Sgt M. Maciejowski joined 317 Squadron from 56 OTU on 10th April 1941.
On the same day, he was invested with the D.F.M. at 15.00hrs by A.V.M. Andrews, A.O.C. No. 13 Group.

In the afternoon of 30th December, a wing of 24 aircraft (12 from 317 Squadron and 12 from 306 Squadron) took off from Bolthead to patrol at 13,500ft. ten miles from the French Coast, North of Brest. Nine enemy bombers and twenty Me109s were sighted, thereupon they attacked the enemy fighters in line astern. During the engagement, Michal attacked an Me 109 and after a short burst from astern the petrol tank of the enemy aircraft exploded and it down vertically out of control. He then attacked a second Me 109 which also went into a veritical dive emitting dense black smoke. The former was claimed as destroyed and the latter as probable.

On 3rd February 1943, Michal was promoted to Flight Sergeant.