At the outbreak of World War II, RAF Bomber Command regularly carried out daylight operations. However it transpired quite soon that the British light bomber aircraft were extremely vulnerable at broad daylight. They were clearly visible by the enemy and they were not able to defend themselves effectively against the fast, agile and well-armed German fighters. Thus the losses were big during these missions. Consequently the choice was made to choose the cover of darkness for large scale bombardments. Bomber Command thereafter carried out only some large operations by daylight. One outstanding mission is the raid on the factories of Schneider in Le Creusot in the French Region of Burgundy. For this daring operation, which took place on the 17th of October, 1942, 94 Avro Lancaster bombers had to penetrate deeply into enemy air space and in broad daylight.
Avro Lancasters of No.5 Group flying over Montrichard.
(Source: Royal Air Force)