Junkers Ju 87

• 1. Introduction

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  The Junkers Ju 87 announced itself with sound before it was ever seen. Mounted to the leading edges of its fixed undercarriage legs, the Stuka carried ram-air sirens officially designated "Lärmgerät" - German for noise device. As the plane descended in its dive, the sirens screamed. That sound became one of the most psychologically potent weapons of the Second World War, a propaganda symbol of Blitzkrieg conquest that carried across the battlefield long before any bomb fell. Yet the aircraft behind that sound was, by the standards of the day, already a design compromise born of accidents, political maneuvers, and one man's almost obsessive faith in the dive-bombing idea. How did a machine with a fixed undercarriage and an acknowledged vulnerability to fighters end up at the center of Germany's war effort from the first minutes of combat in 1939 all the way to 1945? And who was the designer who bet his career that simplicity and robustness mattered more than speed?

• 2. The Man and the Machine

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  Hermann Pohlmann, the Ju 87's principal designer, began from a deliberate philosophy: any dive-bomber had to be simple and robust above all else. That conviction led him to reject the retractable undercarriage in favor of the fixed, spatted landing gear that would become the Stuka's most recognizable silhouette. Pohlmann had been developing his ideas alongside Dipl Ing Karl Plauth, and the two produced the Ju A 48, which underwent testing on the 29th of September 1928. Plauth was killed in a flying accident in November 1927, before that milestone, leaving Pohlmann to continue alone. The military version of the Ju A 48 was designated the Ju K 47, and during trials in 1932 double vertical stabilisers were introduced to give the rear gunner a wider field of fire. After the Nazis came to power, the design gained political priority despite competition from the Henschel Hs 123. The inverted gull wing that would define the Ju 87 emerged as the most distinctive structural choice. Its shape improved the pilot's ground visibility and allowed a shorter undercarriage height, practical benefits in an aircraft expected to operate from rough forward airfields. When Ernst Udet flew the American Curtiss F11C Goshawk and developed what observers called a "growing love affair" with dive-bombing, the Stuka's prospects improved dramatically. Udet went so far as to advocate that all medium bombers should have dive-bombing capability, a position that would distort German aviation procurement for years. At a demonstration in May 1934 at the Jüterbog artillery range watched by Walther Wever and Robert Ritter von Greim, Udet began his dive at 1000 m and released his 1 kg practice bombs at just 100 m, barely pulling out. The Luftwaffe's chief of Command and its Secretary of State for Aviation concluded that such nerve and skill could not be expected of average pilots, yet development pressed on.

• 3. Birth Under Difficulty

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  The first Ju 87 prototype was built not in Germany but by AB Flygindustri in Sweden, then secretly transported to Germany in late 1934. It was meant to be ready by April 1935 but airframe weaknesses pushed completion to October of that year. Ten Rolls-Royce Kestrel liquid-cooled V12 engines had been ordered by Junkers on the 19th of April 1934 at a cost of 20,514 pounds, 2 shillings, and 6 pence. The mostly complete Ju 87 V1, registration D-UBYR, made its maiden flight on the 17th of September 1935. The flight report by Hauptmann Willy Neuenhofen noted only one problem: the small radiator caused the engine to overheat. That aircraft's fate was harsh. On the 24th of January 1936, the V1 crashed at Kleutsch near Dresden, killing both Neuenhofen and his engineer Heinrich Kreft. The square twin fins had proved too weak; they collapsed as the aircraft entered an inverted spin during dive testing. The crash forced a redesign to a single vertical stabiliser. The competing Heinkel He 118 met its own drama when, on the 27th of July 1936, Udet himself crashed the He 118 prototype V1, registered D-UKYM. Charles Lindbergh happened to be visiting Ernst Heinkel that same day, meaning Heinkel could only reach Udet by telephone. According to the surviving account, Heinkel had warned Udet about the propeller's fragility; Udet ignored it, the engine oversped in a dive, and the propeller broke away. Immediately after the crash, Udet declared the Stuka the winner of the development contest. The RLM had actually ordered cessation of Ju 87 development on the 9th of June 1936, preferring the He 118. Udet cancelled that order the very next day.

• 4. Engineering the Dive

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  At 4600 m, a Stuka pilot located his target through a bombsight window built into the cockpit floor. The dive lever was moved to the rear, the dive brakes deployed automatically, throttle reduced, coolant flaps closed. The aircraft then rolled 180 degrees, nosing into a dive at between 60 and 90 degrees, holding a constant speed of 500-600 km/h because the dive brakes kept it in check. A contact altimeter triggered a light at a preset minimum height of 450 m, signaling the bomb release point. An elongated U-shaped crutch under the fuselage swung the heavy bomb clear of the propeller arc. Then the aircraft automatically began a 6g pullout. The dive brakes were a critical safety feature: they ensured recovery even if the pilot blacked out from the g forces or suffered target fixation. Extensive tests at the Junkers works at Dessau measured the physiological limits. At above 6g, half of pilots suffered visual problems or greyout. Above 7.5g, 40 percent lost vision entirely. After more than three seconds above that threshold, half the test subjects blacked out entirely, though the pilot could still maintain consciousness and physical responses. In a crouched position, pilots could endure 8g and possibly 9g for three to five seconds without vision defects, which Junkers concluded was acceptable under war conditions. British test pilot Eric Brown, Commanding Officer of No. 1426 Flight RAF, flew a captured Stuka at RAE Farnborough and offered a striking assessment: "I had flown a lot of dive-bombers and it's the only one that you can dive truly vertically... The Stuka was in a class of its own." Not all pilots welcomed the automatic pullout, however. Helmut Mahlke later said that he and his unit disconnected the system because it let enemy ground defences predict the Ju 87's recovery pattern and height, making the aircraft easier to hit. When American forces occupied the Junkers factory at Dessau on the 21st of April 1945, they took particular interest in those medical flight tests.

• 5. Combat Debut in Spain

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  A single Ju 87 A-0, the V4 prototype, was secretly loaded onto the ship Usaramo and departed Hamburg on the night of the 1st of August 1936, arriving in Cádiz five days later. The aircraft was assigned serial number 29-1 and joined VJ/88, the experimental Staffel of the Condor Legion's fighter wing. The only confirmed record of its combat use places it in the Nationalist offensive against Bilbao in 1937, flown by Unteroffizier Herman Beuer. Spain exposed practical weaknesses immediately. The spatted undercarriage sank into muddy airfield surfaces. The maximum 500 kg bomb load was only achievable by removing the rear gunner entirely, limiting operational loads to 250 kg. In January 1939, during the Catalonia Offensive, a more significant test came. On the morning of the 21st of January 1939, three Ju 87Bs joined 34 Heinkel He 111s in an attack on the Port of Barcelona, five days before the city fell to the Nationalists. Republican pilot Francisco Alférez Jiménez, flying a Polikarpov I-15, claimed a kill near El Vendrell, though the Stuka managed to land on the beach without destroying itself. On the 24th of January 1939, Stukas prevented demolition engineers from destroying a bridge near Barcelona by strafing them at Molins de Rei. During that attack, Republican defenders using a quadruple PM M1910 mounting hit pilot Heinz Bohne in both legs; his gunner Albert Conrad was also injured in the subsequent crash. Those two were the only Stuka casualties of the entire Spanish war. The experience confirmed what the Germans needed to know about air and ground crew performance under real conditions, though it offered no lesson about coordinated fighter opposition. That lesson came later at a far steeper price.

• 6. Poland and the Blitzkrieg Template

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  On the morning of the 15th of August 1939, during a mass-formation dive-bombing demonstration for senior Luftwaffe commanders at Neuhammer training grounds near Sagan, 13 Ju 87s and 26 crew members were lost when they flew through cloud and struck the ground almost simultaneously. The pilots had expected to release practice bombs and pull out below the cloud ceiling; they did not know the ceiling was too low and that unexpected ground mist left no time to recover. The war itself began on the 1st of September 1939, and the opening Stuka operation was precise: destroy Polish demolition charges on rail bridges over the Vistula connecting Eastern Germany to the Danzig corridor. At exactly 04:26 Central European Time, a Kette of three Ju 87s from 3./StG 1, led by Staffelkapitän Oberleutnant Bruno Dilly, carried out the first bombing attack of the entire war, striking 11 minutes before Germany officially declared hostilities. Leutnant Frank Neubert of I./StG 2 "Immelmann" then scored the first air-to-air victory of the war, shooting down a Polish PZL P.11c as it took off from Balice airfield; its pilot, Captain Mieczysław Medwecki, was killed. The absence of meaningful Polish anti-aircraft artillery multiplied the Ju 87's effect. At the Battle of Radom, six Polish divisions trapped by encircling German forces were forced to surrender after a four-day bombardment by StG 51, 76 and 77. During the Battle of Bzura, the Sturzkampfgeschwader alone dropped 388 tonnes of bombs. Naval operations were equally effective: the 1540-ton destroyer Wicher and the minelayer Gryf were sunk in harbour. The torpedo boat Mazur at 412 tons and the gunboat General Haller at 441 tons followed. The Stukawaffe lost 31 aircraft across the entire Polish campaign. By the 30th of September 1939, Junkers had received 2,365,196 Reichsmark for Ju 87 construction orders, with an additional 243,646 RM for development.

• 7. The Limits Exposed

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  The Battle of Britain in 1940-1941 stripped away the conditions that had made the Stuka so fearsome. Without the suppressed air defenses and minimal fighter opposition of Poland, the aircraft's lack of speed, manoeuvrability, and defensive armament became a liability that no amount of experience could offset. It required heavy fighter escort to operate at all, and even then losses climbed sharply. The Luftwaffe withdrew the Ju 87 from the Battle of Britain campaign. Yet there was no replacement. The D-series, developed in 1941, tried to address the deficit through sheer power and bomb-carrying capacity. The Jumo 211J delivered 1,420 PS compared to earlier engines, and maximum bomb load grew from 500 kg in the B-version to 1800 kg in the D-version under overload conditions. The aircraft's expected service life told the real story: from 9.5 months in 1941, the life expectancy fell to 5.5 months and then to just 100 operational flying hours. The G-series found one arena where the Stuka remained relevant: anti-tank work on the Eastern Front. Hans-Ulrich Rudel, who had suggested using 37 mm Flak 18 guns in underwing pods after achieving results with 20 mm cannon against Soviet tanks, became the most highly decorated German pilot of the war. The G-1 variant carried two Bordkanone BK 3,7 cannons loaded with armour-piercing tungsten carbide-cored ammunition. Rudel flew the only official Ju 87 G on the opening day of the Battle of Kursk. By October 1943, Ernst Kupfer reported to the Luftwaffe command that the Ju 87 could no longer survive in operations, and formally recommended the Focke-Wulf Fw 190F as its replacement. The Fw 190F had begun replacing the Stuka for day missions in 1943, but Ju 87s continued flying as night harassment aircraft right through to 1945, used by units including NSGr 1 and 2 during the Battle of Normandy and the Battle of the Bulge.

• 8. Production Under Pressure

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  Germany built an estimated 6,000 Ju 87s of all versions between 1936 and August 1944, with the Weserflug company producing 5,930 of the total 6,500 built across the entire production run. Reaching even that number required constant improvisation. When skilled workers were called up for military service, Junkers supplied 300 German workers to the Weserflug factory at Lemwerder near Bremen, and the remaining shortfall was covered by Soviet prisoners of war and Soviet civilians deported to Germany. By mid-1942, 150 Ju 87 D airframes were coming off the lines each month. Milch pushed for 350 per month in September 1942, a figure the Reich's production capacity could not achieve. The RLM considered setting up facilities in Slovakia, where 3,500-4,000 workers could be found, though no technical personnel were available; the move would have yielded only around 25 additional machines per month. In October 1942, one of the WFG plants burned down, creating a chronic shortage of tailwheels and undercarriage parts. Production of the C-series carrier variant, intended for the aircraft carrier that Germany never finished, was cancelled on the 6th of October 1939, with 120 planned aircraft scrapped from the order. The Ju 87 repair centre at Wels-Lichtenegg processed 746 aircraft between May 1940 and November 1944. In the winter of 1943-1944 alone, the Menibum company converted approximately 300 Ju 87 D-3s and D-5s to night-flying versions, requiring 2,170 technicians and workers. Production finally wound down in May 1944; 78 were built that month and 69 more rebuilt from damaged machines. The Ju 87 repair facility at the Wels aircraft works was destroyed on the 30th of May 1944, and the site was abandoned. Rudel's war, though, continued until the very last day of the conflict.