HMS Ark Royal (pennant number 91) was an aircraft carrier of the Royal Navy that served during the Second World War. Ark Royal served in some of the most active naval theatres of the Second World War. She was involved in the first aerial and U-boat kills of the war, operations off Norway, the search for the German battleship Bismarck, and the Malta Convoys. Ark Royal survived several near misses and gained a reputation as a 'lucky ship'. She was torpedoed on 13 November 1941 by the German submarine U-81 and sank the following day: one of her 1,488 crew members was killed. Her sinking was the subject of several inquiries, with investigators keen to know how the carrier was lost, in spite of efforts to save the ship and tow her to the naval base at Gibraltar. They found that several design flaws contributed to the loss, which were rectified in new British carriers.