Oberleutnant Wilhelm Johnen, Staffelkapit_n of German night fighter Squadron 5./NJG 5, whilst chasing an RAF bomber strayed into Swiss airspace where he was hit by flak and forced to land at Dübendorf where his Messerschmitt Bf 110G-4B./R3, which was equipped with the latest Lichtenstein SN-2b radar, was interned by the Swiss authorities. Fearful that the top-secret radar (which was the Luftwaffe's answer to the Allies "Window" anti-radar system) might fall into the hands of the Allies, the Germans eventually traded twelve new Bf 109G fighters in exchange for a Swiss guarantee that the interned aircraft with its new radar would be completely destroyed.
