Juha, in an earlier post in this thread, I had mentioned Kursk, and you're right about the Soviets interfering more with the Nazis as time went on. One of the things I didn't mention about the air battle was that leading up to the battle and as it went on, the Soviets were changing their tactics from using smaller units to using larger units, with more fighter protection. In addition, they used some IL-2's specifically to suppress the flak, which lessened the aerial losses. The battle of Kursk also helped the Soviets hone the cooperation between the air attack units and the troops they were supporting, which made the air attacks on the German ground forces more and more effective as the war progressed. On the subject of the Barbarossa air assault, that obviously seriously crippled the Red Air Force at the onset of the war. It also had the effect of weeding out a lot of obsolete and obsolescent Soviet warplanes, such as the I-15, I-16, R-5, etc., which were destroyed on the ground in huge numbers. The Soviets were forced to put into large-scale production more advanced aircraft, such as the MiG's, the Lavochkins, IL-2's and so on, to replace their losses. It seems that the law of unintended consequences bit the Nazis on this one.