Born in Pontault-Combault in 1926, René Sébenne joined the Ecole Polytechnique in 1946, where he became friends with Serge Dassault. Following an interview with Marcel Dassault, he was hired in 1949 and assigned to the Mérignac Design Office. After a period spent working at the Boulogne facility, he joined the Saint-Cloud Design Office in 1950 to work on two-seater night fighters, including the Mystère IV N. As head engineer for prototype aircraft, he coordinated development, right up to the flight tests in Melun-Villaroche.
He was subsequently involved in launching series production of the SMB2, and then in developing the Mirage III, for which he helped design air intakes and air ducts.
In 1970, René Sébenne became Xavier d’Iribarne’s right-hand man, managing the Dassault-Breguet merger alongside him. In this role, he took on the management of both the Vélizy and Saint-Cloud sites, and redefined how each operated respectively.