Mavic Air crashed into river

[Christopher Heijkers]

Hi there,

my mavic just crashed into a river yesterday and is non recoverable due to high water currents

At first it took off just fine without any problem, then it jerkes violantly in the yaw axis, i tried to compensate by moving the rudder stick in the opposite direction, no effect.
Then it flew away sidways and was loosing altitude. It was completely unresponsive and didn´t stabilize, after i let go off the sticks. I moved the throttle all the way up but it was going down into the river.

It didn´t throw any error massages.

I pulled the logfile and thoroughly analysed it and came to the conclusion, that it have to be covered by warranty as the logfile indicates, the the drone didn´t react to pilot commands.
also there is a hugh variance in the speed indicated in the logs it jumped from 20 to 40 mph in 100 milliseconds which can´t be true
looks like a gps bug to me

I would be glad to have a second opinion.

and also are there any experiances how supportive DJI is in such cases? I did purchase DJI Care.

 

[Meta4]

my mavic just crashed into a river yesterday and is non recoverable due to high water currents

At first it took off just fine without any problem, then it jerkes violantly in the yaw axis, i tried to compensate by moving the rudder stick in the opposite direction, no effect.
Then it flew away sidways and was loosing altitude. It was completely unresponsive and didn´t stabilize, after i let go off the sticks. I moved the throttle all the way up but it was going down into the river.

This is an unusual flight data record.
It shows the drone starting up in trees beside the river with the battery is showing 41%.
I'm puzzled that it shows a home point 2.8 kilometres to the west in Kirdorf?
Where were you flying from?
Did you land near the river and restart there without switching the drone off?

The drone launched at 12:07.5 without good GPS because of the tree cover.
It did not get good GPS until 17 seconds later at 12:24.8 and was flying in atti mode until then.
Even after getting GPS, the satellite health was still patchy, probably still because of tree cover.

I pulled the logfile and thoroughly analysed it and came to the conclusion, that it have to be covered by warranty as the logfile indicates, the the drone didn´t react to pilot commands.
also there is a hugh variance in the speed indicated in the logs it jumped from 20 to 40 mph in 100 milliseconds which can´t be true
looks like a gps bug to me

At 12:28.8 the drone crashes, tumbles, rolls upside down and falls.
The abrupt speed data changes are after the crash and are not actual speed figures.
I can't see any obvious problem with the GPS data and I suspect that DJI would see this incident as a pilot issue due to the flying environment being under tree cover with poor/no GPS reception.

Did you see it fall into the river?
It may have ended up stuck in a tree near 50.96679N .. 6.609749E

 

[sar104]

I'm afraid that this looks self-inflicted to me. The log indicates that you launched in ATTI mode (have you modified one of the fswitch parameters?) and then lost control of the aircraft. If you compare pitch and roll with elevator and aileron you will notice that the aircraft responded appropriately to your commands:



Similarly for yaw and rudder:



And if you look at velocities, while there is fluctuation on the data due to the computation, the velocity increased because of your stick inputs in ATTI mode:



Once the RC mode switch was set to P at the 744.5 seconds mark the FC took over and attempted to control the aircraft, but by then it appears to have been too late.

 

[Christopher Heijkers]

It is correct, that i started in kirdorf i was driving with my electric unicycle with the drone flying in front of my with no problem. Then there were bikes driving along the bikeway and i landed the drone. then the bicycles passed and i resumed flying.

once i started the drone again you see the unusual behavior it was showing in the log i previosly uploaded.

yes you are right, it did respnd to my commands normally until it startet to shake in the yaw axis then it sped off sideways loosing altitute i let go of the control switch but it didnt self level again. then i gave it the full throttle command but it didn´t react. also why would it loose altitude when not commanded. you can see in the log all problems startet when it moved erratic in the yaw axis.

Also the trees in germany have no leafs on them yet and are cut regularly. on google maps they look so buschy but in reality the are far to the side allowing the drone gps antenna full view of the sky. The river is below the path i was walking on, so tats where the negative altitude comes from.

Shouldn´t it just self level and climb when just commanded full throttle and not speed up sideways and descend ?

why would the speed changed so erretaic at the exact same time as the yaw axis acted up? it also never rotated like that it just shook violantly. even i commanded the rotation i would never be able to rotated her exactly 360 degrees as the log shows. also it should rotate in an even pace consitend with the rate of rotation before seen in 742 and not so fast.




the crash did happen at 748,845 before that the drone just speeded sideways and descented despite user input





i saw it touched the river and I jumped in there aswell but the the water flows to fast to catch it

then i drove my unicycle to my car wet and with no drone

And thanks for the immediate response you guys are awesome DD



Kind regarts

Christoper Heijkers

 

[Roy Rogers]

Sorry about your drone !
I almost had the same thing happen to me . don't read too much into the flight data it was mostly the downward sensors . The reflective surface of Water , Snow , Ice it has a hard time judging where the ground is and messes with its brain . When it happened to me I was flighting - 12' to - 14' and in sports mode . I had just flown under a steel bridge turned around and put it into sports mode thinking it would make a cool FPV video . So negative altitude , Sports mode about 10' about the water I go full throttle forward . I make it out from under the bridge and shortly after it started jerking so violently to the left , the light in the back was red " means internal conflict or some generic thing like that " I immediately gained altitude and in a few feet it turned green . I gave the video and flight data to DJI so they could study it . DJI instantly identified it as flight to close to a reflective surface. I didn't think that was correct I thought maybe it was the coding conflicting with the negative altitude , but a week later I ran a ton of test dealing with negative altitude over land with no problems . DJI was right . I posted the video on a couple of forums to see what people thought about it . In the video I almost hit a powerline before the bridge thing happened , short attention spans , most people committed on the powerline and didn't even see the crazy stuff it did at the bridge !
I was being too risky and got lucky twice . I haven't pushed my luck sense that day . I'm very sorry that happened to yours but DJI does have great customer service If am allowed id like to recommend you contact DJI through the DJI GO 4 app. in a public manor
Keep us posted and I hope your back up and flight soon

 

[sar104]

It is correct, that i started in kirdorf i was driving with my electric unicycle with the drone flying in front of my with no problem. Then there were bikes driving along the bikeway and i landed the drone. then the bicycles passed and i resumed flying.

once i started the drone again you see the unusual behavior it was showing in the log i previosly uploaded.

yes you are right, it did respnd to my commands normally until it startet to shake in the yaw axis then it sped off sideways loosing altitute i let go of the control switch but it didnt self level again. then i gave it the full throttle command but it didn´t react. also why would it loose altitude when not commanded. you can see in the log all problems startet when it moved erratic in the yaw axis.

Also the trees in germany have no leafs on them yet and are cut regularly. on google maps they look so buschy but in reality the are far to the side allowing the drone gps antenna full view of the sky. The river is below the path i was walking on, so tats where the negative altitude comes from.

Shouldn´t it just self level and climb when just commanded full throttle and not speed up sideways and descend ?

why would the speed changed so erretaic at the exact same time as the yaw axis acted up? it also never rotated like that it just shook violantly. even i commanded the rotation i would never be able to rotated her exactly 360 degrees as the log shows. also it should rotate in an even pace consitend with the rate of rotation before seen in 742 and not so fast.

View attachment 67096


the crash did happen at 748,845 before that the drone just speeded sideways and descented despite user input

View attachment 67102

View attachment 67097

i saw it touched the river and I jumped in there aswell but the the water flows to fast to catch it

then i drove my unicycle to my car wet and with no drone

And thanks for the immediate response you guys are awesome DD



Kind regarts

Christoper Heijkers

I you refer to the second graph in my post above, you will see that the CCW yaw was due to your application of full left rudder at 745 seconds. In terms of climb - you didn't apply any throttle until 747.5 seconds - just one second before impact. As I said before - the aircraft responded to all your inputs but it appears that you were unfamiliar with flying in ATTI mode.

 

[Chief Z]

Hi Chris
I had a similar experience with flying 15 feet above the river. I contacted both dji and dji care. I sent them the flight data and the stated it was not pilot error. I argued for about 2 months with both of them. They stated without the bird they would not able to replace my Mavic under the warranty. They did offer me a 30% discount on a new Mavic, 1 battery and props.
Hope it helps

 

[Henry Davis]

Hi there,

my mavic just crashed into a river yesterday and is non recoverable due to high water currents

At first it took off just fine without any problem, then it jerkes violantly in the yaw axis, i tried to compensate by moving the rudder stick in the opposite direction, no effect.
Then it flew away sidways and was loosing altitude. It was completely unresponsive and didn´t stabilize, after i let go off the sticks. I moved the throttle all the way up but it was going down into the river.

It didn´t throw any error massages.

I pulled the logfile and thoroughly analysed it and came to the conclusion, that it have to be covered by warranty as the logfile indicates, the the drone didn´t react to pilot commands.
also there is a hugh variance in the speed indicated in the logs it jumped from 20 to 40 mph in 100 milliseconds which can´t be true
looks like a gps bug to me

I would be glad to have a second opinion.

and also are there any experiances how supportive DJI is in such cases? I did purchase DJI Care.

 

[Henry Davis]

Sorry to hear of your crash.
How do you download the flight logs?

 

[Meta4]

Sorry to hear of your crash.
How do you download the flight logs?

You 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 of the flight.
If you need help interpreting that you can come back and post a link to the report as the OP did in his first post.

 

[Christopher Heijkers]

Just wanted to update you, all.

DJI will replace the drone under warranty

 

[sar104]

Just wanted to update you, all.

DJI will replace the drone under warranty

Sometimes they do that, even when the data don't indicate an aircraft fault.

 

[xspwhite]

Just wanted to update you, all.

DJI will replace the drone under warranty

Glad to hear it. I would recommend staying away from water for now on..

 

[InvisibleName]

Glad to hear it. I would recommend staying away from water for now on..

I'd recommend more practice in VERY open spaces!

 

[djiuser_MLPTTHpRA3yw]

I'd recommend more practice in VERY open spaces!

Don't make him sad .I have also Mavic Air and it done something similar a couple of times already ( Since 2008 I have been running 3d helicopters and planes . and maybe maybe I can control it ? ) ! If this happens on the Mavic flight, he will not listen to any of my commands except RTF ! Last week there was a peaceful direct flight and the only adequate was RTF

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

I've had such a video from the previous case

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

Here see that I'm not trying to interfere with what's happening .Dron dances his own dance ! My Mavic I just got away because that there was 70 m above the ground, I got out . Otherwise, it would have happened the same way as her drone !?

 

[Deleted member 94047]

Don't make him sad .I have also Mavic Air and it done something similar a couple of times already ( Since 2008 I have been running 3d helicopters and planes . and maybe maybe I can control it ? ) ! If this happens on the Mavic flight, he will not listen to any of my commands except RTF ! Last week there was a peaceful direct flight and the only adequate was RTF

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

I've had such a video from the previous case

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

Here see that I'm not trying to interfere with what's happening .Dron dances his own dance ! My Mavic I just got away because that there was 70 m above the ground, I got out . Otherwise, it would have happened the same way as her drone !?

That is very strange! Any idea what might have caused it?