A gas turbine engine includes a core engine that has at least a compressor section, a combustor section and a turbine section disposed along a central axis. A fan is coupled to be driven by the turbine section. A fan nozzle is aft of the fan and defines an exit area. The fan nozzle has a body that defines an airfoil cross-section geometry. The body includes a wall that has a controlled mechanical property distribution that varies by location on the wall in accordance with a desired flutter characteristic at the location.