the t-4 has a sturdy, damage-tolerant airframe that is largely composed of conventional aluminium alloys, although some composite materials are also present in some areas. its structure has sufficient strength to enable high-g manoeuvres, being rated to perform instantaneous dives of 7.33g when flown in a clean configuration. it is furnished with a thick-section transonic aerofoil, which was developed by kawasaki and japan's technical research and development institute (trdi) to provide outstanding high-angle-of-attack handling and favourable spin characteristics. an unusual aerodynamic feature present on the t-4 is the compact leading-edge root extensions (lerx) just forward of its wings along the forward fuselage, these generate additional vortex lift and enhance the aircraft's high-g departure tendencies, such as the suppression of wing-drop and pitch-up during aerodynamic stalls. the use of lerx avoided any need for vortex generators.