Ok i was given a cub arf. It's a white box chinese no name model from value hobbies

it was free from a friend. Ok so i put this arf together this winter i finally got a chance

To take it out. I had my trainer from the club take it up for its madden flight

and man was I happy it was him not me. Right away he was in trouble the plane

just flew like a kite and seemed like it was tail heavy. We checked cg before flight and it was fine.

The plane just out of control it took 5 mins just to get it to land.

After landing we checked the CG again it was still showing fine. It was perfectly level (NOT TAIL OR NOSE HEAVY)

I'm wondering if it should maybe set up a little nose heavy? Couple guys at club suggested setting it up with Aliron differential?

any input would be nice.