RC disconnect, did not RTH. Good thing a tree stopped it...

WilmotCheater · Nov 9, 2018

Hello,

Shortly after takeoff, my drone disconnected from the RC. Rather than initiate RTH (which is what it is set to do in the event of disconnect), it maintained flight path at time of disconnect and flew into a tree. I was less than 20 yards from the drone when this happened, and I had no control during this time.

All 4 propellers are broken, but otherwise everything seems still to function properly, according to the aircraft status screen. I was able to upload the flight log txt file to phantomhelp.com, but it gives me no indication of what went wrong. I do NOT have DJI Refresh Care, but I'm hoping that this might be covered under warranty, since there was literally nothing I could do but watch in horror?

Before trying to deal with DJI Support, I thought I would reach out to you all here to see if anyone has any experience or knows the best way to go about this.

Many thanks.

Mossiback · Nov 9, 2018

If all that was broke was the props, there is no need to make a Refresh claim until you have more information. What type of Mavic were you flying?

ac0j · Nov 9, 2018

Most of the time when people make these "disconnected" posts as their first post, we later find out that the DJI Go4 app just quit. (The phone or tablet IS NOT the remote control, it is a display.), and the remote control was still connected fine. That is why the RTH does not engage.
Then the pilot crashes the drone flying blind without a clue that they are actually still in control.
Post your flight log and will might be able to figure it out.

WilmotCheater · Nov 9, 2018

ac0j said:
Most of the time when people make these "disconnected" posts as their first post, we later find out that the DJI Go4 app just quit. (The phone or tablet IS NOT the remote control, it is a display.), and the remote control was still connected fine. That is why the RTH does not engage.
Then the pilot crashes the drone flying blind without a clue that they are actually still in control.
Post your flight log and will might be able to figure it out.

I get that, however, this was definitely not the case. The drone was right in front of me, and I was watching it the whole time. It just stopped responding, and a couple seconds later hit the tree. Here is a link to the flight log:
DJI Flight Log Viewer - PhantomHelp.com
Not sure if that's what you are looking for, as there doesn't appear to be anything that might indicate what went wrong...

WilmotCheater · Nov 9, 2018

And just to clarify, it is a Mavic 2 Pro, and I'm not all that concerned about the propellers. I just want to figure out what caused this in the first place; I'm just glad it was a tree that stopped it and not something that could sue me.

SpinItUp · Nov 10, 2018

Poor GPS signal (only a few ft off the ground)

Data analysis with Airdata

Dragonfly · Nov 10, 2018

SpinItUp said:
Poor GPS signal (only a few ft off the ground)

View attachment 52903

Data analysis with Airdata

One thing to take into consideration is that when drone is within 60 feet of launch position and RTH or lost signal is ac tivated then drone doe not RTH but just lands where it is.
Well its meant too, maybe M2 has a bug and instead of landing in this senario, it just flys off as its confused on what it is meant to do. Just a thought.
Try recreation of problem by being further away then turn off RC. If RTH okay then do again with drone inside(only 30 to 50 feet away) and turn off RC. Try in open feild and be ready to turn on RC for reconnect and get back control.

WilmotCheater · Nov 10, 2018

So does anyone have any experience in dealing with DJI support? If I send them the DAT file, will they be able to tell me why the random disconnect, and will they then do something to correct it? From what I've read, their customer service is not very helpful...

SpinItUp · Nov 10, 2018

WilmotCheater said:
So does anyone have any experience in dealing with DJI support? If I send them the DAT file, will they be able to tell me why the random disconnect, and will they then do something to correct it? From what I've read, their customer service is not very helpful...

post it here (may need to upload it to a file cloud service) or rename it to .txt instead of .DAT

WilmotCheater · Nov 10, 2018

SpinItUp said:
post it here (may need to upload it to a file cloud service) or rename it to .txt instead of .DAT

File was too large to upload here, so I here is a link:
Meet Google Drive – One place for all your files

SpinItUp · Nov 10, 2018

WilmotCheater said:
File was too large to upload here, so I here is a link:
Meet Google Drive – One place for all your files

Permissions need changing on the file for sharing
just get a link for anyone with the link to view

WilmotCheater · Nov 10, 2018

SpinItUp said:
Permissions need changing on the file for sharing
just get a link for anyone with the link to view

Sorry, should be good to go now.

SpinItUp · Nov 10, 2018

WilmotCheater said:
Sorry, should be good to go now.

Seems corrupted file. I can't get it to open.
Would you mind checking it or upload it again, please.
Edit Oh! sorry it's DJI who can only decrypt the 2 series

WilmotCheater · Nov 10, 2018

SpinItUp said:
Seems corrupted file. I can't get it to open.
Would you mind checking it or upload it again, please.
Edit Oh! sorry it's DJI who can only decrypt the 2 series

DJI_ASSISTANT_EXPORT_FILE_2018-11-10_12-12-08.DAT
Sorry that took so long, slow internet today...

WilmotCheater · Nov 10, 2018

WilmotCheater said:
DJI_ASSISTANT_EXPORT_FILE_2018-11-10_12-12-08.DAT
Sorry that took so long, slow internet today...

Dammit!! I just saw your edit, after all that waiting...ffs. Oh well, I guess that all fits in with the overall experience I've had so far, haha.

WilmotCheater · Nov 10, 2018

So DJI does not have anyway for the user to view detailed flight logs. I was on the Support chat and they said I have to use a 3rd party app or website. But they don't recommend any... And the file is encrypted... So in reality only DJI has the ability to determine what the cause is, and thereby determine who is responsible for damage... How convenient.

SpinItUp · Nov 10, 2018

It's possible to use the DAT files from the 1st gen MP. Which may have been what your chat Support was suggesting.
erm! yes, reality kinda sux sometimes.
Edit; 4 props is no biggy
I chewed a few props when I first flew mine.

WilmotCheater · Nov 10, 2018

SpinItUp said:
It's possible to use the DAT files from the 1st gen MP. Which may have been what your chat Support was suggesting.
erm! yes, reality kinda sux sometimes.
Edit; 4 props is no biggy
I chewed a few props when I first flew mine.

Yeah, I have the props in my shopping cart. I'm not so concerned about the props, but just want to know what happened, and how to prevent this in the future. It's hard to fly safely when you suddenly can't control what your drone is doing.