Help reading Flight Log for a forced landing?

[Ramacher]

I was hovering over some houses between 150' AGL and 200' AGL messing with the camera settings taking pictures of the christmas lights on the houses when all of a sudden it started descending rapidly. I hit the up on the elevator stick and no response, kept descending and thought it was gonna go into a tree, but then it started going back up and I thought I was ok, but then it did it again. It "auto descended" ignoring my controls 3 times in quick succession. Replaying it in my head I do remember at one or two of the descents I lost connection and when signal came back all I saw was it descending. After the 3rd descent I hit RTH and it did the same thing. Thankfully it came down in a small hedge where the only damage was small nicks to the props (yes I swapped them out)

Anyway, I'm trying to read the log using CsvView and Phantom Help log viewer (DJI Flight Log Viewer - PhantomHelp.com). This is my first mavic and could use some guidance on breaking down what happened.

Some things I noticed:

1. Battery temp is jumping between 76C and 2,483.5C at takeoff and down to 76.9C and 834.753C ?!?
2. CsvView is telling me the RTH altitude was set to 5m? that can't be because I check and adjust it after every takeoff for each flight and I had it set to over 100FT (I clearly remember this because I was arguing with a friend if the tallest tree near the takeoff area was 40' or 60' tall and I set it to at least 100'). It's also the first thing I checked after I recovered it and it was definitely not 5m.
3. CsView is showing "OSD:isNotEnoughForce True" right before it started the first decent and shows it's True till it hit the ground. What does this mean?

Flight Log txt file attached. Let me know if the .dat file would be helpful as well. Also what other flight log viewers do others use? I'm syncing my flights to Airdata as well btw.

 

[pmshop]

I ran the record through AirData since i could not see anything on the Phantom Help log viewer.
Although the wind speed may have been around 3mph on the ground, you were being knocked around by almost 22mph gusts up there.

Here is a link to the data:

 

[pmshop]

**Also noted,

Did you upgrade to firmware 0.0300 yet?
I am seeing a lot of "Not Enough Force/ESC Error"s that was mainly seen with 0.0200

 

[Ramacher]

**Also noted,

Did you upgrade to firmware 0.0300 yet?
I am seeing a lot of "Not Enough Force/ESC Error"s that was mainly seen with 0.0200

Yes I did update to 0.0300 6 days ago. That error directly correlates with the altitude drop.

 

[pmshop]

it is going to be the wind you were flying in then.
Dropped because it was using all of its energy to stabilize.

 

[Fly Dawg]

CsvView is telling me the RTH altitude was set to 5m?

Your RTH Altitude was set for 30 meters.

CsView is showing "OSD:isNotEnoughForce True" right before it started the first decent and shows it's True till it hit the ground.

This relates both to motor power and the ESC. Can you supply the device .dat for additional data?

This appears to be related to the wind and the VPS. Wind warnings went true well before the incident. Once the VPS became active, the aircraft climed as you commanded. Not certain if the wind warnings would cause the descent, but possible.

 

[Ramacher]

Your RTH Altitude was set for 30 meters.


This relates both to motor power and the ESC. Can you supply the device .dat for additional data?

This appears to be related to the wind and the VPS. Wind warnings went true well before the incident. Once the VPS became active, the aircraft climed as you commanded. Not certain if the wind warnings would cause the descent, but possible.

View attachment 87803

I remember seeing the wind warning and then dropping altitude and it going away, that was before it just suddenly started dropping. DAT file attached, I think it's the right one.

Edit: That DAT file was pulled off my phone under Flightrecord\MCDATFLIGHTRECORDS\ folder, is that the right place or do I have to pull it off the memory card in the Mavic Mini?

 

[Fly Dawg]

I remember seeing the wind warning and then dropping altitude and it going away, that was before it just suddenly started dropping. DAT file attached, I think it's the right one.

That is the correct .dat file, however it appears to be corrupted.

 

[Ramacher]

That is the correct .dat file, however it appears to be corrupted.

How about now?

 

[Fly Dawg]

How about now?

Same as before. The aircraft .dat will not help as it is not yet de-crypted for analysis. Not sure what else to offer at this point.
Let me ask @BudWalker Error in CSVView????

 

[BudWalker]

Same as before. The aircraft .dat will not help as it is not yet de-crypted for analysis. Not sure what else to offer at this point.
Let me ask @BudWalker Error in CSVView????

View attachment 87836

Works for me.
Can you provide the .CsvViewLog file in your home directory.
Are you running 3.6.9?

 

[DanMan32]

If the AC was within 20m, approx 60ft of HP, then an RTH would have it start landing. This would include signal loss RTH.

When viewing settings, you have to have the AC connected, otherwise you either see nothing or factory defaults for many of the settings.

 

[DanMan32]

Did the DAT file come from the AC or from the app? The AC version is indeed encrypted but the mobile one is useable.

 

[Ramacher]

Did the DAT file come from the AC or from the app? The AC version is indeed encrypted but the mobile one is useable.

The dat file I provided above came off my phone from the app's folders.

 

[BudWalker]

Did the DAT file come from the AC or from the app? The AC version is indeed encrypted but the mobile one is useable.

The .DAT attached to post #9 came from the App since CsvView/DatCon is able to read it. I don't know why @Fly Dawg can't read it. Possibly he's not using version 3.6.9.

 

[Ramacher]

The .DAT attached to post #9 came from the App since CsvView/DatCon is able to read it. I don't know why @Fly Dawg can't read it. Possibly he's not using version 3.6.9.

So I can load that DAT file into CsvView? What should I be looking for to find out why it keeps auto descending? Have you given it a look?

 

[Fly Dawg]

The .DAT attached to post #9 came from the App since CsvView/DatCon is able to read it. I don't know why @Fly Dawg can't read it. Possibly he's not using version 3.6.9.

That is correct. Im still running 3.6.6......Will update....Thanks for the reminder. ???

 

[BudWalker]

So I can load that DAT file into CsvView? What should I be looking for to find out why it keeps auto descending? Have you given it a look?

i did look briefly. sorry for funky typing, im typing one-handed. i dont have a lot of experience with the MM but it looks like the left back motor was commanded to 100% when the uncommanded descending started happening.


i will guess that the MM decided it needed to land because 100% motor commanded wasn't enough to keep it in place. just a theory.....

 

[Ramacher]

I was flying indoors last night and was getting a bunch of Not Enough Force Errors. I did have the prop guards on, but that shouldn't be causing that right? Would this issue be related?

 

[Fly Dawg]

I did have the prop guards on, but that shouldn't be causing that right? Would this issue be related?

That is possible. Did you take the guards off and see if the errors continued? It should not be related, but the MM is so light, any additional weght at all could cause an issue.