Their last raid launched from Polebrook was on 2 September 1941. RAF Fortresses had flown 22 attacks against targets such as Bremen, Brest, Emden, Kiel, Oslo, and Rotterdam. A total of 39 planes had been dispatched, out of which eighteen planes had aborted and two had been forced to bomb secondary targets because of mechanical problems. Eight Fortresses had been destroyed in combat or lost in accidents. Discouraged by these losses, the RAF decided to abandon daylight bombing raids over Europe.