Three Messerschmitt Bf 110 in the sky

Three Messerschmitt Bf 110 in the sky. The BF110s were the most used German heavy warplanes during World War II. Development of the Me 210, which was suppose to replace the BF 110 began before the war, but with severe issues in development the BF 110 remained Germany's primary heavy fighter throughout the war

Source:
http://world-of-warplanes.wikia.com/wiki/Messerschmitt_Bf_110_E