The boat was ordered to operate against enemy aircraft carriers that entered the Western Mediterranean from Gibraltar to launch fighter aircraft for Malta.

On 29 April, U-573 developed engine troubles and headed east while the crew tried to repair the engine. In the afternoon on 1 May, the U-boat was bombed and badly damaged by a Hudson aircraft northwest of Ténès, Algeria. After reporting the distress, the nearby U-74 and U-375 were sent to assist and the Italian submarines Emo and Mocenigo also joined the rescue operation, while the Allies sent other aircraft from Gibraltar and detached two destroyers to intercept the crippled U-boat. Heinsohn initially thought that he had to scuttle the disabled boat, but the engineers managed to restart one of the electrical engines and so they slowly headed northwards, until they were ordered by the SKL to head for Cartagena in neutral Spain, where the boat arrived at 11.36 hours on 2 May. However, the Allied forces searching for U-573 located and sank U-74 during the afternoon.