[1] Begun by Major Donald Nichols as an impromptu extension of his pre-Korean War espionage in 1950, it was first dubbed "Special Activities Unit Number One".
The origin of the 6004th Air Intelligence Service Squadron lies in the confusion following the start of the Korean War on 25 June 1950.
To fill the need for what he deemed "positive intelligence", Chief Warrant Officer (later Major) Donald Nichols improvised spy and espionage operations within the agent net he had formed prewar.
[2] In July 1950, Nichols set up an impromptu parachute training course so espionage agents could be dropped behind the communist enemy's front lines.
Forty-eight others would form the 13 spy teams dropped behind enemy lines during this time; they spotted and reported rear area targets for the Air Force.
Numerous islands lying just off the North Korean coast sheltered UN-backed guerrillas and offered sanctuary to seaborne infiltration missions, as well as refuge for downed UN pilots.
[11] On 17 April 1951, a technical team of five led by commanding officer Donald Nichols staged a daring raid into the enemy's rear to gather aeronautical specifications and some gear from a crashed MiG-15.
[12] On 1 June 1951, in violation of their mandated operational role, Detachment 1 of the 6004th was ordered to drop 15 saboteurs behind enemy lines to destroy a pair of railroad bridges.
After this failure, Detachment 1 was left to its required tasks of standard intelligence operations and prisoner of war interrogations.
Given the impossibility of Caucasians remaining undetected in the Asian populace of communist rear areas, there was a minimal need for Americans in this U.S. Air Force detachment.
[15][16][21] By the spring of 1952, the 6004th was heavily involved in supporting the South Korean guerrilla forces dispersed on offshore islands off both coasts of North Korea.
However, Detachment 3's effort was hampered by lack of radios with the Air Force's aircraft emergency frequency and bureaucratically blocked by the CIA's primacy in E&E.
[27][28][29] In the latter part of 1952, the squadron's mission had stabilized enough that official courses in interrogation, intelligence gathering, and parachute usage were established.