HMS Illustrious : World War 2’s Never Say Die Carrier
HMS Illustrious and her career in WW2, she probably sets a record for an aircraft carrier with the most damage sustained and survived, fighting in all theaters of the war
In 1940 HMS Illustrious was sent to Gibraltar and after refueling in Gibraltar, Illustrious and the battleship Valiant were escorted into the Mediterranean by Force H as part of Operation Hats, during which her Fulmars shot down five Italian bombers and her AA guns shot down two more. Now escorted by the bulk of the Mediterranean Fleet, eight of her Swordfish, together with some from the carrier Eagle, attacked the Italian seaplane base at Rhodes on the morning of 3 September. A few days after the Italian invasion of Egypt, Illustrious flew off 15 Swordfish during the moonlit night of 16/17 September to attack the port of Benghazi.
Aircraft from 819 Squadron laid six mines in the harbor entrance while those from 815 Squadron sank the destroyer Borea and two freighters totaling 10,192 gross register tons (GRT). The destroyer Aquilone later struck one of the mines and sank. During the return voyage to Alexandria, the Italian submarine Corallo made an unsuccessful attack on the British ships. While escorting a convoy to Malta on 29 September, the carrier’s Fulmars broke up attacks by Italian high-level and torpedo bombers, shooting down one for the loss of one fighter. While returning from another convoy escort mission, the Swordfish of Illustrious and Eagle attacked the Italian airfield on the island of Leros on the evening of 13/14 October.
Upon his arrival in the Mediterranean, Lyster proposed a carrier airstrike on the Italian fleet at its base in Taranto, as the Royal Navy had been planning since the Abyssinia Crisis of 1935, and Admiral Andrew Cunningham, commander of the Mediterranean Fleet, approved the idea by 22 September 1940. The attack, with both available carriers, was originally planned for 21 October, the anniversary of the Battle of Trafalgar, but a hangar fire aboard Illustrious on 18 October forced its postponement until 11 November when the next favorable phase of the moon occurred. The fire destroyed three Swordfish and heavily damaged two others, but they were replaced by aircraft from Eagle, whose contaminated fuel tanks prevented her from participating in the attack.
Repairs were completed before the end of the month, and she escorted a convoy to Greece, during which her Fulmars shot down one shadowing CANT Z.506B floatplane. She sailed from Alexandria on 6 November, escorted by the battleships Warspite, Malaya, and Valiant, two light cruisers, and 13 destroyers, to provide air cover for another convoy to Malta. At this time her air group was reinforced by several of Eagles’s Gloster Sea Gladiators supplementing the fighters of 806 Squadron as well as torpedo bombers from 813 and 824 Squadrons and they shot down a CANT Z.501 seaplane two days later. Later that day seven Savoia-Marchetti SM.79 medium bombers were intercepted by three Fulmars, which claimed to have shot down one bomber and damaged another. In reality, they heavily damaged three of the Italian aircraft. A Z.501 searching for the fleet was shot down on 10 November by a Fulmar and another on the 11th. A flight of nine SM.79s was intercepted later that day and the Fulmars claimed to have damaged one of the bombers, although it actually failed to return to base.
Three additional Fulmars had been flown aboard from Ark Royal a few days earlier, when both carriers were near Malta; that brought its strength up to 15 Fulmars, 24 Swordfish, and two to four Sea Gladiators. Three Swordfish crashed shortly after take-off on 10 and 11 November, probably due to fuel contamination, and the maintenance crewmen spent all day laboriously draining all the fuel tanks and refilling them with clean petrol. This left only 21 aircraft available for the attack
Now augmented by reinforcements from the UK, the Mediterranean Fleet detached Illustrious, four cruisers, and four destroyers to a point 170 miles (270 km) south-east of Taranto. The first wave of a dozen aircraft, all that the ship could launch at one time, flew off by 20:40 and the second wave of nine by 21:34. Six aircraft in each airstrike were armed with torpedoes and the remainder with bombs or flares or both to supplement the three-quarter moon. The Royal Air Force (RAF) had positioned a Short Sunderland flying boat off the harbor to search for any movement to or from the port and this was detected at 17:55 by acoustic locators and again at 20:40, alerting the defenders.
The noise of the on-coming first airstrike was heard at 22:25 and the anti-aircraft guns defending the port opened fire shortly afterwards, as did those on the ships in the harbor. The torpedo-carrying aircraft of the first wave scored one hit on the battleship Conte di Cavour and two on the recently completed battleship Littorio while the two flare droppers bombed the oil storage depot with little effect. The four aircraft loaded with bombs set one hangar in the seaplane base on fire and hit the destroyer Libeccio with one bomb that failed to detonate. The destroyer Fulmine, or Conte di Cavour, shot down the aircraft that put a torpedo into the latter ship, but the remaining aircraft returned to Illustrious.
One torpedo-carrying aircraft of the second wave was forced to return when its long-range external fuel tank fell off, but the others hit the Littorio once more and the Caio Duilio was hit once when they attacked beginning at 23:55. The two flare droppers also bombed the oil storage depot with minimal effect, and one bomb penetrated through the hull of the heavy cruiser Trento without detonating. One torpedo bomber was shot down, but the other aircraft returned. A follow on airstrike was planned for the next night based on the pessimistic assessments of the aircrews, but it was canceled due to bad weather. Reconnaissance photos taken by the R.A.F. showed three battleships with their decks awash and surrounded by pools of oil. The two airstrikes had changed the balance of power in the Mediterranean by sinking the Conte di Cavour, and badly damaging the Littorio and the Caio Duilio.
While en route to Alexandria the ship’s Fulmars engaged four CANT Z.506Bs, claiming three shot down and the fourth damaged, although Italian records indicate the loss of only two aircraft on 12 November. Two weeks later, 15 Swordfish attacked Italian positions on Leros, losing one Swordfish. While off Malta two days later, six of the carrier’s fighters engaged an equal number of Fiat CR.42 Falco biplane fighters, shooting down one and damaging two others. One Fulmar was slightly damaged during the battle. On the night of 16/17 December, 11 Swordfish bombed Rhodes and the island of Stampalia with little effect. Four days later Illustrious’ aircraft attacked two convoys near the Kerkennah Islands and sank two merchant ships totalling 7,437 GRT. On the morning of 22 December, 13 Swordfish attacked Tripoli harbor, starting fires and hitting warehouses multiple times. The ship arrived back at Alexandria two days later.
On 7 January 1941, Illustrious set sail to provide air cover for convoys to Piraeus, Greece and Malta as part of Operation Excess. For this operation, her fighters were reinforced by a detachment of three Fulmars from 805 Squadron. During the morning of 10 January, her Swordfish attacked an Italian convoy without significant effect. Later that morning three of the five Fulmars on Combat Air Patrol (CAP) engaged three SM.79s at low altitude, claiming one shot down. One Fulmar was damaged and forced to return to the carrier, while the other two exhausted their ammunition and fuel during the combat and landed at Hal Far airfield on Malta.
The remaining pair engaged a pair of torpedo-carrying SM.79s, damaging one badly enough that it crashed upon landing. They were low on ammunition and out of position, as they chased the Italian aircraft over 50 miles (80 km) from Illustrious. The carrier launched four replacements at 12:35, just when 24–36 Junkers Ju 87 Stuka dive bombers of the First Group/Dive Bomber Wing 1 (I. Gruppe/Sturzkampfgeschwader (StG) 1) and the Second Group/Dive Bomber Wing 2 (II. Gruppe/StG 2) began their attack, led by Paul-Werner Hozzel. Another pair were attempting to take off when the first 250-or-500-kilogram (550 or 1,100 lb) bomb struck just forward of the aft lift, destroying the Fulmar whose engine had failed to start and detonating high in the lift well; the other aircraft took off and engaged the Stukas as they pulled out of their dive.
The ship was hit five more times in this attack, one of which penetrated the un-armoured aft lift and detonated beneath it, destroying it and the surrounding structure. One bomb struck and destroyed the starboard forward “pom-pom” mount closest to the island, while another passed through the forwardmost port “pom-pom” mount and failed to detonate, although it did start a fire. One bomb penetrated the outer edge of the forward port flight deck and detonated about 10 feet (3.0 m) above the water, riddling the adjacent hull structure with holes which caused flooding in some compartments and starting a fire.
The most damaging hit was a large bomb that penetrated through the deck armour forward of the aft lift and detonated 10 feet above the hangar deck. The explosion started a severe fire, destroyed the rear fire sprinkler system, bent the forward lift like a hoop and shredded the fire curtains into lethal splinters. It also blew a hole in the hangar deck, damaging areas three decks below. The Stukas also near-missed Illustrious with two bombs, which caused minor damage and flooding. The multiple hits at the aft end of the carrier knocked out her steering gear, although it was soon repaired.
Another attack by 13 Ju 87s at 13:20 hit the ship once more in the aft lift well, which again knocked out her steering and reduced her speed to 15 knots (28 km/h; 17 mph). This attack was intercepted by six of the ship’s Fulmars which had rearmed and refuelled ashore after they had dropped their bombs, but only two of the dive bombers were damaged before the Fulmars ran out of ammunition.
The carrier, steering only by using her engines, was attacked several more times before she entered Grand Harbour’s breakwater at 21:04, still on fire. The attacks killed 126 officers and men and wounded 91. Nine Swordfish and five Fulmars were destroyed during the attack. One additional Swordfish, piloted by Lieutenant Charles Lamb, was attempting to land when the bombs began to strike and was forced to ditch when it ran out of fuel; the crew was rescued by the destroyer Juno. The British fighters claimed to have shot down five Ju 87s, with the fleet’s anti-aircraft fire claiming three others. German records show the loss of three Stukas, with another forced to make an emergency landing.
While her steering was being repaired in Malta, the Illustrious was bombed again on 16 January by 17 Junkers Ju 88 medium bombers and 44 Stukas. The pilots of 806 Squadron claimed to have shot down two of the former and possibly damaged another pair, but a 500 kg bomb penetrated her flight deck aft of the rear lift and detonated in the captain’s day cabin; several other bombs nearly hit the ship but only caused minor damage.
Two days later, one of three Fulmars that intercepted an Axis air raid on the Maltese airfields was shot down with no survivors. Only one Fulmar was serviceable on 19 January, when the carrier was attacked several times and it was shot down. Illustrious was not struck during these attacks but was near-missed several times and the resulting shock waves from their detonations dislodged enough hull plating to cause an immediate 5-degree list, cracked the cast-iron foundations of her port turbine, and damaged other machinery. The naval historian J. D. Brown noted that “There is no doubt that the armored deck saved her from destruction; no other carrier took anything like this level of punishment and survived.”
Without aircraft aboard, she sailed to Alexandria on 23 January escorted by four destroyers, for temporary repairs that lasted until 10 March. Boyd was promoted to rear admiral on 18 February and relieved Lyster as Rear Admiral Aircraft Carriers. He transferred his flag to Formidable when she arrived at Alexandria on 10 March, just before Illustrious sailed for Port Said to begin her transit of the Suez Canal.
The Germans had laid mines in the canal earlier.
Clearing the mines and the ships sunk by them was a slow process and Illustrious did not reach Suez Bay until 20 March. The ship then sailed for Durban, South Africa, to have the extent of her underwater damage assessed in the drydock there. She reached Durban on 4 April and remained there for two weeks. The ship ultimately arrived at the Norfolk Navy Yard in the United States on 12 May for permanent repairs.
Some important modifications were made to her flight deck arrangements, including the installation of a new aft lift and modification of the catapult for use by American-built aircraft. Her light anti aircraft armament was also augmented during the refit. Captain Lord Louis Mountbatten relieved her acting captain on 12 August, although he did not arrive aboard her until 28 August.
He was almost immediately sent on a speaking tour to influence American public opinion, until he was recalled home in October and relieved by Captain A. G. Talbot on 1 October. The work was completed in November and Illustrious departed on 25 October, for trials off Jamaica and to load the dozen Swordfish of 810 and 829 Squadrons. She returned to Norfolk on 9 December, to rendezvous with Formidable, which had also been repaired there, and the carriers sailed for home three days later. On the night of 15/16 December, Illustrious collided with Formidable in a moderate storm.
Neither ship was seriously damaged, but Illustrious had to reduce speed to shore up sprung bulkheads in the bow and conduct temporary repairs to the forward flight deck. She arrived at Greenock on 21 December and permanent repairs were made from 30 December to late February 1942 at Cammell Laird’s shipyard in Birkenhead. While working up her air group in March, reinforced by the Grumman Martlet fighters (the British name of the F4F Wildcat) of 881 and 882 Squadrons, she conducted trials of a “hooked” Supermarine Spitfire fighter, the prototype of the Seafire.
The conquest of British Malaya and the Dutch East Indies in early 1942 opened the door for Japanese advances into the Indian Ocean. The Vichy French-controlled island of Madagascar stood astride the line of communication between India and the UK and the British were worried that the French would accede to occupation of the island as they had to the Japanese occupation of French Indochina in 1940. Preventing this required a preemptive invasion of Diego Suarez scheduled for May 1942. Illustrious had her work up cut short on 19 March to prepare to join the Eastern Fleet in the Indian Ocean and participate in the attack. She sailed four days later, having embarked twenty-one Swordfish, nine Martlet IIs of 881 Squadron and six Martlet Is of 882 Squadron, and two Fulmar fighters prior to escorting a troop convoy carrying some of the men allocated for the assault.
A hangar fire broke out on 2 April that destroyed 11 aircraft and killed one crewman, but failed to cause any serious damage to the ship. Repairs were made in Freetown, Sierra Leone, where her destroyed aircraft were replaced and augmented by twelve additional Martlet II fighters from HMS Archer, while two Martlet I aircraft were, in turn, transferred to Archer, bringing Illustrious’ total aircraft complement to 47. After her stay at Freetown, Illustrious proceeded to Durban; during the voyage her staff also fitted ASV radar to the replacement Swordfish. One Martlet I was fitted with folding wings.
Illustrious’s aircraft were tasked to attack French naval units and shipping and to defend the invasion fleet, while her half-sister Indomitable provided air support for the ground forces. For the operation the carrier’s air group numbered 25 Martlets, 1 night-fighting Fulmar and 21 Swordfish, and was consequently forced to have a permanent deck park of 5 Martlets and one Swordfish. Before dawn on 5 May, she launched 18 Swordfish together with 8 Martlets. The first flight of 6 Swordfish, carrying torpedoes, unsuccessfully attacked the aviso D’Entrecasteaux, but sank the armed merchant cruiser MS Bougainville.
The second flight, carrying depth charges, sank the submarine Bévéziers while the third flight dropped leaflets over the defenders before attacking an artillery battery and D’Entrecasteaux. One aircraft of the third flight was forced to make an emergency landing and its crew was captured by the French. Later in the day, D’Entrecasteaux attempted to put to sea, but she was successfully bombed by an 829 Squadron Swordfish and deliberately run aground to avoid sinking. Three other Swordfish completed her destruction. The next morning, Martlets from 881 Squadron intercepted three Potez 63.11 reconnaissance bombers, shooting down two and forcing the other to retreat, while Swordfish dropped dummy parachutists as a diversion.
One patrolling Swordfish sank the submarine Le Héros and another spotted for ships bombarding French defenses. On the morning of 7 May, Martlets from 881 Squadron intercepted three Morane-Saulnier M.S.406 fighters on a reconnaissance mission. All three were shot down for the loss of one Martlet. In addition to the other losses enumerated, 882 Squadron’s Fulmar was shot down while providing ground support. Illustrious’ aircraft flew 209 sorties and suffered six deck landing crashes, including four by Martlets.
She was then formally assigned to the Eastern Fleet and, after a short refit in Durban, sailed to Colombo, Ceylon, and became the flagship of the Rear Admiral Aircraft Carriers, Eastern Fleet, Denis Boyd, her former captain. At the beginning of August, the ship participated in Operation Stab, a decoy invasion of the Andaman Islands to distract the Japanese when the Americans were invading the island of Guadalcanal in the South Pacific. Captain Robert Cunliffe relieved Talbott on 22 August. On 10 September the carrier covered the amphibious landing that opened Operation Streamline Jane, the occupation of the remainder of Madagascar, and the landing at Tamatave eight days later, but no significant resistance was encountered and her aircraft were not needed. For this operation she had aboard 6 Fulmars of 806 Squadron, 23 Martlets of 881 Squadron and 18 Swordfish of 810 and 829 Squadrons.
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.
On 26 July, she sortied for the Norwegian Sea as part of Operation Governor, together with the battleship Anson, the American battleship Alabama, and the light carrier Unicorn, an attempt to fool the Germans into thinking that Sicily was not the only objective for an Allied invasion. 810 Squadron was the only unit retained from her previous air group and it had been re-equipped with Barracudas during her refit. Her fighter complement was augmented by 878 and 890 Squadrons, each with 10 Martlet Vs, and 894 Squadron with 10 Seafire IICs. These latter aircraft lacked folding wings and could not fit on the lifts.
The British ships were spotted by Blohm & Voss BV 138 flying boats and 890 Squadron shot down two of them before the fleet returned to Scapa Flow on 29 July. She transferred to Greenock at the end of the month and sailed on 5 August to provide air cover for the ocean liner RMS Queen Mary as she conveyed Prime Minister Winston Churchill to the Quebec Conference. Once the convoy was out of range of German aircraft, the Illustrious left the convoy and arrived back at Greenock on 8 August.
Together with the Unicorn, she sailed for the Mediterranean on 13 August to prepare for the landings at Salerno (Operation Avalanche), reaching Malta a week later.
Her air group was reinforced at this time by four more Martlets each for 878 and 890 Squadrons. She was assigned to Force H for the operation which was tasked to protect the amphibious force from attack by the Italian Fleet and provide air cover for the carriers supporting the assault force. The Italians made no effort to attack the Allied forces, and the most noteworthy thing that any of her aircraft did was when one of 890 Squadron’s Martlets escorted a surrendering Italian aircraft to Sicily. Before the Illustrious steamed for Malta she transferred six Seafires to the Unicorn to replace some of the latter’s aircraft wrecked in deck-landing accidents. Four of these then flew ashore to conduct operations until they rejoined Illustrious on 14 September at Malta.
She then returned to Britain on 18 October for a quick refit at Birkenhead that included further improvements to the flight deck and the reinforcement of her light anti-aircraft armament. She embarked the Barracudas of 810 and 847 Squadrons of No. 21 Naval Torpedo-Bomber Reconnaissance Wing on 27 November before beginning her work up three days later. No. 15 Naval Fighter Wing with the Vought Corsairs of 1830 and 1833 Squadrons were still training ashore and flew aboard before the work up was finished on 27 December.
Illustrious departed Britain on 30 December and arrived in Trincomalee, Ceylon, on 28 January 1944. She spent most of the next several months training although she participated in several sorties with the Eastern Fleet searching for Japanese warships in the Bay of Bengal and near the coast of Sumatra. The fleet departed Trincomalee on 21 March to rendezvous with the American carrier Saratoga in preparation for combined operations against the Japanese facilities in the Dutch East Indies and the Andaman Islands. The first operation carried out by both carriers was an airstrike on the small naval base at Sabang at the northern tip of Sumatra (Operation Cockpit).
The carrier’s air group consisted of 21 Barracudas and 28 Corsairs for the operation; Illustrious launched 17 of the former escorted by 13 of the latter on the morning of 19 April. The American bombers attacked the shipping in the harbour while the British aircraft attacked the shore installations. The oil storage tanks were destroyed and the port facilities badly damaged by the Barracudas. There was no aerial opposition and the fighters claimed to have destroyed 24 aircraft on the ground. All British aircraft returned safely although one American fighter was forced to ditch during the return home.
The Saratoga was ordered to depart for home for a refit by 19 May and Somerville wanted to mount one more attack as she was leaving the Indian Ocean. He chose the naval base and oil refinery at Surabaya, Java (Operation Transom), and the distance from the newly renamed East Indies Fleet’s base at Ceylon required refuelling at Exmouth Gulf on the western coast of Australia before the attack. The necessity to attack from the south, across the full width of Java, meant that the target was outside the Barracuda’s range and 810 and 847 Squadrons were replaced by the 18 Grumman Avengers of 832 and 845 Squadrons for the mission.
Early on the morning of 17 May, the ship launched all 18 Avengers, escorted by 16 Corsairs. One Avenger crashed on take-off and an American Avenger was shot down over the target; only one small ship was sunk, and little damage was done to the refinery. The Saratoga and her escorts separated after refueling again in Exmouth Gulf and the East Indies Fleet was back in Trincomalee on 27 May where No. 21 Wing re embarked.
On 10 June, the Illustrious and the escort carrier Atheling put to sea to simulate another airstrike on Sabang as a means of distracting the Japanese while the Americans were attacking airfields in the Mariana Islands and preparing to invade the island of Saipan. For the planned attack on Port Blair in the Andaman Islands in mid-June her air group was reinforced by the 14 Corsairs of 1837 Squadron; six Barracudas from No. 21 TBR Wing were landed to make room for the additional fighters. On 21 June, the ship launched 15 Barracudas and 23 Corsairs against the airfield and harbor of Port Blair. Two of the Barracudas were forced to return with engine trouble before the attack began and another was shot down over the target. In addition, one Corsair was forced to ditch; the pilot was rescued by a destroyer. Bad weather degraded the accuracy of the Barracudas and little damage was inflicted aside from a few aircraft destroyed on the ground and a few small craft sunk in the harbor.
With over 50 aircraft airborne at one point, the British realized that a single deck accident might result in the loss of every aircraft in the air because there was no other carrier available to land aboard. The carrier and her escorts arrived back at Trincomalee on 23 June where 847 Squadron was merged into 810 Squadron a week later.
Her sister ships, the Indomitable and the Victorious arrived at the end of June although only the latter’s pilots were combat-ready. Captain Charles Lambe was appointed as the new captain of the Illustrious on 21 May, but he could not join his new ship until 9 July. Somerville decided to attack Sabang again (Operation Crimson), although the ships of the East Indies Fleet would bombard the port while the fighters from the Illustrious and the Victorious spotted for them and protected the fleet. As the Barracudas were needed only for anti-submarine patrols, the former embarked only nine while the latter ship flew off all her Barracudas.
On the early morning of 25 July, Illustrious launched 22 Corsairs for CAP and to observe the naval gunfire and take photos for post-attack damage assessments. The bombardment was very effective, sinking two small freighters, and severely damaging the oil storage and port facilities. One Corsair was shot down by Japanese flak although the pilot was rescued after ditching. As the fleet was withdrawing, Illustrious’s CAP intercepted and shot down a Nakajima Ki-43 (codenamed “Oscar”) fighter and a Mitsubishi Ki-21 “Sally” medium bomber on reconnaissance missions. Later in the day her Corsairs intercepted 10 Ki-43s and shot down two of them while driving off the remainder. After arriving in Trincomalee, 1837 Squadron was transferred to the Victorious.
On 30 July, she sailed for Durban to begin a refit that lasted from 15 August to 10 October and arrived back at Trincomalee on 1 November. 810 Squadron and its Barracudas were transferred off the ship the next day and were later replaced by the Avengers of 854 Squadron. For the next six weeks she carried out an intensive flying regime in preparation for the next operations against the Japanese together with the other carriers of the fleet. On 22 November she was assigned to the newly formed British Pacific Fleet (BPF), commanded by Admiral Sir Bruce Fraser. She was assigned to the 1st Aircraft Carrier Squadron (1st ACS), commanded by Rear Admiral Sir Philip Vian when he arrived at Colombo aboard the carrier Indefatigable.
A week later, Illustrious and Indomitable sortied to attack an oil refinery at Pangkalan Brandan, Sumatra (Operation Outflank); the former’s airgroup now consisted of 36 Corsairs of 1830 and 1833 Squadrons and 21 Avengers of 857 Squadron. When the aircraft approached the target on the morning of 20 December, it was obscured by clouds so they diverted to the secondary target of the port at Belawan Deli. It was partially obscured by clouds and heavy squalls so the attacking aircraft had only moderate success, setting some structures on fire and destroying several aircraft on the ground.
On 16 January 1945 the BPF sailed for its primary base in the Pacific Ocean, Sydney, Australia. En route, the carriers of the 1st ACS attacked Palembang on 24 January and 29 January (Operation Meridian). Illustrious’s air group consisted of 32 Corsairs and 21 Avengers by now and she contributed 12 of her Avengers and 16 Corsairs to the first attack, which destroyed most of the oil storage tanks and cut the refinery’s output by half for three months. Five days later, the BPF attacked a different refinery and the ship launched 12 Avengers and 12 Corsairs. The attack was very successful at heavy cost; between the two air operations, her squadrons lost five Corsairs to enemy flak or fighters and one due to a mechanical problem on take-off as well as three Avengers to enemy action.
Her Corsairs claimed four enemy aircraft shot down as did one Avenger pilot who claimed victory over a Nakajima Ki-44 “Tojo” fighter. The fleet’s fire discipline was poor when it was attacked by seven Japanese bombers shortly after the strike aircraft began landing. The attackers were all shot down, but two shells fired by either Indomitable or the battleship King George V struck Illustrious, killing 12 and wounding 21 men.
She arrived on 10 February and repairs began when she entered the Captain Cook Dock in the Garden Island Dockyard the next day, well before it was officially opened by the Duke of Gloucester, the Governor-General of Australia on 24 March. By this time the vibration problems with her centre propeller shaft, which had never been properly repaired after she was bombed at Malta, were so bad that the propeller was removed and the shaft locked in place, reducing her maximum speed to 24 knots.
On 6 March she sailed to the BPF’s advance base at Manus Island and, after her arrival a week later, Illustrious and her sisters Indomitable and Victorious, as well as the carrier Indefatigable, exercised together before sailing for Ulithi on 18 March. The BPF joined the American Fifth Fleet there two days later, under the designation Task Force 57 (TF 57), to participate in the preliminary operations for the invasion of Okinawa (Operation Iceberg). The British role during the operation was to neutralize airfields on the Sakishima Islands, between Okinawa and Formosa, beginning on 26 March. Her air group now consisted of 36 Corsairs, 16 Avengers and two Supermarine Walrus flying boats for rescue work.
From 26 March to 9 April, the BPF attacked the airfields with each two-day period of flying operations followed by two or three days required to replenish fuel, ammunition and other supplies. While the precise details on activities of the carrier’s squadrons are not readily available, it is known that the commanding officer of 854 Squadron was forced to ditch his Avenger on the morning of 27 March with the loss of both his crewmen; he was ultimately rescued that evening by an American submarine. On the afternoon of 6 April, four kamikaze aircraft evaded detection and interception by the CAP, and one, a Yokosuka D4Y3 “Judy” dive bomber, attacked Illustrious in a steep dive. The light AA guns managed to sever its port wing so that it missed the ship, although its starboard wingtip shattered the Type 272’s radome mounted on the front of the bridge.
When the 1,000-kilogram (2,200 lb) bomb that it was carrying detonated in the water only 50 feet (15.2 m) from the side of the ship, the resulting shock wave badly damaged two Corsairs parked on the deck and severely shook the ship. The initial damage assessment was that little harm had been done, although vibrations had worsened, but this was incorrect as the damage to the hull structure and plating proved to be extensive.
Vice Admiral Sir Bernard Rawlings, commander of Task Force 57, ordered the recently arrived Formidable to join the task force to replace Illustrious on 8 April. In the meantime, she continued to conduct operations with the rest of the fleet. On 12 and 13 April, the BPF switched targets to airfields in northern Formosa and her sister joined the task force on 14 April. Since the beginning of the operation, her aircraft had flown 234 offensive and 209 defensive sorties, claiming at least two aircraft shot down. Her own losses were two Avengers and three Corsairs lost in action and one Avenger and six Corsairs due to non-combat causes.
Formidable’s arrival allowed Rawlings to order Illustrious to the advance base in San Pedro Bay, in the Philippines, for a more thorough inspection. She arrived on 16 April and the examination by divers revealed that some of her outer plating was split and that some transverse frames were cracked. The facilities there could provide only emergency repairs, enough to allow her to reach the bigger dockyard in Sydney. Task Force 57 arrived in San Pedro Bay on 23 April for a more thorough replenishment period and Illustrious transferred aircraft, spares, stores, and newly arrived pilots to the other carriers before sailing for Sydney on 3 May. She arrived on 14 May and departed 10 days later, bound for Rosyth for permanent repairs. 854 Squadron was disembarked while at Sydney, but the carrier kept her two Corsair squadrons until after arriving in the UK on 27 June.