When the Fokker D.XXI flew its first flight it was already bordering on obsolete, the Me-109, Heinkel He-112, Hurricane and Spitfire had already flown with much higher maximum speeds. The maximum speed for the Ilmavoimat Fokkers was 285mph, with a range of 574 miles and a service ceiling of 30,675 ft. Armament consisted of 4 × 7.92 mm FN Browning M36 machine guns, two being fuselage mounted and two wing mounted.