Hi,

my Mavic 2 Pro fall out of the sky into the ocean (not recoverable).

This were the last seconds of my drone:
The drone was about 200m height, the video transmission look suddenly as if my mavic went upside down. Then i lost the video transmission. The app told me that the aircraft is going to perform an autolanding, which i was not able to stop by pushing the sticks up. At almost the same moment the notice appeared, that the drone switched to backup IMU. 1-2 Seconds later the link between RC and drone was lost. It wasn't windy at this day.

I have no clear idea what happened with my drone. It would be great if someone could look on the logs an tell me what happened, before i loose my next drone.
Log at Phantomhelp - https://www.phantomhelp.com/logviewer/2K4NYEC9XWXDX3W0ITLR/
Flight Record txt - https://www.dropbox.com/s/myt19yr6hl3xmqa/DJIFlightRecord_2020-08-18_%5B16-44-33%5D.txt?dl=0
Flight Record dat - https://www.dropbox.com/s/4h0g3mm2f9ssjsm/2020-08-18_16-44-11_FLY023.DAT?dl=0

Big thank you in advance.

Log at Phantomhelp
Flight Record txt
Flight Record dat

The incident was caused by the loss of the left front prop. It either partially broke or completely detached.

The loss of left front propulsion can be seen here


The M2 was tumbling pitching down/forward, rolling CCW and yawing CW. These are all consistent with leftFront loss of propulsion.

The leftFront motor data shows the motor commanded set at 100%, speed increased and current draw sharply reduced. This is consistent with lost or broken prop.

BudWalker Posted at 8-26 07:02
The incident was caused by the loss of the left front prop. It either partially broke or completely detached.

The loss of left front propulsion can be seen here

Thank you very much for the detailed analysis.
Just one additional question: Does the accelometer show any indication that something hit my drone?

BudWalker Posted at 8-26 07:02
The incident was caused by the loss of the left front prop. It either partially broke or completely detached.

The loss of left front propulsion can be seen here

Hi BudWalker,

Had a look too at this unfortunately flight.

Before this MP2 started to spin down, the left front motor almost stopped for short moment, well the RPM values from 5641 to 122 to 7070 again, see the data in my chart.
In the eventlog at this moment > CRAFT CTRL FAILED!!!
Then for 8 seconds 'normal' rpm values, than the spinning started and approx 5 seconds later high rpm values for this motor.

Uh, i would think loosing a prop/motor will cause the spin but in this flight the spin started before loosing a prop.

So i am little confused, did this drone lost a prop or ?
Before this a large mismatch in the compass data, guess due to the sudden yaw at shortly 122 rpm.

cheers
JJB

Before this MP2 started to spin down, the left front motor almost stopped for short moment

Could a bird strike have caused that short motor stop

Marcel-Stephan Posted at 8-26 07:46
Just one additional question: Does the accelometer show any indication that something hit my drone?

Interesting. At 439 secs there is acceleration data that is consistent with the M2 being struck from above, left behind. It's coincident with the motor data that JJB observed. AcelZ shows positive acceleration and both the accelX and accelY show negative acceleration



After that and until 450 secs the left front motor data is definitely abnormal but appears not to have affected flight very much. I'll speculate that the prop was damaged and finally broke off at 450 secs.

As an interesting side note I had what I'm sure was a bird strike.
https://mavicpilots.com/threads/my-bird-strike.49634/

I'm not an expert like these guys, but I'll say to you, "That's a bummer."

Hello there Marcel-Stephan. I am sorry to read and to know what happened to your DJI Mavic 2 Pro. Since this unfortunate incident happened and you have lost the said drone. I would recommend for you to contact our DJI Support Team at https://www.dji.com/support?site=brandsite&from=nav for further assistance. If the said drone is still under the warranty period and it is evaluated as a non-pilot error, the warranty service will be provided. Again, I am sorry for your loss and thank you for your understanding.

Any seagull about when you were flying,  they seem to like to attack drones at the moment.  

JJB* Posted at 8-26 07:47
Hi BudWalker,

Had a look too at this unfortunately flight.

Great info JJB

A big thank you to all for the detailed analysis.
I checked the props always befor flying and changed them just 30 flights before.
There were no seagulls that i have noticed. ... happpens.
Let's see wwhat the DJI support offers me for getting a replacement.

A J Posted at 8-27 05:26
Great info JJB

Thanks, charts with a good overview of related data explains more than just a few lines   ;-)

cheers
JJB

JJB* Posted at 8-27 12:06
Thanks, charts with a good overview of related data explains more than just a few lines   ;-)

cheers

Very true

A two-stage failure like this ?
  

This is not too relevant but I wonder why the craft entered into autolanding.

djiuser_MRgOkD25qXOH Posted at 8-28 21:04
A two-stage failure like this ?
  https://www.youtube.com/watch?v=bxVS-_Kmg8o&feature=emb_logo

Cool video.  Were you able to determine what happened and was it ale to be salvaged?