He remained in the Air Service following the end of the war and was assigned to its Engineering Division at McCook Field, Dayton, Ohio, as a test pilot.

He transferred to Crissy Field at the Presidio of San Francisco in 1921 and joined the 91st Observation Squadron, then engaged in aerial forest fire patrol.

Flying a Curtiss R-6 racer, a precursor of the PW-8 design, Maughan won the Pulitzer race with an average speed of 205.86 mph (331.30 km/h), on October 14, 1922.

He also made two attempts in July to fly coast-to-coast in a single day, using the new Curtiss PW-8, but mechanical problems thwarted both flights.

Maughan, promoted to lieutenant colonel, commanded the 60th Transport Group, Pope Field, North Carolina, from July 28, 1941, to April 15, 1942.

Promoted again to colonel, he was advanced to command of the 51st Troop Carrier Wing from June 1, 1942, to October 20, 1942, which included its deployment to England.