 Aerial reconnaissance was often a hazardous task because of the necessity of flying at slow speeds and at low altitude.The task was made more dangerous with the arrival of additional German flying squadrons, including the highly experienced and well equipped Jasta 11 (Manfred von Richthofen) which led to a sharp increase in RFC losses.Although significantly outnumbering the Germans, the RFC lost 131 aircraft during the first week of April (Bloody April).