My DJI Mavic 3 Cine drone crashed during ActiveTrack, it descended suddenly into the water.

It was following the boat I was in with a few friends when it suddenly started to descent towards the water. At that moment I didn't had VLOS for a moment but 2 of my friends did keep VLOS and shouted that the drone was falling down. For a split second I tought this was a joke but I looked back and saw they were right. So just a few seconds after it hit the water I ascended as fast as possible and took manual control back and after a couple of minutes was able to land safely.

For a nice overview I have combined the flight logs with the camera recording into a video. After the crash you see the gimbal shaking and all sort of sensor errors appear.
The full flight logs are also available as attachment.



Today I got the DJI Damage Assessment.

SN:1581F4QZB21AV1BE01YF App record:2022-08-11 02:16:58 (UTC+8) FLY47 1.The aircraft worked in APAS mode; 2.Flight Time T= 06:10, Relative Height H= -1.1 m, Distance to home point D= 456.3 m, Tof measurement= 0.5 m,the pilot pulled down throttle stick and Near Ground Landing was triggered. The aircraft started to descend. 3.Flight Time T= 06:12, Relative Height H= 0 m, Distance to home point D= 456.3 m, the aircraft descended and the flight recorded ended; 4.Last coordinate:51.965224, 5.7565967. Conclusion: The incident was caused by non-manufacturing factors. Therefore, it is concluded to customer responsibility. NO WARRANTY: No physical damage. Liquid damage. ESC Board Module damaged. Auxiliary Bottom Light Board damaged. DJI Mavic 3 Intelligent Flight Battery malfunctioned. Thank you for always supporting us. To provide you a better after-sales service experience, time-limited discount of the repair service fee for some products has been offered on your repair cost.

I honestly think this is an incorrect assessment because:

• The actual crash into the water happens around 01:32 into the flight and not at 06:10. At 06:10 I was able to safely land my drone next to the water. So saying that the incident was cause by non-manufacturing factors because I actually saved it from drowning seems not right.
• The actual interesting part to me seems to be 01:23 to 01:32. At 01:23 the drone ascents from 24.9 ft to 31.2 ft at 01:26. Why? After 01:26 there is the descent into the water at 01:32. How can this descent happen during an ActiveTrack session!? What were the sensors doing? I didn't get any explanation about this.
  

The suggested repair costs are € 275.93.
I have my drone pilot license and have flown many many hours before and I don't see what I did wrong here.
Is there anyone who can shed some light on this case?

Dji, Look at that video. Proof enough that the drone did not function as normal and needs to be fixed/replaced under warranty.

Hi,

Wow, thanks your friends 10x for being so alert. Plus just on time pulling UP, it hit the water!

Flying low over water, streaming / not flat surface water (due to wind and/or boat waves) is tricky.
At a baro height of 6.1 meter (bottom sensor measured 7.3 meter) the bottom sensor lost height, it did not measure height after 1m1.6s.

In track mode, speeding up the drone to 6 m/s it lost for shot moment the subject, from drone pitching down to drone pitching up to down again....
Speeding up again and going down.
Before pulling UP your Mavic3 was out of trackmode, into N mode.

I am not surprised looking at your data, many DJI drones in this circumstances do the same, loosing height and/or hover instabily.

Is it a drone error ??  flying low over water with bad bottom sensor height measuring is a good recipe for disaster.
Should your drone kept his height?  yes ofcourse, that is what we all want,  but if you read the manual with all the cautions...probably not.

BTW DJI wrote "the pilot pulled down throttle stick and Near Ground Landing was triggered."This was not the case when loosing height while tracking and loosing the object.
Guess DJI did not had a proper look at your log  to say it mildly.


cheers
JJB

"He who flies over water with automation must reach for his wallet."

Hi there, we are sorry to know about the accident. If you have any questions about the data analysis results, please feel free to contact DJI EU Technical Support via the channels mentioned in the email. Our team will help you further.