Hey guys. Long story short I was flying my Mavic Mini the other night and had it plumment into the ocean with no warning. Wondering if anyone has any idea what happened? I have contacted DJI Support already but with current global affairs I'm not expecting an answer anytime soon. Here is the info: I spent 45 mins waiting for the perfect lighting with the sun setting. I began everything normally, the drone took off and hovered in front of me without any issues. I was positioned on some rocks about 10 feet above the ocean with a clear view of the drone. It had 8 satellites connected, there were zero obstacles around and the drone wasn't alerting me of any critical errors. I proceeded to fly the drone straight out in front of me. Once it was flying I changed it to cinematic mode to start filming. As I proceeded further outward the drone started to roll to the right. As I noticed this I began to react with the sticks to counter the direction it was going. As it continued to roll the drone completely ignored my commands. As you can see on the logs, I was pulling up at maximum speed but the drone continued to fall towards the water at a very fast rate. It almost seems as if the rear motor died on one side. This drone has only seen a few flights as I just bought it a month or so ago. I uploaded a clip to youtube that you can see of the drone falling here: https://www.youtube.com/watch?v=mOrIy1x3VFY Log attached here: https://we.tl/t-BjjkrpLsAo

We apologize for your loss, as you have contacted our support team, our team will take care of it for you. Please wait patiently for the data analysis result, at the same time, hope other users will also give you some thoughts.

Aloha Wolf,



Aloha and Drone On!

It looks like the dreaded Toilet Bowl Effect. What surface did you take off from?

Might be just about being so close to the water and having a "weak GPS " signal, as shown in the log.

I know the first time I tried to fly at night with few sats available (rushed it), mine went right into a bush on the other side of the road in front of me all by itself.

Geebax Posted at 3-19 18:28
It looks like the dreaded Toilet Bowl Effect. What surface did you take off from?

Took off from a flat rock and hovered over it for a bit before sending it out over the water.

GaryDoug Posted at 3-19 19:03
Might be just about being so close to the water and having a "weak GPS " signal, as shown in the log.

I know the first time I tried to fly at night with few sats available (rushed it), mine went right into a bush on the other side of the road in front of me all by itself.

Minimum sats are apparently 6. I had 8 at takeoff... still you'd think the drone wouldn't drop like that with poor GPS coverage. I have lost all GPS before while flying between trees and my Mavic just stopped and hovered and stopped me from being able to climb in altitude.

DJI Mindy Posted at 3-19 17:56
We apologize for your loss, as you have contacted our support team, our team will take care of it for you. Please wait patiently for the data analysis result, at the same time, hope user will also give you some thoughts.

Thanks Mindy! I have been thoroughly impressed with DJI support so far... they've been extremely quick with replies and they already have the back office looking at my files. I was just curious what other people thought of my situation. I would hate for someone to have the same thing happen to them!

wolfinthewater Posted at 3-19 19:14
Minimum sats are apparently 6. I had 8 at takeoff... still you'd think the drone wouldn't drop like that with poor GPS coverage. I have lost all GPS before while flying between trees and my Mavic just stopped and hovered and stopped me from being able to climb in altitude.

For some reason, being over water is a game changer. I always try to fly over 32 feet to get above the range of the down sensor, especially with GPS error messages like you saw.

GaryDoug Posted at 3-19 19:18
For some reason, being over water is a game changer. I always try to fly over 32 feet to get above the range of the down sensor, especially with GPS error messages like you saw.

I just sold my Phantom for this Mavic Mini so I havnt had experience with poor "over water" flights. The more research I do the more I see how much of a problem it apparently is... There should be some sort of warning by DJI if that is the case.

If you check my logs you'll see the drone was actually completely ignoring my stick commands. It's like it defaults to trust its sensors over the pilot which seems like a bad way to operate a flying object.

I agree. We are seeing a lot of these drop into the water. I put a hand-made flotation "top hat " on mine when over water until this anomaly is resolved. It's just so I can possibly retrieve it when that happens...inevitably.

wolfinthewater Posted at 3-19 19:16
Thanks Mindy! I have been thoroughly impressed with DJI support so far... they've been extremely quick with replies and they already have the back office looking at my files. I was just curious what other people thought of my situation. I would hate for someone to have the same thing happen to them!

Yes, the data analysis is in progress, we will have someone to contact you with the result once it is finished, please note the email later.

Hi,

Sorry for your loss!

Start of the flight with 0 satellites and 0 for reception.
So your MM in ATTI and OPTI mode.
Only after 30.7 after takeoff HomePoint set. (8 sats + 4 bar for reception)

Because of the GPS position errors craft could not hold a accurate steady hover postion.
Height hold is done by baro sensor with the help of vision, guess all signals were disturbed somehow, with the result of dropping in the water.

It is so important to wait for a good GPS lock, if your flight had was not ended this way  but after some time had a lost connection, it had landed in the water as the Homepoint was not set at takeoff point. Well, always find a spot > 20 meters away from water, as it will autoland if connection is lost and craft is < 20 meters of HP.

Hope that DJI can help you out.


Cheers
JJB

What a horrible way to lose it... Please let us know what DJI think went wrong.

Geebax Posted at 3-19 18:28
It looks like the dreaded Toilet Bowl Effect. What surface did you take off from?

afaik, the TBE shouldn't affect altitude. Nor should flying with weak GPS signal.

That was painful to watch sorry for your loss.
Hope you can retrieve it ad get a replacement.

Man this totally sucks.  This is the scenario which keeps me from flying over water to capture marvelous aerial footage.  I really hope you can get a desirable resolve from this.

JJB* Posted at 3-20 01:54
Hi,

Sorry for your loss!

Thanks for the reply!

I totally understand the homepoint not being the proper place. I had noticed that while my drone was flying out but wasnt too worried as I had full batteries and proper connection to my remote. Since GPS was going a bit haywire anyways. I was planning on doing a quick flyby with the sunset and then bringing it in. The drone was only about 100-200 feet in front of me with wide open view and zero obstructions so I was being relient on my remote connection.

Regardless of the GPS connection, as far as I know, the drone shouldn't fall out of the sky like it did. I have flown many times in ATTI mode through forests and in rivers with big cliffs up the side. Everytime it loses GPS it stops in its place and wont let you climb in altitude, but never drops (seems the opposite of what you would want).

If you look at the log I was also pretty much hovering for the first 10-12 seconds until I picked up my 7th satellite at which point I started to accelerate the drone forwards past the rocks I was sitting on and over the water.

wolfinthewater Posted at 3-20 07:51
Thanks for the reply!

I totally understand the homepoint not being the proper place. I had noticed that while my drone was flying out but wasnt too worried as I had full batteries and proper connection to my remote. Since GPS was going a bit haywire anyways. I was planning on doing a quick flyby with the sunset and then bringing it in. The drone was only about 100-200 feet in front of me with wide open view and zero obstructions so I was being relient on my remote connection.

It's something I've already written here.
All sensors for stabilization and position can fail, but one thing never: the transmission of the control commands (exception is radio abort). Something has become independent here ... or ?

wolfinthewater Posted at 3-20 07:51
Thanks for the reply!

I totally understand the homepoint not being the proper place. I had noticed that while my drone was flying out but wasnt too worried as I had full batteries and proper connection to my remote. Since GPS was going a bit haywire anyways. I was planning on doing a quick flyby with the sunset and then bringing it in. The drone was only about 100-200 feet in front of me with wide open view and zero obstructions so I was being relient on my remote connection.

Drone is programmed NOT to rise above 16 if enough gps is not established, unless it is already above 16ft.
I can’t open your flight log for some reason, but looking at the video it’s something that I see frequently when they’re is a problem with compass, as some have already said TBE and although someone has said drone shouldn’t lose altitude, this is not correct drone can suddenly dive as yours has particularly with strong interference.

There is a similar case posted some weeks ago, almost identical in how drone reacted from take off, before plunging into water, this case was adjudged to have been caused by some magnetic interference, which is always very prominent around piers.
On a good news front the user was granted warranty for this loss of drone, so dji accepting some responsibility.

If you need to see this case I’ll try digging it up for you .

hallmark007 Posted at 3-20 08:31
Drone is programmed NOT to rise above 16 if enough gps is not established, unless it is already above 16ft.
I can’t open your flight log for some reason, but looking at the video it’s something that I see frequently when they’re is a problem with compass, as some have already said TBE and although someone has said drone shouldn’t lose altitude, this is not correct drone can suddenly dive as yours has particularly with strong interference.

I would love to see his case if you can find it. Thanks

I was actually below 16 feet the entire time. I think the point I was trying to get across was that my Mavic Mini listened entirely to its sensors and ignored pilot commands. I wasn't just flying straight when it started to fall, I was aggressively pulling up in altitude which did absolutely nothing.

Imagine an airplane telling the pilot they're wrong and nosediving into the ocean.

wolfinthewater Posted at 3-20 08:53
I would love to see his case if you can find it. Thanks

I was actually below 16 feet the entire time. I think the point I was trying to get across was that my Mavic Mini listened entirely to its sensors and ignored pilot commands. I wasn't just flying straight when it started to fall, I was aggressively pulling up in altitude which did absolutely nothing.

https://forum.dji.com/forum.php?mod=viewthread&tid=209328

You can read it here, might also be worth pointing out similarities regarding drone diving in the drink to dji .

hallmark007 Posted at 3-20 08:31
Drone is programmed NOT to rise above 16 if enough gps is not established, unless it is already above 16ft.
I can’t open your flight log for some reason, but looking at the video it’s something that I see frequently when they’re is a problem with compass, as some have already said TBE and although someone has said drone shouldn’t lose altitude, this is not correct drone can suddenly dive as yours has particularly with strong interference.

Here is the uploaded log:

https://app.airdata.com/share/YoxTgN

https://www.phantomhelp.com/logviewer/MMOUJFWFHXIKI5H63U5Y/

wolfinthewater Posted at 3-20 07:51
Thanks for the reply!

I totally understand the homepoint not being the proper place. I had noticed that while my drone was flying out but wasnt too worried as I had full batteries and proper connection to my remote. Since GPS was going a bit haywire anyways. I was planning on doing a quick flyby with the sunset and then bringing it in. The drone was only about 100-200 feet in front of me with wide open view and zero obstructions so I was being relient on my remote connection.

Hi,

True, you waited for #7 satellite, but still zero for reception. That`s why your MM was in OPTI mode.
With 2 for reception MM switching between CineSmooth and OPTI.

Once GPS reception at 4 warning in the log "GpsPositionNonMatch", this while flying forward with a speed of 6-7 m/s. This will cause problems is my experience.

Indeed a MM should not fall out of the sky when it looses GPS, after having GPS at first. This was not  your situation. (it was building up a GPS connetion with warnings...)
But as GPS is not used for height keeping; not the cause of loosing height.

So i do not know the reason of dropping in the water; no data in the log because of disconnection at 6.8 meters. But when the vision is not working correctly above water, weird actions can be seen. Even with a compass fly away (imo this is not a compass fly away) it should not loose height, but flying that low with high stick inputs ; sometimes MM looses height than.

At the end, before the disconnect, 3 axis 100% input (up, yaw and pitch), don`t know what this did to the attitude of the MM flying with a speed of 11 m/s.

PS what is strange (watch the video again) ; that the horizon is tilted at the final part....but the cam is stabilized. uh ??

cheers
JJB

JJB* Posted at 3-20 09:05
Hi,

True, you waited for #7 satellite, but still zero for reception. That`s why your MM was in OPTI mode.

The 100% input was due to it rolling to the right by itself. I was trying get it to climb and fly back to land as quick as possible but it obviously didn't respond to the commands and continued to fall.

I appreciate you taking the time to answer

wolfinthewater Posted at 3-20 09:26
The 100% input was due to it rolling to the right by itself. I was trying get it to climb and fly back to land as quick as possible but it obviously didn't respond to the commands and continued to fall.

I appreciate you taking the time to answer

Thanks, hope that DJI will give a good analyse and if it is a MM error; help you out.

cheers
JJB

Ice_2k Posted at 3-20 03:02
afaik, the TBE shouldn't affect altitude. Nor should flying with weak GPS signal.

If I had any advice for a Mini owner it would be NEVER to fly over water..... the aircraft is a lemon.

mine just dropped today for no reason, screen said transmission error as it happened, luckily it was only low and just a few meters in front of me but i couldnt work out what caused it, kind of knocked my confidence in it, also noticed the height on the screen when it came down said -1.7m??

For what I can see the VPS was fooled in the end (predictably) and the FC was issuing warning notices of unreliable GPS. It tried to auto-correct and it entered into the water.

Despite not understanding why it gradually went lower on water I am questioning why nothing was done to counter if not only just a handful of seconds before the end.

Starting with no-GPS and with fooled VPS played a big role here. I hope DJI can help you somewhat.

Same thing happened to mine today! So sad.

Please post any updates with yours! I just contacted DJI today after reading your post, really hoping it can be replaced

djiuser_ckNSObZJdhf9 Posted at 3-20 14:56
mine just dropped today for no reason, screen said transmission error as it happened, luckily it was only low and just a few meters in front of me but i couldnt work out what caused it, kind of knocked my confidence in it, also noticed the height on the screen when it came down said -1.7m??

Usually, when it says a negative value in altitude it means you took off from a high point and the drone is flying under your initial takeoff point.

Geebax Posted at 3-20 13:26
If I had any advice for a Mini owner it would be NEVER to fly over water..... the aircraft is a lemon.

Hi Geebax,

I live in a county with lots of water ; do fly (and low) over water many times.

Not once i had a problem doing that ; but start of flight is so important!

Good pre flight check, after take off checks.
(start with full battery, check GPS conditions during flight).

So no LEMON for me.

cheers
JJB

wolfinthewater Posted at 3-20 20:32
Usually, when it says a negative value in altitude it means you took off from a high point and the drone is flying under your initial takeoff point.

thats the odd thing i took off on a flat playing field (football pitch) and the drop happened a couple of feet from where it actually took off, very odd

Bezik Posted at 3-21 03:33
thats the odd thing i took off on a flat playing field (football pitch) and the drop happened a couple of feet from where it actually took off, very odd

Hi,

Baro sensor is not very very accurate. After takeoff height is set to sero.
If you fly up to 400 feet and back to the start position ; you would expect to see zero again.
But often it shows value up / down few feet.

Height measuring itself is accurate ; if you fly at some indicated height and you lower your craft few feet, this is perfectly seen.

cheers
JJB

Sorry to hear about that....

Hey guys a quick update. DJI is standing by their product and sending me another Mavic Mini. I'm not sure what the details are regarding why it fell but I have asked for them to elaborate if possible.

I've been thoroughly impressed with their customer service. I opened a ticket on March 18th and have already had a full review of my logs and an answer by March 21st. Even during the current global affairs. I'd like to make a shout out to everyone at DJI and DJI Support! Thanks guys!

Looked like a good outcome.

wolfinthewater Posted at 3-21 20:59
Hey guys a quick update. DJI is standing by their product and sending me another Mavic Mini. I'm not sure what the details are regarding why it fell but I have asked for them to elaborate if possible.

I've been thoroughly impressed with their customer service. I opened a ticket on March 18th and have already had a full review of my logs and an answer by March 21st. Even during the current global affairs. I'd like to make a shout out to everyone at DJI and DJI Support! Thanks guys!

Always good to know what happened, it helps a lot, if you press them they will give you the reason as they should .

Hopefully you’re back flying soon, good luck .

I was so close to buy a mini, but I went into the forums for my luck. Seeing so many Mavic Mini failures I advice you mavic M fans to stay away from water and if possible, attach a floatable landing leg. Im glad your situation is sorted.