The Clash of the Carriers
US and IJN carrier air power in early 1942
by Randy Wilson
Copyright © 1996 by the Confederate Air Force and Randy Wilson. All rights reserved.
When Japanese carrier air forces struck Pearl Harbor on Dec. 7, 1941, many Americans credited the success of the attack solely to surprise. Even U.S naval officers believed that the Imperial Japanese Navy (IJN) carriers were equipped with clumsy copies of outdated United States and European aircraft designs, and their aircrews unskilled and poorly trained. A comparison of the two opposing forces men and machines, however; shows this was far from the truth.
By the end of 1941, Japanese naval air forces had seen combat in China for over four years, both from carriers and ground bases, without serious opposition. However, most aircraft employed by the Chinese and their allies were typical of mid-1930's designs, with little, if any armor protection and only two or three small-caliber guns. In classic dogfights, the Japanese fighters and their pilots proved superior.
One difference between the Japanese and U.S. navies was that the majority of IJN pilots were enlisted seamen, mostly warrant or petty officers, while most U.S. aviators were commissioned officers. At the outbreak of the war, only about 13 percent of U.S. Navy, Marine and Coast Guard airmen were enlisted Naval Aviation Pilots (NAP), all the rest being officers. One cause for this difference was that the Japanese Navy was still dominated by "battleship" mentality, there being little to encourage or reward officers to become pilots. Whereas U.S. aircraft carrier commanders had to be rated aviators, IJN carrier captains and admirals were not required to be pilots, and many had only surface warfare training and experience at the beginning of the war.
Pre-war Japanese naval flight training, especially for the enlisted men, emphasized quality over quantity, and has been called by some quick and brutal. Of 1,500 sailors who applied as pilot trainees in early 1937, only 70 were admitted, and only 25 graduated as naval aviators. Officer trainees received more training and flying time, about 400 flight hours, before graduating from "Basic Aviation Training," while enlisted pilots graduated with only about 260 hours of flight training. For their advanced training, new IJN pilots were posted to operational air units to learn gunnery, combat tactics and carrier operations in what was termed "Joint Aviation Training."
The weakness of this style was not exposed until the elite aircrews who had trained in peacetime and gained combat experience in China began to suffer heavy losses in early 1942. Failure to use experienced combat pilots to expand the training schools, plus the dependence on combat units to provide advanced flight training proved to be disastrous for the IJN. However, at the start of 1942, Japanese carrier air forces were the best trained and most experienced in the Pacific.
In terms of aerial weapons, both U.S. and Japanese carrier air groups were built around three types of aircraft: fighters, dive bombers (which also acted as scouts) and torpedo bombers. In early 1942, U.S. carriers were armed with the Grumman F4F-3 Wildcat fighter, Douglas SBD-2 Dauntless dive bomber and Douglas TBD-l Devastator torpedo bomber. At the same time, the Japanese equivalents were the Mitsubishi A6M2 "Zero," later code named "Zeke," Aichi D3Al "Val" and Nakajima B5Nl "Kate."
A great deal has been written about the initial superiority of the Zero fighter over the Wildcat. Some historians even question whether Japan would have entered World War II if the Zero's design had not been so successful. Tasked with designing the Zero, Jiro Horikoshi had to meet almost impossible specifications, paying particular attention to the design's structural weight. Grumman's Wildcat, on the other hand, traded some performance for structural toughness and protection. Having been privileged to fly both aircraft in mock combat against each other, I have to say that I prefer to fly the Wildcat most of the time unless I'm in a real one-on-one dogfight.
In one area of training, aerial gunnery, U.S. naval aviators did have an advantage over their IJN counterparts. Since the 1920s, the U.S. Navy had trained both pilots and gunners in deflection shooting, where the target was moving at an angle from 20 to 90 degrees relative to the guns. This type of shot allowed attacks from directly above, below, or from the side of a target, with a good chance of hits. The Wildcat's high mounted cockpit and gunsight allowed its pilots to pull enough "lead" on a target at high angles of deflection, while the engine cowling blocked the view from the Zero's lower cockpit.
The value of such gunnery training was illustrated on Feb.20, 1942, when Lt. Edward "Butch" O'Hare single-handedly broke up an attack on his carrier, the USS Lexington, by eight Mitsubishi G4M "Betty" bombers. His F4F-3 Wildcat's four guns each had 450 rounds of ammunition, enough for only about 34 seconds of firing, yet O'Hare downed five of the Bettys and damaged a sixth, becoming the first U.S. Navy ace of the war and winning the Medal of Honor.
The ability to hit at high deflection angles and the Wildcat's solid controllability in a fast dive, let Wildcat pilots use "hit and run" tactics against the more maneuverable Zero. The Zero's long ailerons also became very heavy, almost immovable, in long dives, giving the Wildcat an advantage when escape became necessary.
Development of the dive bomber as an accurate weapon against rapidly maneuvering ships was first initiated by the U.S. Navy. However, by 1936 Germany had begun testing the famed Junkers Ju 87 "Stuka" dive bomber as "flying artillery." The Aichi D3A Val shows traces of various German designs in its elliptical wings, underwing dive brakes and fixed landing gear. Its opponent, the SBD Dauntless with retractable gear, looks more modern, but in performance the two were almost equal (see table below). The Dauntless was able to carry a heavier bomb, but only at shorter ranges.
Dauntlesses were often forced to supplement the meager number of Wildcat fighters by flying defensive anti-torpedo plane patrols at low altitudes close to the U.S. carriers. Armed only with a single forward firing gun and the handheld rear guns, the SBDs were poor substitutes for fighters, but managed to splash a few low flying attackers in the early battles.
The torpedo bomber was probably the greatest aerial threat to warships at the beginning of the war, as shown by the British in their attacks on the Italian fleet and on Germany's battleship Bismark. Nakajima's B5N Kate equipped the Japanese torpedo squadrons, and was also used as a medium-altitude level bomber when attacking both land and ship targets. The Type 91 aerial torpedo could be released from an altitude of over 300 feet and a speed of 200 mph and carried a warhead of 331 pounds of high explosive. Although relatively fast, the Kate lacked protection for the crew or fuel tanks, and had only a single rear gun for defense.
Although the U.S. torpedo squadrons were awaiting replacement of their Douglas TBDs by a new design, the Grumman TBF Avenger, the TBD Devastators bore the brunt of the fighting for the first six months of the war. When loaded down with a Mark XIII aerial torpedo, the Devastator was both slower and shorter ranged than the Kate. While the Mark XIII's 600 pound warhead was almost twice as powerful as the Japanese Type 91's, the U.S. torpedo had to be released no higher than 50 feet above the water at less than 125 mph to function properly. Thus, the Devastators proved very vulnerable to both fighters and anti-aircraft fire during their lengthy approach to an attack.
With the exception of the Devastator, all the U.S. and Japanese carrier aircraft described in this article continued in combat until the end of the war. Having seen early the need for a rapid build up of air strength, the U.S. Navy was able to quickly replace carrier aircrews from advanced training and reserve air groups. However, after the loss of so many experienced pilots and crews in the carrier battles of the Coral Sea, May 7-8,1942, and Midway, June 4-5,1942, the Japanese carrier forces never recovered.
For the rest of the war, the once proud IJN carriers were reduced to acting as bait, trying to lure the U.S. carriers into range of Japan's main battle fleet, where Japanese guns were to finish what their aircraft had started. But that plan, too, failed, and in the end, it was the U.S. carrier forces that bore down on the Japanese homeland, and commanded the Pacific.
Wing Loading and Power Loading figures are included to indicate the maneuverability of the aircraft. Lower numbers indicate a more maneuverable and faster climbing aircraft.
Tora or To...Ra?
Most articles and books on the Japanese attack on Pearl Harbor, Dec. 7, 1941, note that the Japanese codeword for a successful surprise attack radied back to their carriers was "Tora, Tora, Tora." However, on Dec. 7, 1991, the 50th anniversary of the event, Japanese historians at symposia being held both at Pearl Harbor in Hawaii, and at CAF Headquarters in Midland, Texas, revealed that the actual codes were individual syllables, not the word "Tora." The first code, "To," indicated that the attack had begun, and the second "Ra," that success had been achieved.
When these transmissions were heard by the American radio operators in the heat of the attack, they were translated as a single, word, the "To, To, To ... Ra, Ra, Ra" becoming "Tora, Tora, Tora", the Japanese word for "Tiger."
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