Toward the end of the last war, the Allies began to use their scout planes extensively as bombers. The planes carried their bombs on exposed bomb racks underneath the wings, and the pilots had no bombsights. In order to make sure of a hit, they evolved the practice of diving down to the target, dropping their bombs at about two hundred feet above the ground, and zooming away to safety at top speed.
This method of bombing proved exceptionally effective because the speed of the scout plane enabled it to dodge normal antiaircraft fire, as well as machine-gun emplacements protecting the target.
In executing this kind of attack, the pilots were making the best of a bad job. They did not like carrying bombs, because the additional weight curtailed the maneuverability of their planes, and they felt that they could not measure up to the accuracy of the medium-bombing squadron boys who had been through bombing school and learned to operate the existing bombsights. Their habit of diving and letting go was their way of making the best of it, and their planes were the predecessors of the modern dive bomber.
For some reason or other, the British, who had begun the practice , went no further with their experiments in this close-range bombing. In America, military-minded people remembered it and set to work to develop planes designed for the work.
Dive bombing is the practice of aiming an aircraft at a target and releasing the bomb at the moment the nose of the machine is pointing dead at the target and as close as is feasible to enable the pilot to pull his aircraft out of its dive and take evasive action.
The principle of dive bombing is the same as that of aerial gunnery with fixed guns. Pilots of the dive bomber and the fighter both aim their machines at their target. While the fighter pilot has a destructive power limited to the number of rounds of fire he can discharge in the few seconds when his aim is true, the dive-bomber pilot can release a thousand-pound bomb, the trajectory of which, if he has kept his machine steady and aimed true, will follow the line of flight of his dive, if he had continued it. Dive bombing is perhaps the nearest conception to long-range artillery that could be desired.
Your gun is the plane; you fly it to the target, aim it, and "fire" the heavy shell, using the speed of the plane and the weight of the bomb as a propelling force.
The German Stuka is undoubtedly the most famous dive bomber in the world, because of its destructive exploits over Poland, France, Greece, and North Africa. In developing their Stuka, or Junkers 87, about the meanest-looking machine you could ever see in the air, and incidentally one that had been previously foisted on Europe as a civilian, the Germans did a neat and unashamed piece of plagiarism. Their first model, innocently built in Sweden, was fitted with a British Bristol Jupiter engine.
However, the dive bomber happens to be an American invention . To American designers and American military minds goes the credit for having first thought up this formidable weapon, and it might not be out of place here to say that American dive bombers are without doubt the best of the type in the world, being faster and tougher, and packing greater punch than those of the Axis, although, as we shall see later, the other side is still likely to put some of its heavy bombers into the dive-bombing business.
Dive bombing has both advantages and disadvantages over levelflight medium bombing. The latter have been shown up by the Stuka, which is an inferior weapon to the modern American machine mainly because of its great age. Among the advantages are the high degree of accuracy possible in daylight even in bad weather conditions; the dive bomber can approach a target obscured by clouds and still be sure of a direct hit, provided the pilot sticks to his job. In this respect, it is exceptionally effective in attacking ships, airfields, and enemy defenses which must be leveled before an attacking army can advance. It carries a much heavier weight of bombs than the average fighter-bomber, over a greater distance, and it is no more vulnerable to antiaircraft fire than other forms of low-altitude bombing.
Of all aircraft, the dive bomber has the great advantage of being able to approach the target without flying straight and level or on a set course. Only when in its dive need it fly straight, and it takes pretty good shooting for an antiaircraft gunner to hit a plane diving at 250 to 300 miles an hour. It does happen, of course. I saw a Ju-87 sustain a direct hit from a Bofor gun during the Battle of Britain. It was remarkably good shooting, but it might have happened to any plane.
The disadvantages as revealed by the German Stuka are slow speed, and extreme vulnerability to fighter attack through lack of armor and defensive armament. Fully loaded, its maneuverability is limited.
The earliest news of American experiment in dive bombers was in the early twenties, when the United States Navy and Marine Corps undertook experiments using Curtiss and Boeing pursuit planes. In 1928 Glenn Martin produced a specially designed biplane capable of carrying a thousand-pound bomb, a remarkable achievement for those days. Little more was heard of the MB-1, but two years later the Curtiss-Wright Corporation produced the first of the series of dive bombers known as Helldivers.
This first Helldiver was a small two-seater biplane with a sweptback top wing. It was powered by a direct-drive Wasp engine and fitted with two fixed guns firing forward from the upper panel of the center section and a swivel gun in the rear cockpit. The machine carried a fifty-pound bomb beneath the fuselage and was designed specially for dive-bombing operation from aircraft carriers . This model had no dive brakes.
In 1933, the basic design was considerably modified and the United States Navy and Marine Corps took delivery of a new version of the Helldiver, which had a twin-row radial engine and considerably better performance.
Dive-bombing experiments proceeded with these new machines, and practice suggested further alteration. So, in 1937, a newly designed Helldiver, known as the SBC-3, began to operate from carriers of the United States fleet. This model had double split trailing-edge flaps to act as brakes during the dive. It was powered by a Twin Wasp Jr. driving a constant-speed airscrew and it featured a retractible undercarriage.
The SBC-3 operated for several years on United States carriers, to be succeeded in 1939 by the SBC-4, a sturdy little machine powered by a Wright Cyclone engine. The SBC-4, which still flies for the R.A.F. under the name of the Cleveland, has a maximum speed of 245 miles per hour and can carry a thousand-pound bomb load over a short range. The bomb is carried under the fuselage, but there are special bomb racks on the wings, so that on long trips the main bomb rack may be used for an auxiliary fuel tank.
Having experimented for many years with dive bombing and low-flying attack, it was to be expected that the United States Navy entered the war with several types of dive bombers. The type that has probably seen more action than any of the others up to the present is the SBD-3, Douglas Dauntless, termed by the Navy a scout bomber. These planes work from aircraft carriers, the complement of which is usually a squadron of fighters, one of scout bombers, and another of torpedo bombers. The Dauntless, a cousin of the A-20 Boston, is a development of the Northrop A-17 attack plane and is said to be capable of a high degree of maneuverability.
With a span of 41 feet, 6 inches, and a loaded weight of just over 8000 pounds, the shapely Dauntless is only slightly heavier than our new fighters. It carries a crew of two, a pilot who has two forward-firing guns, and a rear-seat man who is radio operator and gunner for the flexible gun. The Dauntless carries its bomb, either a 5 00- or a 1000-pounder, underneath the fuselage. It is fitted with perforated flaps to reduce its speed on the dive.
When these formidable dive bombers first went into action in the Pacific, Jap pilots thought they would be easy meat and swarmed round them like furious gnats expecting to have an easy kill. Again and again the rear-seat men of the Dauntless blew the Zeros to pieces, while the pilots acquitted themselves effectively by swooping and turning to bring their fixed guns on the enemy planes.
Henderson Field on Guadalcanal is named after Major Lofton Henderson, who dived on a Jap carrier so low that he crashed into the "island." It was an act of supreme heroism, typical of the standard of dive bombing adopted by the Marines, who had announced previously that they were going to drop their bombs right on the flight deck of the enemy carriers.
During the Battle of the Coral Sea, Dauntless planes were credited by the Navy as being the most effective of their offensive weapons. They played a major role in the Allied amphibian attack on Casablanca and the adjoining North African coast. Squadrons of these fast tough dive bombers roared down through the most intensive antiaircraft fire to attack Vichy harbor installations, docks, and gun positions. The most outstanding feat of these Navy pilots was putting out of action the great French battleship Jean Bart. SBD-3's. scored several direct hits with small bombs, and when it was found that larger armament was needed to do the job, they returned to their ship and loaded up with heavier material.
One attack with these larger missiles put the big ship's guns completely out of action. The small caliber antiaircraft fire around Casablanca harbor was as heavy as any experienced in this war.
Many of the scout bombers returned riddled with holes. One got back and landed safely on the carrier with its flaps shot away, after surviving more than three hundred bullet holes, demonstrating well the sturdiness of this dive bomber.
Douglas Dauntless dive bombers were included in the air group operating from the U.S.S. Enterprise, the aircraft carrier that has been in the forefront of every naval action in the Pacific. The Enterprise planes accounted for three enemy carriers, helped to sink another, and sank or damaged a long list of enemy vessels ranging from patrol boats to battleships. One of the Enterprise's Dauntless pilots scored a direct hit with a 5 00-pound bomb on a Jap carrier, and the same squadron laid more than 2000 pounds of bombs on a battleship of the Kongo class.
Dauntless pilots and crewmen endured almost incredible encounters with Japanese Zeros and patrol bombers. Captain Robert W. Vaupell, U.S.M.C., whom I met at the Navy's Air Base at Corpus Christi, Texas, gave me some first-hand stories of Dauntless ruggedness. Vaupell was operating at Guadalcanal in the same squadron as Colonel Richard Mangrum, the Marine who sank a Jap battleship. At twenty-five, Vaupell wears the Navy Cross, the Air Medal, and the Purple Heart.
"Two of us were out on a scouting mission on October eighth," he said. "My wingmate was Jack Blumensten. We were carrying bombs, but our primary objective was to locate the position of enemy surface craft. I had just spotted some Jap ships when eleven Zeros jumped on us from out of the clouds. Suddenly there were Zeros all around us, spitting tracers and shells from every direction . I saw Jack go down in a spin. There were three Zeros on his tail, and I figured they must have got him. I was on my own. I got my report back to base as to the position of the Jap fleet, just before a Zero shot my radio out. They had done more than that. I hopped into a cloud for safety and found that all my instruments were out of order. Bullets had ripped up and down the cockpit while we were getting our report off. I couldn't fly in the cloud without instruments, so I put the machine into a spin. I came out about a thousand feet above the Jap ships!
"What happened then is something to remember. The ships' antiaircraft let go with everything they had. That was lucky for us, because the Zeros who had come up to tail me beat it, for fear of being hit by their own gunners. There was another good thing too. The Jap antiaircraft fire was poor, as poor as I've seen, and it did little damage, although a few bits of shrapnel hit our wings. I was too low for any dive bombing, but I wanted to lose some weight, so I let go my bomb. It didn't hit, but it must have shaken the ship below a trifle. I was glad to be rid of that thousand-pound weight, and I made for another cloud. I found a nice one, the big puff-ball kind of cumulus you find in the Pacific, and stayed there for about five minutes, flying by instinct. Then I had to come out.
Waiting for me were eleven Zeros. Three of them got close in and filled my cockpit with bullets. One of the planes that had hit me then did the silliest thing. He came up in front of me in a slow climbing turn. I got him with my forward-firing guns. He simply exploded, and I felt better, even though I'd been hit four times, three times in the right leg, and once in the left. Then my rearseat man gave another Zero the works, and he went down flapping.
"The others made off and left us. Our problem then was to get home. We threw everything overboard to increase our speed and finally we landed on the very edge of our field." When Vaupell got back, he found the pilot of the other dive bomber waiting for him. He had accounted for two or three of the Zeros and had reported Vaupell as surely missing. Both of the Dauntless planes were riddled with bullets, and one had survived several hits by Jap cannon shells. No wonder the United States Marine Corps pilots swear by these dive bombers.
The Dauntless is a comparatively old dive bomber today. Considerable improvement has been made in the design of this plane, as shown by the specification of the Brewster Buccaneer, one of the United States Navy's more recent dive bombers, known as the Bermuda to the British, who have ordered considerable numbers.
The Buccaneer is powered by a Double Row Wright Cyclone and seems to have been designed to eliminate all the faults of the Stuka and the Dauntless, particularly those in regard to vulnerability . It is heavily armored and carries an astonishing number of guns, six .50-caliber firing forward, and two .30-calibers on a twin mounting in the rear-seat man's cockpit. The bombs are carried internally.
The Buccaneer is fitted with perforated double split flaps that act as dive brakes, the perforations, being fitted to reduce tail buffeting brought about by the disturbance of air flow from the resistance offered by solid flaps. Its speed is said to be in the neighborhood of 300 miles per hour, which is probably a conservative estimate.
The Buccaneer was not put into action by the United States Navy, being used for training only, but the British Fleet Air Arm, which has used it extensively, says it is the best dive bomber in the world.
The United States Navy had good reason for not using the Buccaneer—something better. In 1942, an announcement was made that a new Helldiver was in production. This was typed the SB2C-1 and was universally acclaimed as the answer to the German Stuka. The SB2C-1 is a low-winged monoplane weighing about 11,000 pounds loaded and exceedingly heavily armed. It is powered by a Double Row Wright Cyclone of 1700 hp. and is said to be 100 miles per hour faster than current types. It is fitted with trailing-edge dive brakes and with leading-edge slots. The bomb load is carried internally and the machine is readily adaptable for use as a torpedo bomber.
The Helldiver came in for some criticism by the Truman Committee , but the Navy people just smiled and went on developing their new weapon, which they knew was the most up-to-date of its kind. Into it had been put every available combat lesson, formidable armament, and the sturdiest construction. Until the Helldiver went into action for the first time the machine was very much of a mystery. People talked about it, some said it was a lemon, others that it was the super dive bomber. Neither side knew which was right.
On November n, 1943, the Helldiver made an auspicious debut in the United States Navy's raid on Rabaul, and wrote its own history in a few crowded minutes. It taught the Japanese a few things, and entirely justified the confidence placed in it by the Curtiss-Wright Corporation, its designers and builders, and the Navy Bureau of Aeronautics.
The action was as dramatic as any fought in the Southwest Pacific . At dawn a United States carrier task force crept up to within airplane range of the Japanese-held stronghold of Rabaul. The task force was a streamlined unit equipped with the United States Navy's latest weapons, the Helldivers, Hellcat fighters, and Avenger torpedo bombers.
The Helldivers rendezvoused after the take-off, and climbing to their altitude moved in to attack the harbor which was massed with shipping. Lieutenant Commander Vose, the squadron commander , ordered his men to step up their speed and push over into their dives before the ships could break anchorage and make for the sea. The Japanese had got some planes into the air. To the attack came eight Zeros. The enemy planes never reached the formations of Helldivers. The escorting Hellcats saw to that. The sky was filled with burning, bursting Jap fighters.
Down with the Helldivers. The Jap warships tried to escape to the open sea, milling and turning in the harbor like disturbed ants.
The big bomb-laden Helldivers gave them little chance. Each section of the planes chose its target and laid its eggs with precision accuracy. One Jap light cruiser went to the bottom in a few seconds with three direct hits. From another vessel, a heavy cruiser, shot up a tower of bright yellow flames which told the Navy pilots that it had been hit in the magazine. Another dive bomber laid its bomb smack on the fantail of a-destroyer, and two other Helldiver pilots hit a light cruiser, blowing up its superstructure. A second destroyer, wrecked by a hit and a near miss, went out of control. Said the Navy release: "The Helldivers had a field day at Rabaul." Said Admiral DeWitt Clinton Ramsey, Chief of the Bureau of Aeronautics: "The plane had demonstrated that it packs a terrific wallop for the Japs."
The sting of the story is in the tail, however. After the attack, in which more than 28,000 pounds of bombs were dropped, the Helldivers roared back to their carrier utilizing all available cloud and rain squall cover. They had been attacked by enemy fighters when they pulled out of their dives, the dive bomber's most vulnerable moment, and not one had been shot down. Some of them were cut off and encircled by a large number of Zeros. They fought their way through the attacking Japs without loss, leaving three Zeros in the sea, and one in a damaged condition. Then they showed the enemy their tails and made for home. Two of these planes were later lost through fuel exhaustion, landing near their carrier. The personnel was saved.
Thus for the loss of two bombers, the Helldiver squadron sank one light cruiser, and two destroyers, and damaged two heavy cruisers, one light cruiser, and eight destroyers. During the action the escorting fighters destroyed eighty-eight enemy planes.
Five Helldivers remained on defensive patrol over the carrier to keep Jap surface vessels at a distance, and according to the Navy communique: "These played a substantial role in beating off the determined Japanese attack against the American task force." The Helldiver is built by Curtiss-Wright and two Canadian associations, Fairchild of Canada and Canadian Car and Foundry Company. The Helldiver is also being manufactured for the Army, under the designation of A-25.
Another American dive bomber which has won high praise from the British, for whom it was originally made, and which has already been in action with the United States Army Air Forces, is the Vultee Vengeance. The Vengeance, or A-35, is said to have been put into production at the request of the British Purchasing Commission in 1940, when the R.A.F. realized the crushing blows handed out to Allied land forces by the German Stukas. Although the British had two machines which could have been used as landbased dive bombers, superior in performance to the Stuka (the Blackburn Skua and the Hawker Henley), they decided to purchase their dive bombers in America.
The Vultee Vengeance looks rather like the Stuka in form, with its swept-forward wings and slim fuselage. There the resemblance ends. The Vengeance represents a considerable technical advance over the Stuka, and, like the Buccaneer, it is sufficiently well armed to defend itself and act as a ground strafer. The power unit is a Double Row Wright Cyclone, and its range is in the neighborhood of 1400 miles with a 2000-pound bomb load.
The first report of action by the new dive bomber came from the Pacific theater of war and was heavily censored. Its debut was sensational and effective, however. An Allied advance was being held up by a deep pill-box defense system. Five batteries of artillery that had been trying to overcome the defense had been decimated . Six Vengeance dive bombers were dispatched to clean up the nuisance. According to the report, they dived from 11,000 feet at an angle of ninety degrees and dropped their bombs on the target in a perfect pattern. So effective was the attack that the enemy's strongholds were completely knocked out, and the Allied troops were able to advance. The United States had turned the tables on the Axis, giving the Jap a taste of what the Stukas had given the Poles and the French. Each one of the Vengeance planes returned to its base. Said the United States Army, commenting on the action: "The Army wants more of this type of aircraft in this area.
As a land-based dive bomber, the Vengeance seems to have solved the dive-bombing problem of the United Nations. There has been an increasing tendency on the part of the air forces of the United Nations to use light dive bombers. The British set the fashion by employing a modified version of the Hurricane fighter. These machines, each carrying one 500-pound bomb, made their appearance first over the French coast and later in the North African campaign. They were fitted with four 20-mm. cannon and seem to have been extraordinarily successful, performing the double function of strafing as well as dive bombing, without dive brakes.
The use of fighter planes on the part of the British seemed to be a reversion to World War I experiments. It seemed to be an attempt to find a machine to do the same job as the German Stuka, with none of the disadvantages. Better armed and armored than the German dive bomber, and considerably faster, the Hurricane was ideal for its new job. Once rid of its bomb, it could hold its own against the German fighters. Rommel's men soon learned to fear the Hurricane. In one instance, after two dive-bombing attacks by these machines, the German Stuka pilots refused to take the air when threatened again.
Later came the news that the North American Mustang P-51, originally designed for the British as a reconnaissance machine, had been fitted with dive brakes and put into service as a dive bomber under the name of A-36. The A-36's made their first combat sortie against Pantelleria, and according to reports, they bombed with "devastating" accuracy. On one day alone, July 10, 1943, the new dive bombers made seventy sorties on six missions. Their targets were gun emplacements, railway junctions, sidings, depots, supply centers, and the Luftwaffe headquarters in Sicily.
The use of these fast machines as dive bombers is rather like delivering short punches in boxing. One Mustang pilot describing the action in Sicily said that once he had dropped his bombs, his machine became.one of the best fighter planes in the world. On one occasion he chased an Me-109G with a five-mile start and overtook it inside forty miles. He caught the German plane on the top of its loop as it was trying to escape and shattered it. His description of dive bombing is illuminating. "We come over the target high," he said, "and then dive almost straight down, keeping the target in sight for several thousand feet. Then we let go, pull back the stick and start looking for fighters or something to strafe."
The success of the Mustang-turned-dive-bomber may have a considerable effect on our warplane production. If the plane is as good as the reports, it may become the standard single-engined dive bomber of the United Nations. An invading army supported by thousands of these machines would be many times more effective than the Germany army when it marched into Poland and France behind the explosive curtain of destruction dropped by the vulnerable Stukas. With its speed and its invulnerability, the A- 3 6 seems to be the ideal weapon.