This work presents experimental and computational results related to the effects of structural motion on the aerodynamics of the X-56A airfoil. An oscillatory plunging mechanism has been fabricated and installed in a subsonic wind tunnel. The static characteristics of the X-56A were verified before focusing on the unsteady behavior at Re=200k (based on airfoil chord). Some instantaneous angles of attack during the airfoil oscillations are beyond the linear CL-alpha regime (for a nominal angle of 10 degrees). At a nominal angle of 12 degrees, the instantaneous angles of attack due to oscillations extend past those associated with CLmax. Focus is placed on oscillations with dimensionless amplitude and frequency that extend well into the range of CL values that are unattainable for static tests even at higher Re. A comparison with unsteady theory (Theodorsen18) is very good for the lower angle of attack (10 degrees), but unwarranted at the higher angle (12 degrees) as nonlinear effects become prominent. The lower angle of attack is also supported by CFD which reveals more detailed information on the laminar separation bubble near the leading edge and turbulent flow downstream.