On January 12, 1962, US and South Vietnamese forces execute Operation Chopper. The operation entailed the use of American Piasecki H-12 helicopters with American crews to transport a large force of South Vietnamese paratroopers in an assault against a suspect Viet Cong stronghold near Saigon. Operation Chopper marked the first combat operations for American forces during the Vietnam War as well as an early use of air mobility to deliver troops into combat through the use of VTOL (vertical take-off and landing) aircraft such as the helicopter.