The Aviation, or Flying, Corps flies aircraft over the battlefield. "Battlefield aviation", as it is known, was first used widely in the First World War. Originally, these aircraft were used solely to observe enemy positions and movement, but ways were quickly found to arm aircraft to allow attacks on targets on the ground and at sea, as well as on each other. After the war, the responsibility for the development and employment of air power largely passed to the newly formed air forces.
The Second World War confirmed the utility of aircraft over the battlefield. They were used for reconnaissance and attack missions, to transport troops and supplies and to evacuate casualties. Even closer cooperation between ground troops and aircraft became possible with the advent of the helicopter, a craft which could land in places conventional aircraft could not. The helicopter was first used widely in the Korean War for troop transport and casualty evacuation but it has become synonymous with the Vietnam War, where it was the jack of all trades carrying out attack, reconnaissance, search and rescue, transport, propaganda, fire- support and medical evacuation tasks.