First crash of my Mavic Mini

[Thompson973]

Hello. I've become another person to have a crash with the MM. Been flying for just under a month with no real problems. Had one small issue last weekend where mini dropped for no real reason but i seemed to save it before a crash, i put it down to the wind as the gusts where quite strong.
Today was a diffrent kettle fish first flight no issue. Didnt go far as i was checking if the issue from lweekend would occur again but i never. Second flight seemed fine until it dropped and hit the ground in marsh land just past a pond. I was thinking it was same issue as prev wend?
Just really wanting to know if it was my error or an issue with the mini?
Seems fine now but my little confidence has gone i would like to understand why? I always fly near as im newish to mini now. Addtional note my friend was flying his mini in same area with no issue.
Thanks in advance for any help and happy to upload any needed files just let me know?
Thanks again

 

[Flash Grundelore]

Crashed mine the other day for the first time since I took the training cage off and let'er go more than 30 yards away.
Down at our community activity park, I zoomed away, up and over some poplars, off under a set of power lines, flew 3/4 of the way around an old ivy cover shed, but still had visual [sort of]... didn't realize I had already gotten to the limit-of-distance set.
At distance+1yd I clipped a twig on an unseen branch.... the screen spiral of Death! Then, just a dandy view of some grass and the power lines off in the sky. The Mini would spin up the props, but then shut down.

I.GOT.LUCKY!
My lady was doing her health walk and just happened to be on that section of the perimeter path AND looking at the drone when I snapped that twig.
I got a call saying, "You crashed, Didintya?"
She could just walk over, pick it right up and set it back down in a clear zone. Mini took right off and came back [manually of course... it had re-set the RTH point way off over there]
It was a doubly good luck because my walk around to get to the crash site would have been 600-700 yards since there was a creek in the way.

Personally?... I think 90% of the crashes and tragic "fly-aways" are plain, simple, old-fashioned pilot stupidity.

 

[Thompson973]

To be honest i agree totally and if i could prove this instance was error that would suit me. At least then i could learn from it. Been loving the mini and was gaining in confidence each time i fly. But today has set me back.

Just wanting assistance in how to understand where the blame lies me or the unit

 

[Fly Dawg]

Thanks in advance for any help and happy to upload any needed files just let me know?

This sounds like yet another uncommanded descent issue. To confirm that, upload your .txt flight log directly here, or you can upload to this link and share a link back here. DJI Flight Log Viewer | Phantom Help

 

[Thompson973]

Will do as soon as im home. Fly dawg what it cause of this issue and is it something DJI will help with?

This time i was lucky but if its a defect with the mini DJI should help?

No obvious size of damage from today just dirt on the mini niw cleaned as well as getting it wet. Found some water droplets inside. Dried it all out and seems ok.

 

[Fly Dawg]

Fly dawg what it cause of this issue and is it something DJI will help with?

If indeed the data confirms this, the best we have come up with thus far is a possible firmware bug. Other than that, no rhyme or reason for the descents.

 

[new2mavic]

quite similar to this case : DJI Mavic Mini Erratic Aircraft Behavior and Crash

 

[m80116]

Were you flying the Mini at heights ?

 

[Fly Dawg]

Were you flying the Mini at heights ?

Irrelavent to the uncommanded descent issue.

 

[Thompson973]

Flight log DJI Flight Log Viewer - PhantomHelp.com

 

[Fly Dawg]

@Thompson973 This doesn't appear to be the same issue as previous. I suspect this is more related to the VPS. You were flying too close to the ground and the VPS was active for the entire flight. There is descepancy between the VPS and Barometer, so I would suspect that the FC concluded you were too close to the ground and landed. Only a speculation, but as I mentioned this is not the same profile as some others with the uncommanded descent.

 

[Thompson973]

Thanks for looking at the data, so most likely my error fair enough. Just one question before it hit the marsh i did try to raise me altertude should this not overidden the landing.

Lesson learned today dont fly to low.

Thanks again

 

[Thompson973]

@flydawg Could you have a look at the flight from last weekend too pls DJI Flight Log Viewer - PhantomHelp.com

 

[Fly Dawg]

Could you have a look at the flight from last weekend too pls

Same scenario. You never got higher than ~4 meters.

 

[Thompson973]

@flydawg thanks for all your support. Was there the same decrepancy between vps and barometer on both flights? Is this normal? Also could you suggest a low fly limit?

 

[Fly Dawg]

Was there the same decrepancy between vps and barometer on both flights? Is this normal?

Basically yes. And no this is not normal. Being still in a bit of it's infancy, the mini VPS vs Barometer values aren't 100% clear. They should not vary much between the two, depending on the terrain below. The VPS should cease functioning at higher altitude, which leave's the barometer and IMU. If you care to supply the device .dat file, it can be looked at in more detail, but I dought that it will tell much more.

 

[Thompson973]

More than happy to supply if you dont mind looking at it, how do you get to that file?

 

[Fly Dawg]

how do you get to that file?

Mobile device DAT files (DJI GO 4 & DJI Fly)
These are retrieved by the same method as the TXT logs. Under both iOS and Android they are in a subfolder, MCDatFlightRecords, in the folder that contains the TXT logs. The first Flight you posted should be FLY050.DAT and the second, FLY043.DAT.

 

[m80116]

I wouldn't be so sure there's no correlation between altitude, thus barometric pressure and uncommanded descent.

 

[Fly Dawg]

I wouldn't be so sure there's no correlation between altitude, thus barometric pressure and uncommanded descent.

That is where you are mistaken. The correlation is between the VPS/Barometer/FC
The VPS sensors will take over at very low altitudes, however, depending on terrain/lighting etc....It will use both. If these continued to fluctuate, that could be an issue.