John Brennan has authored six Vietnam War helicopter books. His background in this subject begins with a twelve-month military tour in Vietnam's Mekong Delta region, where he was assigned to the Army's 114th Assault Helicopter Company as a flight operations coordinator. This was followed by a BA degree in American studies from California State University at Chico. He was subsequently hired by the Smithsonian's National Air & Space Museum Library in Washington, D.C. Later, when the 114th formed an association, Brennan served as historian. Today, he is retired from federal service and resides with his family in northern California.