Hello- this is my first post and a noob pilot. I have experienced a few cases of random loss of control where the Mavic goes into Atti mode. Luckily I was able to regain control of the drone but I find this a bit unsettling. I am hoping the community can help me explain what might be the cause. The flightlogs of the last instance of this occuring were truncuated and consist of the pre and post loss of control part of the same flight. I downloaded the flights to Healthy Drones and provide the links here:

Flight 2017-06-03 05:54:04

http://app.airdata.com/main?share=hHQcmm

Flight 2017-06-03 05:41:53

http://app.airdata.com/main?share=ouVHwu


Any help appreciated.

/Peder

The TXT files from your mobile device aren't likely to provide enough information to figure out what happened, but if you post the DAT file from the flight we may be able to tell you. The instructions for downloading the DAT file to your PC are here and once you've gotten it you'll need to put it on DropBox and provide a link to the file in this thread.

This is more to do with the environment you were flying in you lost data when flying over some buildings there could have been some interference it lasted 2 seconds, in the same area you lost gps for approx 3 seconds I don't think it's any fault of the aircraft.

You should go to another location open space and try your aircraft there.

When preparing for flight I suggest you do the following.

Raise Aircraft to 8 feet
Hover for 20 seconds
Fly forward 3 feet
Fly back 3 feet
Left 3 feet
Right 3 feet
Yaw left
Yaw right
Up 3 feet
Down 3 feet
Each time returning to hover, if your aircraft returns to a good horizontal each time, you will then know you have a good compass good IMU and good gps, and then go fly and get your confidence back.
This is a worthwhile exercise to use before every flight it takes less than two minutes.

The two most important, most effective tests that can be done prior to flight to insure good compass and GPS are
1) Check that the AC orientation presented by the Go App is correct. I.e. visually check that the orientation of the red triangle on the Go App map display is consistent with the environment. This test is far more effective than checking the magMod number.
2) Check that the GPS level on the RC is at least 4. This is displayed as a bar graph in the top part of the RC. This is much more important than the number of satellites

DroneFlying Posted at 2017-6-6 02:11
The TXT files from your mobile device aren't likely to provide enough information to figure out what happened, but if you post the DAT file from the flight we may be able to tell you. The instructions for downloading the DAT file to your PC are here and once you've gotten it you'll need to put it on DropBox and provide a link to the file in this thread.

Thanks -I tried downloading the DAT files. Not 100% sure I got the right ones as the timestamps on the files and the number of files seems to differ a little from the ones I got off the Healthy drones site. If you could help me look at them that would be awesome. Thanks also for the other suggestions.

https://aix5-my.sharepoint.com/p ... pSs_bLGoko8_vOj6Hr4

hallmark007 Posted at 2017-6-6 08:18
This is more to do with the environment you were flying in you lost data when flying over some buildings there could have been some interference it lasted 2 seconds, in the same area you lost gps for approx 3 seconds I don't think it's any fault of the aircraft.

You should go to another location open space and try your aircraft there.

Good summary. I'm placing this list on my pre-check.

Peder.lindbom Posted at 2017-6-7 04:01
Thanks -I tried downloading the DAT files. Not 100% sure I got the right ones as the timestamps on the files and the number of files seems to differ a little from the ones I got off the Healthy drones site. If you could help me look at them that would be awesome. Thanks also for the other suggestions.

https://aix5-my.sharepoint.com/personal/peder_lindbom_aix_se/_layouts/15/guestaccess.aspx?docid=1a5c0d178b7e64ae0b83db82f920ee26f&authkey=AXc5pSs_bLGoko8_vOj6Hr4

I think BudWalker's first point in his post is the most relevant item here: it appears that you took off with a compass error, probably due to some (steel) rebar or other magnetic alloy present in the sidewalk. Once you were away from the interference, the Yaw and magYaw values began to diverge (the white section). You started your waypoint mission (the pink), and shortly after that the FC recognized that it had a problem (purple). It switched to ATTI mode (blue), and the aircraft began rotating until the Yaw and magYaw values were realigned, at which time it went back to P-mode.

As BudWalker mentioned, make sure the arrow you see in the Go app points in the correct direction -- and that you aren't getting a compass error -- before takeoff to avoid this kind of situation.

DroneFlying Posted at 2017-6-7 06:02
I think BudWalker's first point in his post is the most relevant item here: it appears that you took off with a compass error, probably due to some (steel) rebar or other magnetic alloy present in the sidewalk. Once you were away from the interference, the Yaw and magYaw values began to diverge (the white section). You started your waypoint mission (the pink), and shortly after that the FC recognized that it had a problem (purple). It switched to ATTI mode (blue), and the aircraft began rotating until the Yaw and magYaw values were realigned, at which time it went back to P-mode.

As BudWalker mentioned, make sure the arrow you see in the Go app points in the correct direction -- and that you aren't getting a compass error -- before takeoff to avoid this kind of situation.

Wow -thank you so much for that thorough forensic analysis. It makes me both feel foolish for not realising the importance of the risk for compass interference and also more confident I can avoid this type of situation in the future. It is always worse not to know what the cause was. Now at least I can try and avoid this particular problem...

Thank you so much once more!
/Peder