A kinetic energy projectile intended to be launched toward a selected tar has a projectile body and a plurality of main fins attached to the projectile body to provide stability thereto in flight. A spoiler fin is attached to the projectile body ahead of each associated main fin for reducing the temperature of the main fins during flight of the projectile, and thereby, the burning of the fins in flight. The spoiler fin is adapted and configured to provide the temperature reduction by changing the aerodynamic flow over the edges and surfaces of the associated main fin, and also may be composed of material having a lower coefficient of heat conduction than that of the main fin. A gap of predetermined width is provided between the trailing edge of the spoiler fin and the leading edge of the associated main fin, this width being selected to create recirculating vortices behind the trailing edge of the spoiler fin sufficient to cool the leading edge of the associated main fin. In one embodiment, the spoiler fun is completely separated from the associated main fin by the gap. In another embodiment, the spoiler fin and the associated main fin are formed from a single sheet of material, and are connected by a portion of the common material beneath the gap. In a third embodiment, plurality of gaps may be employed.