Could be a couple things:
1) IMU calibration
2) compass issue
3) controller calibration
Hook your phantom to PC running newest assistant software!
1) IMU calibration
Check your values ( x, y, z, and mod values for ( accelerometer, gyroscope and compass )
A) gyroscope ( 0.0-1.5 ) if more than or less than ( 0.0-1.5 ) calibration needed
B) accelerometer ( .98-1.02 ) if more/less cal needed
C) compass ( 700-2400 ) more/less cal needed ( IMU and compass cal )
That takes care if IMU and COMPASS
Now while still in assistant, recalibrate controller as we'll.
NOTES: when recalibrating IMU, make sure phantom is LEVEL, side-side, and front-back, with no wobbling around
NOTES: when recalibrating compass, take it slow, steady, level turns, should go like this:
Once in recal mode ( solid yellow lights ) pick up phantom a bit like 1 ft from ground still holding it level with ground, spin 360 degrees ( like a record spins ) lights turn green, turn phantom so front or camera faces ground, spin 360 degrees, now light either
Yellow blinking ( less than 6 satellites ) or blinking green ( more than 6 satellites )
This should fix it, let us know!
Jerry D
USA
( J Dot )