 It appeared in this form at the Salon d'Aéronautique in December 1921, but did not fly again until some major changes had been made.These included the replacement of the single outboard interplane struts by double ones, an exchange of the rectangular central engine radiators for tubular Lamblin ones and the addition of a substantial additional pair of wheels placed vertically below the engine bulkhead to prevent nose-overs.All engines now drove four-bladed propellers.