Mavic 3 Crash - Drone flew forward without me controlling it

[Starz]

sat in the car at the time

I’ve never thought this was a good idea.

 

[slup]

...Yaw gets set incorrectly when the AC powers up in a geomagnetically distorted field. And, then continues to be incorrect even after the AC has left the distortion.

The Mavic 2 was/is the only model that could do that to my knowledge, change the IMUYaw I mean...

 

[BudWalker]

The Mavic 2 was/is the only model that could do that to my knowledge, change the IMUYaw I mean...

Not sure I'm following.. Are you referring to the M2 correcting an incorrect IMUYaw by holding it constant and rotating the M2 until magYaw agrees with IMUYaw?

 

[slup]

Not sure I'm following.. Are you referring to the M2 correcting an incorrect IMUYaw by holding it constant and rotating the M2 until magYaw agrees with IMUYaw?

Yeah, imagine that's how it's done, or vise versa, but think the most logical would be if the IMU gets reinitialized once the drone notices the magYaw change+the growing deviation towards IMUYaw when getting higher up, instead of a craft that really rotates... have never seen it happen in a log (because the yaw error incident was avoided I recon) but that's how sar104 explained it once, the only dependency was that the drone wasn't moved after power on... & that it was a M2.

 

[TonyPHX]

When it comes to the "poor satellite quality"... we don't need to speculate, it's right there in the log the OP shared & the quality was good enough & that didn't cause this incident. The GPS message in the log came after the incident started when the drone crashed.

Yes yes @slup ... I agree. I was speaking informally about the overall conditions. When I briefly glanced at the log, it just appeared to be a very low satellite count as well.

 

[BudWalker]

Yeah, imagine that's how it's done, or vise versa, but think the most logical would be if the IMU gets reinitialized once the drone notices the magYaw change+the growing deviation towards IMUYaw when getting higher up, instead of a craft that really rotates... have never seen it happen in a log (because the yaw error incident was avoided I recon) but that's how sar104 explained it once, the only dependency was that the drone wasn't moved after power on... & that it was a M2.

This is the first time I saw this.
Recorded flight data vs real time data
The M2 Mavic Pro actually rotates while holding IMUYaw constant. There were several more incidents following this where this happened. If I'm not mistaken other DJI platforms started doing this.

EDIT: This incident was a Mavic Pro not a Mavic 2.

 

[slup]

...If I'm not mistaken other DJI platforms started doing this.

Interesting that DJI choose to actually rotate the drone! Personally I think all uncommanded movements possesses a risk, wonder why they don't just reinitialize the IMU?

Do you know which more than the M2 series that does this?

 

[sar104]

Yeah, imagine that's how it's done, or vise versa, but think the most logical would be if the IMU gets reinitialized once the drone notices the magYaw change+the growing deviation towards IMUYaw when getting higher up, instead of a craft that really rotates... have never seen it happen in a log (because the yaw error incident was avoided I recon) but that's how sar104 explained it once, the only dependency was that the drone wasn't moved after power on... & that it was a M2.

That's correct. The MP2 doesn't rotate - it simply reinitializes the IMU yaw value to agree with the new, correct magnetic heading.

Compass error demonstration

Ok my apologies, I don’t own a Mavic but I know how my phantom standard and i1 reacted in these exact same locations, pix below. With a compass error. I was totally wrong for flying in these areas but I clearly remember how my drones reacted after take off. I had to walk out of the block to keep...

mavicpilots.com

I never saw this in more recent aircraft flight data, but without the DAT files to see the raw data it may still have been happening.

 

[BudWalker]

That's correct. The MP2 doesn't rotate - it simply reinitializes the IMU yaw value to agree with the new, correct magnetic heading.

Compass error demonstration

Ok my apologies, I don’t own a Mavic but I know how my phantom standard and i1 reacted in these exact same locations, pix below. With a compass error. I was totally wrong for flying in these areas but I clearly remember how my drones reacted after take off. I had to walk out of the block to keep...

mavicpilots.com

I never saw this in more recent aircraft flight data, but without the DAT files to see the raw data it may still have been happening.

You're correct. The Mavic 2 didn't rotate to fix an incorrect Yaw. It was the Mavic Pro that did this.

 

[Capt KO]

Just a reminder, if notified to calibrate compass first move away to another location nearby and see if the warning goes away. Compass calibrations are so seldom needed that it’s a good bet that that location is compromised but a short distance away is not.

 

[Feek]

To my untrained eye, this looks like the drone started drifting backwards away from you, you may have not realised it was facing towards you so you tried bringing it back but actually sent it further away where it hit something.

 

[Meta4]

To my untrained eye, this looks like the drone started drifting backwards away from you, you may have not realised it was facing towards you so you tried bringing it back but actually sent it further away where it hit something.

The flight data shows that there was no joystick input to send the drone toward or away from the home point.
The drone hardly moved any distance during the incident, moving from 1 metres away to 2.5 metres away.

 

[Bluesman1942]

Hey all, Had a pretty crappy night and panicking now how much I'll have to pay in repairs. Trying to understand why my Mavic 3 flew forward without me controlling it to do so. I have uploaded the flight logs to Phantom Logs to try understand what may have went wrong I arrived down at the location this evening. A location I have flew from many many times and never had a single issue. I powered up my drone and noticed a few errors pop up mainly ambient light too low, I was sat in the car at the time with the drone not in motion trying to gage what ND filter I would need as I was planning on taking some long exposure shots of City hall, so gathered that was the cause for that as once I was out of the car this disappeared. Once I had determined the correct ND filter I got out of the car to take off and got a warning saying I needed to calibrate, so I spend some further time recalibrating the drone. Once I had done this, it all corrected itself. This was up to around 32 seconds in the logs, Can be seen that the drone never went higher than 5 foot to this point as I was calibrating the drone. While hovering, I had noticed the two errors that came up between 10 and 14 seconds and again from the logs it can be seen I never raised the drone, I corrected the issues before hovering the drone again. After checking multiple times that everything was working as it should and I was receiving no further error messages I began to ascend around 50 seconds into the log. At around one minute as I was slowly ascending I noticed the drone randomly started to fly forward, I tried to correct this by pulling back but to no avail. It was at 1 min 3.9s the drone collided with the building. I have noticed from looking at the logs that the location is incorrect as by looking at the map it's showing I took off a few stories up on a roof... where as I took off beside the "Margot" building. My instant assumption was that possibly I had lost GPS and my drone had went into ATTI mode but there's no indication this was the case as the drone was in P-GPS(BRAKE) the entire time and never entered ATTI. I can see the satellites dropped but that was already after the drone stopped responding to me. Happy to share the Phantom logs if anyone can help me possibly understand what went wrong, if it was my fault or an issue with the drone. If it makes any difference with regards to signal I'm using an RC Pro controller.​

 

[Bluesman1942]

I had a flyaway too. It was the very first time I tried to fly it at night. So I cranked it up in the courtyard of my apartment. It started hovering so when I raised it up, I completely lost it. I went around in wild circles and finally crashed into the front door of an apartment on the 3d floor. When I heard the sound of the crash, I thought to myself, god, I've lost it. I went into the elevator and to the 3d floor and saw the drone on the ground. The camera was hanging out by a thread (small wire). The front right landing strut was broken and everything else was pretty banged up. I did have the video turned on and was anxious to see it, but it must've gotten fouled in the crash because I couldn't see anything. That's the bad news. The good news is that, after a couple of weeks, I got it back from repairs and was charged around $75 for which I will be eternally grateful. It came back to me in the same box I bought it in and it looked absolutely brand new. I'm wondering if they sent me a replacement instead of fixing the wrecked drone. They said they couldn't tell the cause of the flyaway without the logs which I neglected to send them only because I didn't know how. Either way, it's fine now. but I won't fly it at night EVER from the same place but only if I'm in some wide open spaces. I don't want to go through that again. These things cost too much money to lose due to unforeseen things happening.

 

[Meta4]

I did have the video turned on and was anxious to see it, but it must've gotten fouled in the crash because I couldn't see anything.

You always need to shut down the video before the drone powers off.
If that isn't done, the video file doesn't get closed.
You would have been able to fix that a nd see your video.

They said they couldn't tell the cause of the flyaway without the logs which I neglected to send them only because I didn't know how.

You can still post your flight data here and someone will probably be able to find the cause of the incident.

I won't fly it at night EVER from the same place but only if I'm in some wide open spaces.

The incident had nothing at all to do with flying at night.
If you want to find the cause of your incident so you can avoid making the same mistake again, post your flight data here (in a new thread).

There are a couple of options ...

1. Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report on the flight data.
Come back and post a link to the report it provides and someone might be able to analyse it and give you an understanding of the cause of the incident.
or
2. Just post the .txt file here
or
3. If you use Airdata, you can view the flight data on Airdata and post a link for the Airdata report

 

[Bluesman1942]

You always need to shut down the video before the drone powers off.
If that isn't done, the video file doesn't get closed.
You would have been able to fix that a nd see your video.

You can still post your flight data here and someone will probably be able to find the cause of the incident.

The incident had nothing at all to do with flying at night.
If you want to find the cause of your incident so you can avoid making the same mistake again, post your flight data here (in a new thread).

There are a couple of options ...

1. Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report on the flight data.
Come back and post a link to the report it provides and someone might be able to analyse it and give you an understanding of the cause of the incident.
or
2. Just post the .txt file here
or
3. If you use Airdata, you can view the flight data on Airdata and post a link for the Airdata report

Ok. Thanks. Will do.