During the next air battles in summer to fall 1943, the Germans were able to deal some blows to the British bombing force with the aid of the new tactic. During the bombing raids on Berlin (a deception attack) and Operation Hydra on the Peenemünde research facilities on the night of 17/18 August, 64 bombers were shot down. In another raid on the night of 23/24 August, 56 bombers were shot down, representing 8 percent of the attacking force. Those battles also saw the first operational implementation of "Schräge Musik", which was two fuselage-mounted autocannon of at least 20 mm calibre, which allowed German "Nachtjagdflieger" night fighter pilots to shoot upwards from their aircraft.