The Mk. IX replaced the Mk. V in June 1942 and on September 12, 1942 a Mk. IX brought down a Ju-86R flying at 43,000 feet. Another major achievement of the Mk. IX took place on October 5, 1944 when 401 Squadron became the first allied aircraft to shoot down an Me-262 jet. Even with the arrival of the Griffon powered Mk. XIV the Mk. IX continued in service until the end of WWII. There were 5,665 Mk. IX Spitfires and its variants produced.
On January 5, 1943 Otto Smik was assigned to No. 312 Czechoslovak Squadron and 7 days later to No. 310 Czechoslovak Squadron. Otto changed squadrons a lot, next came No. 131, No. 122 and then No. 222 Squadron where he accumulated most of his 8 air victories. From April 1944 until July 1944 Smik was assigned to No. 310 Squadron again. In June, while flying MJ291/ NN-N he downed 2.5 Fw-190s. On November 28 1944, assigned to No. 127 Squadron and flying Spitfire RR227 Otto Smik was hit by flak and was killed. Specifications for the Spitfire Mk. IX