A servo-tab mechanism was designed for a full-scale rotor blade section, and tested in an open-jet wind tunnel. The intent was to use aerodynamic forces and moments to amplify the stroke and force provided by a compact piezoelectric bender actuator. The design was constrained by the stroke-force characteristics of the piezoceramic benders previously developed for model scale applications. The flap chord was chosen as 25% of the blade chord, and the tab chord was 5% of the blade chord. The flap response to the aerodynamic moment generated by the servotab was predicted using blade element momentum and thin airfoil theory. Testing in an open-jet wind tunnel explored the response of the flap in both steady and oscillating tab conditions.