Bought it day one, have been flying it almost every week. Just went out for a quick flight, it took off fine and then suddenly as I was climbing altiotude it decided to accelerate along a curved path straight into a wall. Absotluely no response from my remote controller either, neither of the sticks did anything to slow or otherwise stop it's path. Just suddenly went full on suicide mission.
I've flown it in the area before with absolutely no issues.

Flight log attached, if anybody is interested.
DJIFlightRecord_2019-12-31_[20-58-39].zip (29.87 KB, Down times: 41)

2019-12-31 Upload

Click on the file name to download attach



Going through the forums, it looks like others have had the exact same issue as mine. Randomly accelerating to it's death.

Has DJI done anything regarding this? Am I at fault? Should I send in a repair/replacement request?

Starworshipper Posted at 12-31 20:27
Flight log attached, if anybody is interested.

Was it already dark for you at time of flying? The log shows flight around 9pm which would be too dark in many places for Altitude mode to work, also looking at your launch location you might of be in a magnetically dirty place as the compass was experiencing issues.

Looking at the Log's the Drone launched in Gps mode but without enough Sat's, the compass orientation looks wrong and when it try to connect to gps the drone is trying to correct it's position but is unable to do so and switches into altitude mode while the drone is trying to correct itself and flew pitch forward and "Took off" on it's own.

Look's like a cause of user error not waiting for enough satellites and the drone corrects it's position in the air and which caused the crash.

ABeardedItalian Posted at 12-31 21:30
Was it already dark for you at time of flying? The log shows flight around 9pm which would be too dark in many places for Altitude mode to work, also looking at your launch location you might of be in a magnetically dirty place as the compass was experiencing issues.

Looking at the Log's the Drone launched in Gps mode but without enough Sat's, the compass orientation looks wrong and when it try to connect to gps the drone is trying to correct it's position but is unable to do so and switches into altitude mode while the drone is trying to correct itself and flew pitch forward and "Took off" on it's own.

It was dark when taking off, in a heavily lit area however. But I've flown it during these conditions before. I had 10 sat. connections prior to taking off, and even calibrated the compass as I haven't flown it for a week or so and everything was showing as good to go in terms of taking off. I'd usually take off and fly to about 200ft to remain above everything.

Starworshipper Posted at 12-31 22:13
It was dark when taking off, in a heavily lit area however. But I've flown it during these conditions before. I had 10 sat. connections prior to taking off, and even calibrated the compass as I haven't flown it for a week or so and everything was showing as good to go in terms of taking off. I'd usually take off and fly to about 200ft to remain above everything.

1.04 changed how lighting effects Altitude mode: https://forum.dji.com/forum.php? ... =205549&pid=2046278

Until you hear "Home point has been updated" it's not safe to take off, rarely you need to hover to acquire signal but your position should remain as stationary as possible during Satellite Acquisition. you had 9 Sat's which is pretty good but it was unable to acquire a lock. When it got close to enough Sat's to lock and set a home point it fails but not before the drone try's and correct it's positioning while flying.

There are more experainced users who will chime in later, just trying to fill the gap with what I've to learned from them.

ABeardedItalian Posted at 12-31 23:04
1.04 changed how lighting effects Altitude mode: https://forum.dji.com/forum.php? ... =205549&pid=2046278

Until you hear "Home point has been updated" it's not safe to take off, rarely you need to hover to acquire signal but your position should remain as stationary as possible during Satellite Acquisition. you had 9 Sat's which is pretty good but it was unable to acquire a lock. When it got close to enough Sat's to lock and set a home point it fails but not before the drone try's and correct it's positioning while flying.

I've never heard "Home point has been updated" until I've taken off and hovered for a bit. This includes flying the drone in wide open fields with 12+ sat connections.  Something that a local Mavic Air pilot had mentioned as odd when we were flying together, as his seems to grab a home point almost immediately.

As for Firmware, I was not on 1.04. It wasn't available at the time of flight, nor was I prompted for a firmware update before flight. I also followed the 'Auto Takeoff/Landing' guidelines within the manual. which includes running through the pre-flight checklist and everything was followed correctly.

At this point, I guess I'll attempt to contact DJI directly to see what they're response is, which I'm sure will be along the lines of a repair bill that ends up costing more than the drone itself. Was a fun month of drone ownership, I suppose. Feels bad.

Starworshipper Posted at 12-31 23:38
I've never heard "Home point has been updated" until I've taken off and hovered for a bit. This includes flying the drone in wide open fields with 12+ sat connections.  Something that a local Mavic Air pilot had mentioned as odd when we were flying together, as his seems to grab a home point almost immediately.

As for Firmware, I was not on 1.04. It wasn't available at the time of flight, nor was I prompted for a firmware update before flight. I also followed the 'Auto Takeoff/Landing' guidelines within the manual. which includes running through the pre-flight checklist and everything was followed correctly.

Slow gps lock is a known issue with the Mini: https://forum.dji.com/forum.php?mod=viewthread&tid=204407 and You would see a Green Indicator and message about the home point being updated on the screen if you have the devices audio off.

I agree, my hobby drones have instant lock even inside my house and the mini outside can take a minute or longer to update it's home point.

Did you try to counter the drone’s movement towards the wall? I had a similar situation but i was able to use the sticks to counter its movement. I too was forced to takeoff without sat lock (it would not acquire it on the ground) and after taking off as it started getting more satellites it began to drift quite fast. It was not in ATTI mode (btw, it’s attitude mode, not altitude) but in position mode but without sufficient satellites. I think the phenomena is similar to looking at your location on google maps after exiting a building and seeing the blue location dot drifting as it acquires a more precise location. I’m guessing that’s what’s happening inside the drone, it thinks it’s really moving and it’s trying to compensate to stay still.
I’m actually curious what the correct procedure is for this situation when the drone cannot acquire enough satellites on the ground and needs to hover for a better reception. Sounds like it would almost be better to takeoff in ATTI mode as with that the pilot has full control.

Thinking about this some more, I think the button sensors are supposed to counter this problem. In your situation it was too dark and in my situation I had launched the Mini from a terrace and as I took it away from the building it was already at 15-20m ground level which obviously rendered the bottom sensors useless.

Ice_2k Posted at 1-1 00:05
Did you try to counter the drone’s movement towards the wall? I had a similar situation but i was able to use the sticks to counter its movement. I too was forced to takeoff without sat lock (it would not acquire it on the ground) and after taking off as it started getting more satellites it began to drift quite fast. It was not in ATTI mode (btw, it’s attitude mode, not altitude) but in position mode but without sufficient satellites. I think the phenomena is similar to looking at your location on google maps after exiting a building and seeing the blue location dot drifting as it acquires a more precise location. I’m guessing that’s what’s happening inside the drone, it thinks it’s really moving and it’s trying to compensate to stay still.
I’m actually curious what the correct procedure is for this situation when the drone cannot acquire enough satellites on the ground and needs to hover for a better reception. Sounds like it would almost be better to takeoff in ATTI mode as with that the pilot has full control.

In the situation where you can't get a strong GPS lock while on the ground , I would not take the risk and lift off at night. Atti mode without being able to see the AC properly is risky unless your super confident

I would move to another location, it wouldn't be the safest flight area anyway given the GPS signals are being blocked or interfered with.

Starworshipper Posted at 2019-12-31 20:27
Flight log attached, if anybody is interested.

Hi Startworshipper,

Sorry for you crash! doesn`t look good at all.

What happend ; started to fly with 9 satellites but GPS reception poor.
So no GPS lock, no LatLon positon in the log.

After take-off some moments in Opti mode, when GPS position was available shortly data was recorded.After that GPS sat count back to 9, 6 to 4. That`s why the message "GpsPositionNonMatch" in the log.

Mini could not hold position, too dark for VPS positioning, and with bad GPS data moved way as you wrote.

I am curious what was seen in the app...

IMO and for this reason its a good idea to fly always with a screen recorder active, to compare FlyApp video with the actual screen video.


cheers
JJB

JJB* Posted at 1-1 01:55
Hi Startworshipper,

Sorry for you crash! doesn`t look good at all.

Thanks JJB, wasn't sure what that gps error was in Frap.

ABeardedItalian Posted at 1-1 02:16
Thanks JJB, wasn't sure what that gps error was in Frap.

oke, not sure exactly but something like this:
- when GPS data differs to much from previous recordings a gpsnonmatch error pops-up.
- with just a few satellites and/or bad reception the data signals are unreliable to be used.

This is the EXACT  same thing that may happened to me. Did dji give you a replacement option?

I hope you're getting a replacement!!!

Sorry for your loss, hope you can get a replacement soon.

fans3beb614d Posted at 1-1 02:31
This is the EXACT  same thing that may happened to me. Did dji give you a replacement option?

I just contacted DJI Support via email and am awaiting a response. Hoping for a replacement or repair, as I truly believe the issue was not my fault as I had 0 control over the drone, otherwise I would have been able to take control and at the very least stop the drone from accelerating.

Hi, I am sorry to know about this unfortunate incident and thank you for sharing your informative insights on what happened. I would recommend you contact our support team to start up a ticket: ( https://repair.dji.com/repair/index ). We have the professional team who would do their best to assists you with regards to this matter. We hope to hear from you as soon as possible for a swift resolution. Thank you.

Just sent the unit back to DJI service in California, will keep this post updated as things progress for anybody with similar issues.

..it is not a first and not a lost crash. The mini is not perfect drone. Not ready.

I don't understand how more people aren't scared of this drone especially the ones where it has gone wrong, crashed, and they are flying again like it would never happen.  My P4PV2.0 had an app failure one time and a complete controller loss but it was near, hovered, and landed w/o issue (I assume because of a defective cable connection from the controller to the Smartphone).  Never happened again and no DJI drone has ever lost total control but some, the gimbal goes wacky (way back) but the flight is still stable.

Starworshipper Posted at 2019-12-31 20:27
Flight log attached, if anybody is interested.

I have seen this happen to a Mavic Pro. After sone major disagrements the guy did get a new drone when he found one of the people there filmed it. It took a while though.

Starworshipper Posted at 1-4 13:12
Just sent the unit back to DJI service in California, will keep this post updated as things progress for anybody with similar issues.

I've been away for two weeks and couldn't kake any sense of your zipped txt file.
Now that i"m home, I get the same result on my home computer so I can't analyse it.
If you post the txt file itself, I can look into it for you.

The incident you described is almost certainly a yaw error which happens when you launch from an area of magnetic interference that causes the drone to initialise with an incorrect directional sense.

Most of the comments and advice you've been given so far are incorrect or irrelevant.

Labroides Posted at 1-4 18:12
I've been away for two weeks and couldn't kake any sense of your zipped txt file.
Now that i"m home, I get the same result on my home computer so I can't analyse it.
If you post the txt file itself, I can look into it for you.

The attached .zip file contains the .txt file, as I can't directly upload .txt files to this forum, for whatever reason.

You can also download the .txt file here, if you'd like: https://app.box.com/s/e4483ms2yrel8w7pucfsw2e4k21ubfud

Starworshipper Posted at 2019-12-31 22:13
It was dark when taking off, in a heavily lit area however. But I've flown it during these conditions before. I had 10 sat. connections prior to taking off, and even calibrated the compass as I haven't flown it for a week or so and everything was showing as good to go in terms of taking off. I'd usually take off and fly to about 200ft to remain above everything.

Maybe I am looking at wrong FlightLog file...
But it looks like you took off in open area near three story apartment or condo building with 9 to 10 GPS sats.

But as you flew closer to building, the number of GPS Satellites decreased down to  6, where GPS Position Match messages appear.  From there GPS Satellite count went down to 5 then 4, with drone appearing to be right next to building, perhaps under an eve.

Real-Close

Theorizing problem was result of building blocking GPS Satellite signals from half of sky from North to East to South.

Starworshipper Posted at 1-4 18:20
The attached .zip file contains the .txt file, as I can't directly upload .txt files to this forum, for whatever reason.

You can also download the .txt file here, if you'd like: https://app.box.com/s/e4483ms2yrel8w7pucfsw2e4k21ubfud

Thanks, that's much better.
My software was unable to make sense of the txt file inside your zip file but this one opens perfectly.
Here's what your flight data looks like:https://www.phantomhelp.com/LogViewer/JC14G59PEOVTFVUG0KI8/

My guess about a yaw error was wrong.
The description sounded like it but the data tells a different story and the explanation for your incident is quite simple.
You launched early, without waiting for GPS and the drone to record a home position.
You briefly had GPS at 0:09.3 and the drone was able to record a tentative position but the number of satellites rapidly fell and the drone was never satisfied with the approximate position it had.  GPS Health never improved from 0/5.

The drone never had the benefit of GPS position holding for the whole flight.
Your joystick inputs were extreme, being full stick in all directions.
Without GPS position holding, your drone also had no "brakes" and would have continued moving when you went hands off on the sticks.

It looks like the crash happened at around 0:10.4 and most data after that is garbled as the sensors were affected by the crash.

I wonder about why GPS was so bad.
Were you out in the open with a clear view of most of the sky or somewhere with a large part of the sky blocked by buildings or other obstacles?

HedgeTrimmer Posted at 1-4 18:54
Maybe I am looking at wrong FlightLog file...
But it looks like you took off in open area near three story apartment or condo building with 9 to 10 GPS sats.

Looking at CSV output file, instead of Phantom Help's display; it looks like drone took off before ever getting a GPS lock.  Drone's GPS position only shows up about 0.6 seconds before Mismatch messages start.

            

Id	Time(seconds)	Time(text)	Latitude	Longitude	FlightMode	Altitude(feet)	Altitude(meters)	HSpeed(mph)	HSpeed(m/s)	GpsSpeed(mph)	GpsSpeed(m/s)
87	8.9	0m 8.9s	0	0	P-GPS	22.3	6.8	6.3	2.8	0	0
88	9	0m 9s	0	0	P-GPS	22.3	6.8	6.5	2.9	0	0
89	9.1	0m 9.1s	0	0	P-GPS	22.3	6.8	7.7	3.4	0	0
90	9.2	0m 9.2s	0	0	P-GPS	22.3	6.8	7.8	3.5	0	0
91	9.3	0m 9.3s	33.75276898	-112.1077967	P-GPS	22.3	6.8	8.3	3.7	0	0
92	9.4	0m 9.4s	33.7527687	-112.1077919	P-GPS	22.6	6.9	8.1	3.6	0	0
93	9.5	0m 9.5s	33.75276855	-112.1077871	P-GPS	22.6	6.9	8.6	3.8	9.8	4.4
94	9.6	0m 9.6s	33.75280559	-112.1077871	P-GPS	22.6	6.9	8	3.6	46.1	20.6
95	9.7	0m 9.7s	33.75287318	-112.1077905	P-GPS	22.6	6.9	8.3	3.7	130.2	58.2
96	9.8	0m 9.8s	33.75289935	-112.1077899	P-GPS	22.3	6.8	7.5	3.4	116.6	52.1
97	9.9	0m 9.9s	33.75287994	-112.1077844	P-GPS	22	6.7	7.4	3.3	10.6	4.7
98	10	0m 10s	33.75287574	-112.1077823	P-GPS	22	6.7	6.8	3.1	30.4	13.6
99	10.1	0m 10.1s	33.75287247	-112.1077816	P-GPS	22.3	6.8	6	2.7	9.7	4.4

Updated:  After refresh, see   Labroides posted about no GPS on takeoff.     

Labroides Posted at 1-4 18:54
Thanks, that's much better.
My software was unable to make sense of the txt file inside your zip file but this one opens perfectly.
Here's what your flight data looks like:https://www.phantomhelp.com/LogViewer/JC14G59PEOVTFVUG0KI8/

As soon as I saw the drone take off on it's suicide mission, I throttled fully in reverse and to gain altitude in order to avoid anything. Pretty difficult to ease into recovery when your drone suddenly takes off without any input on your end.

I was in the middle of my apartments empty parking lot, which is where I usually take off before flying back to the mountains/etc. Clear skies with nothing overhead. Have flown numerous drones in this location before, including drones that require GPS lock and free flying drones and I have had 0 issues and 0 crashes with these drones in the same area. The mini is the only drone I've owned that actually went full suicidal.

Starworshipper Posted at 1-4 20:23
As soon as I saw the drone take off on it's suicide mission, I throttled fully in reverse and to gain altitude in order to avoid anything. Pretty difficult to ease into recovery when your drone suddenly takes off without any input on your end.

I was in the middle of my apartments empty parking lot, which is where I usually take off before flying back to the mountains/etc. Clear skies with nothing overhead. Have flown numerous drones in this location before, including drones that require GPS lock and free flying drones and I have had 0 issues and 0 crashes with these drones in the same area. The mini is the only drone I've owned that actually went full suicidal.

Going full stick in all directions when  the drone is in atti mode is always going to end badly, particularly with nearby obstructions to crash into.
Waiting for confirmation of GPS would have gone a long way to helping you have a safe flight.
Given what your flight data shows, I can't see DJI being very supportive.

Labroides Posted at 1-4 20:38
Going full stick in all directions when  the drone is in atti mode is always going to end badly, particularly with nearby obstructions to crash into.
Waiting for confirmation of GPS would have gone a long way to helping you have a safe flight.
Given what your flight data shows, I can't see DJI being very supportive.

I knew the drones heading and altitude. If the drone would have taken direct input from my controls it would not have crashed, ez. My Mantis G has attempted to fly away due to bugging waypoints and as soon as it gets an input from the receiver it stops, no matter the situation.

Had the greenlight to take off with 9 satellites, otherwise the mini would shoot me an error or hover at a very low altitude and just remain still.

Starworshipper Posted at 1-4 21:35
I knew the drones heading and altitude. If the drone would have taken direct input from my controls it would not have crashed, ez. My Mantis G has attempted to fly away due to bugging waypoints and as soon as it gets an input from the receiver it stops, no matter the situation.

Had the greenlight to take off with 9 satellites, otherwise the mini would shoot me an error or hover at a very low altitude and just remain still.

If the drone would have taken direct input from my controls it would not have crashed,
Your drone didn't make any attempt to "fly away".
It did respond to the joystick input you gave.
Unfortunately for you, it had no GPS position holding ability and you were going crazy on the sticks, pushing them to their limits in all directions.
Without any braking ability and the extreme joystick inputs, it would have appeared to you that the drone was uncontrollable.
You have to be very gentle on the sticks in atti mode with obstacles nearby.


Had the greenlight to take off with 9 satellites, otherwise the mini would shoot me an error or hover at a very low altitude and just remain still.
The recorded flight data shows quite clearly that your GPS Health remained at zero for the entire flight.
It needs to be at 4 or 5 for things to work properly.
The flight controller had no confidence in the position information.
It never recorded a home point and only got a poor quality location fix after you had "flown" for 9.3 seconds.
The crash happened one second later.

Starworshipper Posted at 1-4 21:35
I knew the drones heading and altitude. If the drone would have taken direct input from my controls it would not have crashed, ez. My Mantis G has attempted to fly away due to bugging waypoints and as soon as it gets an input from the receiver it stops, no matter the situation.

Had the greenlight to take off with 9 satellites, otherwise the mini would shoot me an error or hover at a very low altitude and just remain still.

"Had the greenlight to take off with 9 satellites, otherwise the mini would shoot me an error or hover at a very low altitude and just remain still."


Wondering if some MM fly away problems are result of pilots doing an Auto-take off, under false impression their drone was good to go (Green light)?
The MM is using new flight software App, and there could be a bug which shows drone is ready (Green), when it is not.

Search Aliexpress for parts... I noticed that there were already many parts available, including shell and arms

HedgeTrimmer Posted at 1-4 23:49
"Had the greenlight to take off with 9 satellites, otherwise the mini would shoot me an error or hover at a very low altitude and just remain still."

Good question,

This flight started with 9 satellites and 2 bar for reception; and yes you need 4 or 5 to get a proper GPS lock.
But the fligtmode is P-GPS, uhh  why ??  is P-GPS = Green light in the app to  fly ?

cheers
JJB

JJB* Posted at 1-5 04:44
Good question,

This flight started with 9 satellites and 2 bar for reception; and yes you need 4 or 5 to get a proper GPS lock.

Perhaps Green (good to go) and Mavic Mini manual's vaguness is leading to Goodbye problem.

Wait-For

"recommended to wait", and vague "GPS signal is strong"; coupled to Green (good to go) could be leading pilots to do Auto Takeoff when they need to wait???

Additionally, knowing target audience is general public, can see how a person could assume the "Auto Takeoff" feature would hold takeoff until GPS signal was sufficiently strong.

Searching MM manula for "GPS signal is strong" does not turn up a definition or how it would be indicated.  

Closes description uses different wording: "default Home Point is the first location where your aircraft received Home strong GNSS signals"

Not-GPS_UR-Looking-For

HedgeTrimmer Posted at 1-4 23:49
"Had the greenlight to take off with 9 satellites, otherwise the mini would shoot me an error or hover at a very low altitude and just remain still."

The app used on the Mini has a GPS icon that changes color between red and green depending on how many satellites are connected, not based on strength. If I I have 2 bars, but a green connection I assume that I'm good to go albeit with a weak signal. With a weak signal, I'd assume I'd experience some issues with stability, landing, and taking off, but not to the point where the drone fly's numerous yards away from me.

At any rate, DJI is fixing the drone under warranty* so I'm pretty happy about that, and will definitely be more careful in the future and rely on manual take off for a majority of my flights. Shout out to DJI to making the repair process simple and taking care of everything.

* = I can't guarantee the same will happen in your situation, but this is still a good hive on information regarding the process I've gone through.

Starworshipper Posted at 1-8 10:48
The app used on the Mini has a GPS icon that changes color between red and green depending on how many satellites are connected, not based on strength. If I I have 2 bars, but a green connection I assume that I'm good to go albeit with a weak signal. With a weak signal, I'd assume I'd experience some issues with stability, landing, and taking off, but not to the point where the drone fly's numerous yards away from me.

At any rate, DJI is fixing the drone under warranty* so I'm pretty happy about that, and will definitely be more careful in the future and rely on manual take off for a majority of my flights. Shout out to DJI to making the repair process simple and taking care of everything.

I have a feeling they are giving warranty for these incidents because craft was taking off before good lock was established, this has now changed with new FW , so obviously a problem was spotted.
Good luck with your new or repaired craft .

hallmark007 Posted at 1-8 11:05
I have a feeling they are giving warranty for these incidents because craft was taking off before good lock was established, this has now changed with new FW , so obviously a problem was spotted.
Good luck with your new or repaired craft .

Yup, reading the latest patch notes:

  

  
• Added feature that disables takeoff when the GPS signal      is weak (GPS <8) and the environment light is not sufficient. This      feature can be disabled manually (requires DJI Fly v1.0.4 or later).
    
• Added requirement for compass calibration before      takeoff when the environment light is not sufficient and the compass      experiences interference.
  

  
  

Hopefully this takes care of the issues I've seen other posts about and have experienced.

  

Appreciate the informative feedback everybody has provided.

  

Starworshipper Posted at 1-8 10:48
The app used on the Mini has a GPS icon that changes color between red and green depending on how many satellites are connected, not based on strength. If I I have 2 bars, but a green connection I assume that I'm good to go albeit with a weak signal. With a weak signal, I'd assume I'd experience some issues with stability, landing, and taking off, but not to the point where the drone fly's numerous yards away from me.

At any rate, DJI is fixing the drone under warranty* so I'm pretty happy about that, and will definitely be more careful in the future and rely on manual take off for a majority of my flights. Shout out to DJI to making the repair process simple and taking care of everything.

Great news!

Happy many new landings,
cheers
JJB

Starworshipper Posted at 1-8 12:08
Yup, reading the latest patch notes:

   

is DJI going to replace your drone? with the dji care refresh?