Mavic Mini looses altitude and I don't know why.

[cybervet]

I'm wondering if the minis that show the uncommanded descents are from the combo package or not. It seems that is very easy to bend the propellers in the case that is provided if you are not careful.

 

[Cindy12]

Ok. Here are the .txt and .dat files, and the longer explanation so that the files may make sense. I flew for a while before
anything happened. At first I was flying somewhere near 20/25ish feet (I think). I experienced one or two dips in altitude
that recovered. Then it started descending no matter what I did with the controls. It "bounced" of the ground and I tried
to gain some altitude. This happened a couple of times and I couldn't get more than about 1 foot above the ground. Then I
tried to fly in reverse with not much luck. Then I tried to make it to a nearby road so I didn't have to walk through the mud
to retrieve the drone. No luck there either. Then the low battery warning beeped, and I just brought it down because I
wasn't comfortable with it trying to do a return to home.

Just as a side note, I flew again today, same place, similar conditions, same blades and had no problem. It has happened to
me twice. It seems to be an intermittent problem so I have no way of knowing if any fix actually works. I therefore am afraid
to fly the silly thing.

Thanks for any help!

 

[Myha]

Hi there, and thanks for this detailed explanation. How does one go about downgrading to V3? Many thanks.

Download Assistant 2 from the DJI website and install it onto your PC. Mavic Mini - Specs, FAQs, Videos, Tutorials, Manuals - DJI

When you connect your Mini via the USB cable to your PC a list of previous versions of firmware will be listed. Select the one that I have referenced and re-flash your firmware. Don;t for get to repeat for your controller as well.

 

[Myha]

Of course if you're in an authorization zone that LAANC has legally given you authorization, then you need the latest firmware and app to unlock the zone.

But if the duff version of firmware doesn't allow you to fly then unlocking a zone is the least of your problems surely?!

 

[Myha]

Simply No!
I have experienced an uncommanded descending just one single time yet and that has happened with firmware v1.00.00.0300!
So there is NOTHING what you can actually do to ship around this bug for the future.
I have seen the uncommanded descending problem already occuring with a beta unit in a YouTube video just on the first day after announcement. The guy there thought it has been caused by the altitude he was flying, as he was located on a hill.

I take your point, but I repeated programming v1.00.00.0400 firmware and my Mini started losing height again. It was literally bobbing up and down by about 7 metres as I fought to keep it airborne.
v1.00.00.0300 firmware has not exhibited a single problem and this is why I have left it like this. The last thing I need is an unsafe craft. At the moment I classify my a/c as safe with this version.

One other point that I did notice is that I had originally upgraded via the Fly App, but when I first connected the Assistant 2 program it reported that the v1.00.00.0400 firmware was not correctly installed!! So I re-flashed it again this time using the Assistant 2 software and then I never saw this error again. It seems that the upgrade process via the Fly App could be a little flaky. However, even after programming v1.00.00.0400 using the Assistant 2 program I could not maintain level flight, so I am using v1.00.00.0300 until I consider it worthwhile updating - and certainly not for Remote ID reasons (!!!), but that is another story!

 

[Myha]

I'm wondering if the minis that show the uncommanded descents are from the combo package or not. It seems that is very easy to bend the propellers in the case that is provided if you are not careful.

I am not sure where all these reports of the lack of altitude hold originate. I had problems holding altitude, but this was corrected by downgrading to v1.00.00.0300. I did not touch the props.

 

[GerdS]

It has nothing to do with the props. I never changed mine, not even after the one time experience with uncommanded descending. It this would be caused by bended props I would have seen uncommanded descending again for any further flights.
My problem occured just one day before the 0400 firmware was released, so I immediately updated before flying again.

 

[flynsign]

It's a propeller issue people - because they are so incredibly thin, the case design and/or prop holders being sold distorts them just enough to affect the pitch, hence ability to maintain altitude and even 'fall out of the sky' as MANY have reported. The firmware version seems to make no difference - it's a mechanic problem, plain and simple.

 

[Capt KO]

I'll just keep flying with my care refresh + and keep fighting 'The Mini Descent' until DJI comes up with a recall. Using a float over water so I can try to recover. Still flies and makes a nice handheld gimbal camera. OK backup

** Do not recommend; verified purchase

 

[new2mavic]

Ok. Here are the .txt and .dat files, and the longer explanation so that the files may make sense. I flew for a while before
anything happened. At first I was flying somewhere near 20/25ish feet (I think). I experienced one or two dips in altitude
that recovered. Then it started descending no matter what I did with the controls. It "bounced" of the ground and I tried
to gain some altitude. This happened a couple of times and I couldn't get more than about 1 foot above the ground. Then I
tried to fly in reverse with not much luck. Then I tried to make it to a nearby road so I didn't have to walk through the mud
to retrieve the drone. No luck there either. Then the low battery warning beeped, and I just brought it down because I
wasn't comfortable with it trying to do a return to home.

Just as a side note, I flew again today, same place, similar conditions, same blades and had no problem. It has happened to
me twice. It seems to be an intermittent problem so I have no way of knowing if any fix actually works. I therefore am afraid
to fly the silly thing.

Thanks for any help!

The DAT file posted is the wong one. The correct one should have the name ending with FLY032.DAT.

Throughout the flight there was a lot of "max power load reached" warning which is one of the signature of the uncommanded descent problem. Did you see it on the phone's screen in the problemetic flight and the normal one today ? This is the DJI GO screen capture when my Mini went into uncommanded descent :

May be you can also post the .DAT and .TXT files of the flight today so some comparison between the two flights can be made.

 

[GerdS]

It's a propeller issue people - because they are so incredibly thin, the case design and/or prop holders being sold distorts them just enough to affect the pitch, hence ability to maintain altitude and even 'fall out of the sky' as MANY have reported. The firmware version seems to make no difference - it's a mechanic problem, plain and simple.

Again, if it would be a propeller issue then the problem would stay permanently and not disappear again just from one flight to the next one.
In my case it happened during slow flying or even hoovering with very low wind.

 

[Cindy12]

That is the .dat file with the correct date on it. I don't have one with FLY32.dat. I don't remember if the max powere error messages were on the screen, I was more focused on watching the drone. Although I do think I saw that message today.
I have attached todays files.

 

[slup]

It's a bit hard to find longer periods in this flight (your first provided TXT log, Feb 22) enough consistent to judge properly ... It was a low height flight over a field with a lot of combined stick inputs in all directions. But after looking at some sections in the log it's pretty clear the AC didn't generate enough lift anywhere ... From approx 865sec all inputs meant to increase horizontal speed (elevator or Aileron) results in a descent if not backed up with a positive throttle. Once horizontal transport stick inputs were stopped the AC somewhat recovered. From there the logs also show a large AC pitch instability.

My belief is that once/if the correct DAT log is provided (FLY032.DAT) we will again find rear motors on max RPM's, typical for the Mini's "uncommanded descent" events.



Below all the messages from the log ... the winds should have been manageable with 3,8m/s in average with gusts up to 6m/s.

 

[slup]

That is the .dat file with the correct date on it. I don't have one with FLY32.dat. I don't remember if the max powere error messages were on the screen, I was more focused on watching the drone. Although I do think I saw that message today.
I have attached todays files.

These logs (Feb 23) doesn't show any uncommanded descents ... the AC follow your throttle commands pretty good.

 

[Cindy12]

Correct. I didn’t have any problems on the 23. Same propellers.

 

[Cindy12]

It's a bit hard to find longer periods in this flight (your first provided TXT log, Feb 22) enough consistent to judge properly ... It was a low height flight over a field with a lot of combined stick inputs in all directions. But after looking at some sections in the log it's pretty clear the AC didn't generate enough lift anywhere ... From approx 865sec all inputs meant to increase horizontal speed (elevator or Aileron) results in a descent if not backed up with a positive throttle. Once horizontal transport stick inputs were stopped the AC somewhat recovered. From there the logs also show a large AC pitch instability.

My belief is that once/if the correct DAT log is provided (FLY032.DAT) we will again find rear motors on max RPM's, typical for the Mini's "uncommanded descent" events.

View attachment 94907

Below all the messages from the log ... the winds should have been manageable with 3,8m/s in average with gusts up to 6m/s.

View attachment 94911

I don’t know where else to look for the .dat file. I only flew once that day and FLY033.dat is the only file with that date. This is just a curiosity question because I am so new to this, how do you know I should be looking for a FLYO32.dat file? I would eventually like to figure out how to read these things.

 

[BudWalker]

I don’t know where else to look for the .dat file. I only flew once that day and FLY033.dat is the only file with that date. This is just a curiosity question because I am so new to this, how do you know I should be looking for a FLYO32.dat file? I would eventually like to figure out how to read these things.

Just to be clear. Is there a FLY032.DAT - regardless of the date?

 

[cybervet]

Did you synch the fly app?

 

[slup]

I don’t know where else to look for the .dat file. I only flew once that day and FLY033.dat is the only file with that date. This is just a curiosity question because I am so new to this, how do you know I should be looking for a FLYO32.dat file? I would eventually like to figure out how to read these things.

If it's missing then that's it ... it's gone which isn't uncommon when it comes to the Mini, we have seen it in several cases.

The info regarding which DAT that belongs to which TXT is available in the TXT log ...

 

[Cindy12]

Just to be clear. Is there a FLY032.DAT - regardless of the date?

There is no FLY032.DAT of any kind. ?