A week ago, I was planning to create a new aircraft replica (Boeing 717), but when I I started to build the wing, I wanted to test it if it can fly (and it fly) so contuine to build the airline and after I finish the aircraft I test it one last time, after the take off I see the aircraft gradually start to rolling uncontrolablely left side, and after I check it many time for 4 hour.
I check:
Weight
Wing
VTOL
Trim
Engine power
Drag
Elevators
And ecc...
And I didn't found anything wrong and so I restarted build the wings and I solve the problem.
But I see after 2 day a wanted to build another airline (Boeing 707) and it came the same problem.
So whats the problem!!!???