Mavic Pro Platinum "signal loss" "aircraft disconnect" with resulting loss of drone

[Ewelling]

While flying in the MPP in an area of Utah called Cockscombs the controller showed a warning of "signal loss" then "aircraft disconnected." The MPP was at an altitude of around 300' and a distance of 4000 ft when this happened. After 4 hours of searching using the map on the DJI app, the search was called off because of darkness. During the 4 hour search, the map was searched with the MPP location; however, the map and MPP coordinates kept changing because the remote and isolated location (I assume).

1. Does anyone know how to download the flight logs to troubleshoot why the disconnect occurred in a LOS flight?
2. Will the info on these flight logs provide information on the last known location of the drone?
3. It is my understanding that once the "signal loss" and "aircraft disconnected" occurs that the MPP performs a default RTH manuver. The area where the MPP was calibrated was thoroughly searched without luck.

Any suggestions and help would be greatly appreciated.

 

[Gryphon962]

1) For logs, follow instructions here: DJI Flight Log Viewer | Phantom Help
'The logfiles you need to locate will be called something like '19-05-29-11-21-19_FLY0xx.DAT' and 'DJIFlightRecord_2019-05-29_[11-21-36].txt'

2) The log will end at the point the drone lost signal for the last time.

3) The drone should RTH to the Home Point, exact location of which will be stated in the log. Where it was calibrated isn't necessarily the Home Point. Unfortunately, there are numerous ways for the drone to fail to return:

1. If the RTH setting for signal loss was set to Hover, rather than RTH, it will remain in hover until battery falls to min needed to RTH from that location.
2. If low battery RTH setting was OFF, it wont RTH when battery at min needed to RTH, and will land at its hover location.
3. If the altitude set to RTH was insufficient to clear obstacles between the point of signal loss and the home point, it will encounter obstructions. The RTH altitude is relative to home point.
4. If obstacle avoidance was ON, the RTH speed will be about 8mph and this is sometimes not enough to make it back if flying into wind.
5. If obstacle avoidance was ON and it did encounter obstructions, it will stop, climb, and try to continue forward, which might or might not clear the obstruction and make it back.

 

[Ewelling]

Thank you very much for taking the time to write such a detailed and informative response.
Best,
Eric

 

[DanMan32]

Note that RTH OA will not exceed the max altitude setting.