field manual Air navigation / prepared under direction of the chief of the air corps field manual Weather field manual Reviews and inspection / Prepared under direction of the chief of the air corps Photomail operation - USA War Department Field Manual, FM 11-150 Advanced map and aerial photograph reading - USA Basic Field Manual, FM 21-26 field manual Browning machine gun caliber .30, HB, M1919A4 (mounted in combat vehicles) / prep. under dir. of the Chief of Infantry field manual Browning machine gun, caliber .30, M1917 field manual 81-MM mortar, MI / Prepared under direction of the chief of infantry field manual Barrage balloon : operation of matériel and employment of personnel field manual Watermanship field manual 81-MM mortar squad and platoon field manual 75-mm tank gun M 2 : (mounted in medium tank M 3)
