The BF 109E-3 first flew in 1939 and was powered by a Daimler-Benz DB601Aa engine. It fired two 20mm MG FF cannons rather than the 7.9mm machine guns of earlier version.
German Museum of Technology
The Messerschmitt
Bf 109 was the most-produced fighter ever (over 33,000 estimated).
And, the Bf 109E ruled the skies over Europe until mid-1940 when
it first encountered the Supermarine Spitfire. The example pictured
here is a BF 109E-3.