U. S. Anti-Aircraft Battery - Shows Teamwork In Action -- A split second after the 90 mm. anti-aircraft gun is fired, the gunner is kicking the shell case from the platform in order to keep it clear for the loader's next bit of footwork. The whole chain of operations - range-finding, director station, observers, and the gun crew - have synchronized their actions under the battery commander and a chain of 90 mm. shells is hurtling into the air, bursting at exactly predetermined heights to wreck the enemy planes at which the U. S. Army battery is firing. February 08, 1948. (Photo by Interphoto News Pictures, Inc.).