Career
He accompanied Richard East. Byrd as an aerial photographer on his expedition to the South Pole. He joined the Missouri National Guard on June 21, 1916 and served until December 21 of the same year. Following the United States" entry into the First World War, he enlisted in the United States Army Signal Corps on August 7, 1917 and became a dirigible pilot.
He was commissioned as a 1st lieutenant in the Officer"s Reserve Corps on December 7, 1917 to date from November 27.
He was placed on active duty on December 16, 1917. During World War I, he commanded a balloon observation company.
He later taught aerial photography and surveying. He was promoted to the rank of captain on November 20, 1918, shortly after the armistice.
Due to the post war draw down, McKinley"s appointment as captain was vacated and he was made a 2nd lieutenant in the Army Air Service on September 21, 1920 (to rank from July 1, 1920).
He was promoted to 1st lieutenant on April 12, 1921. On April 3, 1926, McKinley resigned from the Army to begin an aerial surveying and photography service. In 1928-1929, he was a photographer for the Byrd Antarctic Expedition.
He was one of four men aboard the first aircraft to fly over the South Pole on November 29, 1929.
In 1941, as the United States prepared to enter the Second World War, McKinley rejoined the Army Air Corps as a major. He was in charge of the cold-weather operations of the Army Air Force at Ladd Field in Fairbanks, Alaska.
McKinley was the first person to suggest that United States. aircraft be constructed to operate in subzero temperatures and that the Air Force should build a facility to test aircraft in subzero temperatures. He was transferred to Eglin Field for the construction of the facility.
He had risen to the rank of colonel by the war"s end in 1945.
He transferred from the Army to the newly created United States Air Force in 1947. He served in of Korea in 1951 during the Korean War. After retiring from the Air Force as a colonel on June 30, 1956, McKinley worked as a civilian consultant to Admiral Richard Byrd.
Colonel McKinley died in Florida and is buried in Arlington National Cemetery.
In June 1971, the McKinley Climatic Laboratory at Eglin Air Force Base was named in his honor.