TAT-101

The TAT-101 was a turret found on the UH-1 Iroquois helicopters used in Vietnam from ca. 1962-1972. The turrets were authorized by the USMC and carried two m60C .30 calibre machine guns that were fitted onto the turret. The Army did not have TAT-101s, preferring to use their m5 automatic 40mm grenade launcher. The TAT-101 had a covering, which was often removed because of jamming problems. The Pilot had a gunsight in the cockpit which let him target enemy positions. 

In 1972, the TAT-101s were removed because the USMC found better ways to unleash firepower from above. There is also the fact that Marines were being phased out of Vietnam and AH-1 Cobras were the new gunships. UH-1E gunships served throughout the war with distinction, but after 1972, used gun pods or externally mounted m60s on the quad skid scheme.