Phantom 3 Profession Fly-away and Error Log

[brokenisbeautiful]

I haven't flown my phantom in a while and today it wouldn't hover but immediately started flying sideways. To avoid hitting a tree I took it up higher and it continued to fly away. Panicked I hit the home button and it DID land safely on it's own. I downloaded the error log and have no idea what this stuff means. Can anyone help me understand where I went wrong?

DJI Flight Log Viewer - PhantomHelp.com

 

[Ken Nash]

It looks as it may have needed a compass calibration having not flown for a while or you may have had wi-fi or electro-magnetic interference.

 

[Fly Dawg]

Compass Errors and Yaw Error's Immediately after takeoff and for the duration of the short flight. If you happened to calibrate the compass before flight and there were metallic objects, such as automobiles ( I noticed this is a tight subdivision) that will give you those errors. I would suggest doing a compass calibration at least 20ft or more from any such objects. If that doesn't correct the issue, try a cold IMU calibration, then re-do the compass cal.

 

[sar104]

The problem is pretty clear. The FC was reporting multiple compass errors and the error is apparent if you compare the motion of the aircraft to the reported heading and stick inputs:

The yaw heading was initialized as close to north (-11°), but when forward elevator was applied at around 19 s, it pitched forwards and moved south-east. That clearly illustrates the compass error, and explains also why it was drifting around - its attempts at positional holding were compromised because its yaw value was out by around 150°.

I would suspect that the problem was caused by taking off from a location with a distorted magnetic field, but it could also be a bad compass or a compass needing calibration due to changes in the magnetic field of the aircraft.

 

[Meta4]

I haven't flown my phantom in a while and today it wouldn't hover but immediately started flying sideways.

The most likely explanation for what happened is that you launched from close to a lot of steel.
And the most common cause is launching from a reinforced concrete or steel surface.

It looks as it may have needed a compass calibration having not flown for a while or you may have had wi-fi or electro-magnetic interference.

Under normal circumstances you should never need to calibrate the compass.
It doesn't go off over time.
Wifi interference doesn't make a Phantom fly erratically.

 

[brokenisbeautiful]

Thanks so much for all the advice. I did calibrate it before take-off. What is an IMU calibration?

 

[Meta4]

Thanks so much for all the advice. I did calibrate it before take-off. What is an IMU calibration?

And was the takeoff from reinforced concrete?

 

[Meta4]

Thanks so much for all the advice. I did calibrate it before take-off. What is an IMU calibration?

IMU is the inertial measurement unit.
It had nothing to do with the flight problem.
That was 100% a compass issue.

 

[macoman]

IMU is the inertial measurement unit.
It had nothing to do with the flight problem.
That was 100% a compass issue.

That's why I never ever calibrate my Phantom. I did in a while and was a perfect one and does not need it anymore. Unless I move my Phantom hundreds of miles away.

 

[Steve7777]

The most likely explanation for what happened is that you launched from close to a lot of steel.
And the most common cause is launching from a reinforced concrete or steel surface.

I had a look at the location on Google Street view. It's all concrete roads everywhere in that region, so almost for sure there's a mass of reinforcement bars in them - and in the driveways too..