It was an all-metal aircraft, the structure mostly Duralumin and covered with narrow aluminium strips applied longitudinally.

There were cabane struts over the fuselage and a trailing edge cut-out in the wing over the pilot's cockpit to enhance his visibility.

The fighter had a fixed conventional undercarriage with mainwheels on a split axle attached to the fuselage underside, supported by a pair of V-struts; there was a small tailskid.

They fitted it with a 410 kW (550 hp) W-12 Napier Lion XI engine and knew it as the Vickers Type 127.

[1][2] When the Service Technique de l'Aéronautique (S.T.Aé, Technical Department of Aeronautics) cancelled the two seat fight specification in 1926, further development by Wibault also ended; though the Wib 121 went on a sales demonstration in Turkey in 1928, no orders were gained.

Data from The Complete Book of Fighters,[1] Jane's all the World's Aircraft 1928[5]General characteristics Performance Armament