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The first ten Do 335A-0's were delivered for testing in May. By late 1944 the Do 335A-1 was on the production line. This was similar to the A-0 but with the uprated DB 603E-1 engines and two underwing hard points for additional bombs, drop tanks or guns. Capable of a maximum speed of 474 mph (763 km/h) at 21,325 ft (6,500 m) with MW 50 boost, or 426 mph (686 km/h) without boost, and able to climb to 26,250 ft (8,000 m) in under 15 minutes, the Do 335A-1 could easily outrun any Allied fighters it encountered. Even with one engine out it could reach about 350 mph (563 km/h), allowing it to escape combat fairly easily.
Delivery commenced in January 1945. When the US Army overran the Oberpfaffenhofen factory in late April 1945, only eleven Do 335A-1 single seat fighter-bombers and two Do 335A-12 conversion trainers had been completed.
http://en.wikipedia.org/wiki/Dornier_Do_335