Lost Mavic

Meta4

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#3
Hi lost mavic today don't really know how to share flight log or healthydrones data
Healthydrones is the old name for Airdata. They are the same thing and neither is particularly useful for most incident investigations.
The preferred way to share flight data is to go to DJI Flight Log Viewer
Follow the instructions there to upload your flight record from your phone or tablet.
Come back and post a link to the report it provides.

However for this case, the cause is obvious without seeing proper flight data.
The flight was doomed because the compass has been screwed up, probably from launching on a steel or reinforced concrete surface.
 
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#5
Healthydrones is the old name for Airdata. They are the same thing and neither is particularly useful for most incident investigations.
The preferred way to share flight data is to go to DJI Flight Log Viewer
Follow the instructions there to upload your flight record from your phone or tablet.
Come back and post a link to the report it provides.

However for this case, the cause is obvious without seeing proper flight data.
The flight was doomed because the compass has been screwed up, probably from launching on a steel or reinforced concrete surface.
Thanks for the info will have a go later today when i finish work it was a proper school boy error on my part
 
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#7
As @Meta4 said, it clearly went into ATTI mode due to serious compass errors, possibly due to the takeoff location have magnetic interference. The good news is that the resulting drift was very consistent in speed and direction, and so it should have kept going until critical battery level initiated autolanding. Estimating by linear regression and extrapolation we get:

DJIFlightRecord_2017-12-18_[15-26-04]_01.png


That suggests it would have drifted out to around 2160 m from the home point. Plotting on GE:

DJIFlightRecord_2017-12-18_[15-26-04].jpg


I'd start looking around there. For what it's worth, error analysis at the 99% confidence level suggests a circle of radius 150 m, but that includes extrapolation assumptions regarding wind speed, direction, power use and autolanding battery level, so not to be taken as definitive. And if it autolanded at 10% instead of 15%, then that would put it around 2600 m and in the field the other side of the railway line.
 
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#9
To all,
and Wow

Since I'm not smart enough to view the remote control stick postions, did you or did he have any control or could have with this many errors.

In other words he should still been able to control it in ATTi mode?

Rod
 
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#10
As @Meta4 said, it clearly went into ATTI mode due to serious compass errors, possibly due to the takeoff location have magnetic interference. The good news is that the resulting drift was very consistent in speed and direction, and so it should have kept going until critical battery level initiated autolanding. Estimating by linear regression and extrapolation we get:

View attachment 92344

That suggests it would have drifted out to around 2160 m from the home point. Plotting on GE:

View attachment 92345

I'd start looking around there. For what it's worth, error analysis at the 99% confidence level suggests a circle of radius 150 m, but that includes extrapolation assumptions regarding wind speed, direction, power use and autolanding battery level, so not to be taken as definitive. And if it autolanded at 10% instead of 15%, then that would put it around 2600 m and in the field the other side of the railway line.
Great thanks for the info will do a recon of that area and keep you posted
 
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#11
To all,
and Wow

Since I'm not smart enough to view the remote control stick postions, did you or did he have any control or could have with this many errors.

In other words he should still been able to control it in ATTi mode?

Rod
Until the uplink was lost he would have had control, but for the latter part of the flight he did not provide any stick input.

DJIFlightRecord_2017-12-18_[15-26-04]_03.png
 
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#12
To all,
and Wow

Since I'm not smart enough to view the remote control stick postions, did you or did he have any control or could have with this many errors.

In other words he should still been able to control it in ATTi mode?

Rod
Flown from that location with my phantom advanced on many times first time with the mavic like i said earlier school boy error lots of compass errors to busy looking at tablet trying to figure out what was going on then looked up and gone lesson learned !
 
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#14
Sorry for your loss and I hope with the help provided you are able to locate it.

On another note, there seems to be missing comments in this thread (or at least for me). So, I must admit, I had to read between the lines to what comments that I am able to read. Is this isolated to me or true to others as well?
 
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#15
Sorry for your loss and I hope with the help provided you are able to locate it.

On another note, there seems to be missing comments in this thread (or at least for me). So, I must admit, I had to read between the lines to what comments that I am able to read. Is this isolated to me or true to others as well?
Where did you get lost?

Had you clicked on the links that were posted, like the first one?
Airdata UAV - Flight Data Analysis for Drones

Rod
 
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#17
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