When it comes to matters of national defense, even the fiercest competitors can put aside their differences. Heraeus Amersil Inc. of Duluth, Ga., and Corning Inc. in Corning, N.Y., manufactured a 994-lb piece of optical-quality glass that will be used as the turret window for the Airborne Laser. Heraeus provided Infrasil, a material suitable for the Airborne Laser's stringent optical transmission requirements. Corning provided the facility for forming the glass, which will be used as a nose-mounted optical window on a modified Boeing 747-400F aircraft. Contraves-Brashear Systems in Pittsburgh polished the shaped window into its final configuration.