Hi! Sorry for the long post, but here goes:

Tonight I had an unpleasant flight with my P4A; Started up as normal, with Litchi. Props check, waited for GPS and RTH to lock on. Started the flight - just some meters away from me. When letting go of the controller forward, the drone drifted right and stopped. Flew to my destionation, approx 200m distance and 60m up to take pictures. I could see that the drone flew in a small circular pattern, but stayed steady after a short while. Took my pictures and decided to return home. But, the remote did not respond. The only reaction i got, was the camera turning slightly when pushing the left stick, othwerwise nothing. Did not get any warnings, and signals showed 100% in app. I pressed RTH on the app and it did as supposed to do, but i couldnt abort the RTH until almost home.

I changed to new props, changed to a new battery. Launched again using the DJI GO 4 app, and after a couple of seconds it showed compas error. Returned manually home and did a successful calibration of the compas. Tried yet another flight, but suddenly the drone drifted left and all LEDs on the drone turned red. Managed to regain controll of the drone and returned home...

Synced flight data with Airdata UAV, but only notification showing up there is a Data Loss of 1,3 seconds midflight in the first flight. Other than that - nothing!

Checked weather, all green-to-go, Kp index of 2 and had 18 sats locked in.

Anyone who may know what this is all about?

All updates etc done

Regards!

Please post the flight LOG data. Thanks

http://www.phantomhelp.com/LogViewer/Upload/
Let's have a wee look inside. ;-)

You like to live dangerously? Haha

RedHotPoker

Log files

sonnavindDF Posted at 2018-5-13 12:50
Log files

Your attachment can't be read.
Try following the instructions at Phantomhelp.com and post a link to the report it gives you

Launched again using the DJI GO 4 app, and after a couple of seconds it showed compas error. Returned manually home and did a successful calibration of the compas. Tried yet another flight, but suddenly the drone drifted left and all LEDs on the drone turned red.
A compass error isn't a fault in the compass that you need to correct.
It's your compass telling you of a problem that it's detected.
Calibrating the compass doesn't "fix" the problem that your compass was warning you about.
(Really there should never be any need to calibrate your compass under normal circumstances)

What can you say about the spot where you launched?
Calibrating the compass

PS .. the KP index is completely irrelevant.
It has no effect on your Phantom flying.

DJI GO4: http://www.phantomhelp.com/LogViewer/MPBEJIJZH043H73Q3XSI/

LITCHI first flight: http://www.phantomhelp.com/LogViewer/V4K0RXSMQFEQQNCDBC15/
It was here i "lost controll" of the drone, sticks not responding other than camera slightly sideways and pushed RTH in app.

LITCHI second flight: http://www.phantomhelp.com/LogViewer/Z2ORWVWCVEIGVLH3GA5V/
This is where it drifted away left, and all four LEDs turned red. Regained control of the drone after a couple of sec.

Labroides Posted at 2018-5-13 12:54
Your attachment can't be read.
Try following the instructions at Phantomhelp.com and post a link to the report it gives you

I launched from my wooden veranda outside the house. No metal except from a some nails in the deck. WIFI inside actually turned off - not purposely ;) Launched several times there before without any issues

Nothing to give interference aroung my house, and the issues occured both nearby and >150m away

There are no compass error messages in the flight logs.
What I see is you switching to atti mode in the first flight
1:57.8-2:12.1  &  5:26.7-5:26.9
In the second flight you also tried atti mode from:
9:27.1-9:29  &  11:28.9-11:33.7
That may account for some disorientation and drifting if you weren't aware of it.

Labroides Posted at 2018-5-13 13:45
There are no compass error messages in the flight logs.
What I see is you switching to atti mode in the first flight
1:57.8-2:12.1  &  5:26.7-5:26.9

Thats the funny part - only switched to atti more once to see if the drift would be the same - which it wasnt....  and the DJI GO4 app showed warning og compass error... Something is not right here... The log file from litchi doesent show any error messages, cant even see when activated rth?

sonnavindDF Posted at 2018-5-13 14:04
[view_image]

If that flight only lasted 49 seconds, it's not one from the flight logs you gave links for.
They were 5 and 12 minutes long and show no problems between 10-30 seconds
Yaw errors are almost always due to launching from close to steel, such as from a car roof or reinforced concrete.
If you launched with your compass close to a nail or bolt, that could be the issue.

ps .. a Yaw Error would display a compass error message.

Labroides Posted at 2018-5-13 14:08
If that flight only lasted 49 seconds, it's not one from the flight logs you gave links for.
They were 5 and 12 minutes long and show no problems between 10-30 seconds
Yaw errors are almost always due to launching from close to steel, such as from a car roof or reinforced concrete.

Yes, it is the first one i linked to, with the dji go 4 app: https://forum.dji.com/forum.php? ... amp;fromuid=1162917

This is what the airdata shows around when i couldnt get control of the drone first flight and had to use the rth from in-app

sonnavindDF Posted at 2018-5-13 14:11
Yes, it is the first one i linked to, with the dji go 4 app: https://forum.dji.com/forum.php?mod=redirect&goto=findpost&ptid=148288&pid=1353571&fromuid=1162917

Sorry ... I missed that log and it's the important one.
It clearly shows the yaw error from 19 seconds to 33 seconds.
That is most likely caused the way I mentioned in post #11.
It will cause flight troubles and is why you should always ensure there is no steel close to your compass where you launch.

Labroides Posted at 2018-5-13 14:18
Sorry ... I missed that log and it's the important one.
It clearly shows the yaw error from 19 seconds to 33 seconds.
That is most likely caused the way I mentioned in post #11.

Ok, i can try to calm myself down with that answer, but...

If it is like you said, why would the "isses" occure so long into the flight, and not continuesly from the start? And the rotation of the compass (28,3) is that something to be afraid of, or does this come
together with taking of close to a nail? ;)

Its just strange since never occured this before, and i have flown several times from the same location

sonnavindDF Posted at 2018-5-13 14:24
Ok, i can try to calm myself down with that answer, but...

If it is like you said, why would the "isses" occure so long into the flight, and not continuesly from the start? And the rotation of the compass (28,3) is that something to be afraid of, or does this come

A nail or bolt is small so it's magnetic influence only extends a short distance.
If the compass was right above the nail at close range it could cause the problem but possibly the compass has been further away on other times.
A yaw error doesn't normally show until the Phantom has flown some distance from the magnetic influence.

Maybe you where wearing a magnet?  Maybe in your phone/tablet/cloths.  Or maybe there is something new on your veranda like a large speaker containing a powerful magnet?

The symptoms definitely look like the aircraft was turned on in a magnetic field and then flew out of it causing problems.

Where did you turn it on?  If it was inside the house and then you carried it outside to launch, that could explain it.

Turned on outside.... Tried another location yesterday - all done according to magnetic rules and updates etc etc - still flew like a drunk bee, spinning in circles and loosing GPS and compass/yaw error....! BUT suddenly it was ok...! Flew a couple of trips afterwards filming some water activities and worked like a charm... I think the earth magnetic field had a bad couple of days.........