Complex sentence: The defender exposes the aircraft to the attacker's guns for only a brief instant, and the maneuver works well because the slower moving defender has a much smaller turn radius, and an aircraft moving in such a direction is very difficult to shoot.
Split into simpler sentences: The defender exposes the aircraft to the attacker's guns for only a brief instant. The maneuver works well because the slower moving defender has a much smaller turn radius, and an aircraft moving in such a direction is very difficult to shoot.