In October, the carrier was transferred to the Home Fleet and departed Gibraltar for Greenock on 13 October together with the battleship King George V. Six days later she was in Scapa Flow to begin patrols to Iceland in company with the battleships Howe and Anson and the American carrier Ranger that lasted for the next three weeks.
On 13 November she flew off her air group and sailed for Belfast to begin a lengthy refit, arriving on 19 November.
The refit was completed in early June and the ship spent the rest of the month working up.
The 18 Corsairs of 1841 Squadron and the 24 Fairey Barracuda torpedo bombers of 827 and 830 Squadrons flew aboard on 29 June and Formidable sailed for Scapa Flow to train with the carriers Furious and Indefatigable before launching an attack on the Tirpitz in Kaafjord on 17 July (Operation Mascot).
Her Corsairs escorted the strike aircraft from the other carriers to the target; one was shot down by German flak.
A smoke screen prevented most of the Barracudas from seeing their target and they failed to hit the Tirpitz.
Upon the ship's return to Scapa Flow, 827 and 830 Squadrons were replaced by 826 and 828 Squadrons, also flying Barracudas.

Formidable's air group was reinforced by a dozen Corsairs of 1842 Squadron on 7 August in preparation for further attacks on Tirpitz (Operation Goodwood).
The two Corsair squadrons were assigned to No.
6 Naval Fighter Wing aboard the carrier on 14 August.
The first attack was on the morning of 22 August when Formidable launched 24 Corsairs and 12 Barracudas against the German battleship and nearby targets, all of which returned.
A smoke screen again protected the Tirpitz and no damage was inflicted.
Another attack scheduled for the afternoon had to be cancelled because of low clouds.
A further attack could not be mounted until 24 August because of bad weather.
The carrier contributed 23 Corsairs and 16 Barracudas, and 3 of the fighters were shot down over the target.
The Tirpitz was lightly damaged by two bomb hits during this attack.
A final attack was made five days later, again without effect.

The carrier arrived at Scapa Flow on 2 September where both Barracuda squadrons disembarked.
She later sailed to Gibraltar, arriving on 21 September to begin a refit that, among other things, augmented her anti-aircraft outfit in preparation for operations in the Pacific.
The Corsairs of No.
6 Naval Fighter Wing flew aboard on 1 January 1945, as did 18 Grumman TBF Avengers of 848 Squadron.
After several weeks of working up, Formidable departed Gibraltar on 14 January to join the British Pacific Fleet (BPF).
She arrived in Sydney, the BPF's main base, on 10 March after several stops en route to refuel and embark stores and ammunition.
On 20 March, Admiral Sir Bruce Fraser, commander of the BPF, inspected the ship and her crew.
In October, the carrier was transferred to the Home Fleet and departed Gibraltar for Greenock on 13 October together with the battleship King George V. Six days later she was in Scapa Flow to begin patrols to Iceland in company with the battleships Howe and Anson and the American carrier Ranger that lasted for the next three weeks. On 13 November she flew off her air group and sailed for Belfast to begin a lengthy refit, arriving on 19 November. The refit was completed in early June and the ship spent the rest of the month working up. The 18 Corsairs of 1841 Squadron and the 24 Fairey Barracuda torpedo bombers of 827 and 830 Squadrons flew aboard on 29 June and Formidable sailed for Scapa Flow to train with the carriers Furious and Indefatigable before launching an attack on the Tirpitz in Kaafjord on 17 July (Operation Mascot). Her Corsairs escorted the strike aircraft from the other carriers to the target; one was shot down by German flak. A smoke screen prevented most of the Barracudas from seeing their target and they failed to hit the Tirpitz. Upon the ship's return to Scapa Flow, 827 and 830 Squadrons were replaced by 826 and 828 Squadrons, also flying Barracudas.
Formidable's air group was reinforced by a dozen Corsairs of 1842 Squadron on 7 August in preparation for further attacks on Tirpitz (Operation Goodwood). The two Corsair squadrons were assigned to No. 6 Naval Fighter Wing aboard the carrier on 14 August. The first attack was on the morning of 22 August when Formidable launched 24 Corsairs and 12 Barracudas against the German battleship and nearby targets, all of which returned. A smoke screen again protected the Tirpitz and no damage was inflicted. Another attack scheduled for the afternoon had to be cancelled because of low clouds. A further attack could not be mounted until 24 August because of bad weather. The carrier contributed 23 Corsairs and 16 Barracudas, and 3 of the fighters were shot down over the target. The Tirpitz was lightly damaged by two bomb hits during this attack. A final attack was made five days later, again without effect.
The carrier arrived at Scapa Flow on 2 September where both Barracuda squadrons disembarked. She later sailed to Gibraltar, arriving on 21 September to begin a refit that, among other things, augmented her anti-aircraft outfit in preparation for operations in the Pacific. The Corsairs of No. 6 Naval Fighter Wing flew aboard on 1 January 1945, as did 18 Grumman TBF Avengers of 848 Squadron. After several weeks of working up, Formidable departed Gibraltar on 14 January to join the British Pacific Fleet (BPF). She arrived in Sydney, the BPF's main base, on 10 March after several stops en route to refuel and embark stores and ammunition. On 20 March, Admiral Sir Bruce Fraser, commander of the BPF, inspected the ship and her crew.
HMS Formidable (67)