So my M2Z crashed in the water today

[powertrip]

So I crashed in the water today, M2Z returned to home and started to to descend , Then took off on it's own and crashed.
Can someone checked this to see if the can tell what happened?

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[Phantomrain.org]

So I crashed in the water today, M2Z returned to home and started to to descend , Then took off on it's own and crashed.
Can someone checked this to see if the can tell what happened?

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Do you also have any of the video footage from the cashe. ?

 

[powertrip]

Do you also have any of the video footage from the cashe. ?

yes, do you just want to see the crash or do you think that would provide some insight?

 

[Phantomrain.org]

yes

See if you can post that from where the % 20 battery alert started. Yes please post the crash footage .

Also was this your flying pattern , or did the drone do that ?



Final resting point.

 

[powertrip]

See if you can post that from where the % 20 battery alert started. Yes please post the crash footage .

Also was this your flying pattern , or did the drone do that ?

View attachment 110772

Final resting point.
View attachment 110773

This was a mission. The Little loop the drone did itself. The M2Z was landing when it just took off dive bombing into the water. I thought it was just lining up with home point. It started to descend and I was just waiting for it to come down

https://www.facebook.com/video.php?v=303961920677145

 

[xunhui]

You really need to go and recover your drone as soon as you can. I'm not sure how deep that water is there or the possibility of alligators nearby but you need to recover it soon. A boat, fabricated poles and a hook or even dive down into the water if your swimming skills are good. Hopefully you have DJI Care Refresh.

 

[boblui]

This is something I have never seen before. When the craft was sliding leftward towards the water. The IMU told the FC that the craft was banking to the right by about 35 degrees :



From the footage, the craft was clearly banking to the left, ie, opposite to what the IMU indicated. As the result of this erroneous sensor information, the FC was unable to come up with the correct commands to the motors to keep the craft in position.



The crash may well be due to sudden failure of the IMU but this is too early to tell. The .DAT and .TXT files in the phone will be needed to verify that. Follow this thread to get the files : Mavic Flight Log Retrieval and Analysis Guide

 

[Phantomrain.org]

This was a mission. The Little loop the drone did itself. The M2Z was landing when it just took off dive bombing into the water. I thought it was just lining up with home point. It started to descend and I was just waiting for it to come down

https://www.facebook.com/video.php?v=303961920677145

Thank you for posting the video , Im sure it helped out everyone. I have to ask the question as this is somewhat odd , I was assuming this was a drone that was never crashed but im wondering now if i had that wrong. ?

 

[slup]

... the craft was banking to the right by about 35 degrees ... From the footage, the craft was clearly banking to the left.

Yeah, something odd is going on there ...

... The .DAT and .TXT files in the phone will be needed to verify that.

As this was a Litchi mission the ordinary set up of logs aren't created ... This will unfortunately severely limit the possibility to gain access to the raw sensor data that usually exist in the DJI DAT log on the mobile device.

"Litchi, create their own custom log files in various formats using the DJI SDK, generally in CSV format. None that I have seen are as comprehensive as the DJI TXT log, let alone the DJI DAT log. Litchi creates its own CSV log and a standard DJI TXT log in a separate directory. No DAT file though."

The log already provided in this thread was Litchis own CSV log ... even though I don't believe anything more useful can be seen in the other standard DJI TXT log it could be good if you provided that also so every thing is ruled out ... the location of it as per below:

On iOS devices, the DJI TXT logs are in Litchi » Documents » SDK_logs » FlightRecord.

On Android devices the DJI TXT log is stored in a subdirectory in the DJI app directory, DJI » com.aryuthere.visionplus » FlightRecord.

Further more for the OP's knowledge ... DJI have usually been very reluctant to honor any kind of warranty if the AC have been used with another app than their own.

 

[powertrip]

There is no DJI Dat file
Here is what Litchi made
2020-08-16_10-25-28_v2
2020-08-16_10-25-28_v2
If there is something else to help, let me know

 

[AtortPhotography]

Not sure how so many It seems lose their drones in the water. I live Hawaii and never come close to losing my drones in the ocean and surrounded by water And been flying for last 4 years. Not sure what happened here, but many sound like they could have saved them if they would have taken more initiative and didn’t resign. Just observation I find it hard to believe any drone dive bombs into the water. Good luck though!

 

[slup]

There is no DJI Dat file
Here is what Litchi made
2020-08-16_10-25-28_v2
2020-08-16_10-25-28_v2
If there is something else to help, let me know

The by Litchi created DJI SDK log doesn't give any more firm insight to what went wrong than the Litchi .csv log.

Everything went good on the AC approach to the HP during the RTH phase ... the AC braked & came to a stand still just above the HP.

Looking into the differences between GPS & registered IMU velocity gives us the chart below, the marker is placed just where the braking is done & the AC have leveled out. The velocity differences is really close to zero as it should be, but then ... especially the northward speed direction starts to generate a big deviation. This usually is a proper sign of IMU problems, either due to a disturbed compass during power on or wrong IMU fusions of the sensor data.



Your crash movie clearly show the AC speed away in a southward direction ... that should show a tilt in the same direction. But here it's evident that the IMU misinterpret the sensor data & instead decides that the tilt direction is in a northward direction.

Here below in the pic the green bar show the AC heading ... & the blue one the tilt direction (tilt = combined angle of pitch & roll from the vertical axis. A leveled AC = 0 degrees).



Showing the same in a chart (markers placed where the AC is in the pic above) show a large tilt inclination on par with using Sport mode according to the specs for a M2. The darker blue background area indicate a positional error & just there after, the AC behave unbalanced tilt inclination wise but also tilt direction wise. The most probable cause is a IMU failure ... but without a .DAT log everything ends here I'm afraid.

Not sure how so many It seems lose their drones in the water. I live Hawaii and never come close to losing my drones in the ocean and surrounded by water And been flying for last 4 years. Not sure what happened here, but many sound like they could have saved them if they would have taken more initiative and didn’t resign. Just observation I find it hard to believe any drone dive bombs into the water. Good luck though!

This incident had nothing to do with partly flying over water & ending up there ... just to avoid a lot of speculation about that.

 

[Ken-Mav-Mtl]

I have just experienced a dive into water over the weekend. Luckily I was able to retrieve my drone the next day. It's now in a bag of rice to try to wick all the moisture from the drone. Also, lucky I have Care Refresh so once I get it dried out I will evaluate the need to use that service. If it works again, my loss so far is one battery (with less than 40 cycles and the props).

By the way, if anyone knows what can happen to a drone spending the night in a fresh water pond, please let me know. If there are any tests to perform to check the airworthiness of my drone, please chime in.

I have read quite a few reports of drones simply dropping out of the sky due to loss of power when batteries had enough charge to get them down safely.

This incident is also a good reminder not to fly over people or cars where a falling drone can cause injury or damage.

In my case, the reason the drone took a dive into water was clear. The battery separated from the drone while I was descending rapidly from 90 to 60 meters. The screen gave the red warning "disconnected" and as I looked up, the drone was falling with the battery about 10 feet above and beside the falling drone.

I discussed this failure with an industrial designer and pilot with 30 years of experience. His conclusion was that this is a design flaw, as a critical non-moving part such as the power source must have a fail-safe mechanism.

I had checked my battery for any sign of swelling or abnormality before every flight and I make sure to push it down firmly to hear the clicks by the locking mechanism so there was no error on my part.

The sudden and rapid descent caused the separation. Somehow the locking mechanism failed.

From now on, I will try the following fix:
Wrap a velcro strap around the body of the Mav Zoom and add a compressible material on the top to always maintain pressure, in case the locking mechanism fails again. Perhaps someone with talent can design this and add this fail-safe to existing models that use the same design as the Mavic Zoom.

Should I upload any other info? Flilght log, video, etc.? Not sure how to do this. Any suggestions?

 

[hiflyer201]

Should I upload any other info?

What model drone?

 

[slup]

What model drone?

Most probably a Mavic zoom as mensioned in the end of the post.

@Ken-Mav-Mtl ... as this is totally unrelated to the OP's thread & that you already know the reason for the crash, I suggest you post your question in a more appropriate thread section to avoid confusion.

I suggest this thread instead: General Mavic 2 Discussion

 

[hiflyer201]

ohh RFQ

 

[Phantomrain.org]

I am thinking IMU failure with a possible crash sometime in the past or previous water damage. Maybe the OP can fill in those details ?

 

[Ken-Mav-Mtl]

Most probably a Mavic zoom as mensioned in the end of the post.

@Ken-Mav-Mtl ... as this is totally unrelated to the OP's thread & that you already know the reason for the crash, I suggest you post your question in a more appropriate thread section to avoid confusion.

I suggest this thread instead: General Mavic 2 Discussion

Thank you Slup. Will post in appropriate forum.

 

[DronePride]

The by Litchi created DJI SDK log doesn't give any more firm insight to what went wrong than the Litchi .csv log.

Everything went good on the AC approach to the HP during the RTH phase ... the AC braked & came to a stand still just above the HP.

Looking into the differences between GPS & registered IMU velocity gives us the chart below, the marker is placed just where the braking is done & the AC have leveled out. The velocity differences is really close to zero as it should be, but then ... especially the northward speed direction starts to generate a big deviation. This usually is a proper sign of IMU problems, either due to a disturbed compass during power on or wrong IMU fusions of the sensor data.

View attachment 110803

Your crash movie clearly show the AC speed away in a southward direction ... that should show a tilt in the same direction. But here it's evident that the IMU misinterpret the sensor data & instead decides that the tilt direction is in a northward direction.

Here below in the pic the green bar show the AC heading ... & the blue one the tilt direction (tilt = combined angle of pitch & roll from the vertical axis. A leveled AC = 0 degrees).

View attachment 110804

I am thinking IMU failure with a possible crash sometime in the past or previous water damage. Maybe the OP can fill in those details ?

What software do you use to read the .dat file?

Showing the same in a chart (markers placed where the AC is in the pic above) show a large tilt inclination on par with using Sport mode according to the specs for a M2. The darker blue background area indicate a positional error & just there after, the AC behave unbalanced tilt inclination wise but also tilt direction wise. The most probable cause is a IMU failure ... but without a .DAT log everything ends here I'm afraid.

View attachment 110805



This incident had nothing to do with partly flying over water & ending up there ... just to avoid a lot of speculation about that.

 

[slup]

... What software do you use to read the .dat file?

I use CsvView --> CsvView Downloads which reads both DAT, TXT & CSV logs. But the above wasn't from a DAT log ... it was from Litchis own logs as a DAT log isn't created using that app.