In the spring of 1966, to counter the offensive of Ho Chi Minh’s troops, the American command decided to deploy B-26K strike aircraft in Southeast Asia. They were stationed in northeastern Thailand, as geographically it was close to likely combat areas. They were based at the Thai Nakhon Phanom airfield. In order to stay in Thailand, B-26K Counter Invader aircraft were designated as A-26A attack aircraft, because this country did not officially allow the deployment of bombers on its territory. Included aircraft in the 609th special operations squadron. Most Counter Invader combat missions took place in the dark, the reason for this was Vietnamese air defense, which posed a serious threat to piston aircraft with a relatively low speed. Together with B-26K, in Nakhon Phanom were based and light piston aircraft O-2 Skymaster. They were also involved in special tasks, and some of them had black fuselage painting for night sorties.