Captain Maynard was an aerial observer with Headquarters Battery, 63rd Field Artillery Battalion, 24th Infantry Division. He was taken Prisoner of War while fighting the enemy along the Kum River, South Korea on 14 July 1950, forced to march to North Korea on the "Tiger Death March", and died while a prisoner at An-Dong, North Korea on 30 June 1951. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

For his leadership and valor, Captain Maynard was awarded the Distinguished Flying Cross, the Purple Heart, the Air Medal, the Prisoner of War Medal, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal, the Korean Presidential Unit Citation and the Republic of Korea War Service Medal.