Most naval aircraft fall into one of four main classifications: spotters, patrol aircraft, land-based attack aircraft, and carrier-based aircraft. Battleships and cruisers usually carried catapult-launched spotter aircraft to correct gunfire against enemy vessels or shore targets. Most spotter aircraft tended to be relatively slow floatplanes (e.g., Mitsubishi F1M2 ["Pete" in the Allied identification system] and Vought OS2U Kingfisher), as the design parameters were restricted by the launch and recovery mechanism. These aircraft were also very useful in search and rescue missions.

Patrol aircraft were designed to keep track of enemy ships and (in some cases) to attack small vessels such as submarines. The major performance requirements for patrol aircraft were range and endurance; the sea covers a vast area and an enemy fleet occupied a relatively tiny part of it, so the ability to search large areas and remain on station for a long time was important. Flying boats were widely used as patrol aircraft (e.g., the Consolidated PBY Catalina, Kawanishi H8K, and Short Sunderland), but land-based patrollers with longer ranges (e.g., Lockheed Hudson, Ventura, and Consolidated B-24 Liberator) were used toward the latter part of the war, initially to patrol colder areas such as the Aleutians and Iceland, where flying boats found operation difficult.

Land-based attack aircraft were employed by most combatants and were sometimes successful, provided that they employed specialist antiship attack techniques. Torpedo-bombing was probably the most effective form of attack, but results varied depending on the efficiency of the weapon. American torpedoes suffered from problems and were largely ineffective until the second half of 1943, whereas the Japanese 18-inch "Long Lance" torpedo was extremely effective with a large warhead. Italian, German, and British torpedoes were all moderately effective. Dive-bombing and skip-bombing were also effective, but attacks by high-level bombers were universally unsuccessful against moving ships, as the target had plenty of time to take avoiding action.

Great Britain employed purpose-designed torpedo attack aircraft (the Beaufort and Beaufighter). The United States mainly used conversions of existing aircraft as torpedo carriers (the B-25 Mitchell and B-26 Marauder), but it usually employed skip-bombing in preference to torpedoes. Medium bombers were also used as torpedo-aircraft by Japan (the GM-4 "Betty"), Germany (He-111H), Italy (SM.79), and the Soviet Union (Ilyushin DB-3T/Il-4). German and Japanese bombers were particularly effective.

The following two types of specialist torpedo-bombers were widely used during World War II.

1. The Italian Savoia-Marchetti S.M.79, originally designed as a commercial transport, was adapted to use as a bomber when its excellent performance became known. The SM.79-I entered service in 1936 and was used with some success during the Spanish Civil War. The more powerful SM.79-II was employed throughout World War II in the Mediterranean Theater as a torpedo-bomber (carrying two 17.7-inch torpedoes), medium bomber, reconnaissance aircraft, close-support aircraft, and transport/training aircraft. A total of 1,330 were built between 1936 and 1944.

2. The Bristol Beaufort was the standard British land-based torpedo-bomber until it was replaced by the Bristol Beaufighter TF.X in 1943. Entering service late in 1939, the Beaufort was also used for bombing and minelaying operations. It was reasonably successful, although occasionally let down by malfunctioning torpedoes. A total of 1,429 were built in the United Kingdom, and 700 were built under license in Australia.

Flying an aircraft off and onto an aircraft carrier places many more stresses and strains on the aircraft's structure than comparable activities on land. As a consequence, carrier-based aircraft were generally heavier and more robust—and thus slower and less maneuverable (at least in theory)—than their land-based counterparts. Parts of their structure usually folded to allow the aircraft to be taken below to the hangar, further increasing the weight. On top of that, landing characteristics had to be superior, which required a light wing loading, large flaps, good stall behavior, and a compliant undercarriage. Combining all of these characteristics in a single aircraft was not easy; many of the aircraft that served on carrier decks during World War II had flaws.

Of the major combatants, only the United States, Japan, and Great Britain had aircraft carriers, and each had a different approach to design of carrier-based aircraft.

United States

In 1941, the United States had several large carriers and well-organized carrier operational procedures; it used scout/dive-bombers (SBD Dauntless), torpedo/level-bombers (TBD-1 Devastator), and fighters (F4F Wildcat). Generally speaking, U.S. carrier aircraft were rugged and quite suitable for maritime use. The Douglas TDB-1 Devastator carrier-based torpedo-bomber entered service late in 1937 and was obsolescent when the United States entered the war. Its combat career was terminated by the Battle of Midway when it proved to be vulnerable to fighter attack while unescorted. A total of 129 TBD-1s were built.

The Douglas SBD Dauntless entered service with the U.S. Marine Corps in mid-1940 and with the U.S. Navy later in 1940. It was the standard navy carrierborne dive-bomber in December 1941 when Pearl Harbor was attacked. Operationally, the Dauntless was very successful and could absorb a lot of battle damage, having the lowest attrition rate of any U.S. carrier aircraft in the Pacific Theater. It played a major part in the 1942 Battles of the Coral Sea and Midway and later flew off escort carriers on antisubmarine and close-support missions. A total of 5,936 Dauntless were built.

The Grumman F4F Wildcat entered service with the Royal Navy late in 1940, and it became operational with the Marine Corps and U.S. Navy at the beginning of 1941. The F4F-3 was the standard navy shipboard fighter when the United States entered the war, and it was generally inferior to the Japanese A6M2 Zero in performance and maneuverability. However, the F4F was very rugged and had good dive performance, giving a good account of itself when using the correct tactics. Later in the war, the Wildcat gave sterling service on escort carriers. Approximately 8,000 Wildcats were built.

The Grumman TBF Avenger first flew in August 1941 and became the standard navy carrier-based torpedo-bomber. It entered service in mid-1942 in time for the Battle of Midway. It could take a lot of punishment and, although it was not very maneuverable, it was easy to land on deck. A total of 9,836 Avengers were built; most served with the U.S. Navy, but 958 were supplied to the British navy.

The Curtiss SB2 Helldiver was the most successful carrier-based dive-bomber in U.S. Navy service, in spite of its handling faults and a reputation for structural weakness. Entering service early in 1943, its first major action was the Rabaul Campaign in November 1943, and it took part in almost every major naval/air action during the remainder of the war. The navy was the major user of the Helldiver, although some were flown by the Marine Corps and the British Royal Navy. A total of 7,200 Helldivers were built in the United States and Canada.

The Vought F4U Corsair entered service with the Marine Corps early in 1943; it was not an easy aircraft to deck-land and was initially rejected by the U.S. Navy in favor of the Hellcat. The gull-winged F4U operated from land bases in the Pacific and flew off Royal Navy carriers from late 1943. The Corsair was a very good fighter, convincingly superior in performance to the Mitsubishi Zero and much better than the P-51B Mustang below about 20,000 ft. Eventually the Corsair matured into a reasonable deck-landing aircraft, and it began to supplant the F6F Hellcat as the standard U.S. Navy carrier fighter by the end of the war. It saw extensive service after the war and continued in production until 1952. A total of 12,571 were built.

The Grumman F6F Hellcat entered service early in 1943. It was the most successful carrier-based fighter of the war, accounting for 76 percent of the total enemy aircraft destroyed by U.S. Navy carrier pilots. It was extremely rugged and had much better speed and dive capabilities than the Mitsubishi Zero, which it could normally beat in an even fight. Many of the U.S. Navy aces flew Hellcats. The Hellcat was also employed with some success at night; approximately 1,300 of the 12,272 produced were dedicated radar-equipped night-fighter versions.

Japan

The Imperial Japanese Navy (IJN) had several carriers at the start of the war, the air groups of which were weighted toward attack aircraft rather than fighters. Its aircraft were lightly built and had very long range, but this advantage was usually purchased at the expense of vulnerability to enemy fire. The skill of Japanese aviators tended to exaggerate the effectiveness of the IJN's aircraft, and pilot quality fell off as experienced crews were shot down during the Midway and Solomon Islands Campaigns.

The Nakajima B5N ("Kate" in the Allied designator system) first entered service in 1937 as a carrier-based attack bomber, with the B5N2 torpedo-bomber appearing in 1940. The B5N had good handling and deck-landing characteristics and was operationally very successful in the early part of the war. Large numbers of the B5N participated in the Mariana Islands campaign, and it was employed as a suicide aircraft toward the end of the war. Approximately 1,200 B5Ns were built.

The Aichi D3A ("Val") carrier-based dive-bomber entered service in mid-1940, and it was the standard Japanese navy dive-bomber when Japan entered the war. It was a good bomber, capable of putting up a creditable fight after dropping its bomb load. It participated in the attack on Pearl Harbor and the major Pacific campaigns including Santa Cruz, Midway, and the Solomon Islands. Increasing losses during the second half of the war took their toll, and the D3A was used on suicide missions later in the war. Approximately 1,495 D3As were built.

When it first appeared in mid-1940, the Mitsubishi A6M Zero was the first carrier-based fighter capable of beating its land-based counterparts. It was well armed and had truly exceptional maneuverability below about 220 mph, and its capabilities came as an unpleasant shock to U.S. and British forces. It achieved this exceptional performance at the expense of resistance to enemy fire, with a light structure and no armor or self-sealing tanks. Its Achilles heel was the stiffness of its controls at high speed, the control response being almost nil at indicated airspeed over 300 mph. The Zero was developed throughout the war, a total of 10,449 being built.

The Nakajima B6N ("Jill") carrier-based torpedo-bomber entered service late in 1943 and was intended to replace the B5N, but the initial B6N1 was plagued with engine troubles. The B6N2 with a Mitsubishi engine was the major production model, appearing early in 1944. Overall, it was better than its predecessor but not particularly easy to deck-land. It participated in the Marianas Campaign and was encountered throughout the Pacific until the end of the war. A total of 1,268 were built.

The Yokosuka D4Y ("Judy") reconnaissance/dive-bomber entered service on Japanese carriers early in 1943 and was very fast for a bomber. Initially assigned to reconnaissance units, it was intended to replace the D3A, but it was insufficiently armed and protected and suffered from structural weakness in dives. In common with most other Japanese aircraft, it was used for kamikaze attacks, and a D4Y carried out the last kamikaze attack of the war on 15 August 1945. A total of 2,819 D4Ys were built.

Great Britain

During the 1930s, Great Britain had a limited number of air assets with which to patrol a far-flung empire; the Admiralty was therefore obliged to buy multirole aircraft and accept the inevitable compromises in performance. The Royal Navy entered the war with low-performing aircraft, and its efforts to introduce better aircraft were compromised by conflicts in engine supply. In 1943 it was only too pleased to have the use of F4U Corsairs that were surplus to the requirements of the U.S. Navy.

The Fairey Swordfish carrier-based torpedo/spotter/reconnaissance aircraft entered service late in 1936 and participated in the night raid on Taranto, the battle of Cape Matapan, and the sinking of the Bismarck. It was very slow but was astonishingly agile with excellent flying qualities. Very easy to deck-land, it was a natural choice for use on Atlantic convoy escort carriers. It remained in service until mid-1945, outlasting its replacement (the Fairey Albacore). A total of 2,391 Swordfish were built.

The Blackburn Skua came on line late in 1938 as a carrier-based fighter/dive-bomber. It was not easy to deck-land and had poor stall characteristics, but it was an effective dive-bomber, sinking the German cruiser Königsberg in Bergen harbor during the Norwegian Campaign. A total of 190 were built.

The Fairey Albacore carrier-based torpedo/dive-bomber/reconnaissance aircraft entered service as a replacement for the Swordfish early in 1940 and took part in many of the Middle East operations, including the Battles of Cape Matapan and El Alamein and the Allied landings at Sicily and Salerno. The Albacore had only a slightly better performance than the Swordfish and few redeeming features, and its service with the Royal Navy ended late in 1943. A total of 800 were built.

The two-seat Fairey Fulmar carrier fighter entered service in mid-1940 and was principally designed to combat unescorted bombers and maritime patrol aircraft. It had adequate range, but it was underpowered and its performance was insufficient to deal with contemporary fighters. Nevertheless, it filled a gap until better aircraft became available. A total of 600 were built.

The Hawker Sea Hurricane was first used on catapult-armed merchantmen (CAM) ships during early 1941. Many were conversions of existing land-based fighters. Sea Hurricanes were operational on carriers from late 1941; they were maneuverable and well armed but usually had a lower performance than their adversaries. Approximately 800 Sea Hurricanes were built or converted.

The Supermarine Seafire was an adaptation of the land-based Supermarine Spitfire VB fighter. When it appeared in mid-1942, it was the fastest operational carrier fighter in the world, but it was difficult to deck-land and was not sufficiently robust for use at sea. Later versions were very effective at low altitude, the Seafire LIIC having an outstanding climb and roll performance. Approximately 1,900 were built or converted before the end of the war.

The Fairey Barracuda carrier-based dive/torpedo-bomber entered service early in 1943. It was usually used as a dive-bomber and was not popular with its crews; its performance was mediocre and its defensive armament was poor. It was, however, a reasonably good dive-bomber and was easy to deck-land. A total of 1,718 were built.

Andy Blackburn

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Further Reading
Brown, Eric M. Duels in the Sky. Shrewsbury, UK: Airlife, 1989.; Jarrett, Philip, ed. Aircraft of the Second World War. London: Putnam, 1997.; Munson, Kenneth. Fighters, Attack and Training Aircraft, 1939–45. Poole, UK: Blandford Press, 1969.; Munson, Kenneth. Bombers, Patrol, and Transport Aircraft, 1939–45. Poole, UK: Blandford Press, 1975.