Wing flutter is a complex event that arises from a combination of forces. Dynamic, fluid and structural forces all combine to create an unstable reaction. Although not restricted to just wings it is most commonly associated with wings. Due to its highly complex nature it is often misunderstood. It is a type of resonance, when, if the combined forces approach a particular (resonant) frequency, the induced amplitudes grow and can easily cause the wing to break.
The aerofoil suspended on springs within a frame is a NACA 0015 profile. At both ends of the aerofoil are mounting places that allow you to increase the angle of attack. String tethers are in place to limit amplitude during extreme oscillations to protect the aerofoil from damage.
