The 1943 Gibraltar Liberator AL523 crash was an aircraft crash that resulted in the death of General Władysław Sikorski, the commander-in-chief of the Polish Army and Prime Minister of the Polish government-in-exile. Sikorski's Liberator II crashed off Gibraltar almost immediately after takeoff on 4 July 1943. An estimated sixteen people died, including many other senior Polish military leaders. The plane's pilot was the only survivor.