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Crash! - Flight Data Analysis service worthwhile?
1551 10 2019-6-19
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RocketChap
Second Officer
Flight distance : 902034 ft
United Kingdom
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My Mavic Pro crashed recently – went out of control, full speed into some trees.  It wouldn't respond to controls or stop button.   

Its out of warrantee and DJI want 240 Euro to fix it.  I'm pretty miffed as I don't see the crash as my fault.  DJI do offer a flight data analysis service – if I take it up and the A/C is at fault will it make any difference to the repair cost?

Here is the flight log:


The Mavic flew into the wind so it wasn't just blown into the trees (wind was coming from the South West).  There was P4 in the air at the same location at the same time with no problems.

2019-6-19
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JJB*
Captain
Flight distance : 9917238 ft
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Netherlands
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Hi RocketChap,

During takeoff you had warning #1 on the screen ; Strong interference, Fly with Caution'
At 18 seconds in flight Magnetic field Interference, Exit P-GPS warning ; 10 seconds flying in ATTI mode.

Why did you not stop this flight??

A lot of Yaw, Compass, Speed and Gps position errors in flight, so no wonder it was not under control by you. Drone started to live his own life at the end....not controllable.

I would do the repair for 240 euro. Mayby not your fault (why so many errors) but the crash would not have taken place if you did not ignore the warnings. If a drone gets into ATTI > land it ASAP or if possible fly her back (only when you can do that in a controlled safe way)

Few times High Wind Warning, really weird when hovering steady with <= 5 degrees of pitch and roll.


cheers
JJB


Cheers
JJB
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2019-6-19
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RocketChap
Second Officer
Flight distance : 902034 ft
United Kingdom
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The Strong interference at 2 seconds was almost certainly the P4 taking off at the same time - I expected it and it disappeared almost immediately.
I wasn't aware of the 10 seconds of ATTI mode as I flying the drone visually and it was going where I wanted - when I looked at the controller it was in GPS.
By the later compass and speed errors its all too late - its not responding to control.   Clearly the drone is not trying to hover as its accelerating into the wind - its got a mind of its own at that point.

2019-6-19
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Dean01
Captain
Flight distance : 15513100 ft
South Africa
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Hi rocketchap...sorry to hear about yr crash..wish i could say differnently (cause if it is dji fault i am sure they would see you right) but seems to me that pilot error casued this crash.
I agree with cpt JJB assesment.
my additional views are: whist you were being blown backwards into the shrubs there was no stick input from you - just before the drone hit the tree line you made some red zone stick input (extreme up and forward at the same time) however this was too little too late - yet somehow your drone made it through the tree line and came out the other side alive.
Yet during this excursion under the trees satelite conection was lost and if you had stayed out in the open field on the other side within due course reconnections would be made and the drone may have become stable again (i say 'may" because lost of satelites was not your only problem.
However instead of staying out in the open field you then made red zone stick input which indicate that you flew forward into the tree line (red stick) and then red stick raised altitude - judging from the height data it appears to me that you flew up and got snagged in the branches.
which i had better news and would not mind being wrong but thats the way i see it.
2019-6-19
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AntDX316
Captain
Flight distance : 3327126 ft
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United States
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You must be flying over a geographic fault line or something.  Maybe directly in between a strong Military wave band.  There are a lot of things we do not see or know about their existence that severely affect our flying.  Maybe the moon is beaming stuff directly to Earth where you are.  With life, I find whether we know or not may make Zero change in what goes on.  That is considering your life is mostly technology-oriented instead of social-oriented that if you don't know how to use Facebook, it's ok.  Just think about all the motorcyclists who have crashed hard because they don't know how to ride.  It's like the same thing it's just one is seen more seriously than the other.
2019-6-19
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SD_Pilot
Captain
Flight distance : 10278435 ft
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United States
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As JB stated, here you're answer.

"During takeoff you had warning #1 on the screen ; Strong interference, Fly with Caution'
At 18 seconds in flight Magnetic field Interference, Exit P-GPS warning ; 10 seconds flying in ATTI mode."





That spells disaster. When confronted with WARNINGS like those, best advice MOVE!  go somewhere else with out mag inter and wait until all is clear with ready to fly and DO NOT fly in atti mode.

2019-6-20
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JJB*
Captain
Flight distance : 9917238 ft
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Netherlands
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RocketChap Posted at 6-19 08:18
The Strong interference at 2 seconds was almost certainly the P4 taking off at the same time - I expected it and it disappeared almost immediately.
I wasn't aware of the 10 seconds of ATTI mode as I flying the drone visually and it was going where I wanted - when I looked at the controller it was in GPS.
By the later compass and speed errors its all too late - its not responding to control.   Clearly the drone is not trying to hover as its accelerating into the wind - its got a mind of its own at that point.

oke, strong interference cause by P4.

But after 18.4 secs Magn Field Interference, into ATTI. (audio warning ATTI, guess your volume was down)

During your take-off you already pushed the stick forward....

I know, its easy to give comments but there is a better way to start a flight.

Take-off into hover,
Yaw left 360,
Yaw right 360,
Pitch fwd and aft,
Roll left and right,
Back to hover
Check red arrow in compass if aligned with reality,

if all OK, start to fly.  takes few secs and "saves" drones!

cheers
JJB

2019-6-20
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DJI Diana
Administrator
Flight distance : 2408 ft

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Hi, sorry to read the frustrations and issues you had with your repair case. Allow me to forward this with the designated team for further assistance. You will surely be notified for the updates as I have managed to pull up your case using your Forum account. We appreciate your patience. Thank you.
2019-6-21
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RocketChap
Second Officer
Flight distance : 902034 ft
United Kingdom
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DJI Diana Posted at 6-21 11:50
Hi, sorry to read the frustrations and issues you had with your repair case. Allow me to forward this with the designated team for further assistance. You will surely be notified for the updates as I have managed to pull up your case using your Forum account. We appreciate your patience. Thank you.

Thanks - please do forward as I have had no response to my email questions to the repair team
2019-6-23
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RocketChap
Second Officer
Flight distance : 902034 ft
United Kingdom
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JJB* Posted at 6-20 05:07
oke, strong interference cause by P4.

But after 18.4 secs Magn Field Interference, into ATTI. (audio warning ATTI, guess your volume was down)

Yeah agreed there are probably better ways to fly - IIRC I was flying away from some approaching dog walkers - I should have probably waited a few minutes to let them pass before taking off.  I suspect I was oblivious to a waning as 1) I was probably more concerned in putting some distance to the dog walkers and 2) I was expecting a wind warning as it was a little windy and the Mavic wind warns for a sneeze.
2019-6-23
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DJI Diana
Administrator
Flight distance : 2408 ft

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RocketChap Posted at 6-23 03:03
Thanks - please do forward as I have had no response to my email questions to the repair team

Hi, thanks for the reply. This case has been forwarded to the management to further check. They will review your case and contact you during working time. Appreciate your support and understanding.
2019-6-23
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