Chidlaw took flying training at
Brooks and
Kelly Fields, Texas, and got his wings in January 1924. He remained at Kelly five months as a flying instructor. He went to
Clark Field in the Philippines for duty with the
3rd Pursuit Squadron. He returned to Brooks in October 1926 as flying instructor assistant staging commander, and final check pilot. Promoted to first lieutenant in April 1927, Chidlaw remained at Brooks until July 1930 when he entered the USAAC Engineering School at
Wright Field, Ohio, graduating a year later. Then began the first of several long assignments at Wright Field which established Chidlaw as an expert on materiel, especially aircraft. He stayed five years this time, chiefly as project officer of the Materiel Division's Training and Transport Aircraft Branch. Early in 1934 he devoted three months to helping the USAAC inaugurate its flying of the airmail. In succession he took the
Air Corps Tactical School course at
Maxwell Field, Alabama, and the
Command and General Staff School instruction at
Fort Leavenworth, Kansas. He was promoted to captain in August 1935 and assigned to the
2nd Bomb Group at
Langley Field, Virginia, where he became Operations Officer in May 1938. The following January he was named technical assistant to the assistant chief of staff for materiel at the USAAC Headquarters at Langley. He went back to Wright Field for a short time and in March 1939 was assigned to the Supply Division in the Office of the Chief of Air Corps. Three months later he became chief of the Engineer Section and in October chief of the Experimental Engineering Branch, where he monitored the jet engine development.
World War II Chidlaw was promoted to
major in March 1940, to
lieutenant colonel in September 1941, to
colonel in March 1942, and to
brigadier general in November 1942, while assigned to this duty in Washington. In March 1943, he was assigned to the Office of the Assistant Chief of Air Staff for Materiel in Washington. In that capacity he represented the
United States Army Air Force (USAAF), the direct predecessor to the United States Air Force, on several joint
Royal Air Force-USAAF technical missions in London. He went to the Mediterranean Theater in April 1944 as deputy commanding general of the
XII Tactical Air Command. Following the invasion of southern France, he organized and commanded the
XXII Tactical Air Command in that theater. In March 1945 he took command of the
Mediterranean Allied Tactical Air Force and was promoted to
major general the next month. ==Later life==