38,813 Tons (standard)
Her aircraft, operating from both the carrier and a temporary base at Kunda Airfield in Shanghai, flew missions in support of Japanese ground forces throughout February 1932. During one of these missions three of Kaga's Nakajima A1N2 fighters, including one piloted by future ace Toshio Kuroiwa, escorting three Mitsubishi B1M3 torpedo bombers, scored the IJN's first air-to-air combat victory on 22 February when they shot down a Boeing P-12 flown by an American volunteer pilot. Kaga returned to home waters upon the declaration of the cease-fire on 3 March and resumed fleet training with the rest of the Combined Fleet.
Second Sino-Japanese War
Pearl Harbor Attack
On December 7, 1941 Kaga carried a total of 18 Mitsubishi A6M Zero fighters, 27 Nakajima B5N torpedo bombers and 27 Aichi D3A dive bombers, plus three crated aircraft of each type. Kaga's aircraft participated in both First Air Fleet strikes launched from a position 230 nautical miles north of Oahu. In the first strike, 213 aircraft, including 26 Kaga B5N carrier attack bombers attacked American ships in Pearl Harbor with bombs and torpedoes, escorted by nine Zeros. In the second strike of 170 aircraft, 26 Kaga D3A dive bombers targeted Luke Field on Ford Island while nine Zeros escorted and attacked parked aircraft on the ground.
A total of five B5N, four Zeros and six D3A from the ship were lost during the two strikes, along with their aircrews, a total of 31 personnel. Kaga's bomber and torpedo crews claimed hits on USS Nevada, USS Oklahoma, USS Arizona, USS California, USS West Virginia, and USS Maryland. The ship's fighter pilots claimed to have shot down one US aircraft and destroyed 20 on the ground. Upon completion of the attack, the First and Fifth Carrier divisions, including Kaga, returned to Japan.
On February 9, Kaga hit a reef at Palau after she had unsuccessfully sortied against American carrier forces attacking the Marshall Islands. The damage reduced the carrier's speed to 18 knots. After temporary repairs, she continued to the Timor Sea. On 19 February 1942 she, with the other carriers of the First and Second Carrier Divisions, launched air strikes against Darwin, from a point 100 nautical miles southeast of the easternmost tip of Timor. Kaga contributed 27 B5Ns armed with bombs, 18 D3A dive bombers, and 9 Zeros to the attack, which caught the defenders by surprise. Eight ships were sunk, including the destroyer Peary, and fourteen more were damaged, at a cost of only one of Kaga's B5Ns and D3A1 Val 3304.
In March 1942, Kaga, based out of Staring-baai, helped cover the invasion of Java, although her only contribution appears to have been aircraft for the 5 March 1942 airstrike on Tjilatjap. In that attack Kaga contributed 27 bomb-carrying B5N escorted by nine Zeros. The attacking aircraft bombed merchant ships in the harbor, sinking eight of them, and attacked anti-aircraft batteries and a warehouse without loss. Most of the Allied forces in the Dutch East Indies surrendered to the Japanese later in March. Kaga was unable to participate in the Indian Ocean raid in April because of the damage she had received in February. Instead, she sailed for Sasebo arriving on March 15 for repairs, and entered drydock on March 27. The repairs were completed on May 4.
Battle of Midway
At dawn on June 4, 1942 the Japanese fleet was 250 nautical miles northwest of Midway. Eighteen D3A Val dive bombers took off from Kaga escorted by nine A6M2 Zeros on a strike against Midway Island. The carrier's B5Ns were armed with torpedoes and kept ready in case enemy ships were discovered during the Midway raid. One each of the D3As and Zeros was shot down by AA fire over Midway, and another four D3As were damaged. Kaga's Zero pilots claimed to have shot down 12 US aircraft over Midway Island. One Kaga B5N was launched to augment the fleet's reconnaissance of the surrounding ocean. The carrier also put up two A6M2 Zeros on CAP.
Another five Zeros reinforced her CAP at 07:00 and the seven fighters helped to defend the Kido Butai from the first US air attackers from Midway Island at 07:10. Unknown to the Japanese, the US Navy had divined the Japanese MI plan from signals intelligence and had prepared an ambush using its three available carriers, positioned northeast of Midway
At 07:15 Admiral Nagumo ordered the B5Ns still on Kaga and Akagi rearmed with bombs for another attack on Midway itself. This process was limited by the number of ordnance carts used to handle the bombs and torpedoes and the limited number of ordnance elevators. Thus, the torpedoes could not be struck below until after all the bombs were moved up from their magazine, assembled and mounted on the aircraft. This process normally took about an hour and a half; more time would be required to bring the aircraft up to the flight deck and warm up and launch the strike group. Around 07:40 Nagumo reversed his order when he received a message that American carriers had been spotted. At 07:30 Kaga recovered three of her CAP.
The five Zeros launched at 08:15 were recovered aboard at 09:10 and replaced by six more Zeros launched at 09:20. They intercepted the first US carrier aircraft to attack, TBD Devastator torpedo-bombers of VT-8 from the US carrier Hornet at 09:22, and shot down all 15, leaving only a single survivor, George H. Gay, Jr., treading water. Shortly thereafter, 14 Devastators from VT-6 from the US carrier Enterprise, led by Eugene E. Lindsey, were spotted. They tried to sandwich Kaga, but the CAP, reinforced by another six Zeros launched by Kaga at 10:00, shot down all but four of the Devastators, and the carrier dodged the torpedoes.
Soon after the torpedo plane attacks, American carrier dive bombers arrived over the Japanese carriers almost undetected and began their dives. At 10:22, 25 SBD Dauntless dive-bombers from Enterprise, led by C. Wade McClusky, hit Kaga with one 1,000-pound (450 kg) bomb and at least three 500-pound (230 kg) bombs. The first landed near her rear elevator and set the berthing compartments on fire, and the next bomb hit the forward elevator and penetrated the upper hangar, setting off explosions and fires among the armed and fueled planes on her hangar deck. Captain Okada and most of the ship's senior officers were killed by the third bomb, which hit the bridge.[Note 20] The 1000-pound bomb hit amidships and penetrated the flight deck to explode on the upper hangar. The explosions ruptured the ship's avgas lines, damaged both her port and starboard fire mains and the emergency generator powering her fire pumps, as well as knocking out the carbon dioxide fire suppression system. Fueled by the avgas pouring onto the hangar deck, the fires detonated the 80,000 pounds (36,000 kg) of bombs and torpedoes strewn across the hangar deck in a series of catastrophic multiple fuel-air explosions that blew out the hangar sides. At nearly the same time, dive bombers hit and fatally damaged Akagi and Sōryū.
Unable to contain her fires, Kaga's survivors were taken off by the destroyers Hagikaze and Maikaze between 14:00 and 17:00. Around 19:25 she was scuttled by two torpedoes from Hagikaze and sank stern-first at position 30°20′N 179°17′W. Ensign Takeshi Maeda, an injured Kaga B5N aircrew member rescued by Hagikaze, described the scene: "My comrade carried me up to the deck so I could see the last moments of our beloved carrier, which was nearby. Even though I was in pain tears started to run down my cheeks, and everyone around me was crying; it was a very sad sight."
The carrier's crew suffered 811 fatalities, mainly among the aircraft mechanics and armorers stationed on the hangar decks and the ship's engineers. Twenty-one of the ship's aviators were killed.