The squadron began flying operational missions on 1 July 1941. As an army cooperation unit its main duties were photographic and tactical reconnaissance and artillery spotting. From 13 September No. 451 Squadron maintained a detachment of two pilots and two aircraft in the besieged Libyan town of Tobruk to support the Allied garrison; this detachment remained until the siege was lifted in December; during this period several Hurricanes were shot down by Axis fighters. The remainder of No. 451 Squadron was attached to XIII Corps and participated in Operation Crusader during November and December 1941. The squadron frequently operated from airstrips near the front line, and some of its personnel were captured on 26 and 27 November when German forces attacked the airstrip at Sidi Azeiz. All but three of these men were liberated when Bardia fell to the South African 2nd Infantry Division on 2 January 1942. Following the conclusion of Operation Crusader No. 451 Squadron was withdrawn from operations on 24 January 1942 and was refitted at Heliopolis.