TACTICAL EFFECTIVENESS OF NAVAL AVIATION

A prerequisite to control of the sea was control of the air above it. In the first days of the war, the Japanese prevented the British from interfering with the movement of troops to Malaya by a successful aerial attack on the Prince of Wales and the Repulse. To drive the enemy from the air in vital areas was the first mission of naval aviation. With the development of night tactics this became a 24-hour job which required specially equipped night planes as well as conventional day fighters. For patrol planes it meant the ability- to penetrate enemy-held areas alone, to possess the firepower necessary to drive off interceptors, .and to return to base with vital information. When the Catalina proved to have insufficient speed and armament to defend itself, the Navy obtained Liberators for use in forward areas. Even this type did not have enough guns and required other modifications to change it from a high-level bomber into a patrol plane. From experiments that amounted to altering 50 percent of the Liberator’s internal arrangements, the Navy developed the Privateer. In 1944 and 1945, planes of these 2 types flew 15,000 patrols and destroyed 504 of the 937 Japanese aircraft encountered, against a loss of 18. During the same period, Mariner and Coronado flying boats on similar missions shot down 24 enemy planes and lost 3. In 1943, Japanese night torpedo attack indicated a need for night fighters, but neither the Army nor Navy had suitable radar-equipped planes available. Royal Air Force experience favored the development of specially designed twin-engine, two-seater aircraft. Since the Navy could neither wait for the completion of the new planes nor could it hope to operate them from carriers without further design changes, it equipped a number of its standard Hellcats and Corsairs with the necessary instruments and developed special training for night pilots. Before the Army’s Black Widow reached the Pacific theater the Navy had night fighters on all large carriers and at land bases in forward areas. Fighter directors worked out a technique by which interceptions were made as far as 80 miles from base. With a loss to themselves of 3 aircraft. Hellcats alone shot down 163 enemy planes in night combat. Important as were these special aspects of air activities, the enemy lost the major portion of his air forces in conventiona l daylight operations. Although, owing to the destruction of Japanese records, exact figures will never be obtainable, naval aviation accounted for threefifths or almost 15,000 of the total enemy planes destroyed. Of these, the most reliable record credits 9,000 as having been shot down and the remainder as having been knocked out on the ground. In aerial combat the Navy lost only 897 aircraft for an advantage of 10 to 1. Even during the period of heavy losses in 1941-42, naval aircraft destroyed 830 enemy planes while suffering 265 air combat losses for a favorable ratio of 3 to 1. In 1944 when naval aviation cracked the enemy air defenses of Rabaul and carried the offensive to the Marshalls, Carolines, Marianas, and Bonins, and to the extensive chains of enemy air bases in the Philippines and Formosa, the ratio rose to 15 to 1; 4,021 Jap planes shot down against 261 air combat losses. In 1945 when the naval offensive concentrated on the Ryukus and Japan, the ratio rose further to 22 to 1; 3,161 Japanese planes shot out of the air against 146 losses suffered at the hands of enemy pilots. The above figures, include the air engagements 726015--47---4 43 of all types of naval aircraft. Fighter planes naturally enjoyed a superior record and destroyed 13 Japanese planes in the air for each 1 lost in combat. During the last 12 months of the war, the Hellcat, mainstay of the carrier forces, knocked down 3,518 Jap planes against a 1oss of 160; the Corsair, used by both Navy and Marine pilots, 1,042 against 49; the Wildcat, used on escort carriers, 377 against 9 losses. These ratios were 22 to 1, 21 to 1, and 42 to 1, respectively. Control of the air was also reflected in the ability of a bombing effort to reach the enemy and the corresponding ability to break up and prevent an enemy attack from reaching its objective. During 1944 and 1945, Navy and Marine dive-bombing and torpedo planes made 102,000 sorties against the Japanese, engaged in combat on 742 occasions, and lost only 18 planes to enemy fighters. Although many of these flights occurred in areas where the enemy’s air force had already been annihilated, the remainder indicated the effectiveness of the cover furnished by Navy fighters. Even in 1942 when the Japanese air force was at its peak, it customarily lost 20 to 40 percent of its aircraft in any mission encountered by Navy planes. Although complete figures are not available for both land and carrier-based aircraft, the latter destroyed 70 percent of the enemy bombers and 50 percent of the fighters intercepted. No air force could stand such losses over an extended period of time without becoming in fact, if not in name, a suicide force. The Kamikaze merely acknowledged an existing situation. Aerial combat was essentially a defensive function designed to protect the fighter’s own air-borne or surface forces from direct attack. If freed from this duty, the fighter plane could perform operations of an offensive nature. Of 500,000 sorties flown by naval fighter planes in the Pacific war, only 12,000, or 21/2 percent, resulted in aerial combat; the remainder was largely for other purposes. More than able to overcome air-borne opposition, naval aviation pressed its attack against airfields and grounded planes. Because during amphibious operations vast numbers of ships in a restricted landing area were especially vulnerable to bombing, the fast carriers first tried to clear the air of enemy planes and then went on to destroy parked aircraft and to render fields inoperable, thus stopping hostile air activity at the source. Approximately one-third of the sorties by carrier aircraft were for this purpose and in some campaigns the number reached twothirds. Although at no time was it possible to dispense with combat air patrols only about 28 percent of the enemy aircraft destroyed were shot down in the defense of United States forces as against 32 percent in the air over enemy ships and installations and 40 percent on the ground. In overcoming the Japanese in the air, carrier planes destroyed 18 enemy to each of their own that was lost, while naval and Marine land-based aircraft enjoyed an advantage of 8 to 1. The disparity resulted not from a difference in plane types, which were the same, but from the ability to concentrate carriers and send them into the heart of a Japanese-held area. Although before the war it was frequently stated that the added weight and other design factors necessary in carrier planes made it impossible to operate them against shore-based aircraft, this turned out not to be true. Carriers were mobile units that, when assembled in sufficient numbers,
overwhelm an enemy’s airforce in any area that the United States desired to penetrarte. Development of radar and fighter-direction technique insured only a minimum of planes being used for defense and relieved the remainder for offensive missions against either shore installations or hostile fleet movements. With control of the air overhead and with adequarte air support, the Unitd States Fleet could move freely about the sea and land troops and equipment wherever the strategic plan demanded. Command of the sea also required the destruction of Japanese warships which might threaten our ships using Pacific waters. It was further nessary to deprive Japan of its merchant marine both to prevent its use to reinforce and supply enemy bases and to cripple the entire Japanese economy, which was dependent on shipping for the bulk of its oil, iron ore, cooking coal, rubber, aluminum and other nonferrous metals. and for much of its food. Naval aircraft were highly effective against shipping targets. Dive bombers were developed by the Navy as a means of controlling maximum accuracy with minimum hazard to planes in attacks on heavily armed warships. The torpedo plane was designed to launch the most lethal weapon yet devised for shipping attack. To these initial tactics were added three additional means of attacking ships: masthead bombing, pioneered in the Pacific by the Fifth Air Force, rocket attack, and strafing. Armed with these weapons, naval aircraft sank 745,000 tons of Japanese warships and cooperated with other agents in sinking an additional 167,000 tons. Included in the vessels sunk by naval aircraft, either alone or with other agents, were 6 out of Japan’s 12 battleships, 12 of 20 carriers, 18 of 40 cruisers. Of all sinkings in the class of destroyer or larger, naval and Marine aircraft accounted for 48 percent and for about 42 percent of combatant tonnage of all types. Naval aircraft were also responsible for damaging a large number of major enemy warships which then required extended periods of repair. This damage frequently had as important an effect on the course of the war as the sinkings. Hits on units of the Japanese carrier force in the Battle of the Coral Sea were an important factor in the abandoment of plans for invading Port Moresby. Similar damage in the Battle of the Eastern Solomons caused the withdrawal of Japanese naval forces, giving our sea and land forces in the Solomons a needed breathing spell and opportunity for reinforcement. Damage to Japanese carriers by carrier attacks in 1943 resulted in the permanent withdrawal of heavy warships from Rabaul and removed the threat of naval interference with the occupation of Bougainville. After the latter actions the Japanese refused again to risk heavy warships within range of naval aircraft, except with massed carrier support as in the Battle of the Philippine Sea, or on an admittedly- last-ditch sucide mission as in the Battle for Leyte Gulf and the last sortie of the Yamato. Important in naval air action against enemy warships was the ability to inflict damage with a minimum expenditure of effort. Only about 160 bombers and escorting fighters, carrying about 80 tons of bombs and torpedoes, made the attacks which sank 1 Japanese carrier and damaged another at the Coral Sea. In the attacks on the second day of the Battle of Midway, which resulted in the sinking of 4 carriers and proved to be the major turning point of the Pacific war, the hits on enemy carriers were inflicted by about 80 dive bombers. The naval air contribution to the crucial Battle of Guadlalcanal 350 attack sorties and less amounted to less than than 160 tons of bombs and torpedoes. A battleship, a cruiser, and 11 troop transports were credited sunk in whole or in part by these air attacks, and other vessels were damaged. In the battle for Leyte Gulf two elements of the 46 3-pronged attack were routed with a total expenditure of only 750 tons of bombs. Naval aircraft unaided sank over 1,500,000 tons of Japanese merchant vessels during the war; in cooperation with other forces they assisted in sinking another 200,000 tons. These figures included only vessels of 500 tons or over but not the hundreds of small barges, sampans, luggers, and other vessels sunk by- naval aircraft, whose total has never been compiled. About 50 percent, 800,000 tons, went down in the 4 monthS of the Philippines campaign from mid-September 1944 to mid-January 1945; 200,000 tons in the Truk, Marianas, and Rabaul raids of February 1944; and 100,000 more in March 1944 at Palau and elsewhere. The tonnage destroyed by naval planes exceeds that of any other agent except submarines which accounted for over half the total. Complete data on losses of smaller vessels are almost impossible to obtain. It is believed that submarines played a smaller and Army- and Navy aircraft and aerial mines a larger part in sinking these vessels. Carrier fighters devoted an enormous volume of effort to strafing and rocket attack on these vulnerable targets. Naval patrol bombers whose daily searches covered the entire western Pacific made hundreds of individual masthead-bombing and strafing attacks on isolated small ships. Army bombers and fighters were effective against these vessels along the East Indies, the Philippines, and Formosa. In the last months of the war mines laid by B–29’s further crippled the remnants of this junior merchant fleet, by then confined largely to the inland waters of Japan, and harassed even there by both carrier and naval patrol planes. Only 9 naval planes and only about 4 tons of bombs or torpedoes were required, on the average, to sink each 1,000 tons of Japanese war or merchant shipping. In executing its decisive campaigns against the enemy fleet and merchant marine, naval aviation expended only 14 percent of its attack effort and only about 4 percent of its combat sorties. Naval aircraft operated against enemy ground forces in all parts of the Pacific. Much of this effort was devoted to attacks whose main purpose was the attrition of enemy units either in advance of an invasion or on the Japanese from harassing communications. Strikes were also made against specific beachhead defenses and adjacent supply facilities in preparation for a landing. Finally, planes afforded direct close support to ground troops. Although the proportion in each of the three categories is not known, naval aircraft directed 54 percent of their total attack effort to enemy troops, weapons, equipment, defense installations, and supply facilities. This figure is exclusive of sorties to neutralize airfields or attacks on Japanese industrial and transportation facilities. The effectiveness of air support was measured not by the damage inflicted on installations but by the rapidity with which marines and soldiers advanced against the enemy. The variety of targets in close-support missions was very great and was dictated by the need of the troops, the

Japanese Merchant Vessels Sunk. ---Submarines alone accounted for 54 percent of sinkings; naval aircraft alone, 18 percent. Navy units participated in 77 percent of all sinkings and were the sole agents in 76 percent. The principal elements represented in the last bar of the chart are losses to British Empire and Netherlands forces and marine casualties.
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suitability of the target for airplane attack, and the availability of aircraft and other weapons such as naval gunfire and shore-based artillery. Enemy gun positions on the reverse side of a hill could be put out of operation only by aircraft. Planes frequently discovered their own targets behind Japanese lines and, as in the case of supplies or reinforcements, prevented their reaching the front lines. Frequently aircraft were called upon to keep the enemy down as friendly troops moved up. Such activities cannot be represented statistically. Although in ground combat the achievement of victory rested with the foot soldier, naval aviation provided him with invaluable assistance, facilitated his advance, and by its accurate methods of attack saved thousands of American lives. The foregoing discussion has set forth naval aviation’s part in the Pacific war. It demonstrates how effectively the Navy balanced the potentialities of air weapons against their limitations, developed them, and used them with other weapons to implement the strategic plan. Yet it is pertinent briefly to isolate naval aviation from the naval structure as a whole to consider its efficiency as an air force. One of the most pervasive phenomena of the war was the popular tendency to evaluate the effectiveness of air attack in terms of bomb tonnage. This was readily understandable in view of our national predilection for great size and quantitative measures and the ease of comparison which a tonnage figure provides. From the standpoint of military analysis bomb tonnage is to some extent a measure of effort but only occasionally a good measure of effectiveness. It was most significant in attacks on large urban centers made under favorable weather conditions so that most bombs could not help but hit the area. Yet even in the attacks on Japanese cities, there was wide variation in the area laid waste per ton of bombs depending on the type of bombs used and on the concentration of their fall. As the size of the target decreased, or when weather and other factors affected accuracy, the full tonnage dropped remained a cost of the attack, but the effect on the enemy depended on what proportion of the bombs hit the target. For example the Strategic Bombing Survey reported that of 30,- 000 tons of bombs dropped in high-altitude attacks on 3 large German oil and chemical plants with a total area of 31/2 square miles, only 1 bomb in 8 hit within the plant fences and only 1 of 30 inflicted physical damage to manufacturing facilities. Probably the largest Japanese targets customarily bombed by naval aircraft were airfields. The average large runway had an area of about 50 acres, considerably smaller than one of the oil plants mentioned above. The largest type of enemy ship attacked by naval planes, a large aircraft carrier, had a deck area of about 2 acres. Against a submarine, the lethal area in which a bomb had to hit was about a quarter acre and on a beachhead a gun position presented an area of only one two-hundredth of an acre. The tonnage of bombs dropped in attacks against such targets was of very little significance but the question often arose whether the target could he efficiently bombed at all. The statistical chance against hitting a 25-foot diameter gun revetment was 10,- 000 to 1 in high-altitude bombing, 600 to 1 in low-altitude glide bombing, 300 to 1 in the most accurate dive bombing, and about 100 to 1 in masthead bombing. The development of the high explosive rocket reduced the chance to 21 to 1; and, if it was desired to put the gun temporarily out of action while troops advanced or friendly bombers were carrying out an attack, this could he accomplished by a fighter plane with a few hundred rounds of ammunition. Except for patrol planes, naval aviation operated from carriers or from small land fields in advanced areas, both of which required small aircraft with limited bomb capacity. As an integral part of the naval forces, it had as targets primarily 49 naval objecctives--ships, parked aircraft, shore installations and close support of amphibious troops. Because the types of plane and the nature of the targets put a premium on accuracy and effectiveness of each bomb dropped, naval aviation did not engage in high-altilude, pattern bombing. Three methods of bomb attacks were commonly used: glide bombing at altitudes from 1,000 to 4,000 feet; dive bombing at the same altitudes but with an angle of 65° to 90°; and minimum-altitude, or masthead bombing, from 50 to 300 feet. Especially against war vessels aerial torpedoes were used at close range and low altitude. With the introduction of the highexplosive rocket in 1944, naval aviation acquired a weapon more suitable than bombs against such targets as small shipping and ground installations. An index of its importance was the use of over 100,000 rockets in the Okinawa campaign. Finally, naval planes employed machine guns and light cannon against many small targets. In measuring the tactical effectiveness of an air force it was not the volume of effort but attainment of objectives and the cost of results that counted. Each type of target and operation had to be considered separately; there was no common standard. To destroy half of Tokyo required 14,000 tons of bombs. Less than onetwentieth of this tonnage won the battle for Leyte Gulf; a few dozen dive bombers won the Battle of Midway. The comparative importance of these achievements is not found in any measure of sorties or bomb tonnage. They are in fact, not comparable at all, except as each was a vital contribution to victory achieved by skilled application of appropriate weapons.