After a farewell visit from the Eastern Fleet commander, Admiral Sir James Somerville on 12 January 1943, "Illustrious" sailed for home the next day. She flew off her aircraft to Gibraltar on 31 January and continued on to the Clyde where she arrived five days later. She conducted deck-landing trials for prototypes of the Blackburn Firebrand and Fairey Firefly fighters, as well as the Fairey Barracuda dive/torpedo bomber from 8 to 10 February. On 26 February she began a refit at Birkenhead that lasted until 7 June during which her flight deck was extended, new radars were installed, her light anti-aircraft armament was augmented, and two new arrestor wires were fitted aft of the rear lift which increased her effective landing area. While conducting her post-refit trials, she also conducted flying trials for Martlet Vs and Barracudas. Both sets of trials were completed by 18 July, by which time the "Illustrious" had joined the Home Fleet.