Mavic 2 Pro Crash in Miami - Possible Bird Incident?

[Wolffboy]

I've enjoyed reading these forms for the several years I've been flying DJI drones. The analysis and discussions are always highly informative ad entertaining.
Sadly, it's my turn to report a crash, upload my data and hope somebody can help me figure out what happened.

Drone was a 1.5yr old Mavic 2 Pro - Litchi manual flight in wind 11 to 18mph. About 10 minutes into the flight the Mavic tilted to one side started drifting south and I had minimal control for about 10 seconds. I regained control and worked to get the drone coming home. A few seconds later the gimbal seem to wobble violently, followed by the tell-tale spin of a free-falling drone. I've attached the Litchi flight log CSV file for analysis. While I did not see any birds at the time of the accident, I saw a few seagulls in the area and the suddenness of the gimbal and spin seemed like something hit the drone or a prop failed.
It seems the drone fell either on the road or on the water, possibly on those rocks along the water.
I was visiting Miami and had to catch a plane back to Los Angeles so I could not search for the drone.
If anyone is in the Miami area and wants to look for it, I will pay a $400 reward for it's return with the MicroSD Card.
Let me know if any more data is needed. Thanks in advance.

 

[slup]

The log you have attached doesn't seem to be from the flight described ... look at the pic. further below. Litchi create 2 logs, one own custom & a standard DJI TXT log, have copied in a description & a retrieval guide below. See if you can find the 2 right ones & post them up. I don't have high hopes to diagnose anything regarding HW failure though (due to external impact or sudden failures) as Litchi doesn't create a DAT log in which all raw sensor data & motor data usually is.

Mobile device third-party control app log files

Third-party control apps, such as Litchi, create their own custom log files in various formats using the DJI SDK, generally in CSV format. None that I have seen are as comprehensive as the DJI TXT log, let alone the DJI DAT log.

Since Litchi is probably the most common third-party app, it's worth noting that, under iOS and Android, Litchi creates its own CSV log and a standard DJI TXT log in a separate directory. No DAT file though.

Litchi log files

On iOS devices, the Litchi CSV logs are in Litchi » Documents » flightlogs, and the DJI TXT logs are in Litchi » Documents » SDK_logs » FlightRecord.

On Android devices the Litchi CSV logs are in LitchiApp » flightlogs. Litchi also creates a standard DJI TXT log, which for some reason it stores in a subdirectory in the DJI app directory, DJI » com.aryuthere.visionplus » FlightRecord.

 

[Wolffboy]

I have attached a ZIP file with all files for 3.6.20 from both android folders.
Possibly the flight in question was not saved?

Thank You for your feedback!

 

[sar104]

The log you have attached doesn't seem to be from the flight described ... look at the pic. further below. Litchi create 2 logs, one own custom & a standard DJI TXT log, have copied in a description & a retrieval guide below. See if you can find the 2 right ones & post them up. I don't have high hopes to diagnose anything regarding HW failure though (due to external impact or sudden failures) as Litchi doesn't create a DAT log in which all raw sensor data & motor data usually is.

Mobile device third-party control app log files

Third-party control apps, such as Litchi, create their own custom log files in various formats using the DJI SDK, generally in CSV format. None that I have seen are as comprehensive as the DJI TXT log, let alone the DJI DAT log.

Since Litchi is probably the most common third-party app, it's worth noting that, under iOS and Android, Litchi creates its own CSV log and a standard DJI TXT log in a separate directory. No DAT file though.

Litchi log files

On iOS devices, the Litchi CSV logs are in Litchi » Documents » flightlogs, and the DJI TXT logs are in Litchi » Documents » SDK_logs » FlightRecord.

On Android devices the Litchi CSV logs are in LitchiApp » flightlogs. Litchi also creates a standard DJI TXT log, which for some reason it stores in a subdirectory in the DJI app directory, DJI » com.aryuthere.visionplus » FlightRecord.

View attachment 95949

The log above is the flight in question, and ends with a sudden descent into the water:



It looks like a propulsion problem rather than a bird strike - there is no sudden change in velocity but the aircraft enters a tumbling, spinning fall:



The data are a bit sparse to be certain, but it looks like the rear left was the issue - a motor fault or a lost prop. Since you were flying with Litchi there won't be a DAT file with motor speeds to confirm the problem.

 

[Wolffboy]

Thank You for your analysis! Much appreciated.

 

[Airbeaver]

Dang that sucks sorry to hear you lost it. Cant imagine how frustrating that must be to have had to leave without being able to do a proper search. I hope you get it back soon.

 

[Lets Fly]

Going on google map and matching the rock patterns it should easily be located. To bad I live 100 miles away, but if I found it I no need for a reward. Sorry for your loss.

 

[Wolffboy]

The log above is the flight in question, and ends with a sudden descent into the water:

View attachment 96012

It looks like a propulsion problem rather than a bird strike - there is no sudden change in velocity but the aircraft enters a tumbling, spinning fall:

View attachment 96013

The data are a bit sparse to be certain, but it looks like the rear left was the issue - a motor fault or a lost prop. Since you were flying with Litchi there won't be a DAT file with motor speeds to confirm the problem.

Thanks again;
I flew Litchi and DJI GO that day and the flight before the final flight was a DJI Go flight, as well as two others from that day.
I have attached the 3 DJI GO 4 flight record files to see if there were any issues with the motors in the previous flight?
Let me know if these files are correct. Wondering if there were any signs of impending failure in the previous flights.

Thanks again!

 

[slup]

Thanks again;
I flew Litchi and DJI GO that day and the flight before the final flight was a DJI Go flight, as well as two others from that day.
I have attached the 3 DJI GO 4 flight record files to see if there were any issues with the motors in the previous flight?
Let me know if these files are correct. Wondering if there were any signs of impending failure in the previous flights.

Thanks again!

You unfortunately can't draw any firm conclusions regarding the motor performance without the mobile DAT logs ... those are the ones needed, not the TXT.

 

[Wolffboy]

Going on google map and matching the rock patterns it should easily be located. To bad I live 100 miles away, but if I found it I no need for a reward. Sorry for your loss.

Dang that sucks sorry to hear you lost it. Cant imagine how frustrating that must be to have had to leave without being able to do a proper search. I hope you get it back soon.

Indeed it was a touch decision to leave without searching, but

You unfortunately can't draw any firm conclusions regarding the motor performance without the mobile DAT logs ... those are the ones needed, not the TXT.

OK got it - have attached the DAT files for the 3 flights that day
Thanks

 

[slup]

Indeed it was a touch decision to leave without searching, but

OK got it - have attached the DAT files for the 3 flights that day
Thanks

Nope ... nothing makes the left rear stand out, none of the rest either. So no indication of something soon to happen.

 

[Teejag]

this seems very strange similar incident that I had. also guys said that it was rear left motor that failed.