A model-reduction method for linear, parameter-varying systems based on parameter-varying balanced realizations is proposed for a body freedom flutter vehicle. A high-order linear, parameter-varying model with hundreds of states describes the coupling between the short period and first bending mode with additional structural bending and torsion modes that couple with the rigid body dynamics. However, these high-order state-space models result in a challenging control design, and hence a reduced-order linear, parameter-varying model is desired. The objective is to reduce the model state order across the flight envelope while retaining a common set of states in the linear, parameter-varying model.Areduced-order linear, parameter-varying model with tens of states is obtained by combining classical model reduction and parameter-varying balanced realizations reduction techniques. The resulting reduced-order model captures the unstable dynamics of the vehicle and is well suited for the synthesis of active flutter suppression controllers.