Who served as a 3rd Radio Research Unit advisor to the Army of the Republic of Vietnam (ARVN) and was killed by the Viet Cong in 1961?

The 3rd Radio Research Unit advisor to the Army of the Republic of Vietnam (ARVN) who was killed by the Viet Cong in 1961 was Lieutenant Colonel John F. “Jack” McGowan. He was part of U.S. military efforts to support the ARVN during the early stages of the Vietnam War. His death highlighted the dangers faced by American advisors in Vietnam during this tumultuous period.