I have recently noticed when checking the tracking of my trex that if you hold the heli sidewise and power up to at least past 50% power the tracking of the blade tips in the forward path of the blades is perfect but the tracking on the tips on the aft path is slightly off. Not much ,just maybe 1/8 of an inch. Cant seem to get both fwd and aft perfect tracking. Does anyone have any suggestions as to why they would track like this and the way to correct this problem?

Thx