A wind tunnel experimental investigation of limit cycle oscillations (LCO) of a uniform flexible airfoil with root pitch motion occurring at transitional Reynold number regime is presented. Two stable limit cycle regimes are observed: small and large amplitude LCO. The origin of the large amplitude LCO is determined to be coalescence flutter. Whereas, the small amplitude LCO are attributed to laminar boundary layer separation related to transitional Reynold number aerodynamics. In addition, the nonlinear equations of motion for the system are developed. Furthermore, a linear inviscid aerodynamic model is considered using. Despite the linear aerodynamics approximations, a parallel to the experiments can be drawn with the numerical simulations presented for small and large amplitude LCO at the vicinity of the linear flutter speed, with a dominant cause factor being a coalescence flutter. Overall, the structural nonlinearities play a significant role in LCO for both the experimental and numerical investigations.