DatCon to load file recorded during mavic crash

[leeen82]

Hi all,
I recently had the unfortunate luck of having my new mavic fall out of the sky and am now trying to sort out what happened. The mavic was elevating in sight at about 200' elevation when it went completely quiet and proceeded to fall out of the air and slam into a paved area. I was in such shock that i don't recall looking at the controller during the failure but afterwards the controller said disconnected. Based on the evidence I have it appears that the mavic lost power, but I'm hoping to find an explanation in the data. After pulling the .DAT files from the vehicle I found that there were two created for the flight that resulted in a crash, or at least created at the time the flight was started. One is FLY042 @ ~60KB and the other is FLY043 @ 4KB. I've loaded in FLY042 successfully into DataCon and export to csvView successfully. It appears that there is no data recorded after the failure initiated, but before that all of the data appears reasonable with my memory of the flight. My video also stops just before the failure. This evidence along with witnessing the crash seem to indicate a loss of power to me. But I'd like to view the FLY043 file - unfortunately when I load it into DataCon I receive the error "not an acceptable .DAT file because it unable to determine AC type". Anyone know what this means or how to load the file? Upon power failure its possible the file was still open for writing and is missing header information needed to load or something similar. Also has anyone had a power failure related crash and had this problem with the DAT files? I'm open to any ideas or other suggestions on how to get to the bottom of the failure.

 

[Cyberpower678]

Hi all,
I recently had the unfortunate luck of having my new mavic fall out of the sky and am now trying to sort out what happened. The mavic was elevating in sight at about 200' elevation when it went completely quiet and proceeded to fall out of the air and slam into a paved area. I was in such shock that i don't recall looking at the controller during the failure but afterwards the controller said disconnected. Based on the evidence I have it appears that the mavic lost power, but I'm hoping to find an explanation in the data. After pulling the .DAT files from the vehicle I found that there were two created for the flight that resulted in a crash, or at least created at the time the flight was started. One is FLY042 @ ~60KB and the other is FLY043 @ 4KB. I've loaded in FLY042 successfully into DataCon and export to csvView successfully. It appears that there is no data recorded after the failure initiated, but before that all of the data appears reasonable with my memory of the flight. My video also stops just before the failure. This evidence along with witnessing the crash seem to indicate a loss of power to me. But I'd like to view the FLY043 file - unfortunately when I load it into DataCon I receive the error "not an acceptable .DAT file because it unable to determine AC type". Anyone know what this means or how to load the file? Upon power failure its possible the file was still open for writing and is missing header information needed to load or something similar. Also has anyone had a power failure related crash and had this problem with the DAT files? I'm open to any ideas or other suggestions on how to get to the bottom of the failure.

Those files look rather small for DAT files. Are they from the Mavic directly or the RC/Phone?

 

[leeen82]

Those files look rather small for DAT files. Are they from the Mavic directly or the RC/Phone?

My fault, you're correct - they're 60,000 KB (or ~60MB) and 4MB. They were pulled from the mavic using DJI Assistant.

 

[Cyberpower678]

My fault, you're correct - they're 60,000 KB (or ~60MB) and 4MB. They were pulled from the mavic using DJI Assistant.

Can you upload them?

 

[leeen82]

Can you upload them?

Unfortunately the website wouldn't allow me to upload the .DAT files. I can likely upload the text file output from DataCon FLY042. I could also place them in dropbox or google drive and share a link.

 

[leeen82]

FLY042: FLY042.DAT
FLY043 (one thats corrupt): FLY043.DAT
Thanks for the quick response!

 

[Cyberpower678]

Unfortunately the website wouldn't allow me to upload the .DAT files. I can likely upload the text file output from DataCon FLY042. I could also place them in dropbox or google drive and share a link.

Upload the DAT file into the dropbox and send me a link.

 

[leeen82]

Upload the DAT file into the dropbox and send me a link.

Beat you to it . I don't think google drive should present a problem but if so let me know and I'll go the dropbox route.

 

[BudWalker]

Hi all,
I recently had the unfortunate luck of having my new mavic fall out of the sky and am now trying to sort out what happened. The mavic was elevating in sight at about 200' elevation when it went completely quiet and proceeded to fall out of the air and slam into a paved area. I was in such shock that i don't recall looking at the controller during the failure but afterwards the controller said disconnected. Based on the evidence I have it appears that the mavic lost power, but I'm hoping to find an explanation in the data. After pulling the .DAT files from the vehicle I found that there were two created for the flight that resulted in a crash, or at least created at the time the flight was started. One is FLY042 @ ~60KB and the other is FLY043 @ 4KB. I've loaded in FLY042 successfully into DataCon and export to csvView successfully. It appears that there is no data recorded after the failure initiated, but before that all of the data appears reasonable with my memory of the flight. My video also stops just before the failure. This evidence along with witnessing the crash seem to indicate a loss of power to me. But I'd like to view the FLY043 file - unfortunately when I load it into DataCon I receive the error "not an acceptable .DAT file because it unable to determine AC type". Anyone know what this means or how to load the file? Upon power failure its possible the file was still open for writing and is missing header information needed to load or something similar. Also has anyone had a power failure related crash and had this problem with the DAT files? I'm open to any ideas or other suggestions on how to get to the bottom of the failure.

The strategy I like to use when a power loss is suspected is to look at MotorVolts data. The battery data is way too slow (1 HZ) and there is about a 1.5 second delay. MotorVolts is 50 HZ. Look at the very end of the flight. You'll probably want to zoom in using the mouse wheel.

BTW, CsvView can accept the .DAT directly. You don't have to use DatCon. I keep running into this as pilots assume that CsvView only accepts .csv files. Poor marketing on my part.

 

[leeen82]

The strategy I like to use when a power loss is suspected is to look at MotorVolts data. The battery data is way too slow (1 HZ) and there is about a 1.5 second delay. MotorVolts is 50 HZ. Look at the very end of the flight. You'll probably want to zoom in using the mouse wheel.

BTW, CsvView can accept the .DAT directly. You don't have to use DatCon. I keep running into this as pilots assume that CsvView only accepts .csv files. Poor marketing on my part.

Thanks for the tips as well as creating the software! And CsvView does say "load dats..." right there in the load window but I must have missed that in haste. Same error from the CsvView so I'm assuming there is a problem with the file. After plotting MotorVolts in FLY042 it does look like there is a statistically abnormal drop near the end of the file. The decrease near the end is from ~11.8 Volts down to ~7 Volts. After zooming in (second plot below) it appears that the voltage drop occurs over the last data point. I assume the voltage actually continued to drop but the system stopped recording at this point. Anyone seen something similar for a power failure?

 

[BudWalker]

...... Anyone seen something similar for a power failure?

Mavic Fly Away this evening. Shes Gone!