Help mystery crashes
For those of you who like to solve mysteries. I have a good one.
I have a carbon cub s2 1.2m from Horizon Hobby. uses Electric 3cell 2200 . I have a new nx6 transmitter.
I have flown it many times in the past with no issues.
I crashed it nose down one day and had to order a new motor shaft and fuselage. I also replaced both aileron servos with new metal gear.
After restoring it to like new condition I took it out to fly. First, I checked to make sure all controls and trims were set and the as3x was working .
I tried to take of directly into the wind giving it throttle and a little up elevator. It became airborne and got about 4 feet into the air , at that point i gave it a little aileron
and it immediately nosed up and dived to the right into the ground. I examined it and no damage. I tried again and the exact thing happened except this time it nosed up and dived into the ground on the left and broke the fuselage and bent prop.
2nd rebuild.
I suspected maybe the gyro was bad and i believed the gyro to be in the controller . So i replaced the controller with a new one.
All parts working again and testing out just fine for preflight.
Once again it became airborne easily but as soon as i gave it any aileron it nosed upward and dived to the right. Damaging the fuselage again and needing repair.
3rd rebuild
Once again i repaired foam cracks and double checked the Center of Gravity . I also made sure the battery is secured so it cannot shift.
This time i had a friend who has been flying for 40+ years to help me with preflight check and also a range test.
Everything passed inspection and test. As3x works, range test works, trims good. etc...
My friend gave it a try to make sure it wasn't me causing the crash. He was able to get it about 8 ft. off the ground before giving it any aileron input . As soon as he did the plane nose dived into the soil. Not much damage . Just another crack in the fuselage and bent propeller.
He and I both have no idea what it could be. Anybody out there have any suggestions? The only thing I haven't replaced it the receiver since it is separate and plugs into the controller. But the plane passed range test so i didn't suspect it. I tried takeoffs in both safe beginner mode and without safe mode. Nothing seems to help.
??? HELP PLEASE
Tony