Mavic Mini crash: Pilot error, software bug or hardware failure?

DombiF · Jan 8, 2020

Few days ago I had my first Mavic Mini crash. Till this day I had more than 50 flights without any issue. With more than 5 years of droning I consider my self a veteran....
The crash happened during a proximity flight after flashed the new firmware .400. First minute of flight was OK, no sign of what will be happen. Then for no reason it began to lose altitude. I felt that I have no more control over the drone. The drone was very close to me (30meters), so it could not be about signal loss.

Any suggestion how to avoid such failures? I think do not flying in could, fog, wind, sun, near electric cables, near WIFI antennas can be avoided all the time...

netsonic · Jan 8, 2020

Good morning, please share your flight logs. Just by looking at a video your guess is as good as everyone else.

Next steps:

Mavic Flight Log Retrieval and Analysis Guide

With the introduction of the Mavic Mini there has been a noticeable uptick in the number of posts requesting help with lost or crashed aircraft. While there is plenty of help and advice available on this forum, and detailed guidance and options on several other websites, I thought that perhaps a...

mavicpilots.com

LOG FILE RETRIEVAL

Mobile device DJI TXT logs

The log naming convention, based on the date and time of the start of the flight, is: DJIFlightRecord_YYYY_MM_DD_[hr-min-sec].txt.

Detailed instructions are available on @msinger's excellent PhantomHelp website and also on AirData, but the basic details are as follows:

With iOS devices running DJI GO 4 you need to access the app files via computer, either using iTunes or with a file system browser such as iExplorer. The TXT logs are in Apps » DJI GO 4 » FlightRecords. The same method can be used to access DJI Fly files in DJI Fly » FlightRecords, but with DJI Fly they are also accessible using the iOS Files app by selecting Browse » On My iPhone » DJI Fly » FlightRecords.

With Android devices the file system should mount when plugged into a Windows machine, or via various software options on a Mac. With DJI GO 4 the TXT logs are in DJI » dji.go.v4 » FlightRecord. With DJI Fly they are in DJI » dji.go.v5 » FlightRecord.

If you want help analyzing the data then you can either retrieve the logs and post them here directly, or upload them to PhantomHelp or AirData and post the link back here.

UGel · Jan 8, 2020

Very interesting case. I dont think that fog could so badly affect motors, maybe cold. Did you send information to DJI support service, what they analysis say about this case?

LeSchmoo · Jan 8, 2020

Fog causing auto land?

new2mavic · Jan 8, 2020

Sorry for what has happend but MM falling out of the sky for no apparent reasons has been reported quite a number of times. From your footage it seems that one of the motors suddenly failed to produce thrust despite being asked by the flight controller to spin at maximum speed. The fact that it could hover normally afterwards proves that it's not any permanent hardware failure. If you can upload the .TXT and .DAT flight log files, it will be easier for the reasons to be identified.

GerdS · Jan 8, 2020

At least flying with strong fog is no good idea. The humidity can condensate within the aircraft and cause short circuits.
Was the rotation while descending commanded? If not, it is an indication for problems with at least one ESC.

Alan_M · Jan 8, 2020

new2mavic said:
Sorry for what has happend but MM falling out of the sky for no apparent reasons has been reported quite a number of times. From your footage it seems that one of the motor suddenly failed to produce thrust despoite being asked to spin at maximum speed during the flight.

Lets keep in mind that on examination of log files, most of these “no apparent reasons” turned out to be pilot error.

DombiF · Jan 8, 2020

UGel said:
Very interesting case. I dont think that fog could so badly affect motors, maybe cold. Did you send information to DJI support service, what they analysis say about this case?

yes, I sent them app and aicraft logs and camera footage

DombiF · Jan 8, 2020

GerdS said:
At least flying with strong fog is no good idea. The humidity can condensate within the aircraft and cause short circuits.
Was the rotation while descending commanded? If not, it is ań indication for problems with at least one ESC.

"Was the rotation while descending commanded?" No. This is why more than a simple "auto land"

new2mavic · Jan 8, 2020

Alan_M said:
Lets keep in mind that on examination of log files, most of these “no apparent reasons” turned out to be pilot error.

The pilot input is quite clear in this case, just max throttle. The craft was basically hovering when it happened. It suddenly spinned like crazy before it dropped onto the trees. There was the message "max power load reached ... ". There has been almost identical cases reported recently in this forum. Examination of the log file has indicated that one of the motors at the back could not produce sufficient thrust despite asked to spin at maximum speed ( hence the message "max load power.... " ).

netsonic · Jan 8, 2020

new2mavic said:
It suddenly spinned like crazy before it dropped onto the trees. There was the message "max power load reached ... ". There has been almost identical cases reported recently in this forum. Examination of the log file has indicated that one of the motors at the back could not produce sufficient thrust despite asked to spin at maximum speed ( hence the message "max load power.... " ).

Valid, points until proven otherwise, but DombiF is not posting any logs. We can continue and speculate long time, without really knowing what happened. With logs someone would look and shed light on the issue.

Open questions:

What exactly does OP want to achieve?
Get possible reasons?
Finding out the cause ?
Getting views for the video ?
Maybe all of the above together ?

Hey @DombiF, unsere Glaskugeln sind heute ausgeschaltet.

Ohne passenden Logs wird hier pur spekuliert, es sei denn dies ist auch die Absicht. Bitte die Logs nachreichen, wenn du den wahren Grund wissen willst.

Meta4 · Jan 8, 2020

DombiF said:
yes, I sent them app and aicraft logs and camera footage

Making guesses without evidence of what happened is pointless.
If you want to find out, you have to supply the recorded flight data.

Replayman · Jan 8, 2020

DombiF said:
Few days ago I had my first Mavic Mini crash. Till this day I had more than 50 flights without any issue. With more than 5 years of droning I consider my self a veteran....
The crash happened during a proximity flight after flashed the new firmware .400. First minute of flight was OK, no sign of what will be happen. Then for no reason it began to lose altitude. I felt that I have no more control over the drone. The drone was very close to me (30meters), so it could not be about signal loss.

Any suggestion how to avoid such failures? I think do not flying in could, fog, wind, sun, near electric cables, near WIFI antennas can be avoided all the time...

Flying in foggy and cold weather is not good idea. I know where is your broblem. On your propellers was icing and the drone lost its buoyancy and fall down. The air humidity freezes on the propellers.
Here is video about it (but video is only czech language) -

deathmajor · Jan 8, 2020

new2mavic said:
The pilot input is quite clear in this case, just max throttle. The craft was basically hovering when it happened. It suddenly spinned like crazy before it dropped onto the trees. There was the message "max power load reached ... ".

At the same time, the stick configuration on the video reports that he turned it hilmself. The drone suddenly turned left and a second later, it reports the command to turn left. Quickly after, the drone starts to turn right, and command input another second after shows turning right all the way down to the ground. Looking through the whole video, there seem to be a constant delay in reporting the stick commands in comparison with the turns. Hence, I believe the rotation was caused by the pilot.

I second Replayman that ice buildup might be a plausible cause.

new2mavic · Jan 8, 2020

Replayman said:
Flying in foggy and cold weather is not good idea. I know where is your broblem. On your propellers was icing and the drone lost its buoyancy and fall down. The air humidity freezes on the propellers.
Here is video about it (but video is only czech language) -

It seems that at the second part of the video the guy was trying to reproduce the sudden rapid drop in altitude due to the alleged icing problem but he was unable to repeat it ?

deathmajor · Jan 8, 2020

DombiF said:
"Was the rotation while descending commanded?" No.

According to your own video, it was.

Replayman · Jan 8, 2020

new2mavic said:
It seems that at the second part of the video the guy was trying to reproduce the sudden rapid drop in altitude due to the alleged icing problem but he was unable to repeat it ?

In second part of video - he want show that you can have ice on propellers in small height too.. but in bigger height is more freezy than on ground. Don't recommend flying in foggy and cold weather. And i don't recommend flying in cold weather over water...Evaporating water and increased air humidity can cause icing as well.

Dave Maine · Jan 8, 2020

There is no point in long discussions without logs to this forum. You waste everybody’s time with your opinions and speculations.

atsphenomenon · Jan 8, 2020

DombiF said:
Few days ago I had my first Mavic Mini crash. Till this day I had more than 50 flights without any issue. With more than 5 years of droning I consider my self a veteran....
The crash happened during a proximity flight after flashed the new firmware .400. First minute of flight was OK, no sign of what will be happen. Then for no reason it began to lose altitude. I felt that I have no more control over the drone. The drone was very close to me (30meters), so it could not be about signal loss.

Any suggestion how to avoid such failures? I think do not flying in could, fog, wind, sun, near electric cables, near WIFI antennas can be avoided all the time...