Hard Hitting Hell Divers
New Hell Diver Carries On Curtiss Tradition

More than one military expert has argued that no new weapons have appeared in the global war to date. That axiom is particularly true when applied to the military application of vertical, or dive, bombing. The dive bomber made its first appearance in America nearly a decade ago, attracting little interest among tactical leaders, even less among civilians. Then Hitler gave the technique a bloody combat debut during the Spanish Civil War, when the Fascists were generally using the hills and cities of the Iberian Peninsula as a proving ground for weapons of world conquest. Even Mussolini, tactical Puck in the Axis scheme, had used the dive bomber with something more than moderate success during his campaign in Ethiopia. while the Japs were using the technique against Chinese objectives. But the dive bomber as a weapon of military consequence was really born when Stukas blasted the Low Countries and devastated Poland. In that morale-shattering beginning, a new method of warfare came of age. Today, dive bombers are used in almost every battle sky. As a weapon against ground objectives, their effect became less important every day, with their noise far exceeding military effect. But as a striking force against fleet and bridgehead positions, they will play an increasingly important role as the war progresses.

Dive bombing as a combat tactic in America dates back to 1920. The first Navy plane built specifically for dive bombing operations from carrier bases was the Curtiss XF8C-2. This was the first in a Hell Diver series which has since carried forward to the SB2C-3, rated by some as the world's best weapon for vertical bombardment. During the two intervening decades, Curtiss built thirteen distinct dive bomber types — more than 550 airplanes in all — to acquire a tactical and technical knowhow matched by few aircraft organizations anywhere in the world. More important, it has been Curtiss dive bombers which gave US Navy personnel opportunity to develop a dive-bombing technique and an understanding of the limitations of enemy dive bombers. This latter knowledge, if it had been shared by the British, might have handcuffed the Luftwaffe's Stukas during the early war days.

For a full appreciation of the Curtiss contributions to this particular martial science, it is necessary to turn back to 1928, the year the XF8C-2 was built under Navy contract. In this way, the reader can personally trace the major steps in the march of aeronautical progress which fostered the new SB2C-3.

A two-place biplane fitted with a 450 hp Pratt & Whitney radial, the XF8C-2 mounted three machine guns and carried two 100-pound bombs beneath the wings. The guns were mounted in each of the upper wing panels and in a flexible rear cockpit mount. Although the original model washed out at Washington during the initial test performances late in 1928, a successor made its appearance in early 1929 and completed all tests without incident. By the end of 1930, fifty-two planes of this series had been delivered to the Navy. The last ship in the series, known officially as the F8C-6, was powered by a Wright Cyclone engine and heralded the stepped-up performance now typical of all dive bombers.

Credit for selection of the now-famous Helldiver appellation for Curtiss dive bombers must go, in the main, to Charles Hathorn, project engineer on the first Helldiver and now patent engineer at Curtiss-New York plants. Seeking a name for his aeronautical innovation, Hathron recalled that the Dabchick, a small North American bird, was known in some sections as the Helldiver. When further research revealed that this bird was noted for diving speed, the name was adopted and has been synonymous with Curtiss dive bombers throughout the years. The F8C series was followed in more or less rapid succession by such interesting types as the O2C-1 and O2C-2 which appeared respectively in 1931 and 1932 as observation and light bomber service types with the Navy. But dive bombers were still in the 450-hp class. In late 1932, the XF11C-2 made its appearance as the first dive bomber to carry a 500-pound bomb into the skies. More important, this plane answered the growing official demand for a single-place bomber and brought entirely new potentialities to dive bombing operations. Other single-seaters followed in 1935 and 1936 in the form of the XS2C-1, the XF12C-1, and the XSBC-2. Observers have frequently commented on the inconsistency in dive bomber designation during this period, pointing to the fact that Curtiss alone made dive bombers during a two-year span which carried scout, fighter, and scout bomber designations. Without discussing the tactical merits behind this design diversity, the superficial reasoning is obvious.

First of all, the Navy at that time pictured the dive bomber as an ambidextrous fighter plane which could clear the skies of enemy aircraft. Successful operations of that nature necessitated high performance characteristics, maximum maneuverability, and unobstructed vision for the pilot. Thus, design factors which made possible conversion to dive bombing activity were of secondary importance even though such characteristics were specified by the Navy. In the second place, too few military leaders had recognized the tactical importance of dive bombing when these ships were coming off the drafting board.

The F11C series was, therefore, built primarily to fighter specifications. It was, at the same time, the first fighter design which recognized the importance of pilot comfort. To this end, its cockpit was completely lined, gun mountings were outside the fuselage to eliminate explosive fumes from the cockpit enclosure, and controls were arranged carefully for operational convenience. But despite these excellent fighter plane features, dive-bombing excellence actually accounted for the world fame of the F11C. Moreover, successful experiments with this one plane convinced many militarists that dive bombing, because of its element of surprise and its inherent accuracy, offered a most effective offensive use of aircraft against surface craft and ground objectives. And the pilot visibility factor which recommended the design for fighter tactics proved' to be an absolute essential to expert dive bombing. With these precepts firmly established, Curtiss engineers designed the upper wing of the F11C biplane to provide a twelve degree angle of vision between the leading edge and the top of the engine cowling. The lower panel was of smaller chord than the upper, its trailing edge tapered forward to afford clear vision to the rear. That these planes proved effective in tactical tests is particularly amazing in view of their limited bomb capacity. Only two bombs, with a total destructive weight of 232 pounds, could be carried by the F11C. On later models, bomb cradles were added, however, and a single 500-pound bomb was carried between the single-strut landing gear. Thus, a fighter plane became the first airplane successfully to carry into the sky a quarter-ton missile which could be released from any angle of the dive.

Because the F11C incorporated so many features which later became standard on dive bombers, it is interesting to review this ship carefully. The stabilizer outboard of the external bracing slid neatly under the lower wing of an adjacent airplane, solving a major space problem attendant upon carrier operations. Hinged doors forward of the cockpit permitted easy access to any installation and its turtle back was hinged as a unit on one side to permit quick opening by release of two trunk catches. Further, the low pressure tires of the landing gear were streamlined by the addition of fairings and the small-diameter wheels rode easily over deck wires. Altogether, this was more than a dive bomber design. It was a laboratory for aeronautical engineering which fostered a long line of excellent Curtiss dive bombers.

In 1929, William J Crosswell, who made the terminal velocity dives and the 9-G pull-outs on the F11-C, tested the F8C-4, the first dive bomber to carry a center fuselage bomb and in 1933 and early 1934, the Navy made enough experiments during tactical maneuvers to prove conclusively the need for a genuine dive bomber. For all practical purposes, this was the real beginning of dive bomber development as such, with research actually aimed at perfection of a plane which could operate on missions where fighter characteristics were unnecessary, or even undesirable. And the resulting Curtiss XSBC-1 started the SBC line. When the carriers Yorktown and Enterprise were christened in 1936, SBC-3 scout bombers were assigned to each ship — the first new planes to enter service under the squadron system adopted by the Navy in 1937. The SBC-3 was powered by one 700-hp engine. From that day forward, tactical considerations of the dive bomber reached full realization. In Spain, for example, German and Italian pilots used the early Stuka with tremendous success against inadequately armed Loyalist bases, unarmed civilian centers. More important, the dive bomber so completely dominated the skies over Spain's open sea lanes that the infinitesimal Spanish navy was unable to keep supplies moving to the front. Even this major obstacle might have been conquered and the Fascists defeated if Britain, then led by appeasers, had recognized the Loyalist blockade. But on a plane-for-plane basis, Moscas and Chatos flown by American, Spanish, French, and Russian pilots more than matched the early Stukas, shot down almost as many Nazi dive bombers as fighters.

Now, the dive bombers, as originally conceived, may be approaching its tactical twilight. No single dive bomber now in service can match the destructive effect against ground bases which twin-engine Bostons, single-engine Mustangs are demonstrating daily. A surprising development to those who still picture the Stuka as the Dutch and Poles first encountered it three years ago, this dive bomber demise has been expected by infantry, armored force, air force leaders. First of all, the twin-engine attack bomber can, by virtue of its size, carry considerable defensive armament. Even the addition of dorsal turrets and ventral gun emplacements to single engine dive bombers has failed to immunize the latter against heavily-armed interceptors now in the air. In the second place, much space in the twin-engine attack plane can be devoted to installation of detection equipment which gives the ship double utility — as bomber or night fighter. On the other hand, high-speed fighters like the North American Mustang completely out-fly the relatively slow Stukas. Moreover, ground-based antiaircraft batteries can't be operated fast enough to destroy these attackers. Flying close to the ground at blinding speeds, Mustangs can blast trains and gun batteries with cannon fire, then leave the target so fast that ack-ack gunners are helpless. Thus, Allied ingenuity which has produced the Mosquito, Boston, Mustang, and Hurribomber has turned the tables on Nazi dive bombers. At the same time, Allied navy dive bombers have come of age, will soon be blasting Axis ships as effectively as Stukas once devastated Warsaw.

This article was originally published in the March, 1943, issue of Air News magazine, vol 4, no 3, pp 10-13, 62.
The original article includes 13 captioned photos and 2 uncaptioned drawings.
Photos credited to Curtiss-Wright, William Larkins, Rudy Arnold.

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