Becoming operational in July, its work mainly consisted of escorting convoys, carrying out maritime patrols, and search and rescue missions along the coast of West Africa.

It began using the Short Sunderland flying boat in 1944 but by this time the threat that U-boats posed to convoys in the area was largely non-existent and the squadron saw little enemy action.

In the mid-1930s, the Royal Air Force (RAF) was in the process of expanding and required an increasing number of suitable flying personnel.

[2][3] In practice, because the New Zealand government found it difficult to fully staff squadrons in Europe, its Article XV squadrons were formed mostly around cadres of New Zealand flying personnel serving in the RAF, supplemented by newly-trained aircrew from the RNZAF; administrative and other ground staff were provided purely by the RAF.

The first personnel to arrive at Jui, located on a strip of land of extending into an estuary and surrounded by mangrove swamps, was the ground crew.

490 Squadron was tasked with patrolling for submarines, escorting convoys, and search and rescue missions, both from Jui and from Fisherman's Lake in Liberia.

[9][10] On 7 August the squadron rescued its first seamen, 39 survivors from the merchant ship Fernhill that had been sunk by a torpedo about 400 miles (640 km) from Freetown.

In early December, there was a brief flurry of action when a ship was torpedoed near Freetown and the squadron sought out the attacking U-boat, but without success.

[12] Wing Commander B. S. Nicholl took over in December 1943 and oversaw the squadron's conversion to Short Sunderland flying boats the following year.

Two crew members were lost, trapped in the sinking aircraft, and the others spent 24 hours in life rafts without food and water before being rescued.