Mavic crash

[scjerry]

Looking for some help and information on my MP.
Flying a simple mission today and while bringing it straight down from 207' AGL, it suddenly slid left 124 feet into a tree.
3 broken arms, gimbal sheared off and not sure what other damage as it fell 80 ft into the ground .

My question, would someone kindly take a look at the flight data/record and see if they can figure out what the heck happened!? I have looked at Airdata but nothing that would tell me why the MP would all of a sudden veer off and I was sliding left at such a fast speed. Just before it happened I received a message my IPad -CPU overloaded.

Any help would be appreciated. Wont help on the repair bill but I need to know why.

Also, what is the URL or link for the flight dat analysis?

I uploaded your .txt file to Mike Singer's PhantomHelp link and got this: .DJI Flight Log Viewer - PhantomHelp.com
Before the flight's end there were indications that something was amiss with the flight controller. Beginning at 12m 46.5s, several GPS Position No Match errors occurred, then at 12m 47.6s, two Compass Error flags were set. At 13m 4s or so after motor startup, it crashed. So roughly 15 sec. before the crash, there was probably some interference, or malfunction of the flight controller. But I'm not an expert.

Does the church have a tower? Maybe a cell tower inside? Power lines? There appears to be no warning about external interference.

Was the MP under warranty?

OK, so if there was no external interference, and its still under warranty, then its worth sending it in to DJI for analysis, since you can't retrieve the .dat files using DJI Assistant 2. I assume you synched your flight using the Go 4 app on your iPad. If so, DJI will have your .dat file in their cloud. You can still do it if your iPad is still working.

According to my analysis, your iPad pooped out at around 12m 10 s, so before this other stuff. But that didn't show up in PhantomHelp's automated results. Also the compass error did not show up in column OSD.CompassError of my csv, only in column OSD.nonGPSCause, with the codes in OSD.nonGPSCauseRaw. These codes should also be recorded in the .dat file. See Mavic Pro .csv Column Descriptions and the Mavic Pro column headers for .csv files derived from .dat files.


Hope this helps.

 

[sar104]

I uploaded your .txt file to Mike Singer's PhantomHelp link and got this: .DJI Flight Log Viewer - PhantomHelp.com
Before the flight's end there were indications that something was amiss with the flight controller. Beginning at 12m 46.5s, several GPS Position No Match errors occurred, then at 12m 47.6s, two Compass Error flags were set. At 13m 4s or so after motor startup, it crashed. So roughly 15 sec. before the crash, there was probably some interference, or malfunction of the flight controller. But I'm not an expert.

Does the church have a tower? Maybe a cell tower inside? Power lines? There appears to be no warning about external interference.

Was the MP under warranty?

OK, so if there was no external interference, and its still under warranty, View attachment 24135 then its worth sending it in to DJI for analysis, since you can't retrieve the .dat files using DJI Assistant 2. I assume you synched your flight using the Go 4 app on your iPad. If so, DJI will have your .dat file in their cloud. You can still do it if your iPad is still working.

According to my analysis, your iPad pooped out at around 12m 10 s, so before this other stuff. But that didn't show up in PhantomHelp's automated results. Also the compass error did not show up in column OSD.CompassError of my csv, only in column OSD.nonGPSCause, with the codes in OSD.nonGPSCauseRaw. These codes should also be recorded in the .dat file. See Mavic Pro .csv Column Descriptions and the Mavic Pro column headers for .csv files derived from .dat files.

View attachment 24139
Hope this helps.

The position mismatch messages do not indicate the cause of the crash - it was responding correctly to stick inputs and was flown into the tree.

 

[scjerry]

Thanks, sar104. As I said, I'm not an expert. I was confused, though, at your x-axis timeline. Doesn't correspond the what I found.

 

[sar104]

Thanks, sar104. As I said, I'm not an expert. I was confused, though, at your x-axis timeline. Doesn't correspond the what I found.

My time axis is directly from the log file interpreted by PhantomHelp, which uses the start of the log as time zero. There should be no ambiguity in those logs, unlike the DAT files that can have various time offsets. What did not correspond? And clearly the mobile device was connected and working right up to the end of the log, since it is the source of the log.

 

[scjerry]

Sorry I misread the time scale. Collision was about 765-770 seconds or 12.888 minutes. My error.

 

[scjerry]

Just a nit, but Motor Turn-on seems to be a good standard for time-zero. This is not the case for .txt to .csv conversions by ferarript, but is the case for PhantomHelp. See How to retrieve a V3 .DAT File

 

[SGM]

scjerry and sar104,

I thank you for the assistance and interpretations of the logs and while there seems to be good dialog and cross-talk about log interpretation, it is what it is at this point, whether pilot error, GPS/compass or a combination of all? For me and I hope for everyone else whether they have been flying 2 weeks or 2 years (I have built quite a few perfect hours without mishap) - the take-away
is a mishap whether minor or catastrophic can happen when you least expect it and possibly your attention is taken away for just a moment. BL- NO ONE is perfect or the pilot extraordinaire, for me anyway and all of my bragging to my wife about how I am so much more careful than others who have crashed, simply proves my point - it can happen.

Pre-checks/site checks/calibrations/focus....or...another $750-$1000.
To answer your Q: No, I don't have DJI Refresh and no there wasn't any interference I could note.

Thanks again both of you!
Good flying

 

[Hollow Dog]

scjerry and sar104,

I thank you for the assistance and interpretations of the logs and while there seems to be good dialog and cross-talk about log interpretation, it is what it is at this point, whether pilot error, GPS/compass or a combination of all? For me and I hope for everyone else whether they have been flying 2 weeks or 2 years (I have built quite a few perfect hours without mishap) - the take-away
is a mishap whether minor or catastrophic can happen when you least expect it and possibly your attention is taken away for just a moment. BL- NO ONE is perfect or the pilot extraordinaire, for me anyway and all of my bragging to my wife about how I am so much more careful than others who have crashed, simply proves my point - it can happen.

Pre-checks/site checks/calibrations/focus....or...another $750-$1000.
To answer your Q: No, I don't have DJI Refresh and no there wasn't any interference I could note.

Thanks again both of you!
Good flying

Yeah what you said