ArtW

I have flown RC for almost 40 years so I am not a beginner. I fly GA and have extensive engineering and design experience. This is not my first 3D plane, or my first electric. I have a number of planes that have more than 200 flights on them. One with more than 500 flights. I have built gliders, power planes, helicopters, jets, 3D, etc. I have a number of Great Planes Planes. I truly like Great Planes Planes. Most of my planes are Great Planes Planes.

I am stunned by how rapidly this plane developed flutter and was destroyed. I would like to understand the problem. Control system flutter is usually a result of excessive speed or excessive flexibilty in control system. This plane has carbon fiber control rods and light plastic control horns. The combination of a very stiff control arm and a very flexible plastic control horn may allow oscillation. The servos were brand new Futaba servos of the exact make and model in the instructions. I built this plane to the exact specs in the instruction manual.

In GA aircraft loose control linkages, exceeding the Vne, or inadequate balancing or damping of the control systems can lead to control surface flutter and loss of the aircraft. This elevator is extremely light and has extremely light construction. It fluttered at very low speed. Great Planes has strenthened the elevator in the biplane version of this plane. I assume that strengthening was done for a reason.

I am not attempting to criticize this plane. I am trying to get advice on how to avoid this type of problem and see if others have had a similar experience with this aircraft.