I have about 5 flights on this ARF and yesterday with just the right sun angle and about 1/2 throttle with elevaton deflection on low rate I get flutter in the horizontal stabilizer. Has anyone else had this problem. If so, how did you solve - carbon fiber, flying wire bracing or what. I noticed and heard it several more times. On inspection the covering on each side about an inch off centerline on the rear spar is wrinkled. At that point it seems that a hardwood center piece is glued to balsa and the connection is weak. I do not want to lose this plane to failure here so I need some help. thanks