This article details the development of an aero-structural aircraft model created for the purpose of investigating modern challenges in flight control of large commercial aircraft. In particular, the Generic Wide Body (GWB) aircraft model has been developed to support the investigation of flight control systems on airframes where there is a diminishing distinction between rigid body flight-dynamic modes and structural vibration modes. Such airframes are becoming more common, but full aero-structural aircraft models remain scant in the literature. The GWB is a full-vehicle aero-structural model defined using NASTRAN modeling elements. In size, shape, and structure the GWB resembles aircraft in the commercial market segment populated by the Airbus A350-1000 and the Boeing 777-300ER. Note that the model has been developed using only information from the public domain. The modeling process, model composition, and dominant model properties of the GWB are detailed herein.