The angle of movement is so slight that the gun could not be used unless an enemy plane just happened to fly within its limited field of fire. [1942 May 4, Charles A. Lindbergh, The Wartime Journals of Charles A. Lindbergh, New York: Harcourt Brace Jovanovich, published 1970, page 634:]
Get those turrets up! Watch your fields of fire! [2007 September 25, Bungie, Halo 3, spoken by Reynolds (Nathan Fillion), Microsoft Game Studios, Xbox 360, level/area: Crow's Nest:]