Help Needed: DJI Mini 3 Pro Auto-Landed Over Water
1737 26 2023-9-24
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flopbuster
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Hey fellow drone enthusiasts and DJI Team,
I recently had a rather unexpected and worrisome incident with my DJI Mini 3 Pro. I was planning to fly it within an Authorization Zone (Blue), but things took an unexpected turn. Here's the whole story:
  • Unauthorized Takeoff: Initially, there was a warning, but my RC didn't request any authorization, and the drone took off without any issues.
  • Auto-Landing Surprise: While flying over a river, the RC suddenly announced "Landing," and a countdown of 21 seconds for auto-landing was noticed. I tried to cancel it, but there was no option available.
  • Descent Drama: In a panic, I hit the RTH (Return to Home) button and pushed the sticks toward the Home direction. The drone did gain some altitude, but then it started to descend.
  • Unfortunate Landing: Sadly, the drone didn't quite make it across the river and landed very close to the riverbank, still over the water.
  • Water Damage: After waiting for the drone to dry, I attempted to power it on. The battery LEDs lit up, the motors spun slightly, and the startup sound played as usual. However, it seems stuck in this state. The gimbal doesn't work, the arm LEDs don't blink, and I can't connect it to the RC or my PC via DJI Assistant 2 software. It's clear that water damage has occurred.
  • FlightRecord: I'll attach the FlightRecord to this post for your reference. In it, you can see that the 'Aircraft will automatically descend' event starts as soon as the drone takes off, but it was only noticed at the RC when the "Landing" sound played.

Now, I have some questions and concerns about this incident:
  • Was this an operational mistake on my part or could there be a misbehavior with the drone itself?
  • Why did the automatic descent engage after all? I've never encountered this when flying in Authorization Zones with other DJI drones, like the Avata, for example.
  • Why did the drone even take off if it was going to auto-land immediately?
  • Why was there no option to cancel the descent? Doesn't this behavior present a significant risk, not only for the drone but also for the safety of its surroundings?
  • Is there any hope for fixing the drone given its current behavior when attempting to power it on?

I'm really scratching my head over this one, and any insights or advice would be greatly appreciated. Thanks in advance, and fly safe out there!

FlightRecord .txt:

https://we.tl/t-JZwMv3fvyw
https://drive.google.com/file/d/1i3E3i2uGqC2BHFFu-XUVJ6SIft5w3jKx/view?usp=sharing

2023-9-24
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Potato mini
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My guest is that your were in a no fly zone. if you power up the drone then take off right away, it will not have good gps connection and will take off. It will then find more satellites, and realize that it's in a no fly, then it will auto land and nothing you can do about it.
2023-9-24
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flopbuster
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Potato mini Posted at 9-24 16:23
My guest is that your were in a no fly zone. if you power up the drone then take off right away, it will not have good gps connection and will take off. It will then find more satellites, and realize that it's in a no fly, then it will auto land and nothing you can do about it.

Thanks for the reply.

I was at an Authorization Zone, Blue color, this can be seen in the FlightRecord.
Indeed, it appears that the GPS was not fully locked yet when I took off.
But shouldn't it have asked for authorization before take off?
And wouldn't it be better for it to not allow take off under those circumstances?

When I fly my Avata in the same region, there is no way to take off without connecting the DJI Fly app to authorize it.
I find it weird that it would allow take off just to land itself in the water right after.
2023-9-24
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Hi, flopbuster. Thank you for reaching out. It is not recommended to fly an aircraft within 10 meters above the water. The aircraft flies by visual positioning. Be careful to avoid areas with specular reflection such as water or snow. We recommend that you not fly the aircraft close to the water, as flying on the water's surface will affect the normal function of visual positioning, and the aircraft may fall into the water due to the impact on positioning accuracy. For your questions, they can be answered after the data analysis. Please send your unit to our facility for further checking.  You may submit an online repair request through this link: {https://repair.dji.com/repair/index}. If you need assistance with creating a ticket, you may contact DJI support at (https://www.dji.com/support). Should you want to have a data analysis, you may request it as well but please note that there might be a fee depending on the warranty of the device. Hopefully, other users can provide you information that you need. as well.
2023-9-24
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flopbuster
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DJI Gamora Posted at 9-24 17:18
Hi, flopbuster. Thank you for reaching out. It is not recommended to fly an aircraft within 10 meters above the water. The aircraft flies by visual positioning. Be careful to avoid areas with specular reflection such as water or snow. We recommend that you not fly the aircraft close to the water, as flying on the water's surface will affect the normal function of visual positioning, and the aircraft may fall into the water due to the impact on positioning accuracy. For your questions, they can be answered after the data analysis. Please send your unit to our facility for further checking.  You may submit an online repair request through this link: {https://repair.dji.com/repair/index}. If you need assistance with creating a ticket, you may contact DJI support at (https://www.dji.com/support). Should you want to have a data analysis, you may request it as well but please note that there might be a fee depending on the warranty of the device. Hopefully, other users can provide you information that you need. as well.

Thanks for the reply.

I believe the proximity to the water is not related to the incident at all. I was flying over 10m above the river.
As described in the original post, the incident occurred because the Drone engaged in an automatic landing, regardless of what was below it, without any option to cancel the procedure and regain control over the aircraft height.
2023-9-24
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flopbuster
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Dirty Bird Posted at 9-24 18:02
My hunch is you were impatient & took off without allowing the GPS to secure a lock on your location.  After you were airborne. GPS obtained a lock, then determined you were in a restricted zone resuling in a forced landing.  If so, this is normal behavior & demonstrates why it is important to allow the aircraft to obtain a satellite lock before liftoff.  If this is the case, it is 100% pilot error.

Thanks for the reply.

I was in an Authorization Zone. Although the GPS was not fully locked, the Drone was aware of the Zone before takeoff, because there was a warning in the RC. This also can be seen in the log.
It can also be seen in the log that the auto landing countdown started right when it took off.
I find it weird that it would allow takeoff just to land itself in the water right after.

Shouldn't it have asked for authorization and don't allow take off under those circumstances? Which is what happens with the Avata.
2023-9-24
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Labroides
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Here's what the recorded data shows.
Was this an operational mistake on my part
Yes .. you really need to wait for full GPS reception before launching, particularly when you are close to  authorisation zones.
You launched with no GPS at all.
It was 21.9 seconds before GPS was good enough to record a  homepoint, when you werealready inside the NFZ.
At 20.1 when the drone was starting to get good GPS data, there is a warning message:
Aircraft in an authorized zone; Unable to take off before unlocking
At 21.3 seconds you started getting a countdown to autolanding:
Aircraft will automatically descend in 96.
Aircraft will automatically descend in 95.
Aircraft will automatically descend in 94 ... etc.
You ignored and kept flying.
At 2:05.7, the drone started to autoland.

or could there be a misbehavior with the drone itself?
No .. just an impatient operator

Why did the drone even take off if it was going to auto-land immediately?
Because you launched before the drone knew where it was.
It started warning you as soon as it had location data.

Is there any hope for fixing the drone given its current behavior when attempting to power it on?
If it's been in seawater, there's next to no chance.
Even if you did get it working, the corrosion will continue and the drone could never be trusted.
2023-9-24
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Labroides
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flopbuster Posted at 9-24 18:20
Thanks for the reply.

I was in an Authorization Zone. Although the GPS was not fully locked, the Drone was aware of the Zone before takeoff, because there was a warning in the RC. This also can be seen in the log.

I was in an Authorization Zone. Although the GPS was not fully locked, the Drone was aware of the Zone before takeoff, because there was a warning in the RC.
The controller might have known where it was but the drone wasn't aware because it had no GPS data.


2023-9-24
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Labroides
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DJI Gamora Posted at 9-24 17:18
Hi, flopbuster. Thank you for reaching out. It is not recommended to fly an aircraft within 10 meters above the water. The aircraft flies by visual positioning. Be careful to avoid areas with specular reflection such as water or snow. We recommend that you not fly the aircraft close to the water, as flying on the water's surface will affect the normal function of visual positioning, and the aircraft may fall into the water due to the impact on positioning accuracy. For your questions, they can be answered after the data analysis. Please send your unit to our facility for further checking.  You may submit an online repair request through this link: {https://repair.dji.com/repair/index}. If you need assistance with creating a ticket, you may contact DJI support at (https://www.dji.com/support). Should you want to have a data analysis, you may request it as well but please note that there might be a fee depending on the warranty of the device. Hopefully, other users can provide you information that you need. as well.

Hi, flopbuster. Thank you for reaching out. It is not recommended to fly an aircraft within 10 meters above the water. The aircraft flies by visual positioning. Be careful to avoid areas with specular reflection such as water or snow. We recommend that you not fly the aircraft close to the water, as flying on the water's surface will affect the normal function of visual positioning, and the aircraft may fall into the water due to the impact on positioning accuracy.

You frequently give this copy/paste response and it's just not true.
Don't keep spreading this misinformation.
This incident had nothing to do with flying over water.

2023-9-24
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Sean-bumble-bee
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I am curious, in the log there are around 90 "Aircraft will automatically descend in xy" warnings, they run from 21.3 seconds to 123.5 seconds, did they appear on the screen, did you see them? If so, during that count down, why did you fly the drone almost 800ft further AWAY from the 'home point' and presumably you?

Is this the second log that you have posted, either here or on MavicPilots? The area seems familiar for some reason, I'm on the wrong computer to check for another flight in the same area but it does seem familiar.
2023-9-24
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digibud
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This is one of the most common mistakes new pilots make. You will, hopefully, develop the habit of waiting fully till you get a notice that Home Point has been Updated.  The FPV line often takes a bit longer to get all set up so it's less likely that you'd be able to turn it on and launch quick enough but I've found that if I'm quick enough I can turn on my drone and take off before DJI knows I shouldn't.  Therein lies the rub. Eventually it catches up with ya. Best of luck in the future. Hopefully your DJI insurance will kick in.
2023-9-24
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Hi,

As said by others : you started a flight with zero satellites, so no drone GPS location.

At 16.6 sec in flight (approx 10 meters away from takeoff spot)  the first warning:"Aeronave em Zona com autoriza. Incapaz de decolar antes de desbloque"
Google translate
"Aircarft in Authorized zone. Unable to take off before unlocking"

At this point 11 satelites receiving, but with GPS quality of zero in the log (updating this value always few seconds behind reality...)

BUT why a message "...Unable to take off before unlocking" while craft is already flying ??
Yes i know, if user had waited for a GPS lock than takeoff was not possible. Would it not be better, if craft is already in the air, to get a different warning
like "You are flying in warning zone, land you craft immediately" ?

At 21.6s in flight HomePoint was set ; 14 sats and a "4" for quality. [ range 0 - 5, you need 4 or 5 to set HP = white GPS icon top right FlyApp ]
At 22.0s first countdown message "Aircraft will automatically descend in 96"  did DJI forgot to write seconds ?

Rest his already said, at zero coundown > autoland.

This type of autoland cannot be cancelled, but descent speed can be controlled by UP stick, in the last part you applied UP stick (it did slow down the descent, but too late...)

See my chart of your data ; see columns V-z (vertical speed) and RC UpDn.


JJB    [ Charts by FRAP ; the 'best' software for data and visual flightlog analysis (www.jjbfrap.eu) ]









AfonsoPena.png
Analysis1.png
2023-9-25
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DroneApe
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flopbuster Posted at 9-24 16:42
Thanks for the reply.

I was at an Authorization Zone, Blue color, this can be seen in the FlightRecord.

Hi,

After you talk to the DJI engineering team about why the drone can launch outdoors with GPS quality 0 or 1 or 2, please shoot me a private message.  I’m super curious about their response.

Thanks!
2023-9-25
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DroneApe Posted at 9-25 07:10
Hi,

After you talk to the DJI engineering team about why the drone can launch outdoors with GPS quality 0 or 1 or 2, please shoot me a private message.  I’m super curious about their response.

Hi,

Why do you think that a drone cannot launch outdoors with GPS quality < 3 ?

0,1 = red GPS icon = No GPS lock ; craft flying using vision to stablize, or without vision (too dark) flying in ATTI mode.
2,3 = yellow GPS icon = GPS lock, but not enough satellites * to set HomePoint.
4,5 = white GPS icon  = GPS lock, enough sats for setting HomePoint.

* number of satellites is not a fixed number, can be 6 or 9 or 12  ect....

cheers
JJB


2023-9-25
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DroneApe
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JJB* Posted at 9-25 07:26
Hi,

Why do you think that a drone cannot launch outdoors with GPS quality < 3 ?

Howdy,

DJI doesn’t want you to launch the drone outdoors with GPS quality 0 or 1 or 2, yet the software allows you to do it.  I’m just curious why that is.  And my electrical engineer friends are curious too.  Hopefully the DJI engineer can explain it to him. And then he can send me a PM.  
2023-9-25
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DroneApe Posted at 9-25 07:44
Howdy,

DJI doesn’t want you to launch the drone outdoors with GPS quality 0 or 1 or 2, yet the software allows you to do it.  I’m just curious why that is.  And my electrical engineer friends are curious too.  Hopefully the DJI engineer can explain it to him. And then he can send me a PM.

How do you know that DJI does not want you to start a flight < 3 ?
Where is that stated or written ? and why a PM ?

But ofcourse best to start a flight is to wait for GPS lock + HP being set.

cheers
JJB

2023-9-25
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JJB* Posted at 9-25 08:09
How do you know that DJI does not want you to start a flight < 3 ?
Where is that stated or written ? and why a PM ?

Good points you make.  Hopefully the OP can get that sorted out with engineer about user manual and messages on controller screen about GPS and takeoff.  And whether or not it’s user error if it’s not in user manual.  And whether or not DJI wants people to take off outdoors with GPS quality 0 or 1 or 2 and the pros and cons (risks)  of taking off outdoors with GPS quality of 0 or 1 or 2.  Hopefully the DJI engineer can explain all that to him and he’ll report back or send me a PM.  

But at this point, I’ll assume you’re saying it wasn’t user error because it’s not in the user manual to wait for white GPS icon.
2023-9-25
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wrong thread ignore
2023-9-25
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DroneApe Posted at 9-25 08:58
Good points you make.  Hopefully the OP can get that sorted out with engineer about user manual and messages on controller screen about GPS and takeoff.  And whether or not it’s user error if it’s not in user manual.  And whether or not DJI wants people to take off with GPS quality 0 or 1 or 2 and the pros and cons (risks)  of taking off with GPS quality of 0 or 1 or 2.  Hopefully the DJI engineer can explain all that to him and he’ll report back or send me a PM.  

But at this point, I’ll assume you’re saying it wasn’t user error because it’s not in the user manual to wait for white GPS icon.

Ofcourse this is, imo,  a pilot error.

If you ignore autolanding warnings for so long....such a warning should be a trigger to fly your drone back home, not continue flight  and be surprised that it will autoland.

cheers
JJB
2023-9-25
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Yeah, I’m just talking about outdoors.  Not indoors.  
2023-9-25
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JJB* Posted at 9-25 09:20
Ofcourse this is, imo,  a pilot error.

If you ignore autolanding warnings for so long....such a warning should be a trigger to fly your drone back home, not continue flight  and be surprised that it will autoland.

But if the DJI software required a GPS quality of minimum of 3 outdoors before takeoff,  could this crash have been avoided in first place?

I’m just waiting to hear from OP/engineer about pros and cons of taking off outdoors with GPS quality of 0 or 1 or 2. Maybe there are a lot of advantages of taking off outdoors with GPS quality 0 or 1 or 2.  Maybe there aren’t any risks.  I’ll just wait for engineer to explain to OP.
2023-9-25
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Sean-bumble-bee Posted at 9-24 20:38
I am curious, in the log there are around 90 "Aircraft will automatically descend in xy" warnings, they run from 21.3 seconds to 123.5 seconds, did they appear on the screen, did you see them? If so, during that count down, why did you fly the drone almost 800ft further AWAY from the 'home point' and presumably you?

Is this the second log that you have posted, either here or on MavicPilots? The area seems familiar for some reason, I'm on the wrong computer to check for another flight in the same area but it does seem familiar.

Having looked on the correct computer I was mistaken, the other flights were 1000 miles to the west.
2023-9-25
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DroneApe Posted at 9-25 09:38
But if the DJI software required a GPS quality of minimum of 3 outdoors before takeoff,  could this crash have been avoided in first place?

I’m just waiting to hear from OP/engineer about pros and cons of taking off outdoors with GPS quality of 0 or 1 or 2. Maybe there are a lot of advantages of taking off outdoors with GPS quality 0 or 1 or 2.  Maybe there aren’t any risks.  I’ll just wait for engineer to explain to OP.

’m just waiting to hear from OP/engineer about pros and cons of taking  off outdoors with GPS quality of 0 or 1 or 2.   ...   I’ll just wait for engineer to explain to OP.

No DJI engineer is going to explain any thing to you.
That just doesn't happen in this forum.

Maybe there are a lot of  advantages of taking off outdoors with GPS quality 0 or 1 or 2.  Maybe  there aren’t any risks.
If you can't answer that for yourself, you don't know much about GPS or drone flying.


2023-9-25
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Dirty Bird Posted at 9-25 12:20
How is the software to know it is "outside" vs. launching inside with no GPS?  Basically such a restriction would prevent most indoor flights.

Excellent point. Hopefully the DJI engineers will read your post and factor in your point if they do decide to make any changes to which GPS quality level should be required in order for drone to “Go for launch”.
2023-9-25
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DroneApe Posted at 9-25 07:44
Howdy,

DJI doesn’t want you to launch the drone outdoors with GPS quality 0 or 1 or 2, yet the software allows you to do it.  I’m just curious why that is.  And my electrical engineer friends are curious too.  Hopefully the DJI engineer can explain it to him. And then he can send me a PM.

There was a time when pilots needed to be able to fly in ATTI Mode. I for one am glad that the aircraft still has the ability to fly even without sufficient GPS. It is a skill that most don't even know about today.  
2023-9-25
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djiuser_1rdg0OtKm2sc
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Same thing happened to me vacationing in Hanoi.  There is a street called Train street where a train runs through a very narrow street lined with coffee shops about 5x a day.  So I thought I’d capture some wonderful footage right above the train at only 20 feet high in the middle of the street.

I launched the app, it said it was an authorization zone.  Unlocked it.  The train was coming through in 5 min so I did a test flight at 8 ft up.  Flew fine for 30 seconds.  Then it flashed a countdown stating forced landing unauthorized area or some similar warning.  I quickly landed it.  At this point, I didn’t want to launch it for the footage.  The train would have taken 30 seconds to pass through and the drone could very well have force landed on top of the train.  Completely stinks because it would have been great footage with no one at risk at only 20 ft up.

Really disappointed in DJI.  This and its horrible performance flying at night (random wandering) is making me look at alternative
1-9 06:42
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djiuser_1rdg0OtKm2sc
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Same thing happened to me vacationing in Hanoi.  There is a street called Train street where a train runs through a very narrow street lined with coffee shops about 5x a day.  So I thought I’d capture some wonderful footage right above the train at only 20 feet high in the middle of the street.

I launched the app, it said it was an authorization zone.  Unlocked it.  The train was coming through in 5 min so I did a test flight at 8 ft up.  Flew fine for 30 seconds.  Then it flashed a countdown stating forced landing unauthorized area or some similar warning.  I quickly landed it.  At this point, I didn’t want to launch it for the footage.  The train would have taken 30 seconds to pass through and the drone could very well have force landed on top of the train.  Completely stinks because it would have been great footage with no one at risk at only 20 ft up.

Really disappointed in DJI.  This and its horrible performance flying at night (random wandering) is making me look at alternative
1-9 06:42
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