I am a new Mavic Pro owner and have experienced major malfunctions 3 times, 2 times resulted in a crash. The last time was yesterday and I pulled the flight logs and see "Speed error"  but not sure what that even means. Basically I am flying in a park, and near the end, I hover over an open field  to take some photos of a model home being built at 112 ft height. I start heading back home and the drone literally lost control and fell from the sky.  Attached are my flight logs, if I could get guidance on what occured and why, it would be helpful.

Link to Onedrive Folder with Flight Log

<a href="https://ibb.co/fhGhdk"><img src="https://preview.ibb.co/d2xAW5/screen_cap.jpg" alt="screen_cap" border="0"></a>

If you could upload your log to link below, that link I can't open phantomhelp is pretty good, just click on the link and follow instructions. Come back and post your link.

http://www.phantomhelp.com/LogViewer/Upload/

hallmark007 Posted at 2017-9-18 07:29
If you could upload your log to link below, that link I can't open phantomhelp is pretty good, just click on the link and follow instructions. Come back and post your link.

http://www.phantomhelp.com/LogViewer/Upload/

Log Link

djiuser_4FRWO2d Posted at 2017-9-18 08:13
Log Link

Your log ends abruptly at 67ft was it at this altitude when it dropped out of the sky, if so I would think you had a sudden power cut or battery somehow popped out which I would find strange. Your speed error can be caused by sudden movements of flying flat out and then braking by pulling right stick back where as you should let stick back to centre and let aircraft brake that way.

It doesn't offer anything in your log to show battery failure in fact your battery looks perfect at the end of your log.

Off the bat I would think this is a malfunction problem and you should contact dji and start An RMA case.

There is another guy on here very helpful he reads dat files these can sometimes offer more intricate information on what may have caused your AC to suddenly fall from the sky. I will try to contact Droneflying and ask him to pop over to this thread he may be able to give you some more info.

Good luck

hallmark007 Posted at 2017-9-18 09:07
Your log ends abruptly at 67ft was it at this altitude when it dropped out of the sky, if so I would think you had a sudden power cut or battery somehow popped out which I would find strange. Your speed error can be caused by sudden movements of flying flat out and then braking by pulling right stick back where as you should let stick back to centre and let aircraft brake that way.

It doesn't offer anything in your log to show battery failure in fact your battery looks perfect at the end of your log.

Thanks for looking at it. I was headed back home at altitude 111.5 ft and it look like it started loosing altitude at 4:40 and started the fall. I speculate the last data point is at altitutde 68 ft is perhaps due to data transmission lag.

I checked my controller joystick position, the right one was fully pushed forward and I returned to center as soon as it appeared to tumble so no sudden movements.

I have uploaded a video screen capture of the live flight path  4:34-4:42


Video Screen Capture

Oh yea , forgot to mention, when I recovered the mavic, the battery was seated still, even after the crash and it was able to turn on very easily (not connecting to the controller, but none the less, doesn't look like battery issue/failure)

djiuser_4FRWO2d Posted at 2017-9-18 09:58
Oh yea , forgot to mention, when I recovered the mavic, the battery was seated still, even after the crash and it was able to turn on very easily (not connecting to the controller, but none the less, doesn't look like battery issue/failure)

Ok good I really do think it's pretty much impossible to incorrectly insert battery and still fly the Mavic.
I have sent PM to Droneflying he may be able to help you further, but this looks like a warranty because of malfunction.

I'd be interested to know how this one happened. From that flight recording log, it appears the battery still had power at 61%.  Strange.

djiuser_4FRWO2d Posted at 2017-9-18 09:55
Thanks for looking at it. I was headed back home at altitude 111.5 ft and it look like it started loosing altitude at 4:40 and started the fall. I speculate the last data point is at altitutde 68 ft is perhaps due to data transmission lag.

I checked my controller joystick position, the right one was fully pushed forward and I returned to center as soon as it appeared to tumble so no sudden movements.

As Hallmark mentioned, the best way to try to figure out what happened here is to look at the DAT file for the flight that's stored on the Mavic itself. Please retrieve the correct file using these instructions, then upload it to DropBox and provide a link to it here and I'll take a look. The correct file will have a time stamp that corresponds to when the flight occurred and will be at least tens of megabytes in size.

DroneFlying Posted at 2017-9-18 10:39
As Hallmark mentioned, the best way to try to figure out what happened here is to look at the DAT file for the flight that's stored on the Mavic itself. Please retrieve the correct file using these instructions, then upload it to DropBox and provide a link to it here and I'll take a look. The correct file will have a time stamp that corresponds to when the flight occurred and will be at least tens of megabytes in size.

Thanks for the guidance; I am having significant issues pulling the data off (DJI Agent wont even recognize that the Mavic is connected via the supplied USB cable on Win 10)

I'll try a different computer  tomorrow

djiuser_4FRWO2d Posted at 2017-9-18 17:35
Thanks for the guidance; I am having significant issues pulling the data off (DJI Agent wont even recognize that the Mavic is connected via the supplied USB cable on Win 10)

I'll try a different computer  tomorrow

I am not sure but I suspect the speed error may refer to an esc being cooked which would have stopped a motor and hence it fell out of the sky.

I feel sorry for your crash, did the drone hurt by impact damage? For the "speed error", did you see it on DJI GO 4 app? If yes, could you please provide me the screenshot of it? Besides, had you sent an email to support@dji.com to start a data analysis? Please contact them and we will help to investigate the reason.

So I tried another computer (installed DJI Assistant with Win 10: Disabled Driver Enforcement)  still no luck. Looks like the damage from the fall doesn't allow it to connect to the computer.

Any other suggestions on recovering the .dat file?

I will call DJI today to understand the process of diagnosis.

djiuser_4FRWO2d Posted at 2017-9-19 04:33
So I tried another computer (installed DJI Assistant with Win 10: Disabled Driver Enforcement)  still no luck. Looks like the damage from the fall doesn't allow it to connect to the computer.

Any other suggestions on recovering the .dat file?

There is another .DAT on the tablet. Definitely not as good as the .DAT on the AC. But, it may be worth a try - if you want to be the first to try it. On an Android tablet the .DAT will be located in a folder DJI/dji.go.v4/FlighRecord/MCDatFlightRecords. With an iOS tablet you'll have to use iTunes. You'll need to save the folder FlightRecords just as you would if you're saving the .txt files. The .DAT files will be in the subdirectory MCDatFlightRecords.

djiuser_4FRWO2d Posted at 2017-9-19 04:33
So I tried another computer (installed DJI Assistant with Win 10: Disabled Driver Enforcement)  still no luck. Looks like the damage from the fall doesn't allow it to connect to the computer.

Any other suggestions on recovering the .dat file?

Thanks for the Suggestion it worked

The naming nomenclature of the DAT files on my android phone is a bit different than log files so I hope I picked the correct file.

DataCon couldnt open it but CsvView could.

Link to Data File of Crash
https://1drv.ms/u/s!AlQ64-b_hkASgsVuOAT9esvL72o0Vw

Link to Folder with All Files related to Data in Question
https://1drv.ms/f/s!AlQ64-b_hkASgsVpkHUvDKtVvQOf9A

BudWalker Posted at 2017-9-19 07:14
There is another .DAT on the tablet. Definitely not as good as the .DAT on the AC. But, it may be worth a try - if you want to be the first to try it. On an Android tablet the .DAT will be located in a folder DJI/dji.go.v4/FlighRecord/MCDatFlightRecords. With an iOS tablet you'll have to use iTunes. You'll need to save the folder FlightRecords just as you would if you're saving the .txt files. The .DAT files will be in the subdirectory MCDatFlightRecords.

CORRECTED LINKS FOR DAT File

Lets try this one more Time

Link to Data File of Crash

Link to Folder with All Files related to Data in Question

djiuser_4FRWO2d Posted at 2017-9-19 08:22
CORRECTED LINKS FOR DAT File

Lets try this one more Time

I need some more info
The file 17-09-17-05-48-13_FLY017.DAT is in the first folder. Where did it come from?
The file 17-09-17-05-45-22_FLY017.DAT is in the second folder. Where did it come from?

These are both FLY017.DATs but it looks like from different times. In addition, I can't read the first one.

BudWalker Posted at 2017-9-19 09:56
I need some more info
The file 17-09-17-05-48-13_FLY017.DAT is in the first folder. Where did it come from?
The file 17-09-17-05-45-22_FLY017.DAT is in the second folder. Where did it come from?

All of these files were located in my Samsung S8 phone which I was using with the controller at the following location

DJI/dji.go.v4/FlighRecord/MCDatFlightRecords

djiuser_4FRWO2d Posted at 2017-9-19 10:04
All of these files were located in my Samsung S8 phone which I was using with the controller at the following location

DJI/dji.go.v4/FlighRecord/MCDatFlightRecords

So 17-09-17-05-48-13_FLY017.DAT  was in that folder but then you didn't include it in "All Files" folder on the OneDrive? Sorry for the detailed questions. The tablet .DAT files are a new thing for DatCon and there seems to be some aspects to figure out.

BudWalker Posted at 2017-9-19 10:16
So 17-09-17-05-48-13_FLY017.DAT  was in that folder but then you didn't include it in "All Files" folder on the OneDrive? Sorry for the detailed questions. The tablet .DAT files are a new thing for DatCon and there seems to be some aspects to figure out.

I apologize- All the files were located in "DJI/dji.go.v4/FlighRecord/MCDatFlightRecords"

I separated the one since I think that the indicative flight"17-09-17-05-48-13_FLY017.DAT"  into another folder on Onedrive to help you all not have to deal with the clutter

djiuser_4FRWO2d Posted at 2017-9-19 10:23
I apologize- All the files were located in "DJI/dji.go.v4/FlighRecord/MCDatFlightRecords"

I separated the one since I think that the indicative flight"17-09-17-05-48-13_FLY017.DAT"  into another folder on Onedrive to help you all not have to deal with the clutter

No problem. In fact, since you provided all the .DATs I was able to figure out that FLY017 got split and the crtical piece was in the second part. DroneFlying and I are taking a look.

BudWalker Posted at 2017-9-19 12:29
No problem. In fact, since you provided all the .DATs I was able to figure out that FLY017 got split and the crtical piece was in the second part. DroneFlying and I are taking a look.

Sounds good Going to send it in tonight or tomo morning for diagnosis

djiuser_4FRWO2d Posted at 2017-9-19 14:18
Sounds good  Going to send it in tonight or tomo morning for diagnosis

It's a little hard to tell what happened here. It would seem that the incident started with the leftFront motor being commanded, and running, slower. This would happen if the rightBack was having reduced propulsion, but that isn't clear from the rest of the motor data. Also, leftFront running slower would cause CW rotation but it seems there was CCW rotation. Anyway, it's clear that the incident started with the leftFront being commanded lower. It's unclear why that was done.

The SPEED_ERROR_LARGE error is an indication that the flight controller is seeing velocity values that are different from what it's predicting. This happened during the tumbling at the end of the flight. It's not unusual to see these errors if the AC is tumbling.

Might be interesting to look at another flight where this happened. You mentioned there were 3 other incidents. Also be interesting to see if DJI gives you any info.

BudWalker Posted at 2017-9-20 05:35
It's a little hard to tell what happened here. It would seem that the incident started with the leftFront motor being commanded, and running, slower. This would happen if the rightBack was having reduced propulsion, but that isn't clear from the rest of the motor data. Also, leftFront running slower would cause CW rotation but it seems there was CCW rotation. Anyway, it's clear that the incident started with the leftFront being commanded lower. It's unclear why that was done.

The SPEED_ERROR_LARGE error is an indication that the flight controller is seeing velocity values that are different from what it's predicting. This happened during the tumbling at the end of the flight. It's not unusual to see these errors if the AC is tumbling.

Thanks for the analysis! I hope DJI is able to shed some light on this.

djiuser_4FRWO2d Posted at 2017-9-20 08:52
Thanks for the analysis! I hope DJI is able to shed some light on this.

Good luck hope it works out for you let us know how you get on.

fans0a7c786d Posted at 2017-9-22 03:06
Dude, exact same thing happened to my Mavic, flying along sports mode and it simply fell out of the sky. Looked up the flight logs, i got Speed Error, Compass error and then Prop Missing error but it was already on the ground by then. Still haven't found the drone but keeping fingers crossed. Let me know how you get on ? I sent off my flight log and now they're asking for the complete folder so all the flights... so something strange has happened.

will provide an update when I get one from DJI, sucks that it happened to you as well