Yesterday my Mini 2 decided to do a flyaway. It was bizarre; as soon as I selected Dronie (selected the mode, I'd yet to select a subject or anything, it was as soon as I selected the mode) from the quick mode it took off at full speed away from me. It hit a tree and fell 125 feet into a river. Miraculously I recovered the drone and it turns on but seems to not be functional anymore (gimbal and IMU errors).

According to the flight log it reached 19.3 m/s before hitting the trees, despite the fact that it was in Normal mode so it should've peaked around 10. I had zero control over the drone when it flew away. As it's 3 weeks out of warranty, DJI says they're not going to even analyze the log file, which is frustrating. I get (although disagree with) them not replacing the unit despite it 100% being an issue on their end, but the fact they won't even look at the log to try to make sure this kind of stuff doesn't happen is very frustrating.

Post the flight log here. There are some people here that are very good at reading and analyzing flight logs, they might tell you what happened.

ArcticPhoto Posted at 10-29 04:50
Post the flight log here. There are some people here that are very good at reading and analyzing flight logs, they might tell you what happened.

I've not found a way to export it from the DJI Fly app. I tried installing the SJI Assistant and connecting the drone but my computer doesn't seem to see the drone now.

If you go to the webpage https://www.phantomhelp.com/logviewer/upload/
there are instruction there for retrieving the log.
Upload the log to that webpage and then post the URL here.


I normally copy or move the logs to computer and external hard drive. If you do that I would suggest you also copy or move the DAT logs to the computer, if they are still on your phone, so that you have a copy of them, you can not actually do anything with the DATS. The DATs, if they still exist will be in a folder, named MCDAT....something or other, in the folder where you found the flight logs.

djiuser_MDEw2zzqfD3G Posted at 10-29 05:07
I've not found a way to export it from the DJI Fly app. I tried installing the SJI Assistant and connecting the drone but my computer doesn't seem to see the drone now.

Hopefully DJI Fly haven't had time to sync your logs with the cloud and delete them from your phone.
Check the section Locating your Logs on PhantomHelp Log Viewer upload them to the website and share the link here.

Alternatively if you have Airdata already on your device, you can also share it that way.

Yaros1 Posted at 10-29 06:57
Hopefully DJI Fly haven't had time to sync your logs with the cloud and delete them from your phone.

Yaros, syncing deletes, or perhaps moves to the cloud?, ONLY the DAT's. It does not delete the logs we want i.e. the .txt logs, it COPIES them from the 'phone' to the cloud.
From our, the pilot's, perspective, sync'ing's purpose is to create a backup of the .txt flightlogs, in fact if a log that has been synced is deleted from the 'phone' I think you will find that the next sync will copy that log from DJI TO THE PHONE.


The loss of the DAT's has no real consequence for a Mini 2 user because ONLY DJI can read them.
I suggested, in post 4, that, if they are still on the phone, it would be useful to copy them to external memory because, it seems that sometime DJI can not access a DAT that may have been uploaded to the cloud and sometimes DJI ask for them. In such circumstances it would be convenient if they were available from an external back up in the pilot's control.

Sean-bumble-bee Posted at 10-29 08:23
Yaros, syncing deletes, or perhaps moves to the cloud?, ONLY the DAT's. It does not delete the logs we want i.e. the .txt logs, it COPIES them from the 'phone' to the cloud.
From our, the pilot's, perspective, sync'ing's purpose is to create a backup of the .txt flightlogs, in fact if a log that has been synced is deleted from the 'phone' I think you will find that the next sync will copy that log from DJI TO THE PHONE.

I do think that it deletes the TXT and DAT files, if syncing is enabled in DJI Fly settings.
I don't know how it is in the mini 2, but I use an Air 2 and the DAT logs from the phone are readable by Airdata and other programs, but the DAT files from the drone itself are not.

Hi, djiuser_MDEw2zzqfD3G. Thank you for reaching out and we're deeply sorry for the incident that happened. Here's the information for Exporting Flight Records:
Android device:
Connect the mobile device that has been connected to the aircraft to the PC, the path is as follows: internal storage/android/data/dji.go.v5/files/FlightRecord (The path of the version before DJI Fly App V1.4.12 is DJI>dji.go.v5>FlightRecord), and then export the "flightrecord" folder.

iOS device:
Connect the mobile device that has been connected to the aircraft to the PC, open iTunes, and then export all data under the "flightrecord" folder.

I am sorry that your drone is beyond the warranty period, please note that free data analysis may not be supported in this situation. If a data analysis has to be applied, we can provide a paid data analysis, which may cause $65, and the data analysis result will not affect the service solution, you may still need to pay for the service of the drone. Hope for your kind understanding.

In your case, you can send the drone back to our service center, we will provide you with a corresponding solution based on the assessment.
Please start a case here: https://www.dji.com/support/repair

Syncing does not delete anything unless done with Assistant 2.

DJI Gamora Posted at 10-29 10:24
Hi, djiuser_MDEw2zzqfD3G. Thank you for reaching out and we're deeply sorry for the incident that happened. Here's the information for Exporting Flight Records:
Android device:
Connect the mobile device that has been connected to the aircraft to the PC, the path is as follows: internal storage/android/data/dji.go.v5/files/FlightRecord (The path of the version before DJI Fly App V1.4.12 is DJI>dji.go.v5>FlightRecord), and then export the "flightrecord" folder.

Thanks for the help finding the log file. I attempted to open a ticket as I mentioned in the OP. What I find frustrating is the lack of interest from DJI in even looking into what bugs might cause this type of thing so I can have some feeling that it won't just happen again.

I can't seem to upload the log here, so here is a Google Drive link to it: https://drive.google.com/file/d/1CVYkyv9rZ9mkqVMufsX6jultme9RwfWC/view?usp=share_link

I uploaded it to Phantom Help. https://www.phantomhelp.com/logviewer/9UJPUNVPS5GUTDFGE238/

It's interesting how you can see that I wasn't even touching the controls when it took off. And then when I noticed and tried to stop it, there was absolutely no response from the drone. But there were also no error messages until it hit the trees.
Also either a logging error or insane that it hit 58 mph when its top speed should be 36.

Looking at the Phantomhelp page  the drone took off at a road junction. In the first 70 or so seconds is the direction that the drone was facing ( red arrow) correct?

Sean-bumble-bee Posted at 10-29 12:35
Looking at the Phantomhelp page  the drone took off at a road junction. In the first 70 or so seconds is the direction that the drone was facing ( red arrow) correct?

Yes the direction is correct until the time it appears to take off. As I was looking down at my phone to setup a quick shot I'm unsure if it actually did turn as it appeared in the log file or not.

Going by the Phantomhelp (PH) replay I was curious about the very sudden turn in the mid 70sec but I now see that the time intervals between the individual lines of the PH replay are quite coarse at that point, making the turn seem sudden. I was wondering if there was a compass error but now doubt that is correct.
However, in the csv, around 157sec, 2m 37sec, something strange happens to what I understand to be the drone's direction indicators, OSD.Yaw & OSD.Yaw [360], they jump by -172° & 187° respectively in 1/10th of a sec, with, as far as I can see, no rudder input
Hopefully  JJB or Labroides will be along shortly and have a look at the log, I wouldn't mind knowing if there is an explanation for the jump in the yaw readings.

Sean-bumble-bee Posted at 10-29 13:28
Going by the Phantomhelp (PH) replay I was curious about the very sudden turn in the mid 70sec but I now see that the time intervals between the individual lines of the PH replay are quite coarse at that point, making the turn seem sudden. I was wondering if there was a compass error but now doubt that is correct.
However, in the csv, around 157sec, 2m 37sec, something strange happens to what I understand to be the drone's direction indicators, OSD.Yaw & OSD.Yaw [360], they jump by -172° & 187° respectively in 1/10th of a sec, with, as far as I can see, no rudder input
Hopefully  JJB or Labroides will be along shortly and have a look at the log, I wouldn't mind knowing if there is an explanation for the jump in the yaw readings.

That actually matches what I observed. The drone suddenly was at a very steep angle towards it's rear left (from my viewpoint). Like the steepness of when you go full stop from sport mode.

djiuser_MDEw2zzqfD3G Posted at 10-29 13:35
That actually matches what I observed. The drone suddenly was at a very steep angle towards it's rear left (from my viewpoint). Like the steepness of when you go full stop from sport mode.

Yaw/turning would not, or should not, produce tilt.
Yaw on its own will merely turn the drone with the drone remaining horizontal/flat.
Flying forwards/backwards and or sideways or braking or fighting wind will introduce visible tilt of the drone.

When the drone was flying along/across that valley, (away from the bridge) was its nose 'sort of'/actually pointing towards the west? I.e does the PH map show the way it was facing correctly?

Sean-bumble-bee Posted at 10-29 12:35
Looking at the Phantomhelp page  the drone took off at a road junction. In the first 70 or so seconds is the direction that the drone was facing ( red arrow) correct?

The compass heading data shows that the cause of your incident was a small yaw error.
It shows up as you climb from the launch point.
As the drone goes higher than 3 metres just 3.4 seconds into the flight, the compass heading starts to swing from 115° to 99° without any rudder input.
For the rest of the flight, your drone was not able to hover in place and was always flying slowly.

At 2:37.1 the small yaw error became a big yaw error and teh heading data djumps from 66° to 253.7° and just a second later the drone is off chasing itself because of the conflicting directional data it is receiving.

A simple yaw error is the result of launching from somewhere with magnetic interference deflecting the compass to give false heading data.
The false data was used for the initial directional values for the IMU.
When you climbed away from the magnetic interference the compass returned to normal, but the IMU's gyro sensor continued giving false directional data.
The conflicting data from the compass and IMU caused the first small yaw error.
But the increase in the error at 2:37.1 is unusual.

Did you have any accessory fitted to the drone?
What was the surface you launched from?

2:37 would have had the drone very close to steel suspension bridge, if the link works. https://www.google.co.uk/maps/@10.3666743,-84.5948067,3a,75y,182.4h,69.81t/data=!3m8!1e1!3m6!1sAF1QipNfjcukTFz-iCd1StCAB2dnW2H4HEjD8FMdLLnl!2e10!3e11!6shttps:%2F%2Flh5.googleusercontent.com%2Fp%2FAF1QipNfjcukTFz-iCd1StCAB2dnW2H4HEjD8FMdLLnl%3Dw203-h100-k-no-pi-0-ya250.92252-ro0-fo100!7i8704!8i4352

Could that be the cause of the increased error? .... If so would it have a lasting effect?There's a separate steel footpath to the right, west, of the bridge if you look at the images on google's street view.

Labroides Posted at 10-29 14:44
The compass heading data shows that the cause of your incident was a small yaw error.
It shows up as you climb from the launch point.
As the drone goes higher than 3 metres just 3.4 seconds into the flight, the compass heading starts to swing from 115° to 99° without any rudder input.

Fantastic analysis. I launched it from the roof of my car (thus the source of magnetic interference), although I hadn't received any compass calibration error messages from the drone.

I am not sure what direction it was pointed because I was first talking to someone next to me to get them in position for the shot and the quick menu was overlying the camera. Then I was toggling the quick mode and just as I did that I noticed it was off at full tilt and so my first instinct was to tell it to do the opposite of what it was doing (it was dropping and going backwards relative to where it was facing last time I saw it) but it was already out a ways so I'm not 100% sure if it physically rotated or not, but I don't think it did.
EDIT: No accessories were attached either.

Sean-bumble-bee Posted at 10-29 15:04
2:37 would have had the drone very close to steel suspension bridge, if the link works. https://www.google.co.uk/maps/@10.3666743,-84.5948067,3a,75y,182.4h,69.81t/data=!3m8!1e1!3m6!1sAF1QipNfjcukTFz-iCd1StCAB2dnW2H4HEjD8FMdLLnl!2e10!3e11!6shttps:%2F%2Flh5.googleusercontent.com%2Fp%2FAF1QipNfjcukTFz-iCd1StCAB2dnW2H4HEjD8FMdLLnl%3Dw203-h100-k-no-pi-0-ya250.92252-ro0-fo100!7i8704!8i4352

Could that be the cause of the increased error? .... If so would it have a lasting effect?There's a separate steel footpath to the right, west, of the bridge if you look at the images on google's street view.

Yes I was rather close to the bridge as I was lining up a shot standing on that walkway. Although I'd flown both a Mini1 and 2 and my dad a Pro2 at that exact spot before without issues.

djiuser_MDEw2zzqfD3G Posted at 10-29 15:10
Fantastic analysis. I launched it from the roof of my car (thus the source of magnetic interference), although I hadn't received any compass calibration error messages from the drone.

I am not sure what direction it was pointed because I was first talking to someone next to me to get them in position for the shot and the quick menu was overlying the camera. Then I was toggling the quick mode and just as I did that I noticed it was off at full tilt and so my first instinct was to tell it to do the opposite of what it was doing (it was dropping and going backwards relative to where it was facing last time I saw it) but it was already out a ways so I'm not 100% sure if it physically rotated or not, but I don't think it did.

I launched it from the roof of my car (thus the source of magnetic interference), although I hadn't received any compass calibration error messages from the drone.
Launching from close to steel objects is something you should never do.
If the magnetic interference is very strong, you get a warning.
The big problem is when the strenght of the magnetic field is not strong enough to trigger a compass error, but it is enough to deflect the compass.
The compass error message is badly worded to suggest you should re-calibrate the compass.
But there's nothing wrong with the compass and recalibrating won't solve the problem..

I was rather close to the bridge as I was lining up a shot standing on that walkway.
Flying close to a steel bridge doesn't cause yaw errors.
Starting up with false compass data that is used by the gyro sensor is what causes a yaw error.
Why your small yaw error jumped to become a big yaw error is puzzling.

Labroides Posted at 10-29 15:23
I launched it from the roof of my car (thus the source of magnetic interference), although I hadn't received any compass calibration error messages from the drone.
Launching from close to steel objects is something you should never do.
If the magnetic interference is very strong, you get a warning.

Good to know about the car. I often have used the roof as a convenient launching point. Lesson learned for the future there.

Sean-bumble-bee Posted at 10-29 15:04
2:37 would have had the drone very close to steel suspension bridge, if the link works. https://www.google.co.uk/maps/@10.3666743,-84.5948067,3a,75y,182.4h,69.81t/data=!3m8!1e1!3m6!1sAF1QipNfjcukTFz-iCd1StCAB2dnW2H4HEjD8FMdLLnl!2e10!3e11!6shttps:%2F%2Flh5.googleusercontent.com%2Fp%2FAF1QipNfjcukTFz-iCd1StCAB2dnW2H4HEjD8FMdLLnl%3Dw203-h100-k-no-pi-0-ya250.92252-ro0-fo100!7i8704!8i4352

Could that be the cause of the increased error? .... If so would it have a lasting effect?There's a separate steel footpath to the right, west, of the bridge if you look at the images on google's street view.

At worst, flying close to a steel bridge might cause a little wobbling/wandering.
But the drone would have to be closer than 2 metres from the steel.
And the issue would completely go away when the drone moves away from the steel.

I have had many a conversation re taking off from cars (I learnt from experience) and the repercussions from doing so and the other parties claim that its always been ok with their Mini 2, i also stated that just because its been ok in the past it does not mean it will be ok in the future and had i been stood in front of them during these conversations, I'm sure i would have been met with a blank stare lol, anyway this thread puts an emphasis on that.

I will concede though that i think this is the 1st car issue that I have come across with the Mini 2 as i believe that they are more forgiving than previous DJI models, so i suspect that the OP turned on the drone too close to the car and/or put it on the roof before it finished its initialising.

Having seen the google street view of the area, its not really the most ideal take-off spot either what with the bridge, the barriers and the possible rebar in the road itself. Too close to either would have probably met with a similar outcome.

Another point, don't turn it on again until its 100% fully dried, the components inside will take much longer to dry, do not use the battery that got wet either, that's dead to you now and should be binned as it can never be trusted again, 50 for a new one is better than a smashed or fried drone.

Bashy Posted at 10-29 19:16
I have had many a conversation re taking off from cars (I learnt from experience) and the repercussions from doing so and the other parties claim that its always been ok with their Mini 2, i also stated that just because its been ok in the past it does not mean it will be ok in the future and had i been stood in front of them during these conversations, I'm sure i would have been met with a blank stare lol, anyway this thread puts an emphasis on that.

I will concede though that i think this is the 1st car issue that I have come across with the Mini 2 as i believe that they are more forgiving than previous DJI models, so i suspect that the OP turned on the drone too close to the car and/or put it on the roof before it finished its initialising.

Thanks. Although I had a good chuckle at rebar in the road. We're lucky when they put more than 2 cm of asphalt down over an improperly (drainage-wise) prepared road. For sure past performance =/= future guarantees of performance. It makes total sense, just something that never popped in my head about the interference from the car. Whenever I tried to do it with my original mini it usually gave me a compass calibration error so the one time I happened to do it with my Mini2 and it didn't give me an issue it was more of an " oh I guess it's not an issue with the new-gen".

The bridge itself does have a steel grate deck in addition to the steel cables so a fair bit of steel (although single lane bridge).

And yes I was planning to let it completely dry, but as it was in a low-humidity dry cabinet and seemed bone dry I did turn it on this morning. Binned the battery that was in it though. It turns on and connects but gimbal wouldn't function nor would IMU configure. I'm going to leave it in the dry cabinet for a few days before trying again.

djiuser_MDEw2zzqfD3G Posted at 10-29 19:50
Thanks. Although I had a good chuckle at rebar in the road. We're lucky when they put more than 2 cm of asphalt down over an improperly (drainage-wise) prepared road. For sure past performance =/= future guarantees of performance. It makes total sense, just something that never popped in my head about the interference from the car. Whenever I tried to do it with my original mini it usually gave me a compass calibration error so the one time I happened to do it with my Mini2 and it didn't give me an issue it was more of an " oh I guess it's not an issue with the new-gen".

The bridge itself does have a steel grate deck in addition to the steel cables so a fair bit of steel (although single lane bridge).

Good idea, if you can remove the body, this will aid the drying.

When it happened to my P4P, i removed the top body, and stuck it in a cooling down oven (not hot enough for the hot grill to melt it), then once the oven had cooled, i then placed it in the hot airing cupboard overnight, and it had all dried nicely and flew with a new battery, its still going strong now about 3+ years later

Thanks all. I let it dry out for 3 more days but still no dice. The gimbal won't move and the IMU has a calibration error and when it gets to 95% it just hangs there. I was wondering with what Labroides said here:

At 2:37.1 the small yaw error became a big yaw error and teh heading data djumps from 66° to 253.7° and just a second later the drone is off chasing itself because of the conflicting directional data it is receiving.

A simple yaw error is the result of launching from somewhere with magnetic interference deflecting the compass to give false heading data.
The false data was used for the initial directional values for the IMU.
When you climbed away from the magnetic interference the compass returned to normal, but the IMU's gyro sensor continued giving false directional data.
The conflicting data from the compass and IMU caused the first small yaw error.
But the increase in the error at 2:37.1 is unusual.
The drone was three weeks out of warranty so DJI says they won't even look at the log file (which given what happened is frustrating they don't want to find out how to fix this kind of thing). Any chances of getting DJI to do anything about it other than their standard offer of 20% off a replacement or just straight out of luck?

Out of luck I think, sorry.
How does 20% off compare with the price of second hand drones on the likes of ebay there?
If you go the second hand route, ask the seller to undo all bindings associated with flyaway and care refresh insurance. If a second hand drone is 'local' to you I would ask if you would be allowed to test fly it with YOUR controller and YOUR App on YOUR phone. The latter would, I think, show up any "bound" problems whilst you are with the seller etc. etc..

djiuser_MDEw2zzqfD3G Posted at 11-2 08:24
Thanks all. I let it dry out for 3 more days but still no dice. The gimbal won't move and the IMU has a calibration error and when it gets to 95% it just hangs there. I was wondering with what Labroides said here:

At 2:37.1 the small yaw error became a big yaw error and teh heading data djumps from 66° to 253.7° and just a second later the drone is off chasing itself because of the conflicting directional data it is receiving.

Hi,

See my chart of your data.

After take-off compass heading to the actual heading, approx 30 degrees offset at initialisation.
Flying away from start point = south on the map = as compass heading in the log., so far so good.

Normally with a typical yaw error (conflict between gyro and compass) a fly away will start often after moving away from takeoff position and often after yaw input.
Not in your flight. You were able to fly away to approx 90 meters, drone followed RC inputs.

But at 2m36  compass heading changes about 180 degrees!  This change started the fly away.
So not a normal yaw error fly away, but an other error caused the compass 180 "switch".

cheers
JJB