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A Junkers Ju-87 begins to roll in on a target in the Balkans during the invasion of Yugoslavia in April 1941.

Screaming Bird of Prey

By Stephan Wilkinson
8/3/2017 • Aviation History Magazine

Although obsolescent even before World War II began, the Ju-87 Stuka terrorized ground troops and found a late-war niche as a tank-buster.

Never has a warplane so obsolete, vulnerable and technologically basic wrought so much damage to its enemies as did the Junkers Ju-87 Stuka. Even as Germany invaded Poland and triggered World War II, its Ministry of Aviation ( ministerium, or RLM) was hard at work on a replace- Reichsluftfahrtment for its dive bomber, and the early Ju-87B was intended to be the last model made. No surprise, since typically an air force begins development of the next-generation aircraft the instant the current machine goes into service. But hard as they tried, the Germans never came up with a Stuka successor, so the angular, archaic “little bomber,” as the Luftwaffe called it, was the airplane that on September 1, 1939, dropped the first bombs of the war, and on May 4, 1945, flew the final Luftwaffe ground-assault mission. The very last propaganda film made by the Luftwaffe showed Stukas attacking Soviet tanks on the outskirts of Berlin, smoke streaming from their big antitank cannons. That’s 5½ years of nonstop combat by an airplane adjudged by some to be too primitive, too slow and too vulnerable before the war even began.

Granted there have been inexcusably ugly aircraft, but like so many designed-for-a-mission utilitarian airplanes—the Consolidated PBY comes to mind—the Ju-87 looks better the longer you consider its rugged lines. One Stuka admirer calls it “a flying swastika,” thanks to its angularity and coarseness. But that same straightforwardness made the Stuka easy to manufacture, repair and maintain. Who needs elliptical wings, stylish P-51 radiator doghouses or retractable landing gear on a bomb truck intended to fly to a target little farther away than its pilot can see, do a job and rumble back home again?

The Rolls-Royce Kestral-powered Ju-87 V-1 prototype first flew on September 17, 1935. (SDASM/Alamy)
The Rolls-Royce Kestral-powered Ju-87 V-1 prototype first flew on September 17, 1935. (SDASM/Alamy)

The Stuka’s ugly reputation was also influenced by the fact that the airplane is often envisioned—and frequently depicted in newsreels of the day—pummeling Warsaw and the Low Countries, its “Jericho Trompeten” sirens wailing. Nine Ju-87s were also used at one time or another during the Spanish Civil War, but they were operated only occasionally and conservatively. Even Spanish Nationalist pilots weren’t allowed near them, since they were still considered to be secret weapons. The small Spanish market town of Guernica, the subject of Pablo Picasso’s famous antiwar painting, was bombed by Heinkel He-111s and Junkers Ju-52s, horizontal bombers heedlessly killing civilians as they carpet-bombed, exactly the kind of mission the Stuka was not intended to fly. It’s hard to cast a kindly light on any bomber, but the Ju-87 was designed to attack and destroy specific military targets, not civilians. Had Stukas been used to bomb the important bridge that was the primary target of the raid, the world would have long ago forgotten Guernica.

The Spanish war did make it plain that the Ju-87 would be a useful weapon. When Bf-109Bs arrived on the scene, the Nationalist rebels soon claimed control of the air. Republican anti-aircraft artillery was pretty primitive, so the Stukas bombed at will—as they were intended to—and even the worst drops typically landed within less than 100 feet of the target. Good hits were either on target or no more than 15 feet off-center.

Dive bombing was by no means a German invention, though they refined the tactic to a degree never seen before—or since. The British were the first to try moderate-dive-angle attacks, during World War I, and both the U.S. and Japan experimented with diving delivery between the wars. In fact, it was Japanese interest in the tactic that led them to commission Heinkel to design a dive bomber to rival the American Curtiss F8C Helldiver, which became the He-50 biplane. The Japanese actually bought and tested two Ju-87s before WWII, but placed no further orders— probably because their own Heinkel-influenced Aichi D3A1 “Val” dive bomber was already excellent, as Pearl Harbor would prove.

Legend has it that when WWI ace Ernst Udet, then a civilian, attended the 1935 Cleveland Air Races, he saw some U.S. Navy Curtiss F11C-2 Goshawk biplane dive bombers and was dazzled by their performance. Hermann Göring, who wanted to entice Udet back into the reborn Luftwaffe, imported two export-version Hawk IIs for the ace’s use. Udet did divebombing demonstrations during airshows in Germany, the myth continues, and convinced the Luftwaffe that it would be a useful tactic. Thus the Stuka was born, with Udet thereafter credited as its “father.”

Well, not exactly, as the rental car commercials used to say. The Stuka design had already been finalized and was in mock-up form when Udet became enamored of the Curtiss, and he never did airshow bombing, just enthusiastic aerobatics. But Udet certainly was a verticalbombing proponent, and his one important role in the Stuka’s development was that when RLM Technical Director Wolfram von Richthofen (the Red Baron’s cousin) canceled the Ju-87 program— Richthofen thought that a slow, cumbersome, diving Stuka would never survive the anti-aircraft guns toward which it was necessarily pointed—Udet happened the next day to be given Richthofen’s job. His first move was to countermand that order, so the Stuka survived.

“Stuka” became the Ju-87’s popular name, but it’s actually a generic term. Stuka is short for one of those German freight-train words, Sturkampfflugzeug, which translates as “diving combat aircraft.” So to call a Ju-87 a Stuka was just like naming the P-51 “Fighter” or the B-17 “Bomber.” Nobody cares: The Ju-87 will forever remain the Stuka.

Popular accounts of Ju-87 raids invariably mention the airplane’s sirens, wind-driven devices on the front of each landing gear leg that the Germans called Jericho’s Trumpets. The simple wooden props that drove them could be clutched and de-clutched electro-hydraulically— a typical example of German overengineering. What did they sound like? Well, forget fire engines, the noise was exactly like the sound in every classic Hollywood movie’s approximation of an airplane’s final dive to destruction—the rising, grinding wail of an over-revving engine. The noise was apparently as annoying to Stuka pilots as it was to troops being bombed, so many units dispensed with the extra drag and complication of the trumpets, though reports of their occasional use persevere into 1943.

The Germans eventually preferred to mount wind-whistles on the fins of Stuka bombs, another development beloved of the film business. In movies, bombs all whistle. In real life, the only bombs that whistled were some dropped from Stukas.

It’s not widely known that the peace-loving Swedes, those professional neutrals during Europe’s wars, were contributors to the development of the Stuka. To circumvent the punishing provisions of the Versailles Treaty, Hugo Junkers established an aircraft factory in Sweden. The facility was no secret, but it allowed operation free of pesky oversight by treaty inspectors, who had no authority in Sweden. There, Junkers developed the K.47, a heavily strutted and braced radial engine monoplane (other dive bombers of the time were all biplanes) optimized for diving and equipped with both Junkers dive brakes and what would become the Ju-87’s automatic pullout mechanism. Though the K.47 contributed only in the broadest sense to the prototype that became the Stuka, Swedish test pilots enthusiastically performed hundreds of dives with it and refined diving procedures and methods. Hermann Pohlmann designed the K.47 under the direction of Karl Plauth, a WWI fighter pilot, and Pohlmann went on to engineer the Ju-87 after Plauth died in the crash of a Junkers prototype.

The sole benefit of dive bombing is accuracy. Imagine running across a golf green as fast as you can while trying to drop a ball into the cup from eye level. Now imagine standing directly above the  cup and sighting from the ball to the cup, then dropping it. The former is classic horizontal bombing, and its accuracy depends on a bombsight that can calculate a variety of parameters to create the proper parabola from bomb bay to target. The latter is dive bombing, and if the dive is truly vertical, the flight of the bomb will follow the path of the bomber to wherever the airplane is pointed—at a tank, a ship, a bunker, a building.

The Stuka’s ability to perform and recover from a near-vertical dive allowed its pilots to place bombs directly on a specific target. (National Archives)
The Stuka’s ability to perform and recover from a near-vertical dive allowed its pilots to place bombs directly on a specific target. (National Archives)

The Ju-87 was one of the only dive bombers that could actually perform a vertical dive without surpassing V NE— never-exceed speed. Most dive bombers couldn’t put the nose more than about 70 degrees down, though the Vultee Vengeance was also said to be a truly vertical bomber. The Stuka’s under-wing dive brakes, a Hugo Junkers invention, were remarkably effective despite their small size and simplicity, and apparently the airplane’s bluff chin radiator, large wheel pants, upright greenhouse and general avoidance of drag reduction sufficed to maintain a 375-mph vertical dive speed. (Later models could dive at up to 405 mph.)

Some Stuka pilots entered a dive by half-rolling the airplane onto its back and then pulling positive Gs to dive, others simply bunted from level flight into the dive. Standing on the rudder pedals to keep from doing a face-plant into the instrument panel is difficult enough, even with the help of a shoulder harness, but trying to aim at a target while simultaneously ignoring anti-aircraft fire must have been truly challenging.

British test pilot Eric “Winkle” Brown spent an hour flying a captured Ju-87D and later wrote: “A dive angle of 90 degrees is a pretty palpitating experience, for it always feels as if the aircraft is over the vertical and is bunting, and all this while terra firma is rushing closer with apparent suicidal rapidity. In fact I have rarely seen a specialist dive bomber put over 70 degrees in a dive, but the Ju-87 was a genuine 90-degree screamer…the Ju-87 felt right standing on its nose, and the acceleration to 335 mph was reached in about 4,500 feet, speed thereafter creeping up slowly to the absolute permitted limit of 375 mph, so that the feeling of being on a runaway roller coaster experienced with most other dive bombers was missing. I must confess that I had a more enjoyable hour’s dive-bombing practice than I had ever experienced with any other aircraft of this specialist type. Somehow the

Ju-87D did not appear to find its natural element until it was diving steeply. Obviously the fixed undercarriage and large-span dive brakes of the Junkers were a highly effective drag combination.” Ju-87s had “Stuka-vizier” gyro-stabilized bombsights developed by the famous German optical house Zeiss; they were basically gunsights modified for vertical guidance. Stuka pilots also had half a protractor’s worth of angle lines etched in red into the right-hand canopy window, which when matched to the horizon gave them their dive angles. Another unusual Stuka feature was a large window in its belly, between the pilot’s feet, so that he could keep the target in view as he prepared to roll into his dive. Unfortunately, it was usually useless, covered with a thick film of engine oil leakage streaming aft.

One of the Ju-87’s advanced features, at least for that era, was an automatic pullout mechanism, to avoid the possibility of pilots being overcome by target fixation or rendered unable to fly by the effects of high-G pullouts. It was a simple hydraulic device. Once the pilot had trimmed nose-down for the dive and to counteract the increased airspeed, it released the trim setting when the ordnance was pickled and reset the tab to command a pullout that typically ran to between 5 and 6 Gs. In those days long before G-suits and abdomen-tightening yells, only the strongest Stuka pilots and gunners avoided at least briefly graying out, but the Stuka did the flying for them.

If they trusted it to do so, that is. Many Ju-87 pilots were leery of the automatic pullout feature and preferred to do the flying themselves. During training dives against a floating target in the Baltic soon after the automatic pullout mechanism was introduced, at least three Stukas went straight into the sea, which certainly didn’t endear the device to pilots.

The pullout was also the point at which a Stuka was most vulnerable, its speed paying off rapidly as it clawed for altitude, following a predictable course and unable to maneuver. Allied pilots who opposed Stukas didn’t bother trying to catch them in a dive; they waited until the Germans released their bombs and pulled out. Ju-87s were intended to operate only where the Luftwaffe had complete air superiority and could make bomb runs with impunity. Nobody ever meant for them to go head-to-head with eight-gun Spitfires and Hurricanes.

During the Battle of Britain, Stukas were downed by the dozens while trying to do a job—strategic rather than tactical bombing—for which they were never intended. They were ground- support airplanes, designed to work in tandem with tanks. Yet at the classic tank battle of El Alamein, in the North African desert, Stukas were never a factor, since RAF and South African Air Force Kittyhawks, for the most part, had by that time gotten the upper hand over fuel-starved Luftwaffe Me-109s and Italian Macchi MC.202s.

There were Ju-87s in North Africa nonetheless. “Apart from a few improvised fighters, we had no dive bombers at all,”wrote Alan Moorehead in The Desert War. “It is useless for the military strategists to argue, as they will and fiercely, that the Stuka is a failure and very vulnerable. Ask the troops in the field. Its effect on morale alone made it worthwhile in the Middle East as long as we had insufficient fighters.”

After the Battle of Britain, the RAF proclaimed that the Stuka was finished as an offensive weapon, beaten bloody by Spitfires and Hurricanes. That myth has become part of Stuka lore and is one reason why, as a British historian put it, “More crap has been written about the Stuka than about any other airplane in history.” During the five years after the Battle of Britain and the RAF’s haughty pronouncement, the hundreds of thousands of tons of merchant shipping and warships sunk, and thousands of Soviet tanks destroyed, made it obvious the Ju-87 could still get the job done.

Like the Slow-But-Deadly Douglas SBD, the Stuka turned out to be a superb anti-shipping weapon. Stuka pilots quickly learned to attack from astern, so they could easily follow a ship’s evasive actions. They often dived on a ship at a 45- degree angle and fired their machine guns as a telltale.“When the first of our…bullets were observed to be hitting the water in front of the ship’s bow, we pulled the bomb release,” said one former Stuka pilot quoted in Peter C. Smith’s book Junkers Ju 87 Stuka. “There was very little chance for a merchant ship of any size attacked with this Stuka tactic,” Smith wrote.

While the RAF was dismissing the Stuka as irrelevant after its poor showing in the Battle of Britain, Ju-87s essentially destroyed the Royal Navy’s Mediterranean fleet. RAF Air Marshal Arthur Tedder said, “Our fighter pilots weep for joy when they see [Stukas].” At the time, he was reassuring Royal Navy Admiral Andrew Cunningham, whose armored-deck aircraft carrier HMS Illustrious, and its support ships, would soon be battered so badly by Stukas off Malta that it was out of action for nearly a year. Stukas also thoroughly chased the Royal Navy out of Norway’s waters.

Yet Tedder wasn’t far off the mark. Luftwaffe Messerschmitt and Focke Wulf pilots called Ju-87s “fighter magnets,” and depending on whether they preferred to die in bed or collect Iron Crosses, they feared or enjoyed being assigned to Stuka-escorting missions. Two Ju-87 tactics were used to great effect in the Vietnam War. One was employing forward air controllers (FACs), a concept developed by the Germans during the Polish blitzkreig. Stuka UHF radios were mounted in tanks or other armored vehicles, and were manned by Luftwaffe officers schooled in ground-support tactics. They directed strikes by Stukas overhead against any targets impeding the panzers’ advance.

The other was what has come to be called the daisy-cutter—a bomb that explodes several feet above the ground rather than penetrating the earth and dissipating its energy in making a crater. A belt-high blast wreaks terrible damage on personnel. The Germans approached fuzing the bomb to go off at this height in the simplest way possible: They attached a 3-foot-long metal rod to the impact fuze in the bomb’s nose, to set it off when the rod touched the ground. At first, the rods penetrated soft ground without setting off the bomb, so they learned to weld a 3-inch-diameter disk to the tip. The same technique was used 25 years later by the U.S. Air Force.

Many assume that because the Stuka was a bomb truck, it must have flown like one. Untrue, according to former Ju-87 pilots who have talked and written about what a delightful, light and responsive airplane it was to fly—easy to handle, a piece of cake to land and one of those rare flying machines without a vice. The Ju-87 was nose-heavy by design, and Allied pilots who flew captured Stukas said the airplane felt “just right” when dived vertically. One RAF pilot described its handling as “so light that there was a marked tendency to overcontrol.” Perhaps it was a function of the unusual Junkers-design floating ailerons (and flaps). Further proof that the Stuka was not just a manly man’s airplane was that a surprising amount of the preproduction testing of all models was carried out by two women pilots— the famous Hanna Reitsch, whose specialty was dive-brake testing, and Countess Melitta Schenk von Stauffenberg, the sister-in-law of anti-Hitler conspiracist Claus von Stauffenberg.

Ju-87s were produced in several successive variants, inevitably requiring more power, more range, more bomb-lifting ability. The Ju-87B was the classic—the one with the big wheel pants, squared-away greenhouse and vertically louvered, overbite chin radiator. It’s the version that flew during the early-war blitzkreigs and the Battle of Britain, and it could carry a 1,100-pound main bomb. It had been preceded by the Ju-87A, the first production series, but the underpowered “Anton” really wasn’t a combat-ready design.

The later Ju-87D, the “Dora,” was an up-engined, more aerodynamic version with a streamlined canopy, a twin-gun rolling turret rather than the“Bertha’s”single gun pivoting on a hole through the aft canopy, and only an oil cooler under the nose, the engine-coolant radiators having been moved to underwing positions. The Dora could carry a bomb weighing almost 3,900 pounds, which the Luftwaffe felt it needed to penetrate major fortifications.

Between them came “the Stuka that never was,” the Ju-87C. It was to be a tail-hooked, folding-wings navalized version, back when Germany was still working on its potent new carrier, Graf Zeppelin. Flown in prototype form, the C was canceled when work on Graf Zeppelin stopped. Though legend has it that Leroy Grumman invented the Wildcat’s twist-and-fold wings while playing with a paperclip, the Ju-87C also had wings that folded straight aft with the leading edges pointing down. The Wildcat’s first flight preceded that of the folding-wing “Caesar” by almost nine months, but it’s doubtful that either company was aware of the other’s development work.

One of the Ju-87C’s most unusual features was landing gear struts that could be blown off with explosive bolts, to allow the airplane to ditch without the fixed gear digging in and flipping it. This feature was carried over to the Dora, assumedly to clean the airplane up for a belly landing on rough ground. The Caesar also had four air-filled flotation bags—two in the fuselage, one in each wing—that supposedly would have allowed it to stay afloat for up to three days after ditching.

The Ju-87R (the R stood for Reichtweite, or range, rather than being part of a normal alphabetic progression) was a longer-legged version of the Ju-87B, and its extra wing tanks, which increased range from a supposed 340 miles to 875, were incorporated into most succeeding Stukas. Some Ju-87Rs were rigged to tow gliders—not to carry troops but to lug a Stuka unit’s own supplies, tools, spares and other maintenance stores.

Armed with powerful 37mm “Panzerknäcker” anti-tank cannons, the Ju-87G traded the role of dive bomber for that of a potent tank killer. (National Archives)
Armed with powerful 37mm “Panzerknäcker” anti-tank cannons, the Ju-87G traded the role of dive bomber for that of a potent tank killer. (National Archives)

The Ju-87G, one of the most effective Stuka models, was no longer a dive bomber and didn’t even have dive brakes. The G was armed with a huge 37mm, 12-round anti-tank cannon under each wing. The cannons used the barrels and receivers of a cumbersome flak gun that dated back to World War I, but they were potent against Soviet T-34 tanks. Firing one tungsten-cored explosive round at a time required a precise gunner. T-34s were most vulnerable from astern, where there was little armor and lots of gas. Good shots such as Hans-Ulrich Rudel, who claimed 519 Soviet tanks destroyed (see “Eagle of the Eastern Front,” July 2011), could put a round into the unprotected space between the bottom of the turret and the top of even the most heavily armored T-34’s hull and blow the turret off. The top 58 Stuka pilots on the Russian Front eliminated some 3,700 Soviet tanks. But the Soviets were building that many new T-34s every three months in 1943, so Stukas were a small finger in a big dike.

Not all Eastern Front Stukas were tank-busters. Filling what must have been one of the most unusual military occupation specialties in any armed force, Sergeant Hermann Dibbel was one of several special Stuka skywriters. Every clear day, Dibbel would go over the Soviet lines in his Ju-87 and spell out in augmented exhaust smoke appeals to the Russians to surrender. Dibbel had already been credited with sinking a British cruiser and destroying 30 Soviet tanks, and he later flew similar missions over Yugoslavia entreating Tito’s partisans to surrender. Whether or not his smoky appeals worked, they led him to a new career. After the war, he became a skywriting instructor.

The Stuka was finally reaching the end of its useful life. At the beginning of WWII, a Ju-87 had a life expectancy of 10½ months. By 1941, it was little better than half that, and as Soviet fighters found their groove after the disastrous first months of Operation Barbarossa, a Stuka could expect to live for just over four days of combat.

Only two intact Stukas remain—one in the Chicago Museum of Industry and the second in the RAF Museum at Hendon. Neither is flyable, though when the 1969 film Battle of Britain was in production, plans were laid to restore the Hendon Ju-87 to flight for use in the movie. A pilot from the film company, Vivian Bellamy, reportedly climbed into the museum Stuka, cranked it through three blades and the Jumo V-12 lit off and idled perfectly. But the project turned out to be too rich even for a film studio’s mega-million budget. Instead, three Percival Proctor lightplanes were modified to resemble Stukas and were thereafter known as “the Proctukas,” suggesting some fearsome medical instrument. They were also thereafter known as some of the most dangerous and barely airworthy aircraft ever approved for flight. Obviously unable to endure even the most gentle of dives, they were scrapped, and radio-controlled models were used instead.

It was either divine justice or a bad joke that the last operational Ju-87s in the world were two survivors flown as trainers after the war by one of the Reich’s first conquests—the postwar air force of Czechoslovakia, which by then had become a Soviet satellite.

 

For further reading, frequent contributor Stephan Wilkinson recommends: The Junkers Ju 87 Stuka, by Peter C. Smith; and Junkers Ju 87, by Eddie J. Creek. Additionally, read about the legendary Stuka Pilot Hans-Ulrich Rudel’s final mission, from the March 2015 issue of Aviation History Magazine.

Screaming Bird of Prey was originally published in the September 2013 issue of Aviation History Magazine. To subscribe, click here.

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