Naval air did go to sea on the "back of the fleet" during the interwar years, 1919-41. However, Admiral Moffett's vision of naval aviation as the "brunt of attack" was not to become reality until World War II. In 1941, naval air was still viewed as an auxiliary, although an important one, to the battle line. Clashes at sea, it was thought, would ultimately be decided by the firepower of the heavy-gunned, thick-armored ship of the line—with help from the fragile airplane. The evolution in the thinking of how to best use planes came during the fleet problems of the 1920s and 30s when concepts were tested, modified, and then retested. Factors external to this evolutionary process affected its unfolding.
The experience of naval aviation in World War I provided some basis from which to proceed. From shore stations at home and overseas, American naval aviators flew seaplanes, flying boats, and dirigibles on antisubmarine patrol and convoy duty. For ship-based air operations, however, the U. S. Navy had to draw on the experiences of the Royal Navy for guidance.
During World War I, the Royal Naval Air Service (RNAS) operated floatplanes from seaplane carriers and wheeled aircraft from platforms atop battle cruiser gun turrets and from a makeshift carrier. From these ships, RNAS aviators flew scouting missions for the fleet, conducted air-to-air combat against Zeppelins, spotted gunfire during shore bombardment, projected power ashore with bombing raids on Zeppelin sheds, torpedoed merchant ships, and in 1918 conducted unsuccessful attacks with light bombs against the well-armored Turkish battle cruiser Yavuz Sultan Selim (ex-German Goeben).In short, ship-based air had demonstrated during the war its considerable potential for future utility. The U. S. Navy would come to recognize many of those possibilities during the interwar years.
One of the earliest to be implemented, along with scouting, was the spotting of the fall of shot. In March 1919, the battleship Texas (BB-35) conducted a shoot using ship and aerial spotters. Spots from the plane were far superior to those from the ship. This skill showed the battleship admirals that aircraft were valuable assets to have at sea, withthe fleet, instead of ashore. Planes not only helped to find the target, they helped to put ordnance on it.
Prior to the Texas shoot, in January 1919, the General Board of the Navy—an influential advisory body of senior naval officers reporting directly to the Secretary of the Navy—had taken up the question of the future of aviation in the fleet. In April 1919, in an interim report of its findings, the board recommended the conversion of a collier to a flush-deck (i.e., continuous deck) carrier for the operation of wheeled-as opposed to float-airplanes. In June, the board reported that aircraft were "an essential arm of the fleet" and a seagoing "naval air service must be established." Not everyone agreed. For example, the Chief of Naval Operations opposed the concept of ship-based air and the conversion of the collier.
This early postwar opposition to ship-based naval air was transitory. By 1922, the air policy of the Navy directed that the development of ship-based air would be the principal effort of the naval air service. The post-1922 force structure reflected this policy. At the close of World War I, all the Navy's planes were shore-based with over one-half of the entire inventory being of the big, flying boat type. In 1922, flying boats (all but a handful were based ashore) comprised 62% of the combat (non-training, non-experimental) inventory. In the 1930s, aircraft of all types assigned to ashore commands (excluding those in training/experimental/repair status) made up less than one-fifth of the combat force. 6 This force structure shift during the interwar years denotes a Navy air arm that had broken its World War I tie-down chains to the shore and had gone to sea on the back of the fleet, as had been envisaged in 1922. In addition to this policy, the years 1921-22 were important ones in the development of carrier warfare.
In 1921, the Navy and the Army conducted at-sea bombing tests against old American and surrendered German ships. Under noncombat conditions very favorable to the conduct of the attacks, General Billy Mitchell's bombers did what he claimed they could do before the test they sank a battleship, the ex-German Ostfriesland. The underwater concussive effect produced by the near misses of 1,000- and 2,000-pound bombs had done what the RNAS had failed to do with light bombs against the comparable Goeben. As a contemporary commentator opined: "The bombing tests…were perhaps more responsible for the awakening of the Navy…to the possibilities of bombs than any other influence. There is no argument so strong as a practical and successful test.The Navy, however, was not convinced.
The Navy believed the tests were inconclusive due in a large measure to Mitchell's interference. So in 1924, the Navy conducted its own tests under more controlled and methodical conditions. The target this time was a more modern and more formidable ship than the Ostfriesland.The uncompleted Washington (BB-47), a battleship hull laid down in 1919, was due for scrapping under the terms of the 1922 Naval Armament Limitation Treaty. Although unfinished, the Washington withstood repeated torpedoing, bombing, and underwater explosions and finally had to be sunk by gunfire. Thus, the results of the series of bombing tests conducted in the early 1920s were ambiguous-providing support for the views of both the "gun club" and of the air zealots. These tests did, however, spur the development of ship-based aviation, and this was due in some part, to General Mitchell's ardent advocacy of the superiority of air forces over surface forces.
Mitchell also had contributed unintentionally to another factor important to the evolution of naval air warfare, and this was the creation of the Bureau of Aeronautics (BuAer) in 1921. BuAer was formed to an extent as a reaction to Mitchell's espousal of a united air service, which was to be independent at the Navy and Army. BuAer provided naval air with what it had lacked before-centralized direction of the design, procurement, planning, operation, and administration of aeronautics in the Department of the Navy. The creation of the bureau also gave the aviators a flag officer representative at Navy headquarters. The first chief of the bureau was Rear Admiral Moffett. He was an ex-battleship captain and a non-aviator (in 1922, he became the first naval aviation observer). Moffett was also an accomplished administrator, having overseen the expansion of the Great Lakes Naval Training Station during the war. During his 12 years as chief, Admiral Moffett earned the title of the "Father of Naval Aviation." He died in office, at sea, in the crash of the airship USS Akron (ZRS-4) on 4 April 1933. Organization, coupled with Moffett's talented and continuous leadership, did much to send Navy air to sea on the back of the fleet.
Another step in getting naval aviation to sea was the commissioning in 1922 of the Navy's first aircraft carrier, the USS Langley (CV-1), the ex-collier Jupiter. The Langley served as a test bed for carrier aviation in preparation for the coming of the two "real" carriers, Lexington (CV-2) and Saratoga (CV-3). Both of these ships were commissioned in late 1927 from battle cruiser hulls that had been due for scrapping under the 1922 treaty. The treaty also limited U. S. carrier tonnage to 135,000 tons—a limit that was not reached, primarily for budget reasons, until 1940 with the commissioning of the seventh carrier, USS Wasp (CV-7).
In the Navy's view, the 1922 treaty, with its 5:3 (United States to Japan) ratio in capital ship tonnage and its non-fortification clause proscribing further defense improvements in American bases west of Hawaii, exacerbated an already deteriorating security situation in the Western Pacific vis-a-vis Japan. "The General Board [had] decided as early as 1921 that Japan was the future enemy of the United States." Of particular concern to the Navy planners was the Japanese control of the former German-held northern Marianas, Marshalls, and Carolines; for these Japanese mandates sat on the flanks of the sea Lines of communication to Guam and the Philippines. Japanese submarine, fleet support, and air bases, once established on these islands, would have to be destroyed in order to defend or recover America's Far East possessions. In the absence of land air bases within range, neutralizing these island bases and the defending Japanese fleet would require seagoing air power. Thus, the perceived threat in the Western Pacific established a need for carrier air. Satisfying this need would take advances in technology, and it would take dollars.
The primary technical problem to be solved was the development of a combat-effective, carrier-based strike aircraft:
To be a main offensive system for combat and not merely a harassing agent during the preliminaries, carrier strike aircraft would have to carry a reliable torpedo or 1,000-pound bomb. Less of a weapon load was little threat to a large armored warship, including a carrier…A combat radius of at least 250 miles was essential…to prevent enemy battleships from pouncing on one's carriers. Finally, the strike aircraft needed a top speed near that of…fighters. Slow speed over the enemy fleet made…bombers easy targets for defending fighters.
Aeronautical engineers and scientists would not provide this type of performance until the late 1930s.
Besides the advancements needed in endurance, payload capacity, speed, weaponry , and reliability of the frame and engines, many other improvements were required in such areas as communications, navigational aids, arresting and catapult systems, fuels, and landing gear. All of this took time—and money.
During the interwar years, BuAer's portion of the President's budget request for the Navy rose from 4% in 1923 to 9% in 1930, dropped to 6% by 1935, but rose again to 10% by 1940.These budget data show that despite differences of opinion on how to use Navy air, there was considerable support for the air arm at Navy headquarters.
The "external" factors that most affected the development of naval air thought were the early decision to shift from shore-based to ship-based air, recognition of the value of the plane to the battle line, the bombing tests in the 1920s, and the Japanese threat. Sending planes to sea meant thinking about how best to use them: scouting, spotting, and bombing demonstrated the utility of the plane, and the threat provided the impetus for learning to use aircraft at sea. Inherent to the conceptual development process were the competing views of the "gun club" and those of the air proponents. Those views were to be tested during the fleet problems of the interwar years.
The fundamental doctrinal questions at issue during the fleet problems were the same as those being asked ashore. Was the airplane just the eyes of artillery or could it supplement—or perhaps supplant—the artillery? That is, was there more to the airplane than simply finding the target and directing ordnance thereon? Why couldn't the airplane strike the enemy meaningfully and, perhaps, independently of surface action? Aviators (at sea and ashore) thought so. The Navy gun clubbers (and their ground-pounder Army counterparts) would have to be convinced.
Prior to the first official participation by the Langley in a fleet problem (Fleet Problem V in March 1925), there was much supposition as to what sea-based air could or should do; but, without a carrier, there was little experience. The most ardent air enthusiasts, both aviator and non-aviator, argued the carrier, with its main battery of airplanes, would replace the battleship and its gun battery as the "backbone of the fleet." The more moderate, like Moffett and many of the gun clubbers, believed air control over the opposing forces was essential to the main attack by, and defense of, the ships in the battle line. Indeed, this latter view was the one stated in the tactical instructions for aircraft in 1924. By the mid-1920s then,there were few in the Navy who did not recognize the potential value of sea-based air to the fleet, even if they perceived that value differently.
During Fleet Problems I-IV (1923-24), sea-based air participation was limited,with aircraft operating from battleships (employed as "constructive" carriers) and from aircraft tenders. Beginning with the Langley in Fleet Problem V, carrier air played more and more a part in the problems as the number of carriers participating increased from one in the mid-1920s to four in the late 1930s. When the last of the pre-World War II problems ended in 1940, the U. S. Navy had a substantial base of exercise experience upon which to formulate carrier operations.
What emerged from the testing of concepts in the 17 fleet problems of 1925 through 1940 was a transformation in the accepted use of carrier air. From being employed mainly as the" eyes of the fleet" in the problems of 1925-28, carrier air was acknowledged in subsequent problems to be capable of performing two additional and important—if conflicting—functions. These were (1) operations independent of the battle line in the form of the fast-carrier task force for conducting strikes ashore and at sea and (2) air operations in direct support of the battle line so the battleship could close, undamaged, to within gun range of the enemy.
The battleship admirals knew from the bombing tests of the early 1920s and from the fleet problems that planes could damage their ships; hence, they were reluctant to detach the carriers with their protective air screen from the battle line. Also, when the carriers did operate without the battleships, the problems had shown the carrier to be vulnerable to attack by the opposing battle line. Thus, the Beet problems of 1930s demonstrated to the Navy's satisfaction the mutual dependence of the carrier and the battleship, the consensus being neither could prevail without the other.
The burden of proof for independent carrier operations, however, had been on the air zealots, and in the fleet problems they had not shown convincingly that carrier air could be decisive in itself. Consequently, for the most part, fleet doctrine from the late 1930s through 1941 called for carriers to accompany the combatant groups (the battle line and/or the scouting force) and for carrier flying stations to be within gun protection range of the battleships and cruiser. Thus, on the eve of the American entry into World War II, while mutual dependence was recognized, the carrier was to support the battleship and not the other way around.
The conduct of the fleet problems and the force structure trends during the 1930s indicate that this carrier-air support was offensive. Between 1931 and 1940, the ratio of carrier aircraft having a prin1ary fighter mission to those designated as strike (torpedo planes and bombers) decreased from about 2.5:1 to approximately .5:1. Had the emphasis been on providing defensive air cover for the battleship, fighters would have likely remained predominant.
It is clear from the force structure and from the problems that the aviators intended to defend the battleship by striking the enemy—his carriers and his battleships—rather than by intercepting him in the air. Air control, for the support of the battleship, was to be primarily achieved by destroying the enemy's floating air base, not by shooting his planes down. This offensive concept had appeared as early as 1924 and was repeated in the early 1930s. It was certainly doctrine in 1938, for the carrier-air doctrine manual of that year states the following: "It is highly improbable that control of the air can be gained by employing aircraft to shoot down enemy aircraft. The surest and quickest means of gaining control of the air is destruction of enemy carriers…by bombing attacks. An identical statement is in the 1941 version.
Thus, the U. S. Navy entered World War II with a tactically offensive carrier-air doctrine for the defense of the battle line. When the bulk of that battle line sank at Pearl Harbor and the carriers survived, the aviators got, by circumstance, their chance to implement what they had argued so strongly for during the interwar years-task force strike operations built around the fast carrier. Their readiness to execute such operations was the result of a long and difficult process, one which had been fraught with technological, doctrinal, and institutional issues.