 Twin-gun versions of the hydraulic C.C.synchronisation gear were not available until late 1917, and the early examples were required to replace the inferior Sopwith-Kauper gears used in early Camels, so that the armament of the S.E.5a remained the same throughout its production life.On S.E.5s that were used by advanced training units in 1918 the Foster mounting proved amenable for the Hythe camera gun, one of the first of its kind.