So, I was flying my bird one day . . .

[Obsidian Sereniti]

Hello,
can someone tell me what happened here:
I was taking some pictures of the sky and received a couple of errors - Navigation System Redundancy Switch, and an IMU error is one I remember. I started getting intermittent reception from the drone and tried to turn it back to me. It was disconnected from the remote. Return to home didn't work. Knowing my default is set to return to home, I sat and waited, watching it hover for about a minute. Then it started flying away. I tried a couple of times to reconnect, but to no avail.

Anyway, I'm sure there was more I could have done earlier, but, if someone could give me an interpretation of the flight data, I would be very grateful.

Regards

 

[Deleted member 94047]

This will need the mobile device .DAT file. Can you upload it please?

EDIT: The DAT file for this flight is the one named FLY036.DAT

 

[Obsidian Sereniti]

Here you are. Thanks for taking a look.

 

[Deleted member 94047]

Here you are. Thanks for taking a look.

Here you are. Thanks for taking a look.

Hey Obsidian; you will need @sar104 for this one, it is beyond me.

 

[Romonaga]

I suspect possible strong interference, causing the IMU to trigger, or your primary IMU was failing. I suspect it was the interference, seeing that you also lost coms.

Now, what was the upward Obstacle it detected, and did it have anything to do with this. Also, what is with the Take of and try again?

 

[Obsidian Sereniti]

I suspect possible strong interference, causing the IMU to trigger, or your primary IMU was failing. I suspect it was the interference, seeing that you also lost coms.

Now, what was the upward Obstacle it detected, and did it have anything to do with this. Also, what is with the Take of and try again?

Those were the same questions I had. I’ve flown this location for about 3 years now and I’ve not encountered interference. That is not to say there wasn’t any last night. Often there are seagulls but I did not see any near the bird this night. There are times where they approach and then quickly shift direction. I’ve never seen the take off and try again message, but the bird was still in the air when I got that message. Seconds later it just started flying away - out to sea.

Another strange thing is I tried taking a panorama twice before the errors and it kept saying it detected stick movement. But looking at the data, you can see I didn’t touch the sticks. I’m thinking the IMU was failing, but then there is a backup, correct?

 

[Deleted member 94047]

I didn't see any evidence of interference in the logs. The data from the sensors was consistent; the IMU failed and the FC tried to switch to the second IMU but that didn't seem to workout either. Then the FC rebooted several times to no avail. I think this was a case of a faulty IMU or the sensor fusion function of the IMU going haywire. But I may be wrong; like I said this is way above my level and you will need sar104.

 

[Romonaga]

Yes, it went to the backup, this is clear, but some of the messages are odd in the context. That message talking about upward obstacle, I can not help but think this was the trigger. But heck, I am no expert, will be interesting to see what the experts here see.

Looking at this data without software is hard, as I discovered.

 

[Romonaga]

I didn't see any evidence of interference in the logs. The data from the sensors was consistent; the IMU failed and the FC tried to switch to the second IMU but that didn't seem to workout either. Then the FC rebooted several times to no avail. I think this was a case of a faulty IMU or the sensor fusion function of the IMU going haywire. But I may be wrong; like I said this is way above my level and you will need sar104.

So the loss of coms would have been the reboot. Hmm, now some of them messages are a bit clearer if this is the case.

 

[sar104]

Hey Obsidian; you will need @sar104 for this one, it is beyond me.

It's hard to say exactly what happened here. The default IMU(1) stopped communicating at 89 s, causing the first IMU switch. IMU(0) ran the show until IMU(1) came back at 119 s, and then IMU(1) stopped again at 155 s. IMU(0) took over again until 195 s when both logs abruptly stopped with no warning.

My guess, just looking at the logs, is that the FC crashed and the aircraft shut down. I'm very surprised at the OP's comment that it flew away. @Obsidian Sereniti - it was dark and the aircraft was over 1000 ft away - are you sure it flew away or could it just have dropped?

Other than that, the logs do not indicate any connection issues until the sudden end, and also show no stick inputs after 56 s - is that correct?

 

[Obsidian Sereniti]

It's hard to say exactly what happened here. The default IMU(1) stopped communicating at 89 s, causing the first IMU switch. IMU(0) ran the show until IMU(1) came back at 119 s, and then IMU(1) stopped again at 155 s. IMU(0) took over again until 195 s when both logs abruptly stopped with no warning.

My guess, just looking at the logs, is that the FC crashed and the aircraft shut down. I'm very surprised at the OP's comment that it flew away. @Obsidian Sereniti - it was dark and the aircraft was over 1000 ft away - are you sure it flew away or could it just have dropped?

Other than that, the logs do not indicate any connection issues until the sudden end, and also show no stick inputs after 56 s - is that correct?

View attachment 102082

That is correct. Lighting was dim but not dark yet - I had beacons on the top and rear legs so definitely saw it start to drift away, slowly at first and then quicker. I do appreciate you taking a look, like I mentioned I may have been able to do something sooner which might have saved it, but I just really wanted to know what happened here.

Thanks to everyone for your inputs on this, I truly appreciate it. Will contact DJI and see if it will qualify as a fly away. Will let you know what happens. If that doesn’t work, it is insured through State Farm so I will get it replaced. Or maybe just hold on to the check to see if the MP3 is around the corner. ?

You all have been awesome, and I will “see“ you when I get a replacement!

Regards

 

[sar104]

That is correct. Lighting was dim but not dark yet - I had beacons on the top and rear legs so definitely saw it start to drift away, slowly at first and then quicker. I do appreciate you taking a look, like I mentioned I may have been able to do something sooner which might have saved it, but I just really wanted to know what happened here.

Thanks to everyone for your inputs on this, I truly appreciate it. Will contact DJI and see if it will qualify as a fly away. Will let you know what happens. If that doesn’t work, it is insured through State Farm so I will get it replaced. Or maybe just hold on to the check to see if the MP3 is around the corner. ?

You all have been awesome, and I will “see“ you when I get a replacement!

Regards

Which direction did it drift, relative to your position?

 

[Obsidian Sereniti]

Which direction did it drift, relative to your position?

It was actually spinning a bit slowly and horizontally and drifting backwards from me. It was losing altitude but it was out of my sight before it certainly hit the water.

 

[sar104]

It was actually spinning a bit slowly and horizontally and drifting backwards from me. It was losing altitude but it was out of my sight before it certainly hit the water.

And you are quite sure that it was not just falling - it can be deceptive at a distance?

 

[Obsidian Sereniti]

And you are quite sure that it was not just falling - it can be deceptive at a distance?

Very possible. Especially based on what you all found, that is more likely. Again, I definitely appreciate it. I don't know how you got so good at this, but I for one (and I'm sure many others) are certainly glad you are.

 

[sar104]

Very possible. Especially based on what you all found, that is more likely. Again, I definitely appreciate it. I don't know how you got so good at this, but I for one (and I'm sure many others) are certainly glad you are.

Unfortunately much of it was just inference from a mixture of sparse evidence and lack of evidence. I tend to discount the disconnect/flew away hypothesis because that requires multiple separate aircraft system failures (IMU(1), comms, RTH) but not complete FC failure. The M2 has a documented, though uncommon, history of the FC crashing/rebooting, and that would certainly explain this case if the aircraft fell from the sky.

 

[offtheback]

Very possible. Especially based on what you all found, that is more likely. Again, I definitely appreciate it. I don't know how you got so good at this, but I for one (and I'm sure many others) are certainly glad you are.
[/QU.Possessing powers beyond those of mortal men
Sar 104 came from a distant planet.
He sought truth,justice,and the American way.Plus he's really good at reading and interpreting data.

 

[Obsidian Sereniti]

sar104 is the Man!

 

[STS-Mavic-Mini]

This is right out of the blue, but can a drone be hacked? Could someone actually assume control of a drone that someone else is flying and steal it? Would explain what happened here. I sure hope not!

 

[sar104]

This is right out of the blue, but can a drone be hacked? Could someone actually assume control of a drone that someone else is flying and steal it? Would explain what happened here. I sure hope not!

Alien abduction would also explain it. But it wasn't that either.