DJI Mini 3 - Fell Out Of The Sky With Props Stopping Mid Air

[osibek]

I was flying the drone today in an open field. There were around 10-12 GPS satellites available but it was still showing "hover with caution". I had started another hovering, when the blades simply stopped rotating around and it fell out of the sky, causing damage to the rear right rotor (attached). There was no collision. I have attached the log and there was ample battery, it just stopped hovering. This seems like a manufacturing issue. (Attached flight logs to for you to check if there was any error on my end for such a situation to occur)

LOG

 

[msinger]

Your flight log doesn't show anything unusual. It just abruptly ends mid-flight. This looks like a case where the battery disconnected from drone.

 

[osibek]

Your flight log doesn't show anything unusual. It just abruptly ends mid-flight. This looks like a case where the battery disconnected from drone.

This is a brand new drone - not even a week old! Why will the battery disconnect? No crashes nothing. What do you suggest? Am I eligible for a refund?

 

[Phantomrain.org]

There are Two clicks on the battery , the first one can fake you out if the lights come on, its the second click that you need to secure the battery. Do you slam your battery in or did you just place it in gently.

Phantomrain.org
Gear to fly your Mini 3 in the Rain.

 

[Cafguy]

Why will the battery disconnect? No crashes nothing. What do you suggest? Am I eligible for a refund?

Many reasons- Maybe you didn't make sure it was seated properly, Maybe the battery was bad and swelled enough to detach, -vibration. I would start a ticket with DJI. I am not DJI BUT you should explain it to them Perhaps they will send you a replacement.

 

[osibek]

Many reasons- Maybe you didn't make sure it was seated properly, Maybe the battery was bad and swelled enough to detach, -vibration. I would start a ticket with DJI. I am not DJI BUT you should explain it to them Perhaps they will send you a replacement.

There are Two clicks on the battery , the first one can fake you out if the lights come on, its the second click that you need to secure the battery. Do you slam your battery in or did you just place it in gently.

Phantomrain.org
Gear to fly your Mini 3 in the Rain.

The battery was absolutely secured and never got wet ever. Batteries are in perfect condition. The latching was perfectly secure too. No issues with that. Yes there were two clicks.

 

[osibek]

Many reasons- Maybe you didn't make sure it was seated properly, Maybe the battery was bad and swelled enough to detach, -vibration. I would start a ticket with DJI. I am not DJI BUT you should explain it to them Perhaps they will send you a replacement.

The battery was absolutely secured and never got wet ever. Batteries are in perfect condition. The latching was perfectly secure too. No issues with that. Yes there were two clicks.

 

[Cafguy]

The battery was absolutely secured and never got wet ever. Batteries are in perfect condition. The latching was perfectly secure too. No issues with that. Yes there were two clicks.

Start a ticket.

 

[osibek]

Start a ticket.

I am from India. DJI is asking me to visit registered service centre here, who will charge money. Can anyone suggest a way to claim refund/replacement?

 

[slup]

If we take your 2 issues one at a time...

...There were around 10-12 GPS satellites available but it was still showing "hover with caution".

You took this flight just near a horse shoe shaped high building... this mainly shielded the sky from 3 directions, only leaving a small patch of clear sky just above.



This made the positional data very unreliable... this is indicated in the log by a value called Gps level. This value spans from 0 (worst) up to 5 (best). The HP isn't recorded until this value reaches 4 for instance. This value was on 2 the whole flight which meant that the flight controller had little confidence in the positional accuracy.

You need to wait until the satellite icon near the top of your screen turns white. If it's red or yellow, the GPS positional data is unreliable.

I had started another hovering, when the blades simply stopped rotating around and it fell out of the sky...This seems like a manufacturing issue.

This is... as already said, most likely a some kind of full or partial power failure (not necessarily coming from the battery)... & this doesn't look to be a pilot error at all, would surprise me if DJI doesn't honor a warranty in this case.

Below is the relevant log data both for the "hover with caution" message" & the drone shut down mid air...

(The time line doesn't start from 0sec as this probably was the last flight of several from the same drone power on)

You have an explanation over what each graph represent in the legend under the chart... the values there is from the very end of the chart (log) where I've placed the chart marker... the interesting facts here is that:

-You didn't had a HP recorded
-The GPS level was only 2
-The battery seemed to behave normal
-The cell voltages corresponds well with the calculated battery percentage
-The battery didn't suffer from any noticeable cell deviation
-The drone was airborne...
-When the motors is reported to be shut off (isMotorOn=False)
-This log type ends when the motors is shut off

(click on the chart to make it larger)

 

[osibek]

If we take your 2 issues one at a time...


You took this flight just near a horse shoe shaped high building... this mainly shielded the sky from 3 directions, only leaving a small patch of clear sky just above.

View attachment 171844 View attachment 171845

This made the positional data very unreliable... this is indicated in the log by a value called Gps level. This value spans from 0 (worst) up to 5 (best). The HP isn't recorded until this value reaches 4 for instance. This value was on 2 the whole flight which meant that the flight controller had little confidence in the positional accuracy.

You need to wait until the satellite icon near the top of your screen turns white. If it's red or yellow, the GPS positional data is unreliable.

View attachment 171846


This is... as already said, most likely a some kind of full or partial power failure (not necessarily coming from the battery)... & this doesn't look to be a pilot error at all, would surprise me if DJI doesn't honor a warranty in this case.

Below is the relevant log data both for the "hover with caution" message" & the drone shut down mid air...

(The time line doesn't start from 0sec as this probably was the last flight of several from the same drone power on)

You have an explanation over what each graph represent in the legend under the chart... the values there is from the very end of the chart (log) where I've placed the chart marker... the interesting facts here is that:

-You didn't had a HP recorded
-The GPS level was only 2
-The battery seemed to behave normal
-The cell voltages corresponds well with the calculated battery percentage
-The battery didn't suffer from any noticeable cell deviation
-The drone was airborne...
-When the motors is reported to be shut off (isMotorOn=False)
-This log type ends when the motors is shut off

(click on the chart to make it larger)
View attachment 171847

This is super helpful. Thank you for this. I have written to DJI and they said they will reply in 24 hours. I am also keen to understand, how you got the motor data ? (From which website)

I would attach this to the DJI Thread.
Really helpful, once again. I will keep this thread updated as it progresses.

 

[osibek]

Hi @slup, also need your help to understand

1. What does the OSD vpsheight mean ? Why does it rise post crash?
2. How does GPS number and GPS signal vary?

 

[Yorkshire_Pud]

Uuuum do DJI officially sell drones in India, I have a nagging feeling that they do not since they are not allowed to import them or something like like. Hopefully I am wrong but..........if not they may not honour warranty,
@slup 's plot is produved by CsvView I think.

CsvView Downloads

or perhaps DatCon.
VPS height is the height of the drone as measured by the sensors on the bottom of the drone.
I haven't looked at the log yet but if it was a battery disconnection then the rise seen in the VPS height is PRIOR to the disconnection and crash.

If you have not synced logs with DJI can you find the corresponding DAT file in the MCDatFlightRecords folder. Its name will contain "FLY0006". If you do find it can you it can you upload it to a file hostong website, make its page public and post a link here.
If you have sync'ed logs with DJI the DAT will have been deleted.

 

[msinger]

I am also keen to understand, how you got the motor data ?

TXT flight logs show whether or not the motors are running. You can see they turned off in the last line of your flight log here:



The most likely cause was an abrupt loss of power since there was no command from the remote controller to stop the motors. For example, the battery might not have been fully inserted before takeoff or some other power related hardware failed.

 

[slup]

...I am also keen to understand, how you got the motor data ? (From which website)

This is simply a indication in the .TXT log about motors on or off... much more motor related data is in the 2 other logs that ends with .DAT... one of them is stored in the drone itself (encrypted, not readable for anyone besides DJI) & one in the screen device you used when you flew (this can be readable, but don't know about the one for a Mini 4 Pro... it can be encrypted also though).

Hi @slup, also need your help to understand

1. What does the OSD vpsheight mean ? Why does it rise post crash?
2. How does GPS number and GPS signal vary?

VPS height (visual positioning sensor) is the actual height beneath the drone in each & every moment & comes from the sensors on the belly of the drone... so even though the height above the home point is constant the VPS height can fluctuate if the ground the drone flies over is uneven... added that data in the chart to show that the drone really was airborne.

The # of locked satellites & how reliable the position is can differ major... what matter for a good reliable position is that the locked in satellites are spread out in the sky... if you have dozens of sats locked but all are straight above you the positional accuracy/reliability will be lousy... if you instead have a minimum # of sats (usually it's around 5-8 for it to work) & they are well spread out in the sky the positional accuracy/reliability will be good.

As you flew where you did... you blocked the larger part of the sky, depriving the drone a full view of the sky & by that it could just lock to those right above you.

 

[slup]

...much more motor related data is in the 2 other logs that ends with .DAT... one of them is stored in the drone itself (encrypted, not readable for anyone besides DJI) & one in the screen device you used when you flew (this can be readable, but don't know about the one for a Mini 4 Pro... it can be encrypted also though)...

Sorry, don't know why, but assumed you had a Mini 4 Pro... when it actually was a Mini 3.

The screen device stored .DAT log with the motor data isn't encrypted for a Mini 3... meaning we can read it.

If you want more info when discussing with DJI, you can retrieve the log that ends with FLY0006.DAT... it's stored in the same place as the .TXT log but in a sub-folder there called MCDatFlightRecords & share it with us.

 

[osibek]

Sorry, don't know why, but assumed you had a Mini 4 Pro... when it actually was a Mini 3.

The screen device stored .DAT log with the motor data isn't encrypted for a Mini 3... meaning we can read it.

If you want more info when discussing with DJI, you can retrieve the log that ends with FLY0006.DAT... it's stored in the same place as the .TXT log but in a sub-folder there called MCDatFlightRecords & share it with us.

Attached

 

[osibek]

Uuuum do DJI officially sell drones in India, I have a nagging feeling that they do not since they are not alloowed to import them or something like like. Hopefully I am wrong but..........if not they may not honour warranty,
@slup 's plot is produved by CsvView I think.

CsvView Downloads

or perhaps DatCon.
VPS height is the height of the drone as measured by the sensors on the bottom of the drone.
I haven't looked at the log yet but if it was a battery disconnection then the rise seen in the VPS height is PRIOR to the disconnection and crash.

If you have not synced logs with DJI can you find the corresponding DAT file in the MCDatFlightRecords folder. Its name will contain "FLY0006". If you do find it can you it can you upload it to a file hostong website, make its page public and post a link here.
If you have sync'ed logs with DJI the DAT will have been deleted.

 

[BudWalker]

Attached

I have several Mavic Mini 3 .DATs that are not encrypted. However, the MM3 .DATs you submitted are encrypted. I'm supposing that this is due to a FW update.
@slup

 

[slup]

I have several Mavic Mini 3 .DAT that are not encrypted. However, the MM3 .DATs you submitted are encrypted. I'm supposing that this is due to a FW update.
@slup

Yeah... sitting with it right now & came to the same conclusion.