Complex sentence: Polar Bear One encounters an aircraft carrier on its return trip, two fighter jets get ready to shoot them down when their own carrier gets torpedoed by a Soviet submarine and the fighter pilots lose the will to shoot down one of their own planes.
Split into simpler sentences: Polar Bear One encounters an aircraft carrier on its return trip. Two fighter jets get ready to shoot them down when their own carrier gets torpedoed by a Soviet submarine, and the fighter pilots lose the will to shoot down one of their own planes.