Mavic Mini going crazy (log inside)

[darrepac]

Hi

Second time I have a strange behaviour of my Mini.
After takeoff and wait for enough satellites, I 've just gone upwards. Then, at about 30m, the Mini start to go strongly right and start to escape from my eyes... I just had time to press RTH but it tooks him time to come back: it first goes about 500m from my place (!), I thought I lost it and then it comes back.
It was like there was strong wind/storm while there was no wind at all

very strange. Log here: DJI Flight Log Viewer - PhantomHelp.com

 

[grahamjohnson10]

You should not take off until you have about 11 - 12 satellites.

You were very lucky to have got it back.

 

[deathmajor]

At around 107 ft (1) it's starting to roll to stay in place. Likely due to wind. You continue to climb and the roll become worse (2) until it starts drifting away sideways.

After a while, you begin to descend and you can see (3 - colored red) how the roll is reduced. Imho the wind took the drone.

 

[grahamjohnson10]

Very strange I downloaded the original log from phantomhelp and got a totally different flight. !

 

[darrepac]

I agree that it is like the wind took the drone...but the top of the trees (about 20tall) are not moving at all...so I am doubting it was the wind.
Furthermore, once I got it back, I flew without any issue up to 70m high.

 

[darrepac]

The 2 times, I got this issue, it was soon after take off... may-be, as mentionned by Graham I should have waited for more satellites view.... but having 8 satellites should be more than enough to get a position.

 

[Fly Dawg]

@darrepac .. This most certainly looks like a wind issue. As the aircraft was climbing to RTH altitude, it was also drifting away from you. Once the home trek began after reaching RTH altitude, it came right back without issue. GPS is not an issue here at all.

 

[darrepac]

@darrepac .. This most certainly looks like a wind issue. As the aircraft was climbing to RTH altitude, it was also drifting away from you. Once the home trek began after reaching RTH altitude, it came right back without issue. GPS is not an issue here at all.

View attachment 90207

Where this picture come from?

Let's say it is a wind problem. So the aircraft was not able to maintain its position due to the wind (and not slightly drifting, drifting a lot!). But then when it reaches RTH altitude, it came back very easily at about the same speed than when it was drifting. Something weird no?

 

[Fly Dawg]

So the aircraft was not able to maintain its position due to the wind (and not slightly drifting, drifting a lot!). But then when it reaches RTH altitude, it came back very easily at about the same speed than when it was drifting.

Not really weird. It appears to be a narrow band between ~30 and 70 meters. Think of it like a wind river. Notice the roll values and the forward speed. You were rolled severely one way and then the other. It recovered when below 30 meters.

 

[darrepac]

something more: I got no strong wind alert....

 

[Fly Dawg]

something more: I got no strong wind alert....

You may not have seen it from the app but it was there.

 

[slup]

Not really weird. It appears to be a narrow band between ~30 and 70 meters. Think of it like a wind river. Notice the roll values and the forward speed. You were rolled severely one way and then the other. It recovered when below 30 meters.

View attachment 90217

Yeah ... comes to the same conclusion. This is one of the rare occations were a Mini got saved by flying higher

Looked over the topography in Goggle Earth & saw that the flying area were surrounded by really high mountains & the ground were falling in the flying direction leaving HP.



AirData wind map showed a bit unusual picture indicating much stronger winds in the lower part of the flight path.



And last, the log together with that we know that the RTH mode managed to turn the AC in the flight direction towards the HP (turn was to the right in the chart).
The tilt angle were the whole time very near the max 20 degrees that the Mini should manage during RTH (=P-mode). The higher up & further away from
the HP the Mini came the the less wind it was. Actually also thought about a "wind" river that streamed down the falling ground.

 

[old man mavic]

the wind will increase its speed as it comes down a slope a bit like a venturi effect

 

[sar104]

Not really weird. It appears to be a narrow band between ~30 and 70 meters. Think of it like a wind river. Notice the roll values and the forward speed. You were rolled severely one way and then the other. It recovered when below 30 meters.

View attachment 90217

Just a suggestion - the CALC_hSpeed data are always incorrect. If you want horizontal speed use the CUSTOM_hSpeed field instead.

 

[Deleted member 113929]

Yeah ... comes to the same conclusion. This is one of the rare occations were a Mini got saved by flying higher

Looked over the topography in Goggle Earth & saw that the flying area were surrounded by really high mountains & the ground were falling in the flying direction leaving HP.

View attachment 90221

AirData wind map showed a bit unusual picture indicating much stronger winds in the lower part of the flight path.

View attachment 90220

And last, the log together with that we know that the RTH mode managed to turn the AC in the flight direction towards the HP (turn was to the right in the chart).
The tilt angle were the whole time very near the max 20 degrees that the Mini should manage during RTH (=P-mode). The higher up & further away from
the HP the Mini came the the less wind it was. Actually also thought about a "wind" river that streamed down the falling ground.

View attachment 90223

23,36 m/s = 84,09 km/h ? ?

 

[slup]

23,36 m/s = 84,09 km/h ? ?

Yeah ... not so unusual up high, so you never can judge wind speed on altitudes by just feel off the winds in your face & look a bit on the trees.
The unusual in this case was the wind layer with high winds in between one higher & one lower with much calmer winds.

The wind data function in AirData.com are also using the Spark profile for the Mini ... our estimation is that it's showing approx 30% to much for the Mini ...

 

[Deleted member 109934]

Where this picture come from?

Let's say it is a wind problem. So the aircraft was not able to maintain its position due to the wind (and not slightly drifting, drifting a lot!). But then when it reaches RTH altitude, it came back very easily at about the same speed than when it was drifting. Something weird no?

Pilot is the problem in this one.

Starting with 0 satellites on 40% of the battery... many people finish the flight when they see 40%

No matter what people will say or expect, I have noticed MM is quite ok on the first 50% of the battery, the second 50% is just to come back home, especially on windy days. With zero wind, it is a bit different.

 

[Captain.rick]

the wind will increase its speed as it comes down a slope a bit like a venturi effect

Katabatic winds ?