Brutal crash, need help figure out what went wrong.

[Bjorn Jarnankar]

After a 10 minute flight i was about to land my bird and let it hover a while in the air (1.5 m above ground roughly). A little later it started drifting a bit, and I thought it was odd considering wind wasn't very strong. I looked briefly on the controller and when I looked up again it was drifting rather quick and crashed into a garage door.

Gimbal ribbon snapped off and 3 props destroyed. Also som scratches here and there.

Overall software status says:
• Gimbal gyroscope error
• Hardware Malfunction . Contact DJI Support for repairs
• Aircraft Motor Overloaded. Check wether gimbal clamp is removed.
• Gimbal is restarting. Check that the gimbal rotates smoothly if restarts fails again.

Now I have 2 questions:
1) What data can I extract (and how) to better understand what happened?
2) Anyone have a gut feeling if this is even worth repairing or if it will cost as much as a new one?

Any help most appreciated.
I'm in deep mourning.

/Björn

 

[Cyberpower678]

After a 10 minute flight i was about to land my bird and let it hover a while in the air (1.5 m above ground roughly). A little later it started drifting a bit, and I thought it was odd considering wind wasn't very strong. I looked briefly on the controller and when I looked up again it was drifting rather quick and crashed into a garage door.

Gimbal ribbon snapped off and 3 props destroyed. Also som scratches here and there.

Overall software status says:
• Gimbal gyroscope error
• Hardware Malfunction . Contact DJI Support for repairs
• Aircraft Motor Overloaded. Check wether gimbal clamp is removed.
• Gimbal is restarting. Check that the gimbal rotates smoothly if restarts fails again.

Now I have 2 questions:
1) What data can I extract (and how) to better understand what happened?
2) Anyone have a gut feeling if this is even worth repairing or if it will cost as much as a new one?

Any help most appreciated.
I'm in deep mourning.

/Björn

If you have DJI scare Refresh, now is the time to use it. To answer your questions I would like to see the DAT and TXT file of the flight.

How to retrieve a .DAT

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

 

[Bjorn Jarnankar]

Thank you for your pointers.

I have no care insurance I'm afraid, didn't know it existed until after crash. I'm assuming DJI is very restrictive with (free) repairs?

Flight record TXT:
DJIFlightRecord_2017-05-13_[16-19-00].txt or Phantom Log Viewer - PhantomHelp.com

Flight replay (video recording of app replay):
Flight movie 480p.mov

Not sure which .dat-file is correct but should be one of these i guess:
DJI_ASSISTANT_EXPORT_FILE_2017-05-15_12-18-43.DAT

From what I can see it's due to sudden compass error.

 

[Cyberpower678]

Downloading them now.

 

[Davzone]

The log is full of compass error and yaw error. I'm interested in what a yaw error is? Is that another way to say compass error? Like the drone can't yaw because it has no compass reading what so ever?
It wasn't really sudden, you had it 7 minutes into the flight at 280ft high that lasted a few seconds.

The last 25 seconds were constant compass error. Did you have anything close by? Metal man hole cover or electric box? Electric wire overhanging? Active track was also turned on in the weirdest places. Looks like a busy city area from the map.

Anything attached to the drone? Light,led,tracker?

 

[Cyberpower678]

Reading magnetic interference the moment your GPS momentarily dipped and has been struggling to maintain a good lock. Your compass wigged out.

 

[Cyberpower678]

BTW, you uploaded the wrong DAT file. The TXT and phantom log viewer gave me some info, but the DATs have all of the info. The one you uploaded has no flight on it. With a flight that long, it would be probably split into 2 files the first one being 400MB.

 

[Bjorn Jarnankar]

The log is full of compass error and yaw error. I'm interested in what a yaw error is? Is that another way to say compass error? Like the drone can't yaw because it has no compass reading what so ever?
It wasn't really sudden, you had it 7 minutes into the flight at 280ft high that lasted a few seconds.

The last 25 seconds were constant compass error. Did you have anything close by? Metal man hole cover or electric box? Electric wire overhanging? Active track was also turned on in the weirdest places. Looks like a busy city area from the map.

Anything attached to the drone? Light,led,tracker?

Watching the log, it wasn't sudden. But these kinds of warnings doesn't show on the iPhone's display right? In any even't, it felt sudden to me since from start to slightly drift into impact only took 3 seconds.

Location is suburban and take off point had no electric wire overhanging. I didn't spot anything that could interfere. The bird had no special set up, no extras attached.

Active track was me trying to track my family standing on the balcony and then just back away/elevate and keep camera fixed on the family. Didn't work out that great so I gave up that idea ... probably a dumb spot to try that.

 

[Bjorn Jarnankar]

Reading magnetic interference the moment your GPS momentarily dipped and has been struggling to maintain a good lock. Your compass wigged out.

OK. Is that, from a DJI-perspective, pilot error? Not that keen on paying a full 1000 dollars for a new one.

 

[Bjorn Jarnankar]

BTW, you uploaded the wrong DAT file. The TXT and phantom log viewer gave me some info, but the DATs have all of the info. The one you uploaded has no flight on it. With a flight that long, it would be probably split into 2 files the first one being 400MB.

From what I can tell there's only one entry from the specific time. However, I've extracted a data-file from that time that is 360mb, so that might be the one.

DJI_ASSISTANT_EXPORT_FILE_2017-05-15_12-18-43.DAT

 

[Cyberpower678]

OK. Is that, from a DJI-perspective, pilot error? Not that keen on paying a full 1000 dollars for a new one.

From what I can tell there's only one entry from the specific time. However, I've extracted a data-file from that time that is 360mb, so that might be the one.

DJI_ASSISTANT_EXPORT_FILE_2017-05-15_12-18-43.DAT

I'll take a look at that to see if I can see more revealing information.

 

[Bjorn Jarnankar]

I'll take a look at that to see if I can see more revealing information.

Thank you so much for all your help so far!

 

[BudWalker]

From what I can tell there's only one entry from the specific time. However, I've extracted a data-file from that time that is 360mb, so that might be the one.

DJI_ASSISTANT_EXPORT_FILE_2017-05-15_12-18-43.DAT

Very interesting. In many respects, this incident is the exact opposite of a launch-from-geomagnetically-distorted-site incident. If the Mavic had been launched from the landing site it would have been a launch-from-geomagnetically-distorted-site incident.

The Mavic had returned and was hovering at 1.5 meters in a location that was geomagnetically distorted. (over a manhole cover, metal picnic table, etc.?). The result was magYaw separated from Yaw. But, unlike the launch-from-geomagnetically-distorted-site situation Yaw is correct and magYaw is incorrect.

If the flight were to end here (at time 659) there would have been no incident to report. But, since there is a Yaw/magYaw separation the Mavic starts rotating (at time 671) to reconcile the separation. This can be seen by looking at totalGyroZ.

As a result Yaw then becomes incorrect resulting in a confused Flight Controller and erratic flight.

The is not pilot error. This is a DJI error. The Mavic should have switched to ATTI mode but did not. Note, that a compass error was indicated, as it should be. How hard can it be to change the Flight Controller to switch to ATTI mode when a compass error is detected?

 

[Cyberpower678]

Thank you so much for all your help so far!

@BudWalker beat me to it. I also think this is not pilot error.

 

[Bjorn Jarnankar]

I'm forever grateful for your effort. This is giving me some hope, I'm assuming the next step is contacting DJI.

Out of curiosity, would it be worth if to repair this drone in case DJI somehow finds a way to not be held
accountable?

 

[Cyberpower678]

I'm forever grateful for your effort. This is giving me some hope, I'm assuming the next step is contacting DJI.

Out of curiosity, would it be worth if to repair this drone in case DJI somehow finds a way to not be held
accountable?

Upload a picture, and I can tell you.

 

[Bjorn Jarnankar]

Upload a picture, and I can tell you.

Here's a full description of hardware and software status. Am I correct to assume the gimbal ribbon is for vision of the camera and the metal wires for controlling it? My guess would be that sending to DJI the would change entire gimbal (300 dollars?) and also it possibly needs repair to the motor arms? I'm not sure how sensitive they are to scratches and bumbs ...

Description of physical damage
• Gimbal ribbon snapped off and two rubber band straps dislocated.
• 3 props destroyed.
• Cosmetic scratches on the battery
• Cosmetic scratches on the “nose”
• Scratches on 2 of the propeller holders (motor?)



This is the worst damaged of them.





Gimbal ribbon (?) snapped off?




Description of software damage
• No camera feed at all (all black)

Overall software status says:

• Gimbal gyroscope error
• Hardware Malfunction . Contact DJI Support for repairs
• Aircraft Motor Overloaded. Check wether gimbal clamp is removed.
• Gimbal is restarting. Check that the gimbal rotates smoothly if restarts fails again.

 

[Cyberpower678]

Here's a full description of hardware and software status. Am I correct to assume the gimbal ribbon is for vision of the camera and the metal wires for controlling it? My guess would be that sending to DJI the would change entire gimbal (300 dollars?) and also it possibly needs repair to the motor arms? I'm not sure how sensitive they are to scratches and bumbs ...

Description of physical damage
• Gimbal ribbon snapped off and two rubber band straps dislocated.
• 3 props destroyed.
• Cosmetic scratches on the battery
• Cosmetic scratches on the “nose”
• Scratches on 2 of the propeller holders (motor?)


View attachment 12909
This is the worst damaged of them.




View attachment 12908
Gimbal ribbon (?) snapped off?




Description of software damage
• No camera feed at all (all black)

Overall software status says:

• Gimbal gyroscope error
• Hardware Malfunction . Contact DJI Support for repairs
• Aircraft Motor Overloaded. Check wether gimbal clamp is removed.
• Gimbal is restarting. Check that the gimbal rotates smoothly if restarts fails again.

View attachment 12910

It looks like the gimbal is broken and those run up to $300 to replace. @Thunderdrones may be able to help.

 

[Davzone]

The black cable is gimbal control. Silver is video. If the silver is fine than make sure it stays like that. Silver is expensive and hard to find.
Black is much easier. No video is not a good sign. The silver cable looks ok but it might be damaged at the connector side.
The rubber feet is like $3. And the little L shaped holder is not broken so you could put the gimbal back for storage.

Contact DJI. They replaced drones for free when it was not pilot error.
They will need the same files. Make sure to upload the log in the djigo app to the cloud under your account. Save the DAT file. DO not power up the drone too many times because it will overwrite the dat files. Save them now.

 

[Bjorn Jarnankar]

It looks like the gimbal is broken and those run up to $300 to replace. @Thunderdrones may be able to help.

Mhm. I know it's pure guessing but I believe your guessing would be better than mine. How likely is it that it also need repairs/changing of the motors?