Aircraft mechanics of the Swiss Air Force working on a Messerschmitt Bf 109E-3 at Thun Airfield in Switzerland (1940, colorized). Switzerland took delivery of its initial batch of BF109s in 1938, with the introduction of ten Bf 109Ds. Shortly afterwards, the country purchased an additional 80 Bf109E-3s which commenced arriving from April 1939 until just prior to Germany's invasion of France in 1940