Hi!




Three times during the flight I had error "Compass Erros" and my "Standard" switch to ATTI Mode.

Before the start, I always check tab Sensors (Compass abt -1500), fly on abt 2 meters and I check everything.
No Interference in my area (in my opinion ).
GPS: 10 satellites



This is my flight log.
My Flight log





What could be wrong?

It's hard to say without more information.
But compass error messages don't mean there is a problem with your compass.
They indicate your compass sensor has detected an error - the magnetic field is significantly different from what it has been calibrated for.
The most common reasons are:
1.  You calibrated the compass close to iron or steel
2.  You've flown quite close to a large iron or steel object

I understand, but at a height of 2 meters I did not have errors.
Today, I was checked cable from compass - no change value in sensors value.

ksiecio@interia Posted at 2016-1-2 22:14
I understand, but at a height of 2 meters I did not have errors.
Today, I was checked cable from com ...

You've given no information about when/where you calibrated the compass.
That may be important.
If you had calibrated your compass close to iron or steel, it would read correctly down close to the magnetic influence but it would not when up higher in the air and away from the steel.
Saying the compass mod value was 1500 is only saying that it has been calibrated to correctly resolve the magnetic field it is in.
That is of no help if it happens to be in a distorted magnetic field.

Having your Phantom switch to atti mode would suggest that the flight controller was unable to resolve a conflict between the data coming from GPS and the compass.
This is likely when you fly with a bad compass calibration.
If that happens you end up with no GPS for position holding and you have to deal with a Phantom that can't fly straight - not a good combination for safe flight.

labroides@yahoo Posted at 2016-1-2 01:06
It's hard to say without more information.
But compass error messages don't mean there is a problem  ...

Sometimes the metal object doesn't even have to be really large.

I have a tower for my amateur radio system. The lower 15-feet or so of each guy wire is steel cable.  That's protection against brush fires and/or vandalism - 3/16" EHS is pretty hard to cut, even with a huge pair of bolt cutters. The remainder of each guy is Phillystran - basically a carbon fiber product. It is popular because it's one of the solutions that makes the guy wire essentially "invisible" to electronic transmissions.

As small as that lower-portion-steel-cable is, if I fly very close to it, the "compass error" warning comes on. That and the actual metal of the tower make it very difficult to do what I want to do. My original "excuse" to my wife for buying the Phantom in the first place, was to use it to inspect connections at the top of my tower. Now that I've discovered I can't fly really close to my tower (safely), I need a better/different excuse!

Old marriage philosophy - for men - "It is easier to beg forgiveness than it is to seek permission!"

I bought a Phantom. My brother bought a gun. We're both still fighting (begging!) with our wives!

Art - N4PJ
Leesburg, FL

Thank you my friend for your suggestions.
I flew and start from here :  https://goo.gl/maps/rPUBxEW5uBm
The problem appeared to be around 25 meters - more than buildings. I got the shot from some antenna?

so I want to shoot some video of the downstream side of the Lake Texoma Dam. Power generation is 24/7 (9000 cps) as the lake is still almost 10' high. But the flood gates are releasing 28,500 cps. Hence the video opp.
That could present some dangerous magnetic hazards perhaps??.... esp. because I'll be flying over the Red River.