<P> The month of April 1918 began with the consolidation of the separate British RFC and RNAS air services into the Royal Air Force , the first independent air arm not subordinate to its national army or navy . By the end of April the new Fokker , Pfalz and Roland fighters had finally begun to replace the obsolescent equipment of the Jagdstaffeln , but this did not proceed with as much dispatch as it might have , due to increasing shortages of supplies on the side of the Central Powers , and many of the Jastas still flew Albatros D types at the time of the armistice . The rotary engined Fokker D. VIII and Siemens - Schuckert D. IV , as well as surviving Fokker Triplanes , suffered from poor reliability and shortened engine life due to the Voltol - based oil that was used to replace scarce castor oil -- captured and salvaged Allied aircraft ( especially Sopwith Camels ) were scrounged , not only for engines and equipment , but even for their lubricants . Nonetheless , by September casualties in the RFC had reached the highest level since `` Bloody April '' -- and the Allies were maintaining air superiority by weight of numbers rather than technical superiority . </P>
what accounted for british military superiority in the first years of the war
weight of numbers