Launched my mini with a full battery, was positioned next to a lake, was higher up than water level on launch. Piloted it about 300 feet away, was about 6 to 8 metres height above launch location which amounted to roughly 10 to 14 metres above the water. Was snapping still photos with DJI Fly app. Went to adjust the exposure and while I was doing that over a 12 second span of time, the unit lowered itself slowly, then progressively faster until it hit the surface of the water. I didn't notice it was losing altitude as I was adjusting the camera exposure. I did not fly it into the water or direct it to descend. Not idea why it happened. Wasn't windy, air was warm, no alarms, software/firmware was up to date, she just crashed. I sent a support request via email to DJI. I don't have the Care Refresh package. I was able to retrieve it. It was in 4 feet of water for 12 hours before I found it. I'm so sad. I'm hoping DJI will show me some love. I also don't trust this thing at all now. I got roughly three dozen flights out of her since purchasing last November. Couldn't use it much until this spring. I'm seeing a couple reports so far of similar instances happening to others and wanted to share the bad news with mine.

I am so sorry for what happened. Please, publish the flight log, here are very wise people who know how to interpret it and can surely give an explanation of what happened. I wish you the best of luck with the request to DJI.

Can you link me to directions on how to post the flight log please and thanks? All new to me.

Yellowknife3 Posted at 6-15 11:02
Can you link me to directions on how to post the flight log please and thanks? All new to me.

Hello, sorry to hear about your crash. If you could follow the instructions Phantom Help(It works with the mavic mini) and post back with the link, it will help us analyze your flight information.

That's my worst nightmare. I am always afraid when sending the mini over water.  Just curious, did you update the firmware to the latest?

Here is the flight log - thank you all;

https://www.phantomhelp.com/logviewer/BV2C8OAX66W16DVOS3JG

The sensors cannot detect the ground to maintain position over water. The exact same thing happened to me. I was shooting boats at a harbour, I was in exposure settings and noticed the drone descending without any input. I quickly flew it back up. You can't fly and hover low over water. It's well know with all DJI drones, they say in the manual to be careful over water. If you are flying around it's fine it's just hovering it has issues with. The reflective surface causes issues with the bottom sensors and as a result it cannot determine the ground to maintain drone height.

22340179 Posted at 6-15 13:20
The sensors cannot detect the ground to maintain position over water. The exact same thing happened to me. I was shooting boats at a harbour, I was in exposure settings and noticed the drone descending without any input. I quickly flew it back up. You can't fly and hover low over water. It's well know with all DJI drones, they say in the manual to be careful over water. If you are flying around it's fine it's just hovering it has issues with. The reflective surface causes issues with the bottom sensors and as a result it cannot determine the ground to maintain drone height.

Do you have the flight log from that flight by chance? Sounds more like a UD then VPS fault, the most we've seen with mini over water is the VPS carrying the mini down stream not lowering in altitude. I fly regularly over a highly reflective still pond and have never experienced what you are describing, I have out on the ocean experienced my drone drifting when hovering close to the surface but it was following the current/motion of the water.


@Op, I haven't had time to review your flight yet but thank you for providing us with the link.

A common mini problem.  No command descent.   You did nothing wrong, other than not watching it like a hawk, which you shouldn't have to do.

ABeardedItalian Posted at 6-15 13:41
Do you have the flight log from that flight by chance? Sounds more like a UD then VPS fault, the most we've seen with mini over water is the VPS carrying the mini down stream not lowering in altitude. I fly regularly over a highly reflective still pond and have never experienced what you are describing, I have out on the ocean experienced my drone drifting when hovering close to the surface but it was following the current/motion of the water.

No I don't have the log. It happens though on water where the bottom isn't visible. The surface of the water causes issues with the sensors. DJI even put out a website page dedicated to flying over water with their drones here: https://store.dji.com/guides/how-to-fly-safely-over-water/

What if someone put a tape over that bottom sensor? would that prevent the Mini from landing over the water? I saw people putting tape over that sensor so they could fly close to objects indoor...

22340179 Posted at 6-15 14:14
No I don't have the log. It happens though on water where the bottom isn't visible. The surface of the water causes issues with the sensors. DJI even put out a website page dedicated to flying over water with their drones here: https://store.dji.com/guides/how-to-fly-safely-over-water/

I've read the manual, I've seen other users reports and video experience with rivers.

I'm not advocating everyone go out and fly over water but with first hand experience with the very conditions you speak of I've never experienced height loss. The water I fly over is very murky sooty so you can't see the bottom, and on a calm day's has a mirror finish that can be really pretty some day's, the most I've ever experienced was drifting. My guess is the moss on the water was floating away by the wind and the VPS was being carried. See videos for .

Daniella3d Posted at 6-15 14:44
What if someone put a tape over that bottom sensor? would that prevent the Mini from landing over the water? I saw people putting tape over that sensor so they could fly close to objects indoor...

I don't recommend it. It goes into ATTI mode and drifts etc. I fly over water all the time without any issues. So long as you are aware that if you hover too low to water it can slowly drop you can adjust the remote for it. It's not an issue if you are prepared for it, just something to be wary of.

Yellowknife3 Posted at 6-15 12:25
Here is the flight log - thank you all;

https://www.phantomhelp.com/logviewer/BV2C8OAX66W16DVOS3JG

Your Mini showed very poor altitude holding for the whole flight.
At 0:38.9 it started climbing without joystick input and went from 12.5 ft to 18.7 ft in 10 seconds.
From 1:22.5 it started descending without joystick input for the rest of the flight.

It would be interesting to inspect the area where this was happening to better understand if hot-cold air pouches could have played a role in altitude (pressure) measurements.

m80116 Posted at 6-15 18:27
It would be interesting to inspect the area where this was happening to better understand if hot-cold air pouches could have played a role in altitude (pressure) measurements.

It's got nothing to do with hot/cold air or pressure measurement.
The Mini was measuring air pressure the whole time and showing that the drone was slowly sinking.
It just didn't or couldn't do anything about it.

Where do you get these whacko ideas from?

Sorry for Your loss! What version of firmware were you using?  The logfile shows 1.0.244. Before v1.0.5 the uncommanded descends happened offten.

Hi Yellowknife,

Had a look at your log too.

First warning in the log " Lighting environment too dark. Visual positioning inaccurate. Fly with caution"
An important one as the VPS height assist the height holding performance when in VPS range.

At the end VPS height was measuring YES/NO values. see the chart.
Hovering in low light conditions within VPS range is not a good idea.
It went slowly down from 6 meter to water level.

MM is not as good as other DJI drones to keep height steady with RC input changes ( fwd to zero = pitching up = often some climb)
As you can see after releasing fwd stick to zero MM climbed. This is a 'habit' of the MM.
See the blue height lines ; where they are red MM ascend/descend without Up/Dn stick input.
This is not to be confused with a UD some MM had, in loosing their MM. This almost always with NotEnougPower, Max power reached warnings and often with low batt value (not in your flight)
IMO your loss due to VPS sensor in low light conditions, plus VPS is sometimes above water not as good as above land (more different texture/reflections)
As you can see ; VPS height lines are intermittent, the cause of the drop.

PS
if you like locate on your mobile device the DAT file, it is FLY063.DAT. This file has more and other flight data in it.

cheers
JJB

JJB* Posted at 6-15 22:53
Hi Yellowknife,

Had a look at your log too.
[Image]

My friend JJB, you never disappoint. You really are a great help in this forum, thanks with all my heart.

Hi JJB - here is the dat file: https://filebin.net/uefcoot2i1zz6gw6

Yellowknife3 Posted at 6-16 06:14
Hi JJB - here is the dat file: https://filebin.net/uefcoot2i1zz6gw6

Hi,

No errors (as far as i understand DAT files) in the dat in relation with loosing height, few times a DARK_ENV_DETECTED.
Your compass calibration was not that good but has imo nothing to do with this drop.

cheers
JJB

Thank you all for the review of the logs, the comments, advice. I will update when I have a final response from DJI. With Covid, I expect to be without this drone for the summer. I never really got to use this thing in prime time up North yet, we still have ice on some of our lakes - and most of my use would be over or near water as I camp and fish, and most of the Northwest Territories in Canada is lakes and rivers. I did not pay special attention to the warning in the manual regarding the VPS, even though I had read the manual. To suggest It's well known with all DJI drones to not fly low over water is something I didn't know. Low is also subjective, as i didn't think I was flying too low, (I supposed I'd consider 5 feet or less over flat water too low?) I thought the unit could hold its position without inputs in good weather. I see now that I should never be under 10m above the water to eliminate the risk of the VPS failing or engaging incorrectly, potentially a $700 CAD lesson right now. It's tough to see that I should be monitoring known issues online to prevent a malfunction or avoid an accident because of a drone's limitation that wasn't well known to me. I hope that's not the standard of service and expectations set by DJI? The website page dedicated to flying over water was another bucket of info I was unaware of. Regardless, I don't trust this unit anymore and it sounds like the wrong one for my needs. My friend has been using his Mavic Air over water during the past year without issue. I see the Mavic Air 2 boasts active tracking for boats. I do wonder how reliable it will be over water. I'll take away 2 expensive lessons here - the VPS is going to screw me over water at 10m or less in height, and low light will further restrict the VPS capabilities. And maybe to invest regular time on this forum reading about mistakes others have made, as well as reading about drone issues that are identified to become better informed about the issues and risks with a particular unit. Cheers and thanks again all. (I've not confirmed the firmware version but will do so - though I assume the log is correct).

Cheers,
YK

Yellowknife3 Posted at 6-16 09:32
Thank you all for the review of the logs, the comments, advice. I will update when I have a final response from DJI. With Covid, I expect to be without this drone for the summer. I never really got to use this thing in prime time up North yet, we still have ice on some of our lakes - and most of my use would be over or near water as I camp and fish, and most of the Northwest Territories in Canada is lakes and rivers. I did not pay special attention to the warning in the manual regarding the VPS, even though I had read the manual. To suggest It's well known with all DJI drones to not fly low over water is something I didn't know. Low is also subjective, as i didn't think I was flying too low, (I supposed I'd consider 5 feet or less over flat water too low?) I thought the unit could hold its position without inputs in good weather. I see now that I should never be under 10m above the water to eliminate the risk of the VPS failing or engaging incorrectly, potentially a $700 CAD lesson right now. It's tough to see that I should be monitoring known issues online to prevent a malfunction or avoid an accident because of a drone's limitation that wasn't well known to me. I hope that's not the standard of service and expectations set by DJI? The website page dedicated to flying over water was another bucket of info I was unaware of. Regardless, I don't trust this unit anymore and it sounds like the wrong one for my needs. My friend has been using his Mavic Air over water during the past year without issue. I see the Mavic Air 2 boasts active tracking for boats. I do wonder how reliable it will be over water. I'll take away 2 expensive lessons here - the VPS is going to screw me over water at 10m or less in height, and low light will further restrict the VPS capabilities. And maybe to invest regular time on this forum reading about mistakes others have made, as well as reading about drone issues that are identified to become better informed about the issues and risks with a particular unit. Cheers and thanks again all. (I've not confirmed the firmware version but will do so - though I assume the log is correct).

Cheers,

Hi YK,

I live in a country with water all over the place.
Both my current drones, a MM and a MA2, fly great above water ; even at low low heights.

But i never fly low when its getting dark. In general low over water flying is risky, as not always are the VPS measurements correct, also in daytime.So when i fly low over water, it is always in my eye-ball mark1 sight!  
So hard lesson learned, but don`t stop with this hobby    it is so much fun to fly and make good footage!

cheers
JJB

My Mavic mini also took a dive four days ago. Did not respond to controller. Lost in the river. Regret that I didn't paint it in a fluorescent color.

Hello there YK. I am sorry to read and to know what happened you your DJI Mavic Mini. This is not the experience we want you to have with your DJI Mavic Mini. In addition it is great to know that you were already communicating with out DJI Support team with regards to this matter. Rest assured that our DJI support team will do there best to evaluated the said drone and the best resolution will be provided for your. Please keep us posted on the said issue. Again I am sorry for the trouble this has caused you and thank you for your support.

matstrd Posted at 6-16 12:59
My Mavic mini also took a dive four days ago. Did not respond to controller. Lost in the river. Regret that I didn't paint it in a fluorescent color.

wow, sorry for your loss.  Nice adding copter noise....  ;-)
if you like upload your flightlog using this > https://www.phantomhelp.com/LogViewer/Upload/
This is another case as in post #1, enough light for all the vision systems.

Did you open a case with DJI ?

cheers
JJB

@JJB*
It was probably my own fault as (I have learned now) I let the mini hover over the river as I was stepping on some stones. When I become aware of the mini was descending I tried to make it ascend but no sucsess. It was sucked underwater and with perfect camouflage impossible to find..
I will try to upload the flight log if/when I understand how to retrieve this from my iPhone se (2016)

Okay, I'm starting to get a feeling that DJI support can be frustrating. 4 to 9 days between replies, I'm not getting the service I expect. Also the serial number I provided was generated through my online account/registration of the unit and their instructions for me are not working on their website.  See below exchanges (read bottom up due to email format;

repair.dji.com does not work for me because of my location in Canada according to your site. It advises me to contact DJI support. Please advise.

From: DJI Support (DJI Support) <support.us@dji.com>
Sent: June 27, 2020 6:51 PM
To: xxx
Subject: [DJI Support] : RE Re: [DJI Support] : RE [North America][Canada][Mavic Mini]Uncontrolled crash into water

##- 请在此行以上输入您的回复 -##
Your request（#2864558）has been updated, please reply the email below.

       
DJI Support （DJI Support）

2020年6月28日 GMT+8 上午8:51

Dear xxx

Thank you for contacting DJI Technical Support.

We are unable to find any drone with the serial number that you have provided in the previous email. The serial numbers should be found inside the battery compartment of your drone, beside the QR Code. You may submit an online repair request in our website: repair.dji.com. After submitting the request, you will receive a shipping label via email. Print that shipping label out and send your drone back to us.

Let us know if you have further questions regarding this matter. Thank you!

Best Regards,

Sab
DJI Technical Support
Website: http://www.dji.com/support
YouTube: http://s.dji.com/Youtube-DJI


Hi,

My complete shipping address is xxx

I do not have DJI Care

Date of incident: June 13, 2020
Time of incident: 9pm Mountain Time

Email account used: xxx

I have synchronized the Flight Record and Cached Video files from your mobile device by DJI FLY app.

I was not recording video when the incident occurred.

Thank you,
xxx

From: Alec (DJI Support) <support.us@dji.com>
Sent: June 18, 2020 5:00 PM
To: xxx
Subject: [DJI Support] : RE [North America][Canada][Mavic Mini]Uncontrolled crash into water

##- 请在此行以上输入您的回复 -##
Your request（#2839810）has been updated, please reply the email below.

       
Alec （DJI Support）

2020年6月19日 GMT+8 上午7:00

Dear xxx

Thank you for contacting DJI Technical Support.

We are sorry to hear about this unfortunate incident. Due to the sensitive electrical components, and given that the units are not waterproof, water damaged units are ineligible for a repair service. It is advised to send it in and offer us the flight records for data analysis. After analysis, we will offer solution accordingly.

Complete Shipping Address (No PO Box. Kindly send us your complete shipping address to avoid further issues for shipping):
Do you have DJI care (refresh): Please offer us the agreement number if yes.
Date and time of the incident:
Email address associated with your DJI Account you used for your last flight:

To claim data analysis and warranty service, below is also required. And please follow the steps in the file attached about how to synchronize the Flight Record and Cached Video files from your mobile device by DJI FLY app.

If you fail to sync your flight records to the cloud, please send us the flight record's txt files on your mobile device. Please also export the cached video to us if you were recording a video when the incident happened. Attached is the PDF instruction for your reference.

We are looking forward to your early reply and have a great day.

Thank you for choosing DJI and stay safe!
Best Regards,

Alec
DJI Technical Support
Website: http://www.dji.com/support
YouTube: http://s.dji.com/DJI-Tutorials

       
Nalla12

2020年6月15日 GMT+8 下午10:15

Products: Mavic Mini

Serial Number: 1sdlgap00403xh

Consultation Type:

Purchase Way:

Order Num:

Name: xxx

Location: North America

Country: Canada

Email: xxx

Dealers: Dr.Drone

Tel: xxx

Subject: Uncontrolled crash into water

Message: On June 3rd my Mavic Mini was hovering above water at 6 to 8m. I was taking photos. I began to adjust the exposure when the drone quickly descended without any inputs. It lost 7m of altitude in 12 seconds without warning, crashing into 4 feet of water. I was able to recover it 12 hours later. Unit was shipped to me November 9th, 2019 and arrived November 23, 2019. I believe the unit malfunctioned and this was not due to operator error. I would like DJI to please replaced the unit or repair it free of charge, or issue a full credit towards another unit.

Happened to me in the past too. Here is the video at exactly 2min you can see drone dropping down very fast, its not as scary in the video as it was from my perspective. I thought drone was a goner. It didnt respond to inputs at all, then it recovered somehow. I had another accident too which i didn't record, but it was similar, from that point  on I don't fly above the water anymore.

Hello all, first time poster here and I wish it were under better circumstances.

I just had the exact same issue occur with my MM. I was flying at approximately 2.5 metres over a lake and had been having no issues thus far, when the MM suddenly plunged into the water in a matter of seconds.

I realized what was happening party way through the descent and pushed the altitude stick up as far as it would go, but the MM was completely unresponsive.
and continued its descent until making contact with the water. Unfortunately, I was unable to retrieve the MM from the lake.

I was hoping that someone could help me to analyze the flight logs before I reach out to DJI support, as I am having a hard time reading the logs on my own.

Any help would be hugely appreciated, thank you!

I believe this is the proper format for the flight log, with both the .CSV and .TXT files, please let me know if something else is required though:

https://www.dropbox.com/sh/8sph79xgkw86zr7/AADjEzpOzFYMMerqpG_5en1wa?dl=0

The customer service from DJI since my MM went down has been awful. I'm still trying to get them to sort out getting me a shipping label as they want me to send it in but I haven't received the label yet. This is worse than dealing with a cell phone company, not impressed.

.............

DrivingBraeside Posted at 7-7 19:43
Hello all, first time poster here and I wish it were under better circumstances.

I just had the exact same issue occur with my MM. I was flying at approximately 2.5 metres over a lake and had been having no issues thus far, when the MM suddenly plunged into the water in a matter of seconds.

Are you sure that is the last file? It shows you landing just 6 feet away from the start point. It also shows the flight to be mostly about 6-8 meters above the lake.

My apologies, and thank you for checking.

I've reuploaded the files here: https://www.dropbox.com/sh/8sph79xgkw86zr7/AADjEzpOzFYMMerqpG_5en1wa?dl=0

Not sure if this helps as well.

Looking at the flight log viewer, the flight path looks like the drone returns home. However, this wasn't the case, I would have noticed it RTH as we remained at the launch site for several hours and the area was free from trees for the RTH function.

While flying the MM, I watched it hit the water on the video feed. Also, I have attached an image from the 'Find My Drone' function in the app, showing the coordinates of the crash site.

Thanks again, and please let me know if I can provide any other info!

DrivingBraeside Posted at 7-7 19:43
Hello all, first time poster here and I wish it were under better circumstances.

I just had the exact same issue occur with my MM. I was flying at approximately 2.5 metres over a lake and had been having no issues thus far, when the MM suddenly plunged into the water in a matter of seconds.

Hi,

Your log is not complete  use this link for your flight > https://www.phantomhelp.com/LogViewer/Upload/

after upload put that link to your flight on here.

What i think i see in the CSV,  flying at 0,5 meters VPS height > into forcelanding.
This happens when flying low at for few moments stick down = into a user (un) wanted landing.

But a full log using the link above will explain it all.
cheers
JJB

Hi JJB,

Thank you for pointing me in the right direction, and for the preliminary diag!

Here is the link as requested: https://www.phantomhelp.com/LogViewer/RMG5OFPQMXAVN59H8UX9

If there's anything else I can provide, just let me know

Hi JJB,

Quick afterthought as well - as the altitude was doing a rapid descent, I had been pushing upwards on the altitude stick with no response from the MM.

Is this something that we'd be able to verify with the logs?

Thanks again!

DrivingBraeside Posted at 7-8 11:25
Hi JJB,

Thank you for pointing me in the right direction, and for the preliminary diag!

Hiya,

Your log is from a mavic pro and not a Mavic Mini ?

Looks a great flight....

cheers
JJB

Hey!

Thanks so much for pulling this, I've made a very embarrassing mistake and pulled data from the Mavic Pro I was flying that day instead of the MM that I had out shortly thereafter.

I'll upload the appropriate logs ASAP!

Thanks again, and my apologies for the hassle.