Skalski then became commander of No. 601 (County of London) Squadron, the first Pole to command an RAF squadron. He then took part in the invasion of Sicily and invasion of Italy. From December 1943 to April 1944 Wing Commander Skalski commanded No. 131 Polish Fighter Wing. On 4 April 1944 he was appointed commander of No. 133 Polish Fighter Wing, flying the Mustang Mk III. On 24 June 1944 Skalski scored two air victories over Rouen.