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Crashed Mavic Mini 2 - help with strange pre-crash uninitiated course changes

jnobile

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I could use some help understanding why my done was drifting up and sideways while the controls were neutral. DJI support seems unwilling to analyze the flight data prior to my emergency attempt to fly home. I am hoping to prove the drone was operating erroneously on its own before I started flying home and crashing. Here's my report to DJI:

I planned a flight on a snowy day over a river.

Shortly after takeoff, the drone started drifting sideways and gaining elevation without controller input. I tried to hold a steady altitude and fly back to the takeoff location but was unable to overcome the drone's own actions. Since the drone was close to drifting into nearby trees, I tried to fly faster back home and ran into some branches about two meters from the landing location. The drone collided with some branches, lost the ability to fly, and fell into the fast-moving river below.

I tried to find the drone in the river, but it was too deep and moving too fast.
Cached video:New video by watchr enl
Airdata: Attached: DJIFlightRecord_2021-12-27_[12-55-29].txt
 

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SmilingOgre

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Watching this thread as I have had something somewhat similar. In my case it was drifting to the right and down. It was a struggle to regain some control over the drone but I was able to land it without damage. I have subsequently flown it without problem but I don't have a lot of trust in it.
 

Phantomrain.org

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Shows it was only in the air for 33 seconds and blocked motor.

Just looks like the Motor were blocked , something that happens rather easily on the Mini and one of the reasons why we made the Prop covers for the Mini Wet Suit . Sand / Salt / Stones an bugs can block those motors.

Phantomrain.org
Gear to fly your Mini 2 in the Rain. Float on the River.
 
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Meta4

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I could use some help understanding why my done was drifting up and sideways while the controls were neutral. DJI support seems unwilling to analyze the flight data prior to my emergency attempt to fly home. I am hoping to prove the drone was operating erroneously on its own before I started flying home and crashing. Here's my report to DJI:
The flight data suggests that you launched and flew over a drop down to the creek with the water 13-15 ft below the drone for a short time.
But from 24.2 sec the VPS height data indicates the drone was 2 ft or less above whatever was below it until the crash at 35.6 seconds.

Does that seem right?
Was there something within 2 ft below the drone for the last 10 seconds?
 

Meta4

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Shows it was only in the air for 33 seconds and blocked motor.

Just looks like the Motor were blocked , something that happens rather easily on the Mini and one of the reasons why we made the Prop covers for the Mini Wet Suit . Sand / Salt / Stones an bugs can block those motors.
It would help if you didn'tt view every incident as a sales opportunity.

The Motor Blocked notification came 0.3 seconds after the crash impact.
The OP admitted that he flew the drone into a branch and the data confirms that.
 
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SmilingOgre

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Shows it was only in the air for 33 seconds and blocked motor.

Just looks like the Motor were blocked , something that happens rather easily on the Mini and one of the reasons why we made the Prop covers for the Mini Wet Suit . Sand / Salt / Stones an bugs can block those motors.

Phantomrain.org
Gear to fly your Mini 2 in the Rain. Float on the River.
Oh happy, happy, joy, joy...... So these things can't break free from a grain of sand or salt? How about a splash of water? Would that also stall the motor(s)? I guess I'll bring my camera cleaning kit and blow the motors our before each use. Good grief.....
 

Meta4

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The video shows mist, which is probably what the VPS was picking up.
It's likely that the VPS was unable to provide horizontal position holding over moving mist and that probably explains the drift that you observed.
It was a very risky choice of flying location with so many obstacles so close and over moving mist and/or water.
 

SmilingOgre

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The video shows mist, which is probably what the VPS was picking up.
It's likely that the VPS was unable to provide horizontal position holding over moving mist and that probably explains the drift that you observed.
It was a very risky choice of flying location with so many obstacles so close and over moving mist and/or water.
You answered my question before I asked it. I know little about the flight logs but I did notice that at 10S in the IMU and VPS altitudes started deviating greatly. Good to know that caused that. Thanks!
 

Phantomrain.org

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Oh happy, happy, joy, joy...... So these things can't break free from a grain of sand or salt? How about a splash of water? Would that also stall the motor(s)? I guess I'll bring my camera cleaning kit and blow the motors our before each use. Good grief.....
2022-01-03_19h52_38.png

This is what I was seeing at first glance and thought it was the start of the flight.. I completely missed the video , but I do know that mist , rain and fog has never done that to my mini 2 .
 
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The video shows mist, which is p
Does it?
This is not an argument, rather it is a question. The "mist" covers only a portion of the screen and there is no evidence of it when the drone turns back towards the people. I am left wondering if it is smoke from a fire etc. ( not that that would change its affect) or some bizarre problem (I can't think what could cause such a problem) with the camera?
 
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Question, can anyone else NOT download the csv?
I am getting a message about needing to log in to my airdate account, I did and am but still can not download the csv. I don't remember see such a message with any other posted air data analyses.
 

Gagey52

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It would help if you didn'tt view every incident as a sales opportunity.

The Motor Blocked notification came 0.3 seconds after the crash impact.
The OP admitted that he flew the drone into a branch and the data confirms that.
Never let a chance go by, 😁. I thought that was the American way.
Regards
 

Meta4

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Does it?
This is not an argument, rather it is a question. The "mist" covers only a portion of the screen and there is no evidence of it when the drone turns back towards the people. I am left wondering if it is smoke from a fire etc. ( not that that would change its affect) or some bizarre problem (I can't think what could cause such a problem) with the camera?
It's mist that's rising from the water.
The section of bridge from where he flew, is not over water so there's no mist rising from below there.
 

sar104

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Question, can anyone else NOT download the csv?
I am getting a message about needing to log in to my airdate account, I did and am but still can not download the csv. I don't remember see such a message with any other posted air data analyses.
Click the link in the top left of the window - that will open the flight in a new window and let you download the files.

grab32.png
 

jnobile

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But from 24.2 sec the VPS height data indicates the drone was 2 ft or less above whatever was below it

Yes! There was a light mist rising from a waterfall on the other side of the bridge. I didn't know that could cause unexpected course changes which you can see start at 10s in the video.

It was a very risky choice of flying location with so many obstacles so close and over moving mist and/or water.

Yeah, I think a lot of flying in more ideal conditions left me unaware of what could happen in a more dynamic environment.

I am hoping to prove the drone was operating erroneously on its own

So, if the drone was deceived by rising mist and disregarded its other position sensors like accelerometer, GPS, other(?), is there a warranty claim case to be made, or should I resort to using Fly Away coverage with DJI Care Refresh?
 

Meta4

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So, if the drone was deceived by rising mist and disregarded its other position sensors like accelerometer, GPS, other(?), is there a warranty claim case to be made, or should I resort to using Fly Away coverage with DJI Care Refresh?

Thinking from DJI's perspective ..
They give a warning on p17 of the manual about conditions that will be difficult for the VPS sensors.
It was you that chose to fly in a dodgy environment and it was you that pushed the right stick full forward when the drone was pointing towards the tree.
But you can always try.
Sometimes it's hard to predict what DJI will decide.
 
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IronSky1

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Mini 1 and Mini 2 are very prone to problems related to wind (I am on number 6 since they released)
I have had two flyaways and multiple crashes over the past 2 years. The main issue I have
noticed is keep wind below 20mph and make sure you keep in site at a reasonable altitude less then 100 feet.
(and keepaway from shrubs, dirt and trees)

I have been using drones since 2015 and own all types however, I still fly the small light ones the most.
I have far fewer problems with my Parrot Anafi 350g drones (however camera is not as good as Mini 2)

Use B4UFly and AIRData UAV to verify wind before take off.
 
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crlmjohnson

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lesson learned.
 

Meta4

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Mini 1 and Mini 2 are very prone to problems related to wind (I am on number 6 since they released)
I have had two flyaways and multiple crashes over the past 2 years. The main issue I have
noticed is keep wind below 20mph and make sure you keep in site at a reasonable altitude less then 100 feet.
(and keepaway from shrubs, dirt and trees)

Use B4UFly and AIRData UAV to verify wind before take off.
Wind was not a factor in this incident.
 
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