

With no errors etc I wonder if the battery failed somehow. Even a bird strike would give some errors before complete failure.

 

[pixl]

"RTH was set to "auto-land" so that's part of the problem.

With no errors etc I wonder if the battery failed somehow. Even a bird strike would give some errors before complete failure.

i don't think the auto land vs. hover setting would have made a difference in this case.. he had 37% battery at last reading, and was over land. This should not have resulted in anything other than coming home, with or without app connection.

 

[sar104]

"RTH was set to "auto-land" so that's part of the problem.

With no errors etc I wonder if the battery failed somehow. Even a bird strike would give some errors before complete failure.

It may not have been aircraft failure - it could just have been a downlink loss, especially since there was a weak signal warning just before it happened. Or, of course, those could have been related. Really hard to tell what happened.

 

[pixl]

It may not have been aircraft failure - it could just have been a downlink loss, especially since there was a weak signal warning just before it happened. Or, of course, those could have been related. Really hard to tell what happened.

Regardless, even without link to the RC, the Mavic is designed to complete the RTH command autonomously once it has commenced.

I think in this case the OP has a legitimate claim with DJI, and I encourage him to contact them about a warranty replacement. I'm not saying they'll honor it, but I see no sign of operator error.

 

[lisadoc]

Hmmm... I'm not seeing an obvious problem, and I even looked at the terrain on Google maps...nothing appears to have obstructed your path.

That was my first thought too - that the OP miscalculated the RTH height and ran smack into the side of the cliff. But I too checked on Google Earth and the craft seemed to be well above the terrain (and not headed into anything) when the signal just dropped. Unfortunately, I don't have any answers either.

 

[pvidamaster]

Thanks guys! Happy to see you come to the same conclusion, even this does not explain anything for me.

When at home yesterday evening, I checked the "find my drone" function in the App. It shows a point far out at sea. While maybe the wind would have been able to blow it out, I am wondering how I would get to position without an RC-link. Checking on Google Earth with the route it seems the "lost point" is on the fly route. So old data and maybe a flaw in the app.

To the question how long I tried to connect. When I lost the connection I tried to position myself better and walked (run) to the last point. I tried to reconnect and again press the RTH button but only go a beep and "connecting" on the remote. Finally there was no beep at all. Hard to tell how long as in these situation I am not time aware, but sure more than 30 minutes.

 

[robertschroeck]

Hi ! It was in my second flight today, when I engaged RTH. The drone was in GoHome-Mode 1180 ft away from the homepoint, at 325 ft height when I lost RC communication. RTH was set to "auto-land", it worked on the previous flight, but did not happen here. I never saw the drone again. Battery was at 37 %, GPS OK with 17 Satellites...

We searched for 2 hrs without success. Curious is, that from home, when checking the "find drone" on the app it shows the drone lost far away from the lost signal point. Unfortunately as the flight was on the cliffs of an island, far out on the water.

Can anyone get more out of the log files and/or confirm that this maybe a technical problem under warranty and how to process with DJI ?

Regards Robert

what are you using to read your .txt file? i am seeing gibberish seems to be compressed. thanks

 

[pixl]

what are you using to read your .txt file? i am seeing gibberish seems to be compressed. thanks

it's neither. The images above show the read file. See the links.

 

[BigAl07]

what are you using to read your .txt file? i am seeing gibberish seems to be compressed. thanks

See post #2 and the link will take you there

*Edited post # for error I made... thanks @pixl

 

[pixl]

See post #3 and the link will take you there

#2

 

[pvidamaster]

Hi ! Some positive news on this incident. Today we searched for the drone, yesterday was heavy rain, and...- success !
We found it near the position where it lost the RC-link. Luckily the terrain is open, but it still took a great deal of luck to find it. Seeing the damage it must have fallen from great height, last recorded height 106 mtrs, and hit a rock (there is also soft ground and grass around....).
Eager to see the last movie, as recording was on on the way home, I learned that the last three mov-files are not readable.
- Anyone has a tip if and how I may be able to repair it ?
- Any other hits of hidden flight data on the drone itself ?

I also opened a case with DJI, they will analyse the data and asked for patience....

 

[BigAl07]

Glad you found it but hate to hear it's damaged. This def sounds like a major power failure as I mentioned before but it's still a wild guess.

The last video file wasn't "completed" if it was a power failure. If your aircraft was operational you would simply power it back on with the SD card inside and let the controller finalize the file for you. That's not an option now so you'll need to try some recovery programs instead.
NOTE: Make a COPY of the files and use any "repair tools" on the copied files not the originals.

DJIFix is one I've used with GREAT success many times. Here's a thread where you can learn more about it and how to use it. Be sure to go all the way through it so you see the latest and greatest versions and suggestions.

App to fix corrupted Video Files (new one)


Good luck

 

[pvidamaster]

Here is an update.

I could power up the Mavic with a new battery, but the controller does not connect. After a few seconds the backlight quick-flashes yellow (?).

I could not read the last three mov-files from the card on my new MacBook Pro running OSX 10.13. I also got the error -36 when trying to copy, the card is read only. Putting the card into my old MacBook Air, running OSX 10.12.1 it showed with a preview and I was able to play the videos in Quicktime.
Copying the vids from the MBA to the MBP was no problem, could then read and import into iMovie.

Whatching the last video supports my case, that a sudden powerloss must have brought my bird down. I share 4 pics of the last minute with you. The last pic is where I found the drone down below.

 

[sar104]

Here is an update.

I could power up the Mavic with a new battery, but the controller does not connect. After a few seconds the backlight quick-flashes yellow (?).

I could not read the last three mov-files from the card on my new MacBook Pro running OSX 10.13. I also got the error -36 when trying to copy, the card is read only. Putting the card into my old MacBook Air, running OSX 10.12.1 it showed with a preview and I was able to play the videos in Quicktime.
Copying the vids from the MBA to the MBP was no problem, could then read and import into iMovie.

Whatching the last video supports my case, that a sudden powerloss must have brought my bird down. I share 4 pics of the last minute with you. The last pic is where I found the drone down below.

View attachment 25439 View attachment 25440 View attachment 25441 View attachment 25442

Can you get the DAT file off the Mavic?

 

[pvidamaster]

Pleas help where and how.