Mavic Air drifting after crash

[Lubos III.]

Hello all,

After startup I flied several meters from my side forward, after that dron without my control continued in movement forward and did hit busches. I tried to stop movement with controller, but drone was not reacting. Fell down from 4 meters to the grass. Nothing visibly broken. I tried to fly again if something is not working well, and I saw that drone started drifting. Sometimes it is Ok, but sometimes I try to go forward, but visible "drifting" is there.

Newest version of software. DJI GO 4. Samsung A520.

I tried both calibrations - drone and controller. But As I mentioned sometimes there is a visible drift. And also can see sometimes strange movements (for example quick change in rotation during flight, duration below 1s) of drone itself during flight.

I checked flight record from crash and directly after that and see some deviations. Any idea what is broken or where is the problem?

Thanks in advance for any idea.

Lubos

flight after crash - see picture below from this flight

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

flight with crash - I am novice nothing special visible from my side

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

 

[skunky1]

I’m also a novice but what stands out is the low number of satellites that will influence stability

 

[lannes]

18 is quite a lot of satellites, minimum is around 11

 

[skunky1]

18 is quite a lot of satellites, minimum is around 11

The links he posted were not 18

 

[lannes]

The links he posted were not 18

Ah right, 2nd flight had 18

 

[nigel]

Ah right, 2nd flight had 18

sounds like it could be dust/dirt in the motors

 

[slup]

In the first flight you didn't wait until you had enough satellites locked until you took off ... this meant that you didn't had any homepoint recorded during the whole flight & even though you in the end got 7 sats locked the IMU/Flight controller still considered the positional accuracy as 0 in navhealth (scale from worst 0-5 best). Several times during the flight & particular in the end you was reverted into ATTI mode ... which don't give any horizontal positional hold at all and no auto breaking when releasing the sticks.

Everything shown in the log depicted in the chart below ... dark blue background areas = ATTI mode, red graph = #satellites locked & green graph = navhealth



Then for the second flight ... I can see some drifting (0,1m/s) in between your aileron & elevator stick commands, have circled them in red. But mainly the MA1 behaves & do what it's commanded.

Red graph = heading speed, blue graph = aileron command (right stick, left right direction) & green graph = elevator command (right stick, forward/backwards).



You say that you've calibrated the drone ... what does that mean, have you calibrated the IMU? Calibrating the IMU is often necessary after drops, crashes or impacts ... try to do that on a very flat (horizontal) surface preferably in a temperature that is slightly colder than where you will be flying (this so the IMU preheating doesn't delay the startup).

 

[pansta]

have you checked the props for damage ???

 

[deathmajor]

have you checked the props for damage ???

This was the first thing that crossed my mind as well. My drone started drifting backwards every time I took off from the ground, until it climbed 1.5 m and stabilized. There wasn't much of a mark, but I replaced the propellers on one arm and then it behaved correctly.

 

[Lubos III.]

Hi All,

thanks for lot of advices!

Yes, i did not wait for enough sattelites, but I had no idea that drone started moving without my control, I moved with that several meters after that it was out of my control

PS: it was not my first flight with this drone, it was I dont know 39th start? Something like that.

1) I did IMU calibration - as described above
2) changed props for a new ones

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

And even with this still drifting. See todays report. Visible drifting is about 11 minute. It should fly in the direction of red arrow, but drifting on the green one. Strange is that it happen only sometimes. See below blue marked direction (from same flight) and it was Ok, no drift. I will probably ask for DJI service support.