Hello,
my Mavic Mini decided to commit suicide in the water, as soon as he took off he threw himself into the water. I tried to take control but failed. It is also impossible to recover it.
How can I do?
I have a DJI Care Refresh, can I hope to have a new one?
The fault was not entirely mine
https://youtu.be/krNDUhhNC9k

Here the logs with the flight data:
https://app.airdata.com/share/JDESvN/GENERALOverview
Export Flight Records from DJI Fly APP
https://www.dropbox.com/s/et7lchv504xo9xe/FlightRecord.zip?dl=0

Thanks

http://www.phantomhelp.com/LogViewer/Upload/

Can you upload file from device to link above, better SW for reading your log and many use this on this forum

hallmark007 Posted at 2-19 06:29
http://www.phantomhelp.com/LogViewer/Upload/

Can you upload file from device to link above, better SW for reading your log and many use this on this forum

Here they are
https://www.phantomhelp.com/LogViewer/U5LJQZT4PHE8PODVAE2N

Thanks

Eragorn87 Posted at 2-19 06:35
Here they are
https://www.phantomhelp.com/LogViewer/U5LJQZT4PHE8PODVAE2N

Hi,

Guess your Italian language is better than mine

Lots of warnings etc, see this

Flight starts in ATTO / OPTI, after just enough GPS signal MM didn`t know what to do, how to keep position.
When drifting started too low above water, so no free air space below to recover in time (for you and for the software)
Cheers
JJB

JJB* Posted at 2-19 06:50
Hi,

Guess your Italian language is better than mine

Yes I read the various notices but I swear to you that I had just lifted the drone and the time to put down the briefcase that went mad and threw itself into the water.Luckily he threw himself into the water, think if he ended up on someone or something, I would have done a lot of damage (I'm also insured)

Eragorn87 Posted at 2-19 06:55
Yes I read the various notices but I swear to you that I had just lifted the drone and the time to put down the briefcase that went mad and threw itself into the water.Luckily he threw himself into the water, think if he ended up on someone or something, I would have done a lot of damage (I'm also insured)

Lesson learmed the hard way.

Tip, if possible find a starting position > 20 meters away from the waterfront.

Why, well   if a MM looses connection within 20 meters from the RC it will just land. And because of no connection nothing you can do about it. It may not happen often but if it does....

Its weird that the fly app did allow you to takeoff, with only 5 satellites and zero level for good reception. Or mayby because there was enought light it let you fly in OPTI mode.

Best is always to wait for enough gps signal/reception, take off and do the after take off checks.

In your flight the HomePoint was not set at your starting position, that is another issue where it can go wrong.

cheers
JJB

Eragorn87 Posted at 2-19 06:55
Yes I read the various notices but I swear to you that I had just lifted the drone and the time to put down the briefcase that went mad and threw itself into the water.Luckily he threw himself into the water, think if he ended up on someone or something, I would have done a lot of damage (I'm also insured)

It is good practice to wait for GPS lock before take off. GPS symbol on screen goes white and there's voice info that "homepoint has been updated, check it on the map".

EDIT: Warning Errore bussola and Calibrare la bussola is very important. Compass calibration was needed before take off in this case. That's why the AC crashed.

virtual Posted at 2-19 07:05
It is good practice to wait for GPS lock before take off. GPS symbol on screen goes white and there's voice info that "homepoint has been updated, check it on the map".

EDIT: Warning Errore bussola and Calibrare la bussola is very important. Compass calibration was needed before take off in this case. That's why the AC crashed.

Warning Errore bussola
It is an error that was often reported but as soon as it took off it always disappeared ... on Friday I will try to dive to recover it but it is a non-swimming lake and I hope not to get a fine

JJB* Posted at 2-19 07:04
Lesson learmed the hard way.

Tip, if possible find a starting position > 20 meters away from the waterfront.

It's late now and the drone is lying at the bottom of the lake

virtual Posted at 2-19 07:05
It is good practice to wait for GPS lock before take off. GPS symbol on screen goes white and there's voice info that "homepoint has been updated, check it on the map".

EDIT: Warning Errore bussola and Calibrare la bussola is very important. Compass calibration was needed before take off in this case. That's why the AC crashed.

Even during this flight he had reported the problem to me
https://app.airdata.com/share/CGeJFV

I’m not sure this was a gps problem you had 5 satellite taken off up to 9 almost immediately, your drone took a swift movement and seemed to be out of control very soon after.

1/ if it’s in opti mode craft will and should have some hold over ground and water depending on how water might be flowing.
2/ if gps was the problem then craft would not have moved away so fast unless it was caught by the wind, and the movements you made towards end of flight would not have been as responsive, also no gps or opti mode would not cause craft to dive into the water.
3/ I would be more concerned with location you took off from, was it concrete or close to concrete or close to metal, I ask this because I’ve seen very similar recently on this forum and the crash you talk about was very similar except road in other case and water in your case.

And if this was the case that you could have picked up magnetic interference, this is exactly how your craft would have reacted and also on this the other case I refer to was given a warranty claim by dji.
So I wouldn’t be inclined to call this so quick, 9 satellites is enough to have craft hold its position, in fact 4 satellites but because you have two receivers or you can receive two different sats IE glonass and gps having 9 is a guarantee that you were flying on minimum of 5 so enough to fly.


Waiting for homepoint was not an option here .
So if you could let us know where you took off from would be helpful.

Just to give you an indication of what I think happened, and this is not from wiki but from training I received at drone flight training.

The best way I can explain this is. If you put your Aircraft on the ground in normal circumstances, start it up, then lift it up and turn it 90 degrees to the right both your compass heading and IMU will both move together 90 degrees and no problems.
If you put your Aircraft on the ground and there is magnetic interference only the heading of your compass will change, your aircraft will still take off. But when it clears magnetic interference compass will then move to correct heading which you would think was great. But No, what happens is IMU is then conflicted and confused because of this sudden movement by compass, so you receive IMU exceptional heading warning, your aircraft cannot deal with data conflict so decides to switch to Atti mode dropping gps in favour of compass simply because aircraft can fly without gps but not compass.

While I can’t be certain OP picked up interference from the ground or surrounding area it is the most common cause.
I have seen many cases where people start their aircraft in or on their car in their house and then bring it outside so damage is already done and we will see exact same warnings and and reaction from aircraft.

We all should check our compass when we start our aircraft and maybe more of this could be avoided, you can do this by checking the compass values in your app also check small red triangle in the lower left corner of your telemetry, it should be on the same heading as your aircraft.

Hi, thank you for reaching out and we're sorry for the incident happened to your DJI Mavic Mini. I will highly recommend you to contact our support team at https://www.dji.com/support to open up a ticket case. We do have our professional team who will handle and perform further analysis on what would be the exact reason for the crashed. A corresponding resolution will be provided once we receive the unit. Please note that DJI can only perform data analysis for units falling within the warranty period; otherwise, valid charges will apply. Thank you for your kind and understanding.

hallmark007 Posted at 2-19 07:35
I’m not sure this was a gps problem you had 5 satellite taken off up to 9 almost immediately, your drone took a swift movement and seemed to be out of control very soon after.

1/ if it’s in opti mode craft will and should have some hold over ground and water depending on how water might be flowing.

Point


the drone took off from my hand

Eragorn87 Posted at 2-19 08:03
Point
[view_image]

Your pretty close to the railings .

Compass distances.

Natural and Artificial Magnetic Anomalies Warning
Note
The following information has not been objectively tested to determine it’s impact on a Drones compass accuracy in flight.
        1        Many things can distort the earth’s magnetic field in the area you are flying:
        •        Steel framed or reinforced concrete buildings, bridges and roadways, iron pipes and culverts, high power electric lines, heavy equipment, trucks and automobiles, steel tanks, electric motors and even computers.
        •        Flying between steel framed or reinforced high rise buildings will distort the magnetic field in addition to causing GPS multi-pathing.
        2        Safe distances for compass calibration
        •        6” (15 cm) minimum: Metal rim glasses, pen/pencil, metal watch band, pocket knife, metal zipper/buttons, belt buckle, batteries, binoculars, cell phone, keys, camera, camcorder, survey nails, metal tape measure.
        •        18” (50 cm) minimum: Clipboard, data collector, computer, GPS antenna, 2-way radio, hand gun, hatchet, cell phone case with magnetic closure.
        •        6 ft (2 m) minimum: Bicycle, fire hydrant, road signs, sewer cap or drain, steel pole, ATV, guy wire, magnets, chain-link fence, bar-wire fence, data collectors
that use a magnet to hold the stylus.
        •        15 ft (5 m) minimum: Electrical box, small car/truck, powerline, building with concrete & steel.
        •        30 ft (10 m) minimum: Large truck, metal building, heavy machinery.

DJI Gamora Posted at 2-19 08:01
Hi, thank you for reaching out and we're sorry for the incident happened to your DJI Mavic Mini. I will highly recommend you to contact our support team at https://www.dji.com/support to open up a ticket case. We do have our professional team who will handle and perform further analysis on what would be the exact reason for the crashed. A corresponding resolution will be provided once we receive the unit. Please note that DJI can only perform data analysis for units falling within the warranty period; otherwise, valid charges will apply. Thank you for your kind and understanding.

Thanks so much for reporting.
I have already contacted the support by sending all the flight logs, the drone is under warranty and I purchased the dji care refresh

virtual Posted at 2-19 07:05
It is good practice to wait for GPS lock before take off. GPS symbol on screen goes white and there's voice info that "homepoint has been updated, check it on the map".

EDIT: Warning Errore bussola and Calibrare la bussola is very important. Compass calibration was needed before take off in this case. That's why the AC crashed.

Thanks for the translation, I knew it was not due to gps as even from log picture it was very obvious.

Eragorn87 Posted at 2-19 07:32
Even during this flight he had reported the problem to me
https://app.airdata.com/share/CGeJFV

To make it more clear to all,

GPS count from 5 to 9 but reception only 2 on range 0 - 5,  level 2 is too low to get good hover accurancy.
With these signals simply no way to hover steady.Unfortunately VPS height did not measure height, happens sometimes above water, so hover on VPS height/vision was no option.
See the line in the upper part of the chart.
At the white dotted line OP gave his first yaw input, this is normal the trigger to act on compass and yaw data to get into error, thus fly away.
Not in this moment. Craft started to move away with VPS not measuring and no good GPS signals to hold position.

Compass and yaw signals equal and inline witch each other, so i do not think that this compass was the cause of this.But i agree that this compass had to be calibrated, need some italian lessons i think  ;-)
Just my 2 cents. But let DJI give their final true verdict.

cheers
JJB

hallmark007 Posted at 2-19 08:05
Your pretty close to the railings .

Compass distances.

I understand, but deciding to crash yourself is wrong, the spirit level should warn you that you are at the wrong angle

Eragorn87 Posted at 2-19 08:12
I understand, but deciding to crash yourself is wrong, the spirit level should warn you that you are at the wrong angle

It does show you but not always give clear indication or stop you from flying, and perhaps this is one reason they may offer warranty.

It’s a hot topic sometimes, it’s something you see often in spark and now with mini, but almost never with M2 or Mavic Air.

JJB* Posted at 2-19 08:11
To make it more clear to all,

GPS count from 5 to 9 but reception only 2 on range 0 - 5,  lever 2 is too low to get good hover accurancy.

Wow!
I am very pleased with all these analyzes but thinking of a 400 euro drone that commits suicide so it makes me angry

hallmark007 Posted at 2-19 08:22
It does show you but not always give clear indication or stop you from flying, and perhaps this is one reason they may offer warranty.

It’s a hot topic sometimes, it’s something you see often in spark and now with mini, but almost never with M2 or Mavic Air.

Anyway, thank you very much for your answers

I actually think the warning to calibrate your compass is a bit of a give away, your gps almost immediately after take off was 9 and you can hover perfectly on 9 in fact With VPS you should have easily been able to hover.

Eragorn87 Posted at 2-19 08:24
Wow!
I am very pleased with all these analyzes but thinking of a 400 euro drone that commits suicide so it makes me angry

Hope you will not stop with this great hobby!

So for use with your next drone, see my checklist for a MM.
BTW for a MM check the craft blue arrow in the map view, looks like this


cheers
JJB

JJB* Posted at 2-19 08:28
Hope you will not stop with this great hobby!

So for use with your next drone, see my checklist for a MM.

Unfortunately, I had invested a lot of money.
We will talk about it again next Christmas

Eragorn87 Posted at 2-19 08:26
Anyway, thank you very much for your answers

No problem hopefully dji will look on this favorable for you .

hallmark007 Posted at 2-19 08:28
I actually think the warning to calibrate your compass is a bit of a give away, your gps almost immediately after take off was 9 and you can hover perfectly on 9 in fact With VPS you should have easily been able to hover.

It did pop up to 9 GPS satellites nearly straight away, but the GPS Level (bars) was at 0 until the 21.9s point and didn't go to 4 bars until 23.6s.  Also, you can see that the home point wasn't marked until 20.6 and GPS speed wasn't being marked until 20.8.

All of these indicate that even though it was registering 9 satellites early on, it didn't have a lock on its location until just moments before its fateful end.

I think when you combine that with the compass errors others have mentioned and the risk of a negative outcome was extremely high.

KlooGee Posted at 2-19 08:55
It did pop up to 9 GPS satellites nearly straight away, but the GPS Level (bars) was at 0 until the 21.9s point and didn't go to 4 bars until 23.6s.  Also, you can see that the home point wasn't marked until 20.6 and GPS speed wasn't being marked until 20.8.

All of these indicate that even though it was registering 9 satellites early on, it didn't have a lock on its location until just moments before its fateful end.

agree, i do no believe in coincidences, moving away started when VPS stopped measuring/indication.
That was the drop wich overflow the bucket....see data in post#18
No ATTI due to compass/yaw error btw.

cheers
JJB

Eragorn87 Posted at 2-19 07:29
Warning Errore bussola
It is an error that was often reported but as soon as it took off it always disappeared ... on Friday I will try to dive to recover it but it is a non-swimming lake and I hope not to get a fine

I'm just advanced beginner but this warning can indicate compass interference while AC power up. There were other similar flyaways.
I hope DJI will help You to get airborne again.

virtual Posted at 2-19 09:18
I'm just advanced beginner but this warning can indicate compass interference while AC power up. There were other similar flyaways.
I hope DJI will help You to get airborne again.

Thanks I hope so too

hallmark007 Posted at 2-19 08:08
Thanks for the translation, I knew it was not due to gps as even from log picture it was very obvious.

Well I found it at JJB*'s list of MM messages. I don't understand italian but the first warning speaks about "metal or magnetic objects near the drone, calibrate before use", so the railing or that pole near could be part of the problem.
I agree with JJB* that's strange app alloved to takeoff with compass error (or compass calibration request) and no GPS lock...

KlooGee Posted at 2-19 08:55
It did pop up to 9 GPS satellites nearly straight away, but the GPS Level (bars) was at 0 until the 21.9s point and didn't go to 4 bars until 23.6s.  Also, you can see that the home point wasn't marked until 20.6 and GPS speed wasn't being marked until 20.8.

All of these indicate that even though it was registering 9 satellites early on, it didn't have a lock on its location until just moments before its fateful end.

I suppose if you look at it your way, he had no gps up to 20s but his craft stayed in the air perfectly steady or just moved to 16 ft, ok we could say VPS except it’s already been said that VPS was not working , I don’t agree with this.
Then his craft records homepoint showing he had gps, but as soon as he gets gps his craft goes mad and not only moves on the wind at a serious rate of knots but also looses altitude (nothing to do with gps) as we all know loosing gps will not cause craft to do anything except continue at its present altitude and drift.

So if you are saying gps caused crash, then maybe explain how craft suddenly moves away at speed and looses altitude to crash into water.
Also take into account virtual translation of compass warning need for calibration before take off.

We all know what happens when gps is lost and it has Nothing to do with loosing altitude. So what caused the crash is what the OP was trying to find out .

virtual Posted at 2-19 09:57
Well I found it at JJB*'s list of MM messages. I don't understand italian but the first warning speaks about "metal or magnetic objects near the drone, calibrate before use", so the railing or that pole near could be part of the problem.
I agree with JJB* that's strange app alloved to takeoff with compass error (or compass calibration request) and no GPS lock...

I fully agree and if gps was low it will never cause any craft to lose altitude, so this is why I believe compass problem was a cause of this crash.

hallmark007 Posted at 2-19 09:59
I suppose if you look at it your way, he had no gps up to 20s but his craft stayed in the air perfectly steady or just moved to 16 ft, ok we could say VPS except it’s already been said that VPS was not working , I don’t agree with this.
Then his craft records homepoint showing he had gps, but as soon as he gets gps his craft goes mad and not only moves on the wind at a serious rate of knots but also looses altitude (nothing to do with gps) as we all know loosing gps will not cause craft to do anything except continue at its present altitude and drift.

I don't see where I said it was GPS that definitively caused the crash.  I simply said that not having a GPS signal  (especially if combined with compass issues) significantly increases the risk of a negative outcome.

However, now that you mention height, lets look closely at that and something I don't think anybody has pointed to (or I missed).

Firstly, the logs never show the height as getting to a negative value.  The operator mentioned they hand launched from shore.  So the drone was very likely 4-5 feet off the ground at launch point and then probably at least another foot or two above the surface of the water.  You can see this from the photo he attached in post #14.  Based off of that, at launch, the drone was probably at least 5 ft above the surface of the nearby water.

So when the logs show the height towards the end of the flight at "0", that should have still been at least 5ft (1.5m) above the surface of the water.  Also, having looked at Google Maps/Earth, it looks likely that the water near where he launched was likely a bit higher than the water on the other side of the lake where it crashed due to a dam/weir.

In fact, the last few entries in the log actually show the throttle being pushed up and the height increasing to about 4.3 feet in the last log entry.  So that would have been nearly 9ft (~3m) above the surface of the water.  

The other thing I'm curious about is that had the drone impacted the water, ground, or another object, I would have expected to see some crazy pitch/roll/yaw values in the last few entries.  I don't see any of that.  I guess the impact could have been severe enough that it immediately killed the power or transmission, but that isn't what I've normally seen.

I still have more questions about this flight than I do actual answers as to exactly what ended up happening.

Was the drone recording when this flight happened?  If so, could we see the cached video from the app?  It would be interesting to be able to match up the video to what we see in the logs.

KlooGee Posted at 2-19 11:25
I don't see where I said it was GPS that definitively caused the crash.  I simply said that not having a GPS signal  (especially if combined with compass issues) significantly increases the risk of a negative outcome.

However, now that you mention height, lets look closely at that and something I don't think anybody has pointed to (or I missed).

My bad it wasn't you who was implying gps was the root of this crash.
The height is a given I agree , the height 9ft would help out greatly with gps being able to control the craft hold and it completely didn’t and at this stage it registered 4 bars on graph representing V good gps so if sticks are in neutral then craft should not be moving and it clearly dived into the water.

There have been other discrepancies in Mavic mini logs for whatever reasons, but recently we see a case almost similar low gps but craft reacting like it was out of control until it crashed, yes a small amount of yaw showed but flight was longer than this, in this instance dji did offer warranty.
So I believe it was important not to send OP away thinking gps was the cause of this crash, because it wasn’t or at least no graph shows it was a result of low gps that caused this crash.

It’s very common with low gps to see craft move on the wind both fast and slow, I have never seen a craft lose altitude or act as this craft did, first no movement then very fast movement and that certainly doesn’t represent atti mode.

I think when someone comes to ask why or what occurred they see a chart rolled out and they’re told gps was cause of crash and because this is accompanied by a chart it must be right, but in this case and others it’s not correct.
Much of the info was available here and it should be pertinent to not only post a chart but to look at all the information before coming to a decision that people are expecting will resemble what is most likely to have happened, but ignoring how craft asked for calibration as well as taking into account that the crash was completely odd and nothing like any other gps crash.

KlooGee Posted at 2-19 11:25
I don't see where I said it was GPS that definitively caused the crash.  I simply said that not having a GPS signal  (especially if combined with compass issues) significantly increases the risk of a negative outcome.

However, now that you mention height, lets look closely at that and something I don't think anybody has pointed to (or I missed).

Hi Kloogee,

Final part of the log, where it drops in the water is not there, as the log shows a disconnection.
So no high pitch and roll data to be seen ofcourse.

Last VPS height indicated at 20.5 seconds, 3.1 meter. as reference 2.2 for baro height.
Just before loosing VPS height roll angles start to increase from almost flat to 19 degrees right.
So i have to change my opinion, looks like loosing VPS height is not the cause (did not help either ) as the increasing angles thus speed started just before VPS was lost.
Pitch angles increase as well, so MM needs to power up to keep height.
Height baro dropped from 2.2 to zero and got higher again (uh?, RC input up so logical), last record 1.3 meters.
So what happend after the disconnection?? No pictures or video taken in this flight.

In general loosing GPS does not mean loosing  height, Loosing VPS does not mean loosing height, slow powering up does mean loosing height when rapid pitch/roll are there.

So its a mystery what caused this crash, sure what happend at the end wich is not logged.

This MM was flown earlier with the same compass warning and 'survived'.

cheers
JJB

KlooGee Posted at 2-19 11:25
I don't see where I said it was GPS that definitively caused the crash.  I simply said that not having a GPS signal  (especially if combined with compass issues) significantly increases the risk of a negative outcome.

However, now that you mention height, lets look closely at that and something I don't think anybody has pointed to (or I missed).

You are correct last height recorded would be around 9ft or just above unless OP is vertically challenged and this is where log ends .

Eragorn87 Posted at 2-19 08:06
Thanks so much for reporting.
I have already contacted the support by sending all the flight logs, the drone is under warranty and I purchased the dji care refresh

You're welcome and we're glad that you already contacted them. Hope that you could get your drone as soon as possible. Thank you for your understanding

thats not good

Good GPS reception at 9 sat can be steady enough. Not a problem here.

You did not calibrate the compass and you stood too close to the metal fence. I moved the slider on phantomhelp to track the flight, and it really did not match up with the stick input (some roll must be used but none shown) in FRAP. I think the compass was not working for the whole flight. If you show us a screen record of the flight in DJI app, go to your flight record and tap on the flight and hit play, I believe we will see the compass was disabled as shown by the indicator at the bottom of your screen.

You lost about 2m in altitude as soon as VPS height went to 'no data' until your stick up command pushed it up for you. That is normal for MINI with no VPS assistance. DJI quotes +/-1.5m accuracy but realistically 2m can happen in my past flight records.

Everything points towards the end here. No one knows why the connection was lost. No connection means no one can see that part of the data. We have no data to tell what made it crash. Your only hope is providing a video but I think that is not possible because of the loss of connection. Were you watching the drone or has anyone else with you watched it? A witness description of the crash is better than nothing. Otherwise, this is a dead-end. I am very sorry for your loss. I hope DJI will look after you.