Hi to all !
I am Evan from Greece and i think i have an IMU problem like other Mavic Air owners here ...


Today during flight over sea, My Mavic air became unstable and drifted left !!!

Then i pressed RTH and everythg was ok ...

The message was "Warning:In flight,working IMU encounters attitude exception, please slowly get craft back behave abnormaly"

Attaching photos

Sorry photos order descending !!!

have you done an imu calibrate

Not today but i did.

More data

engelo Posted at 2018-6-9 08:59
More data[view_image]

Can you post logs to link below.
Just click on link and follow instructions come back here and post your link


http://www.phantomhelp.com/LogViewer/Upload/

Please consider adding your polite and readable  views on this post.
https://forum.dji.com/thread-151889-1-1.html

http://www.phantomhelp.com/LogViewer/5H091A8V0STZ0ZSMLPHD/

Do not see anything wrong with the flight so not sure.  I just suggest reinstalling the firmware on the AC/RC using DJI assistant plugged into PC/MAC then reinstall DJI GO 4 app  and do a IMU/Gimbal/Compass/RC/VPS calibration.  If that does not work then open a ticket with DJI and send in.  

SparksBird Posted at 2018-6-9 10:15
Do not see anything wrong with the flight so not sure.  I just suggest reinstalling the firmware on the AC/RC using DJI assistant plugged into PC/MAC then reinstall DJI GO 4 app  and do a IMU/Gimbal/Compass/RC/VPS calibration.  If that does not work then open a ticket with DJI and send in.

Minutes ago i did all that you said.

BUT  i am afraid to fly again because other pilots where not so lucky and lost their craft !!!

Maybe i wil try tomorrow ... maybe...

engelo Posted at 2018-6-9 10:18
Minutes ago i did all that you said.

BUT  i am afraid to fly again because other pilots where not so lucky and lost their craft !!!

Totally understand.  Possible in open field flying low do some tests through a battery or two and see if the error returns but obviously up to you as it is a risk.   Sorry cannot be more help.  

Maybe you were saved by the second IMU in the Mavic Air after the first one went wonky.

Thank you all.

Hummingbird.UAV Posted at 2018-6-9 12:50
Maybe you were saved by the second IMU in the Mavic Air after the first one went wonky.

Are you sure about double IMU?

engelo Posted at 2018-6-9 21:16
Are you sure about double IMU?

Mavic Air: Double IMU - Single magnetic compass & Vision Compass
How many IMU's and Compass has the new Mavic Air?

Thank you...

engelo Posted at 2018-6-9 21:16
Are you sure about double IMU?

Yes if you read the specification it states dual IMU, dual compass for the Mavic Air.

engelo Posted at 2018-6-9 10:09
http://www.phantomhelp.com/LogViewer/5H091A8V0STZ0ZSMLPHD/

Imu exceptional heading is often caused by problems with compass, I see from your log that you seem to have taken off from what looks like an industrial yard of some sort. Is it possible you picked up some interference on the ground there before take off, it won’t necessarily show on your app but problems can start in thr air and not always straight away, I will explain below.

Magnetic interference on the ground taking off on ground which contains rebar concrete underground cables, a few things you need to know, what happens to aircraft resulting from taking off in these areas.

I will try to explain.
First if you start up your Aircraft in a safe area, without taking off lift up your Aircraft by hand and rotate 90 degrees, both compass and IMU will follow to this new heading, so no problem this is how it should be.
Taking off from mag interference ground will cause your compass to move it’s heading this does not always show up in your app, so it will still allow you to take off.
Once you take off and get clear of mag interference your compass will then correct itself but the movement made by compass causes confusion in your IMU because it is designed to move with compass.
This you will see reported on your app as IMU exceptional heading compass error, switch to Atti mode, your aircraft cannot cope with conflicting data so it will usually drop gps in favour of compass.

And although all of above didn’t pan out, it’s most likely that your compass was off the heading at launch corrected itself but at the same time confusing IMU causing exceptional heading.

hallmark007 Posted at 2018-6-10 03:56
Imu exceptional heading is often caused by problems with compass, I see from your log that you seem to have taken off from what looks like an industrial yard of some sort. Is it possible you picked up some interference on the ground there before take off, it won’t necessarily show on your app but problems can start in thr air and not always straight away, I will explain below.

Magnetic interference on the ground taking off on ground which contains rebar concrete underground cables, a few things you need to know, what happens to aircraft resulting from taking off in these areas.

I am flying there with my Mavic Pro, Phantom 4 Pro, Inspire1 and Inspire 2.

ONLY Mavic air did this. I dont think its the place.

engelo Posted at 2018-6-10 07:07
I am flying there with my Mavic Pro, Phantom 4 Pro, Inspire1 and Inspire 2.

ONLY Mavic air did this. I dont think its the place.

i think you might find mavic air because it is very near the ground much more susceptible and prone to picking up interference on the ground. but you will know this better than I.

Hi,there. Engelo, with regards to this, may I know if you have done all of the pre-flight checklists, for example, making sure that everything is up to date, having done the calibrations, like the IMU and the Compass?

DJI Gamora Posted at 2018-6-10 08:35
Hi there Engelo, with regards to this may I know if you have done all of the pre-flight checklists such as making sure that everything is up to date and you have done the calibrations like the IMU and the Compass?

Hi,
yes EVERYTHING is up to date (ipad ios, DJI App) and yes to Compass calibration. IMU calibration  not so often.

Its not my first drone.