Hy,

my plane is almost perfect, but it has a bad habit and I can't cure it. If I fly knife edge from right to the left, it is dead perfect, but if I fly it from left to the right it pulls to the belly (the plane is correctly trimmed, no CG problem). After 200m knife edge flying it turns about 20-30 degree. I made some templates to check wing and stab incidences, and everything seems right. I've checked the control throws too. Last I tryed to twist stab halves againist right to the left, and this partiallly cured the problem (200m -> 10 degree deviation, reverse direction is dead perfect). I twisted left stab LE up by 0,4 degree and right stab LE down by 0,4 degree. Other direction gave worse results, the problem was bigger. I can't understand what can be the problem, everything is straight and square.

Have anybody seen similar problem? Any suggestion?