He transferred into the French air service in July 1915.
Six months later, in January 1916, de Romanet received his brevet (permit) as a pilot.
His first assignment to Escadrille 51 as a Caudron reconnaissance pilot.
He trained as a fighter pilot in February 1917 and made the transition to flying single-seater Nieuport fighters for Escadrille 37.
His first victory was scored on 3 May 1917.
He waited almost a year before continuing, with his second triumph coming on 31 March 1918.
He became an ace on 30 June 1918, and a double ace on 22 August.
That was his last victory and last day with Escadrille 37.
He was then charged with forming Escadrille 167, a Spad squadron, assumed its command, and scored eight more victories while leading it.After the war de Romanet became a successful sporting pilot, breaking the World Air Speed record on two occasions in 1920.
Barny de Romanet died in a flying accident on 23 September 1921, testing the aircraft he was to fly in the 1921 Coupe Deutsch de la Meurthe race: the accident was ascribed to the fabric becoming detached from the aircraft's wing.He is buried in the Cimetière Saint Brice in Mâcon.