In 1939, he became an engineering officer at the Hawaiian Air Depot. After Pearl Harbor, he directed the Depot’s assembly on new aircraft, rushed supplies to the battle zones, and tested every aircraft for combat readiness.
In 1944, he was the Deputy Chief and later Chief of the Maintenance Division at Patterson Field, Ohio, directing eleven air material depots.
Commanded the Eighth Air Force Service command in the Pacific after Germany’s surrender in 1945.
After World War II, he became Chief of the Flight Test Division at Wright Field, Ohio.
Responsible for developing the Test Pilot School and transferring it to Muroc Army Air Field (now Edwards AFB), California, with its ideal conditions for testing supersonic aircraft, and recommended establishing a Flight Dynamics Laboratory and Flight Test Division.
On June 19th, 1947 he set a new world’s speed record of 623.85 mph in an F-80R Shooting Star.
Directed the testing of the Bell X-1 rocket plane and Chuck Yeager’s breaking of the sound barrier.
Became commander of Edwards AFB in 1949.
Promoted to commanding general of the Air Force Test Center in 1951, where he personally flight tested most of the X-series and of the experimental aircraft.
In 1952, Boyd became commander of the Wright Air Development Center at Wright-Patterson AFB, Ohio.