| Junkers Ju 87 | |
|---|---|
| Ju 87Ds in October 1943 | |
| Role | Dive bomber |
| Manufacturer | Junkers |
| Designer | Hermann Pohlmann |
| First flight | 17 September 1935 |
| Introduction | 1936 |
| Retired | 1945 (Luftwaffe) |
| Primary users | Luftwaffe Regia Aeronautica Royal Romanian Air Force Bulgarian Air Force |
| Number built | Estimated 6,500[a] |
The Junkers Ju 87 or Stuka (from Sturzkampfflugzeug, "dive bomber") was a two-man (pilot and rear gunner) German ground-attack aircraft. Designed by Hermann Pohlmann, the Stuka first flew in 1935 and made its combat debut in 1936 as part of the Luftwaffe's Condor Legion during the Spanish Civil War.
The aircraft was easily recognizable by its inverted gull wings, fixed spatted undercarriage and its infamous Jericho-Trompete ("Jericho Trumpet") wailing siren, becoming the propaganda symbol of German air power and the blitzkrieg victories of 1939–1942. The Stuka's design included several innovative features, including automatic pull-up dive brakes under both wings to ensure that the aircraft recovered from its attack dive even if the pilot blacked out from the high acceleration.
Although sturdy, accurate, and very effective, the Ju 87 was vulnerable to modern fighter aircraft, like many other dive bombers of the war. Its flaws became apparent during the Battle of Britain; poor manoeuvrability and a lack of both speed and defensive armament meant that the Stuka required heavy fighter escort to operate effectively.
The Stuka operated with further success after the Battle of Britain, and its potency as a precision ground-attack aircraft became valuable to German forces in the Balkans Campaign, the African and Mediterranean Theaters and the early stages of the Eastern Front campaigns where Allied fighter resistance was disorganised and in short supply.
Once the Luftwaffe had lost air superiority on all fronts, the Ju 87 once again became an easy target for enemy fighter aircraft. In spite of this, because there was no better replacement, the type continued to be produced until 1944. By the end of the conflict, the Stuka had been largely replaced by ground-attack versions of the Focke-Wulf Fw 190, but was still in use until the last days of the war. An estimated 6,500 Ju 87s of all versions were built between 1936 and August 1944.
Oberst Hans-Ulrich Rudel was the most notable Stuka ace and was the most highly decorated German serviceman of the Second World War. On 29 December 1944, he became the only serviceman to receive the highest German military award, the Knight's Cross with golden Oak Leaves, Swords and Diamonds.
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The Ju 87's principal designer, Hermann Pohlmann, held the opinion that any dive-bomber design needed to be simple and robust.[1] This led to many technical innovations, such as the retractable undercarriage being discarded in favour of one of the Stuka's distinctive features, its fixed and "spatted" undercarriage. Pohlmann continued to carry on developing and adding to his ideas and those of Dipl Ing Karl Plauth (Plauth was killed in a flying accident in November 1927), and produced the Ju A 48 which underwent testing on 29 September 1928. The military version of the Ju A 48 was designated the Ju K 47.[1]
After the Nazis came to power, the design was given priority. Despite initial competition from the Henschel Hs 123, the Reichsluftfahrtministerium (RLM) - German for the "Aviation Ministry" - turned to the designs of Herman Pohlmann of Junkers and co-designer of the K 47, Karl Plauth. During the trials with the K 47 in 1932, the double vertical stabilizers were introduced to give the rear gunner a better field of fire. The main, and what was to be the most distinctive, feature of the Ju 87 was its double-spar inverted gull wings.[2] After Plauth's death, Pohlmann continued the development of the Junkers dive bomber. The Ju A 48 registration D-ITOR, was originally fitted with a BMW 132 engine, producing some 450 kW (600 hp). The machine was also fitted with dive brakes for dive testing. The aircraft was given a good evaluation and "exhibited very good flying characteristics".[1]
Ernst Udet took an immediate liking to the concept of dive-bombing after flying the Curtiss Hawk II. When he invited Walther Wever and Robert Ritter von Greim to watch Udet perform a trial flight in May 1934 at the Jüterbog artillery range, it raised doubts about the capability of the dive bomber. Udet began his dive at 1,000 m (3,280 ft) and released his 1 kg (2 lb) bombs at 100 m (330 ft), barely recovering and pulling out of the dive.[3] The Chief of the Air Weapons Command Bureau, Walther Wever, and the Secretary of State for Aviation, Erhard Milch, feared that such high-level nerves and skill could not be expected of "average pilots" in the Luftwaffe.[3] Nevertheless, development continued at Junkers.[3] Udet's "growing love affair" with the dive bomber pushed it to the forefront of German aviation development.[4] Udet went so far as to advocate that all medium bombers have dive-bombing capabilities.[5]
The design of the Ju 87 had begun in 1933 as part of the Sturzbomber-Programm. The Ju 87 was to be powered by the British Rolls-Royce Kestrel engine. Ten engines were ordered by Junkers on 19 April 1934 for £ 20,514, 2 shillings and sixpence.[6] The first Ju 87 prototype was built by AB Flygindustri in Sweden and secretly brought to Germany in late 1934. It was to have been completed in April 1935, but, due to the inadequate strength of the airframe, construction was not completed until October 1935. However, the mostly complete Ju 87 V1 W.Nr.c 4921 (less non-essential parts) took off for its maiden flight on 17 September 1935. The aircraft originally did not carry any registration, but later was given the registration D-UBYR.[7] The flight report, by Hauptmann Willy Neuenhofen, stated the only problem was with the small radiator, which caused the power plant to overheat.[8]
The Ju 87 V1, powered by a Rolls-Royce Kestrel V12 cylinder liquid-cooled engine, and with a twin-tail, crashed on 24 January 1936 at Kleutsch near Dresden, killing Junkers' chief test pilot, Willy Neuenhofen, and his engineer, Heinrich Kreft.[9] The square twin fins and rudders proved too weak; they collapsed and the aircraft crashed after it entered an inverted spin during the testing of the terminal dynamic pressure in a dive.[10] The crash prompted a change to a single vertical stabilizer tail design. To withstand strong forces during a dive, heavy plating was fitted, along with brackets riveted to the frame and longeron, to the fuselage. Other early additions included the installation of hydraulic dive brakes that were fitted under the leading edge and could rotate 90°.[11]
The RLM was still not interested in the Ju 87 and was not impressed that it relied on a British engine. In late 1935, Junkers suggested fitting a DB 600 in-line engine, with the final variant to be equipped with the Jumo 210. This was accepted by the RLM as an interim solution. The reworking of the design began on 1 January 1936. The test flight could not be carried out for over two months due to a lack of adequate aircraft. The 24 January crash had already destroyed one machine.
The second prototype was also beset by design problems. It had its twin stabilizers removed and a single tail fin installed due to fears over stability. Due to a shortage of power plants, instead of a DB 600, a BMW "Hornet" engine was fitted. All these delays set back testing until 25 February 1936.[12] By March 1936, the second prototype, the V2, was finally fitted with the Jumo 210Aa power plant, which a year later was replaced by a Jumo 210 G (W.Nr. 19310). Although the testing went well, and the pilot, Flight Captain Hesselbach, praised its performance, Wolfram von Richthofen told the Junkers representative and Construction Office chief engineer Ernst Zindel that the Ju 87 stood little chance of becoming the Luftwaffe's main dive bomber, as it was underpowered in his opinion.[13] On 9 June 1936, the RLM ordered cessation of development in favour of the Heinkel He 118, a rival design. Apparently, Udet cancelled the order the next day, and development continued.
On 27 July 1936, Udet crashed the He 118 prototype, He 118 V1 D-UKYM.[14] That same day, Charles Lindbergh was visiting Ernst Heinkel, so Heinkel could only communicate with Udet by telephone. According to this version of the story, Heinkel warned Udet about the propeller's fragility. Udet failed to consider this, so in a dive, the engine oversped and the propeller broke away.[15] Immediately after this incident, Udet announced the Stuka the winner of the development contest.[14]
Despite being chosen, the design was still lacking and drew frequent criticism from Wolfram von Richthofen. Testing of the V4 prototype (A Ju 87 A-0) in early 1937 revealed several problems. The Ju 87 could take off in just 250 m (820 ft) and climb to 1,875 m (6,150 ft) in just eight minutes with a 250 kg (550 lb) bomb load, and its cruising speed was 250 km/h (160 mph). However, Richthofen pushed for a more powerful engine.[16] According to the test pilots, the Heinkel He 50 had a better acceleration rate, and could climb away from the target area much more quickly, avoiding enemy ground and air defenses. Richthofen stated that any maximum speed below 350 km/h (217 mph) was unacceptable for those reasons. Pilots also complained that navigation and powerplant instruments were mixed together, and were not easy to read, especially in combat. Despite this, pilots praised the aircraft's handling qualities and strong airframe.[17]
These problems were to be resolved by installing the Daimler-Benz DB 600 engine, but delays in development forced the installation of the Jumo 210 Da in-line engine. Flight testing began on 14 August 1936. Subsequent testing and progress fell short of Richthofen's hopes, although the machine's speed was increased to 280 km/h (173 mph) at ground level and 290 km/h (179 mph) at 1,250 m (4,100 ft), while maintaining its good handling ability.[18]
The Ju 87 was a single-engined all-metal cantilever monoplane. It had a fixed undercarriage and could carry a crew of two. The main construction material was duralumin, and the external coverings were made of Duralumin sheeting. Parts that were required to be of strong construction, such as the wing flaps, were made of Pantal and its components made of Elektron. Bolts and parts that were required to take heavy stress were made of steel.[19]
The Ju 87 was fitted with detachable hatches and removable coverings to aid and ease maintenance and overhaul. The designers avoided welding parts wherever possible, preferring moulded and cast parts instead. Large airframe segments were interchangeable as a complete unit, which increased speed of repair.[19]
The airframe was also subdivided into sections to allow transport by road or rail. The wings were of standard Junkers double-wing construction. This gave the Ju 87 considerable advantage on take-off; even at a shallow angle, large lift forces were created through the aerofoil, reducing take-off and landing runs.[19]
In accordance with the Aircraft Certification Center for "Stress Group 5", the Ju 87 had reached the acceptable structural strength requirements for a dive bomber. It was able to withstand diving speeds of 600 km/h (373 mph) and a maximum level speed of 340 km/h (211 mph) near ground level, and a flying weight of 4,300 kg (9,480 lb). Performance in the diving attack was enhanced by the introduction of dive brakes under each wing, which allowed the Ju 87 to maintain a constant speed and allow the pilot to steady his aim. It also prevented the crew from suffering extreme g forces and high acceleration during "pull-out" from the dive.[19]
The fuselage had an oval cross-section and housed a water-cooled inverted-V inline engine. The cockpit was protected from the engine by a firewall ahead of the wing center section where the fuel tanks were located. At the rear of the cockpit, the bulkhead was covered by a canvas cover which could be breached by the crew in an emergency, enabling them to escape into the main fuselage. The canopy was split into two sections and joined by a strong welded steel frame. The canopy itself was made of Plexiglas and each compartment had its own "sliding hood" for the two crew members.[19]
The engine was mounted on two main support frames that were supported by two tubular struts. The frame structure was triangulated and emanated from the fuselage. The main frames were bolted onto the power plant in its top quarter. In turn, the frames were attached to the firewall by universal joints. The firewall itself was constructed from asbestos mesh with dural sheets on both sides. All conduits passing through had to be arranged so that no harmful gases could penetrate the cockpit.[20]
The fuel system comprised two fuel tanks in the center section of the port and starboard wings, each with 250 L capacity. The tanks also had a predetermined limit which, if passed, would warn the pilot via a red warning light in the cockpit. The fuel was injected via a pump from the tanks to the power plant. Should this shut down, it could be pumped manually using a hand-pump on the fuel cock armature.[20]
The powerplant was cooled by a 10 L (3 US gal) ring-shaped aluminium water container situated between the propeller and engine. A further container of 20 L (5 US gal) was positioned under the engine.[20] The control surfaces operated in much the same way as other aircraft, with the exception of the innovative automatic pull-out system. Releasing the bomb initiated the pull-out, or automatic recovery and climb, upon the deflection of the dive brakes. The pilot could override the system by exerting significant force on the control column and taking manual control.[21]
The wing was the most unusual feature. It consisted of a single center section and two outer sections installed using four universal joints. The center section had a large negative dihedral (anhedral) and the outer surfaces a positive dihedral. This created the gull, or "cranked", wing pattern along the Ju 87's leading edge. The shape of the wing improved the pilot's ground visibility and also allowed a shorter undercarriage height. The center section protruded by only 3 m (9 ft 10⅛ in) on either side.[21]
The offensive armament was two 7.92 mm (.312 in) MG 17 machine guns fitted in each wing, operated by a mechanical pneumatics system from the pilot's control column. The rear gunner/radio operator operated one 7.92 mm (.312 in) MG 15 machine gun for defensive purposes.[19]
The engine and propeller had automatic controls, and an auto-trimmer made the aircraft tail-heavy as the pilot rolled over into his dive, lining up red lines at 60°, 75° or 80° on the cockpit side window with the horizon and aiming at the target with the sight of the fixed gun. The heavy bomb was swung down clear of the propeller on crutches prior to release.[22]
Flying at 4,600 m (15,000 ft), the pilot located his target through a bombsight window in the cockpit floor. The pilot moved the dive lever to the rear, limiting the "throw" of the control column.[23] The dive brakes were activated automatically, the pilot set the trim tabs, retarded his throttle and closed the coolant flaps. The aircraft then rolled 180°, automatically nosing the aircraft into a dive. Red tabs protruded from the upper surfaces of the wing as a visual indicator to the pilot that, in case of a g-induced black-out, the automatic dive recovery system would be activated. The Stuka dived at a 60-90° angle, holding a constant speed of 500–600 km/h (350-370 mph) due to dive-brake deployment, which increased the accuracy of the Ju 87's aim.[23]
When the aircraft was reasonably close to the target, a light on the contact altimeter came on to indicate the bomb-release point, usually at a minimum height of 450 m (1,500 ft). The pilot released the bomb and initiated the automatic pull-out mechanism by depressing a knob on the control column.[23] An elongated U-shaped crutch located under the fuselage swung the bomb out of the way of the propeller, and the aircraft automatically began a 6 g pullout.[23] Once the nose was above the horizon, dive brakes were retracted, the throttle was opened, and the propeller was set to climb. The pilot regained control and resumed normal flight. The coolant flaps had to be reopened quickly to prevent overheating.
Physical stress on the crew was severe. Human beings subjected to more than 5 g forces in a seated position will suffer vision impairment in the form of a grey veil known to Stuka pilots as "seeing stars". They lose vision while remaining conscious; after five seconds, they black out. The Ju 87 pilots experienced the visual impairments most during "pull-up" from a dive.[24]
Eric "Winkle" Brown, a British test pilot from the Royal Navy, and General Officer Commanding "Captured Enemy Aircraft Flight" section, tested the Ju 87 at RAE Farnborough. He remarked:
I had a high opinion of the Stuka because I had flown a lot of dive-bombers and it’s the only one that you can dive truly vertically. Sometimes with the dive-bombers, pilots claim that they did a vertical dive. What a load of rubbish. The maximum dive is usually in the order of 60 degrees. In a dive when flying the Stuka, because it’s all automatic, you are really flying vertically. You feel that you are over the top and feel you are going that a way! The Vengeance and Dauntless were both very good but could dive no more than 60 or 70 degrees. The Stuka was in a class of its own.[25]
Extensive tests were carried out by the Junkers works at their Dessau plant. It was discovered that the highest load a pilot could endure was 8.5 g for three seconds, when the aircraft was pushed to its limit by the centrifugal forces. At less than 4 g, no visual problems or loss of consciousness were experienced.[26] Above 6 g, 50% of pilots suffered visual problems, or "grey" out. With 40%, vision vanished altogether from 7.5 g upwards and black-out sometimes occurred.[27] Despite this blindness, the pilot could maintain consciousness and was capable of "bodily reactions". However, after more than three seconds, half the subjects passed out. The pilot would regain consciousness two or three seconds after the centrifugal forces had dropped below 3 g and had lasted no longer than three seconds. In a crouched position, pilots could withstand 7.5 g and were able to remain functional for a short duration. In this position, Junkers concluded that ⅔ of pilots could withstand 8 g and perhaps 9 g for three to five seconds without vision defects which, under war conditions, was acceptable.[28] During tests with the Ju 87 A-2, new technologies were tried out to reduce the effects of g forces. The pressurised cabin was of great importance during this research. Testing revealed that at high altitude, even 2 g could cause death in an unpressurised cabin and without appropriate clothing. This new technology, along with special clothing and oxygen masks, was researched and tested. When the United States Army occupied the Junkers factory at Dessau on 21 April 1945, they were impressed and interested in the medical flight tests with the Ju 87.[28]
The concept of dive bombing became so popular among the leadership of the Luftwaffe that it became almost obligatory in new aircraft designs. Later bomber models like the Junkers Ju 88 and the Dornier Do 217 were equipped for dive bombing. The Heinkel He 177 strategic bomber was initially supposed to have dive bombing capabilities, a requirement that contributed to the failure of the design.[29]
Once the Stuka became too vulnerable to fighter opposition on all fronts, work was done to develop a replacement. None of the dedicated close-support designs on the drawing board progressed far due to the impact of the war and technological difficulties. So the Luftwaffe settled on the Focke-Wulf Fw 190 fighter aircraft, with the Fw 190F becoming the ground-attack version. The Fw 190F started to replace the Ju 87 for day missions in 1943, but the Ju 87 continued to be used as a night nuisance-raider until the end of the war.[30]
The second prototype had a redesigned single vertical stabiliser and a 610 PS (449 kW, 602 hp) Junkers Jumo 210 A engine installed, and later the Jumo 210 Da. The first A series variant, the A-0, was of all-metal construction, with an enclosed cockpit. To ease the difficulty of mass production, the leading edge of the wing was straightened out and the ailerons' two aerofoil sections had smooth leading and trailing edges. The pilot could adjust the elevator and rudder trim tabs in flight, and the tail was connected to the landing flaps, which were positioned in two parts between the ailerons and fuselage. The A-0 also had a flatter engine cowling, which gave the pilot a much better field of vision. In order for the engine cowling to be flattened, the engine was set down nearly .25 m (10 in). The fuselage was also lowered along with the gunner's position, allowing the gunner a better field of fire.[31]
The RLM ordered seven A-0s initially, but then increased the order to 11. Early in 1937, the A-0 was tested with varied bomb loads. The underpowered Jumo 210A, as pointed out by von Richthofen, was insufficient, and was quickly replaced with the Jumo 210D power plant.[31]
The A-1 differed from the A-0 only slightly.[32] As well as the installation of the Jumo 210D, the A-1 had two 220 L (60 US gal) fuel tanks built into the inner wing, but it was not armoured or protected.[32] The A-1 was also intended to be fitted with two 7.92 mm (.312 in) MG 17 machine guns in each wing, but this was dropped due to excessive weight. The two that remained were fed a total of 500 rounds of ammunition, stored in the undercarriage "spats". The pilot relied on the Revi C 21C gun sight for the two MG 17s. The gunner had only a single 7.92 mm (.312 ) MG 15, with 14 drums of ammunition, each containing 75 rounds. This represented a 150-round increase in this area over the Ju 87 A-0.[32] The A-1 was also fitted with a larger 3.3 m (10.8 ft) propeller.
The Ju 87 was capable of carrying a 500 kg (1,100 lb) bomb, but only if not carrying the rear gunner/radio operator as, even with the Jumo 210D power plant, the Ju 87 was still underpowered for operations with more than a 250 kg (550 lb) bomb load. All Ju 87 As were restricted to 250 kg (550 lb) weapons (although during the Spanish Civil War missions were conducted without the gunner).[33]
The Ju 87 A-2 was retrofitted with the Jumo 210Da fitted with a two-stage supercharger. The only further significant difference between the A-1 and A-2 was the H-PA-III controllable-pitch propeller.[34] By mid-1938, 262 Ju 87 As had been produced, 192 from the Junkers factory in Dessau, and a further 70 from Weserflug in Bremen. The new, more powerful, Ju 87B model started to replace the Ju 87A at this time.[35]
Prototypes[36]
Production variants
The Ju 87 B series was to be the first mass-produced variant. A total of six pre-production Ju 87 B-0 were produced, built from Ju 87 A airframes.[38] Test flights began from the summer of 1937. A small number, at least three, served as conversion Cs or Es for potential naval variants.
The first production version was the Ju 87 B-1, with a considerably larger engine, its Junkers Jumo 211D generating 1,200 PS (883 kW, 1,184 hp), and completely redesigned fuselage and landing gear. This new design was again tested in Spain, and after proving its abilities there, production was ramped up to 60 per month. As a result, by the outbreak of World War II, the Luftwaffe had 336 Ju 87 B-1s on hand.[23] The B-1 was also fitted with "Jericho trumpets", essentially propeller-driven sirens with a diameter of 0.7 m (2.3 ft)[39] mounted on the wing's leading edge directly forward of the landing gear, or on the front edge of the fixed main gear fairing. This was used to weaken enemy morale and enhance the intimidation of dive-bombing. After the enemy became used to it, however, they were withdrawn. The devices caused a loss of some 20–25 km/h (10-20 mph) through drag. Instead, some bombs were fitted with whistles on the fin to produce the noise after release.[40]
The trumpets were a suggestion from Generaloberst Ernst Udet (but some authors say the idea originated from Adolf Hitler).[41] The Ju 87 B-2s that followed had some improvements and were built in a number of variants that included ski-equipped versions (the B-1 also had this modification[42]), and at the other end, with a tropical operation kit called the Ju 87 B-2 trop. Italy's Regia Aeronautica received a number of the B-2s and named them the "Picchiatello", while others went to the other members of the Axis, including Hungary, Bulgaria and Romania. The B-2 also had an oil hydraulic system for closing the cowling flaps. This continued in all the later designs.[43]
The tropicalised versions were initially named the Ju 87 B-2/U1. This was eventually designated the Ju 87 B-2 trop, equipped with tropical emergency equipment and sand filters for the powerplant.
Production of the Ju 87 B started in 1937. 89 B-1s were to be built at Junkers' factory in Dessau and another 40 at the Weserflug plant in Bremen by July 1937. Production would be carried out by the Weserflug company after April 1938, but Junkers continued producing Ju 87 up until March 1940.[44] Total production amounted to 697 B-1s (311 by Junkers, 386 by Weserflug) and 225 B-2s (56 by Junkers, 169 by Weserflug). The last Ju 87B rolled off the production lines in October 1940 [45]
A long range version of the Ju 87 B was also built, known as the Ju 87 R. They were primarily intended for anti-shipping missions. The Ju 87R had a B-series airframe with an additional oil tank and fuel lines to the outer wing stations to permit the use of two 300 L (79,25 US gal) under-wing drop tanks. This increased fuel capacity to 1,080 litres (500 L in main fuel tank of which 480 L where usable + 600 L from drop tanks).[46] To prevent overload conditions, bomb carrying ability was often restricted to a single 250 kg (550 lb) bomb if the aircraft was fully loaded with fuel.
The Ju 87 R-1 had a B-1 airframe with the exception of a modification in the fuselage which enabled an additional oil tank. This was installed to feed the engine due to the increase in range after the addition of the extra fuel tanks.[47]
The Ju 87 R-2 had the same airframe as the B-2, and strengthened to ensure it could withstand dives of 600 km/h (370 mph). The Jumo 211D in-line engine was installed, replacing the R-1s Jumo 211A.[47] Due to an increase in overall weight by some 700 kg (1,540 lb), the Ju 87 R-2 was 30 km/h (20 mph) slower than the Ju 87 B-1 and had a lower service ceiling. The Ju 87 R-2 had an increased range advantage of 360 km (220 mi).[44] The R-3 and R-4 were the last R variants developed. Only a few were built. The R-3 was an experimental tug for gliders and had an expanded radio system so the crew could communicate with the glider crew by way of the tow rope. The R-4 differed from the R-2 in the Jumo 211J powerplant. [48]
Total production amounted to 972 Ju 87R (105 R-1, 472 R-2, 144 R-4), all built by Weserflug. The last Ju 87R rolled off the production lines in October 1941 [49]
Known prototypes[50]
On 18 August 1937, the RLM decided to introduce the Ju 87 Tr(C). The Ju 87 C was intended to be a dive and torpedo bomber for the Kriegsmarine. The type was ordered into prototype production and available for testing in January 1938. Testing was given just two months and was to begin in February and end in April 1938.[51] The prototype V10 was to be a fixed wing test aircraft, while the following V11 would be modified with folding wings. The prototypes were Ju 87 B-0 airframes powered by Jumo 211 A engines.[51] Owing to delays, the V10 was not completed until March 1938. It first flew on 17 March and was designated Ju 87 C-1.[51] On 12 May, the V11 also flew for the first time. By 15 December 1939, 915 arrested landings on dry land had been made. It was found the arresting gear winch was too weak and had to be replaced. Tests showed the average braking distance was 20–35 metres (65-115 feet).[52] The Ju 87 V11 was designated C-0 on 8 October 1938. It was fitted out with standard Ju 87 C-0 equipment and better wing-folding mechanisms. The "carrier Stuka" was to be built at the Weserflug Company's Bremen plant between April and July 1940.[53]
Among the "special" equipment of the Ju 87 C was a two-seat rubber dinghy with signal ammunition and emergency ammunition. A quick fuel dump mechanism and two inflatable 750 L (200 US gal) bags in each wing and a further two 500 L (130 US gal) bags in the fuselage enabled the Ju 87 C to remain afloat for up to three days in calm seas.[53] On 6 October 1939, with the war already underway, 120 of the planned Ju 87 Tr(C)s on order at that point were cancelled. Despite the cancellation, the tests continued using catapults. The Ju 87 C had a takeoff weight of 5,300 kg (11,700 lb) and a speed of 133 km/h (82 mph) on departure. The Ju 87 could be launched with a SC 500 kg (1,100 lb) bomb and four SC 50 kg (110 lb) bombs under the fuselage. The C-1 was to have two MG 17s mounted in the wing with a MG 15 operated by the rear gunner. On 18 May 1940, production of the C-1 was switched to the R-1.[54]
Known prototypes[50]
Despite the Stuka's vulnerability to enemy fighters having been exposed during the Battle of Britain, the Luftwaffe had no choice but to continue its development, as there was no replacement aircraft in sight.[55] The result was the D-series. In June 1941, the RLM ordered five prototypes, the Ju 87 V21–25. A Daimler-Benz DB 603 powerplant was to be installed in the Ju 87 D-1, but it did not have the power of the Jumo 211 and performed "poorly" during tests and was dropped.[56] The Ju 87 D-series featured two coolant radiators underneath the inboard sections of the wings, while the oil cooler was relocated to the position formerly occupied by the coolant radiator. The D-series also introduced an aerodynamically refined cockpit with better visibility and space.[57] In addition, armor protection was increased and a new dual-barrel 7.92 mm (.312 in) MG 81Z machine gun with an extremely high rate of fire was installed in the rear defensive position. Engine power was increased again, the Jumo 211J now delivering 1,420 PS (1,044 kW, 1,401 hp).[57] Bomb carrying ability was massively increased from 500 kg (1,100 lb) in the B-version to 1,800 kg (3,970 lb) in the D-version (max. load for short ranges, overload condition), a typical bomb load ranged from 500-1,200 kg (1,100-2,650 lb).[58]
The internal fuel capacity of the Ju 87D was raised to 800 L (of which 780 L were usable) by adding additional wing tanks while retaining the option to carry two 300 L drop tanks.[59] Tests at Rechlin revealed it made possible a flight duration of 2 hours and 15 minutes. With an extra two 300 L (80 US gal) fuel tanks, it could achieve four hours flight time.[57]
The D-2 was a variant used as a glider tug by converting older D-series airframes. It was intended as the tropical version of the D-1. It was to have heavier armour to protect the crew from ground fire. The armour reduced its performance and caused the Oberkommando der Luftwaffe to "place no particular value on the production of the D-2".[57] The D-3 was an improved D-1 with more armour for its ground-attack role. A number of Ju 87 D-3s were designated D-3N or D-3 trop and fitted with night or tropical equipment.[57] The D-4 designation applied to a prototype torpedo-bomber version, which could carry a 750–905 kg (1,650-2,000 lb) aerial torpedo on a PVC 1006 B rack. The D-4 was to be converted from D-3 airframes and operated from the aircraft carrier Graf Zeppelin.[60] Other modifications included a flame eliminator and, unlike earlier D variants, two 20 mm MG 151/20 cannon, while the radio operator/rear gunner's ammunition supply was increased by 1,000 to 2,000 rounds.[61]
The Ju 87 D-5 was based on the D-3 design and was unique in the Ju 87 series as it had wings 0.6 metres (1 foot) longer than previous variants. The two 7.92 mm MG 17 wing guns were exchanged for more powerful 20 mm MG 151/20s to better suit the aircraft's ground-atack role. The window in the floor of the cockpit was reinforced and four, rather than the previous three, aileron hinges were installed. Higher diving speeds were obtained of 650 km/h (408 mph) up to 2,000 m (6,560 ft). The range was recorded as 715 km (443 mi) at ground level and 835 km (517 mi) at 5,000 m (16,400 ft).[58]
The D-6, according to "Operating instructions, works document 2097", was built in limited numbers to train pilots on "rationalised versions". However, due to shortages in raw materials, it did not go into mass production.[62] The D-7 was another ground attack aircraft based on D-1 airframes upgraded to D-5 standard (armor, wing cannons, extended wing panels), while the D-8 was similar to the D-7 but based on D-3 airframes.[62] The D-7 and D-8 were both were fitted with flame dampers, and could conduct night operations.[62]
Production of the D-1 variant started in 1941 with 495 ordered. These aircraft were delivered between May 1941 and March 1942. The RLM wanted 832 machines produced from February 1941. The Weserflug company was tasked with their production. From June to September 1941, 40 Ju 87 Ds were expected to be built, increasing to 90 thereafter.[63] Various production problems were encountered. Just one of the planned 48 was produced in July. Of the 25 the RLM hoped for in August 1941, none were delivered.[63] Only in September 1941 did the first two of the planned 102 Ju 87s roll off the production lines.[64] The shortfalls continued to the end of 1941. During this time, the WFG plant in Bremen moved production to Berlin. Over 165 Ju 87s had not been delivered and production was only 23 Ju 87 Ds per month out of the 40 expected. By the spring of 1942 to the end of production in 1944, 3,300 Ju 87s, mostly D-1s, D-2s and D-5s had been manufactured.[64]
Total production amounted to 3639 Ju 87D (592 D-1, 1559 D-3 and 1448 D-5), all built by Weserflug. The last Ju 87 D-5 rolled off the production lines in September 1944 [65]
The Ju 87 E and F proposals were never built, and Junkers went straight onto the next variant. Another variant derived from the Ju 87D airframe, the Ju 87H saw service as a dual-control trainer.
In January 1943, a variety of Ju 87 Ds became "test beds" for the Ju 87 G variants. At the start of 1943, the Luftwaffe test centre at Tarnewitz tested this combination from a static position. Oberst G. Wolfgang Vorwald noted the experiments were not successful, and suggested the cannon be installed on the Messerschmitt Me 410.[66] However, testing continued, and on 31 January 1943, Ju 87 D-1 W.Nr 2552 was tested by Hauptmann Hans-Karl Stepp near the Briansk training area. Stepp noted the increase in drag, which reduced the aircraft's speed to 259 km/h (162 mph). Stepp also noted that the aircraft was also less agile than the existing D variants. D-1 and D-3 variants operated in combat with the 37 mm (1.46 in) BK 37 cannon in 1943.[66]
Known prototypes
With the G variant, the aging airframe of the Ju 87 found new life as an anti-tank aircraft. This was the final operational version of the Stuka, and was deployed on the Eastern Front. The reverse in German military fortunes after 1943 and the appearance of huge numbers of well-armoured Soviet tanks caused Junkers to adapt the existing design to combat this new threat. The Hs 129B had proved a potent ground attack weapon, but its large fuel tanks made it vulnerable to enemy fire, prompting the RLM to say "that in the shortest possible time a replacement of the Hs 129 type must take place."[67] With Soviet tanks the priority targets, the development of a further variant as a successor to the Ju 87D began in November 1942. On 3 November, Erhard Milch raised the question of replacing the Ju 87, or redesigning it altogether. It was decided to keep the design as it was, but to upgrade the powerplant to a Jumo 211J, and add two 30 mm (1.18 in) cannon. The variant was also designed to carry a 1,000 kg (2,200 lb) free-fall bomb load. Furthermore, the armoured protection of the Ilyushin Il-2 Sturmovik was copied, to protect the crew from ground fire now that the Ju 87 would be required to conduct low level attacks.[68]
Hans-Ulrich Rudel, a Stuka ace, had suggested using two 37 mm (1.46 in) Flak 18 guns, each one in a self-contained under-wing gun pod, as the Bordkanone BK 3.7, after achieving success against Soviet tanks with the 20 mm MG 151/20 cannon. These gun pods were fitted to a Ju 87 D-1, W.Nr 2552 as "Gustav the tank killer". The first flight of the machine took place on 31 January 1943, piloted by Hauptmann Hans-Karl Stepp.[66] The continuing problems with about two dozens of the Ju 88P-1, and slow development of the Hs 129 B-3, each of them equipped with a large BK 7.5 cm (2.95 in) cannon in a conformal gun pod beneath the fuselage, meant the Ju 87G was put into production. In April 1943, the first production Ju 87 G-1s were delivered to front line units.[66] The two 37 mm (1.46 in) cannons were mounted in under-wing gun pods, each loaded with a six-round magazine of armour-piercing tungsten carbide ammunition. With these weapons, the Kanonenvogel ("cannon-bird"), as it was nicknamed, proved spectacularly successful in the hands of Stuka aces such as Rudel. The G-1 was converted from older D-series airframes, retaining the smaller wing, but without the dive brakes. The G-2 was similar to the G-1 except for use of the extended wing of the D-5. 208 G-2s were built and at least a further 22 more were converted from D-3 airframes.[69]
Only a handful of production Gs were committed in the Battle of Kursk. On the opening day of the offensive, Hans-Ulrich Rudel flew the only "official" Ju 87 G, although a significant number of Ju 87D variants were fitted with the 37 mm (1.46 in) cannon, and operated as unofficial Ju 87 Gs before the battle. In June 1943, the RLM ordered 20 Ju 87Gs as production variants.[70] The G-1 later influenced the design of the A-10 Thunderbolt II, with Hans Rudel's book, Stuka Pilot being required reading for all members of the A-X project.[71]
The Soviet Air Force practice of harassing German ground forces using antiquated Polikarpov Po-2 and R-5 biplanes at night to drop flares and fragmentation bombs, inspired the Luftwaffe to form its own Störkampfstaffeln (harassment squadrons). On 23 July 1942, Junkers offered the Ju 87 B-2, R-2 and R-4s with Flammenvernichter ("flame eliminators"). On 10 November 1943, the RLM GL/C-E2 Division finally authorised the design in directive No. 1117.[72] This new equipment made the Ju 87 more difficult to detect from the ground in darkness.
Pilots were also asked to complete the new "Blind Flying Certificate 3", which was especially introduced for this new type of operation. Pilots were trained at night, over unfamiliar terrain, and forced to rely on their instruments for direction. The Ju 87's standard Revi C12D gunsight was replaced with the new Nachtrevi ("Nightrevi") C12N. On some Ju 87s, the Revi 16D was exchanged for the Nachtrevi 16D. To help the pilot see his instrument panel, a violet light was installed.[73] On 15 November 1942, the Auxiliary Staffel were created. By mid-1943, Luftflotte 1 was given four Staffeln while Luftflotte 4 and Luftwaffe Kommando Ost (Luftwaffe Command East) were given six and two respectively. In the first half of 1943, 12 Nachtschlachtgruppen had been formed, flying a multitude of different types of aircraft, including the Ju 87, which proved itself ideally suited to the low-level slow flying needed.[74]
Despite teething problems with the Ju 87, the RLM ordered 216 Ju 87 A-1s into production and wanted to receive delivery of all machines between January 1936 and 1938. The Junkers production capacity was fully occupied and licensing to other production facilities became necessary. The first 35 Ju 87 A-1s were therefore produced by the Weserflug Aircraft Company Limited (WFG). By 1 September 1939, 360 Ju 87 As and Bs had been built by the Junkers factories at Dessau and Weserflug factory in Bremen. By 30 September 1939, Junkers had received 2,365,196 Reichsmark (RM) for Ju 87 construction orders. The RLM paid another 243,646 RM for development orders. According to audit records in Berlin, by the end of the financial year on 30 September 1941, 3,059,000 RM had been spent on Ju 87 airframes.[75] By 30 June 1940, 697 Ju 87 B-1s and 129 B-2s alone had been produced. Another 105 R-1s and seven R-2s had been built.[75]
The range of the B-2 was not sufficient, and it was dropped in favour of the Ju 87 R long-range versions in the second half of 1940. The 105 R-1s were converted to R-2 status and a further 616 production R-2s were ordered. In May 1941, the development of the D-1 was planned. It was ordered into production by March 1942. However, the expansion of the Junkers Ju 88 production lines to compensate for the withdrawal of Dornier Do 17 production meant this did not take place. The Weserflug plant in Bremen experienced production shortfalls. This prompted Erhard Milch to visit and threaten the company into meeting the RLM's Ju 87 D-1 requirements on 23 February 1942.[76] To meet these demands, 700 skilled workers were needed.[76] Skilled workers had been called up for military service in the Wehrmacht. Junkers were able to supply 300 German workers to the Weserflug factory, and as an interim solution, Soviet prisoners of war and Soviet civilians deported to Germany.[76] Working around the clock, the shortfall was made good. WFG received an official commendation.[76] By May 1942, demand increased further. Chief of Procurement General Walter Herthel found that each unit needed 100 Ju 87s as standard strength and an average of 20 per month to cover attrition. Not until June–December 1942 did production capacity increase, and 80 Ju 87s were produced per month.[76]
By 17 August 1942, production had climbed rapidly after Blohm & Voss BV 138 production was scaled down and licence work had shut down at WFG. Production now reached some 150 Ju 87 D airframes per month, but spare parts were failing to reach the same production levels. Undercarriage parts were particularly in short supply. Milch ordered production to 350 Ju 87s per month in September 1942. This was not achievable due to the insufficient production capacity in the Reich.[76]
The RLM considered setting up production facilities in Slovakia. But this would delay production until the buildings and factories could be furnished with the machine tools. These tools were also in short supply, and the RLM hoped to purchase them from Switzerland and Italy. The Slovaks could provide 3,500–4,000 workers, but no technical personnel.[77] The move would only produce another 25 machines per month at a time when demand was increasing. In October, production plans were dealt another blow when one of WFGs plants burned down, leaving a chronic shortage of tailwheels and undercarriage parts. Junkers director and member of the Luftwaffe industry council Carl Frytag reported that by January 1943 only 120 Ju 87s could be produced at Bremen and 230 at Berlin-Tempelhof.[77]
After evaluating Ju 87 operations on the Eastern Front, Hermann Göring ordered production limited to 200 per month in total. General der Schlachtflieger (General of Close-Support Aviation) Ernst Kupfer decided continued development would "hardly bring any further tactical value". Adolf Galland, a fighter pilot with operational and combat experience in strike aircraft, said that abandoning development would be premature, but 150 machines per month would be sufficient.[77]
On 28 July 1943, strike and bomber production was to be scaled down, and fighter and bomber destroyer production given priority. On 3 August 1943, Milch contradicted this and declared that this increase in fighter production would not affect production of the Ju 87, Ju 188, Ju 288 and Ju 290. This was an important consideration as the life expectancy of a Ju 87 had been reduced (since 1941) from 9.5 months to 5.5 months to just 100 operational flying hours.[78] On 26 October, General der Schlachtflieger Ernst Kupfer reported the Ju 87 could no longer survive in operations and that the Focke-Wulf Fw 190F should take its place. Milch finally agreed and ordered the minimal continuance of Ju 87 D-3 and D-5 production for a smooth transition period.[78] In May 1944, production wound down. 78 Ju 87s were built in May and 69 rebuilt from damaged machines. In the next six months, 438 Ju 87 Ds and Gs were added to the Ju 87 force as new or repaired aircraft. It is unknown whether any Ju 87s were built from parts unofficially after December 1944 and the end of production.[78]
Overall, some 550 Ju 87 As and B2s were completed at the Junkers factory in Dessau. Production of the Ju 87 R and D variants were transferred to the Weserflug company, which was to produce 5,930 of the 6,500 Ju 87s produced in total.[79] During the course of the war, little damage was done to the WFG plant at Bremen. Attacks throughout 1940-45 caused little lasting damage and succeeded only in damaging some Ju 87 airframes, in "contrast" to the Focke-Wulf plant in Bremen.[80] At Berlin-Templehof, little delay and damage was caused to Ju 87 production, despite the heavy bombings and large-scale destruction inflicted on other targets. The WFG again went unscathed. The Junkers factory at Dessau was heavily attacked, but not until Ju 87 production had ceased. The Ju 87 repair facility at the Wels aircraft works was destroyed on 30 May 1944, and the site abandoned Ju 87 links.[81]
Among the many German aircraft designs that participated in the Legion Condor, and as part of other German involvement in the Spanish Civil War, a single Ju 87 A-0 (the V4 prototype) was allocated serial number 29-1 and was assigned to the VJ/88, the experimental Staffel of the Legion's fighter wing. The aircraft was secretly loaded onto the Spanish ship Usaramo and departed Hamburg harbor on the night of 1 August 1936, arriving in Cadiz five days later.
The only known information pertaining to its combat career in Spain is that it was piloted by Unteroffizier Herman Beuer, and took part in the Nationalist offensive against Bilbao in 1937. Presumably the aircraft was then secretly returned to Germany.[82]
In January 1938, three Ju 87 As arrived. Several problems became evident - the spatted undercarriage sank into muddy airfield surfaces, and the spats were temporarily removed. In addition, the maximum 500 kg (1,100 lb) bomb load could only be carried if the gunner vacated his seat, therefore the bomb load was restricted to 250 kg (550 lb). These aircraft supported the Nationalist forces and carried out anti-shipping missions until they returned to Germany in October 1938.[82]
The A-1s were replaced by five Ju 87 B-1s. With the war coming to an end, they found little to do and were used to support Heinkel He 111s attacking Republican positions. As with the Ju 87 A-0, the B-1s were returned discreetly to the Reich.[83]
The experience of the Spanish Civil War proved invaluable - air and ground crews perfected their skills, and equipment was evaluated under combat conditions. Although no Ju 87s had been lost in Spain, however, the Ju 87 had not been tested against numerous and well-coordinated fighter opposition, and this lesson was to be learned later at great cost to the Stuka crews.[84]
All Stuka units were moved to Germany's eastern border in preparation for the invasion of Poland. On the morning of August 15, 1939, during a mass formation dive bombing demonstration for high ranking commanders of the Luftwaffe at Neuhammer training grounds near Sagan, 13 Ju 87s and 26 crew members were lost when they crashed into the ground almost simultaneously. The planes dived through cloud, expecting to release their practice bombs and pull out of the dive once below the cloud ceiling, unaware that on that particular day the ceiling was too low and unexpected ground mist formed, leaving them no time to pull out of the dive.[85]
On 1 September 1939, the Wehrmacht invaded Poland, triggering World War II. Generalquartiermeister der Luftwaffe records indicate a total force of 366 Ju 87 A and Bs were available for operations on 31 August 1939.[23] At exactly 0426, a Kette ("chain" or flight of three) of Ju 87s of 3./StG 1 led by Staffelkapitän Oberleutnant Bruno Dilly carried out the first bombing attack of the war. The aim was to destroy the Polish demolition charges wired to the Tczew bridges over the Vistula River. The Stukas attacked 11 minutes before the official German declaration of hostilities and hit the targets. However, the mission failed and the Poles destroyed the bridge before the Germans could reach it.[41][86]
A Ju 87 achieved the first air victory during World War II on the morning of 1 September 1939, when Rottenführer Leutnant Frank Neubert of I./StG 2 "Immelmann" shot down a Polish PZL P.11c fighter while it was taking off from Balice airfield; its pilot, Captain Mieczysław Medwecki, was killed.[87] The Luftwaffe had a few anti-shipping naval units such as 4.(St)/TrGr 186. This unit performed effectively, sinking the 1540-ton destroyer ORP Wicher and minelayer ORP Gryf of the Polish Navy (both moored in a harbour).[87]
On one occasion, six Polish divisions trapped by encircling German forces were forced to surrender after a relentless four-day bombardment by StG 51, 76 and 77. Employed in this assault were 50 kg (110 lb) fragmentation bombs, which caused appalling casualties to the Polish ground troops. Demoralized, the Poles surrendered. The Stukas also participated in the Battle of Bzura which resulted in the breaking of Polish resistance. The Sturzkampfgeschwader alone dropped 388 tonnes (428 tons) of bombs during this battle.[88]
Once again, enemy air opposition was light, the Stukawaffe (Stuka force) losing just 31 aircraft during the campaign.[89]
Operation Weserübung began on 9 April 1940 with the invasions of Norway and Denmark, Denmark capitulated within the day whilst Norway continued to resist with British and French help.
The campaign was not the classic Blitzkrieg of fast-moving armoured divisions supported by air-power as the mountainous terrain ruled out close Panzer/Stuka cooperation. Instead, the Germans relied on Fallschirmjäger (paratroops), airborne troops transported by Junkers Ju 52s and specialised ski troops. The strategic nature of the operation made the Stuka essential. The Ju 87s were given the role of ground attack and anti-shipping missions. The Stuka was to prove the most effective weapon in the Luftwaffe's armoury carrying out the latter task.[89]
On 9 April, the first Stukas took off at 10:59 from occupied airfields to destroy Oscarsborg Fortress, after the loss of the German cruiser Blücher, which disrupted the amphibious landings in Oslo through Oslofjord. The 22 Ju 87s had helped suppress the Norwegian defenders during the ensuing Battle of Drøbak Sound, but the defenders did not surrender until after Oslo had been captured. As a result, the German naval operation failed.[90] StG 1 caught the 735 ton Norwegian destroyer Æger off Stavanger and hit her in the engine room. Æger was run aground and scuttled.[91] The Stukageschwader were now equipped with the new Ju 87 R, which differed from the Ju 87 B by having increased internal fuel capacity and two 300l underwing drop tanks for more range.[89]
The Stukas, however, had numerous successes against Allied naval vessels. HMS Bittern was sunk on 30 April.[92] The French large destroyer Bison was sunk along with HMS Afridi by Sturzkampfgeschwader 1 on 3 May 1940 during the evacuation from Namsos. Bison's forward magazine was hit, killing 108 of the crew. Afridi, which attempted to rescue Bison's survivors, was sunk with the loss of 63 sailors.[91]
The Stukawaffe had learned some lessons from the Polish and Norwegian campaigns. The failures of Poland and the Stukas of I.StG 1 to silence the Oscarborg fort ensured even more attention was paid to pin-point bombing during the Phoney War period. This was to pay off in the Western campaign.[93] When Fall Gelb began on 10 May 1940, the Stuka helped swiftly neutralise the fortress of Eben Emael. The headquarters of the commander responsible for ordering the destruction of the bridges along the Albert Canal was stationed in the village of Lanaeken (14 km/ mi to the north). However, the Stuka demonstrated its accuracy when the small building was destroyed by four direct hits. As a result, only one of the three bridges was destroyed, allowing the German Army to rapidly advance.[93]
The Sturzkampfgeschwader were also instrumental in achieving the breakthrough at the Battle of Sedan. The Stukawaffe flew 300 sorties against French positions, with StG 77 alone flying 201 individual missions.[94] When resistance was organised, the Ju 87s were vulnerable. For example, on 12 May, near Sedan, six French Curtiss H-75s from Groupe de Chasse I/5 attacked a formation of Ju 87s, shooting down 11 out of 12 unescorted Ju 87s without loss.[95][96]
The Luftwaffe benefited from excellent ground-to-air communications throughout the campaign. Radio equipped forward liaison officers could call upon the Stukas and direct them to attack enemy positions along the axis of advance. In some cases the Stukas responded in 10–20 minutes. Oberstleutnant Hans Seidemann (Richthofen's Chief of Staff) said that "never again was such a smoothly functioning system for discussing and planning joint operations achieved".[97]
During the Battle of Dunkirk, many Allied ships were lost to Ju 87 attacks. The French destroyer Adroit was sunk on 21 May 1940, followed by the paddle steamer Crested Eagle on 28 May. The British destroyer HMS Grenade was sunk on 29 May and several other vessels damaged by Stuka attack. By 29 May, the Allies had lost 31 vessels sunk and 11 damaged.[98] In total, 89 merchantmen (of 126,518 grt) were lost, and the Royal Navy lost 29 of its 40 destroyers (8 sunk, 23 damaged and out of service).[99] Allied air power was ineffective and disorganised, and as a result, Stuka losses were mainly due to ground fire. Some 120 machines, one-third of the Stuka force, were destroyed or damaged by all causes.[100]
For the Battle of Britain, the Luftwaffe's Order of battle consisted of five Geschwader equipped with the Ju 87. Lehrgeschwader 2's IV.(St), Sturzkampfgeschwader 1's III. Gruppe and Sturzkampfgeschwader 2's III. Gruppe, Sturzkampfgeschwader 51 and Sturzkampfgeschwader 3's I. Gruppe were committed to the battle. As an anti-shipping weapon, the Ju 87 proved a potent weapon in the early stages. On 4 July 1940, StG 2 made a successful attack on a convoy in the English Channel, sinking four freighters: Britsum, Dallas City, Deucalion and Kolga. Six more were damaged. That afternoon, 33 Ju 87s delivered the single most deadly air assault on British territory in history, when 33 Ju 87s of III./StG 51, avoiding Royal Air Force (RAF) interception, sank the 5,500 ton anti-aircraft ship HMS Foylebank in Portland Harbour, killing 176 of its 298 crew. One of Foylebank's gunners, Leading Seaman John F. Mantle continued to fire on the Stukas as the ship sank. He was awarded a posthumous Victoria Cross for remaining at his post despite being mortally wounded. Mantle may have been responsible for the single Ju 87 lost during the raid.[101][102]
During August, the Ju 87s also had some success. On 13 August the opening of the main German attacks on airfields took place. It was known to the Luftwaffe as Adlertag (Eagle Day) Messerschmitt Bf 109s of Jagdgeschwader 26 were sent out in advance of the main strike and successfully drew off RAF fighters, allowing 86 Ju 87s of StG 1 to attack RAF Detling unhindered. The attack killed the station commander, destroyed 20 RAF aircraft on the ground and a great many of the airfield's many buildings. However, Detling was not an RAF Fighter Command station.[103]
The Battle of Britain proved for the first time that the Junkers Ju 87 was vulnerable in hostile skies against well-organised and determined fighter opposition. The Ju 87, like other dive bombers, was slow and possessed inadequate defences. Furthermore, it could not be effectively protected by fighters because of its low speed, and the very low altitudes at which it ended its dive bomb attacks. The Stuka depended on air superiority, the very thing being contested over Britain. It was withdrawn from attacks on Britain in August after prohibitive losses, leaving the Luftwaffe without precision ground-attack aircraft.[104]
Steady losses had occurred throughout their participation in the battle. On 18 August, known as the Hardest Day because both sides suffered heavy losses, the Stuka was withdrawn after 16 were destroyed and many others damaged.[105] According to the Generalquartiermeister der Luftwaffe, 59 Stukas had been destroyed and 33 damaged to varying degrees in six weeks of operations. Over 20% of the total Stuka strength had been lost between 8 August and 18 August;[106] and the myth of the Stuka shattered.[106][107] The Ju 87s did succeed in sinking six warships, 14 merchant ships, badly damaging seven airfields and three radar stations, and destroying 49 British aircraft, mainly on the ground.[108]
On 19 August, the units of VIII. Fliegerkorps moved up from their bases around Cherbourg-Octeville and concentrated in the Pas de Calais under Luftflotte 2, closer to the area of the proposed invasion of Britain.[108] On 13 September, the Luftwaffe targeted airfields again, with a small number of Ju 87s crossing the coast at Selsey and heading for Tangmere.[109] After a lull, anti-shipping operations attacks were resumed by some Ju 87 units from 1 November 1940, as part of the new winter tactic of enforcing a blockade. Over the next 10 days, seven merchant ships were sunk or damaged, mainly in the Thames Estuary, for the loss of four Ju 87s. On 14 November, 19 Stukas from III./St.G 1 with escort drawn from JG 26 and JG 51 went out against another convoy; as no targets were found over the estuary, the Stukas proceeded to attack Dover, their alternate target.[108]
Bad weather resulted in a decline of anti-shipping operations, and before long the Ju 87 Gruppen began re-deploying to Poland, as part of the concealed build-up for Operation Barbarossa. By spring 1941, only St.G 1 with 30 Ju 87s remained facing the United Kingdom. Operations on a small scale continued throughout the winter months into March. Targets included ships at sea, the Thames estuary, the Chatham naval dockyard and Dover and night-bomber sorties made over the Channel. These attacks were resumed the following winter.[108][110]
In response to the Italian defeats in Greece and North Africa, the Oberkommando der Wehrmacht ordered the deployment of some German forces to these theatres. Amongst the Luftwaffe contingent deployed was the Geschwaderstab StG 3, which touched down in Sicily in December 1940. In the next few days, two Gruppen - some 80 Stukas - were deployed under X. Fliegerkorps.
The first task of the Korps was to attack British shipping passing between Sicily and Africa. The Ju 87s first made their presence felt by subjecting the British aircraft carrier HMS Illustrious to heavy attack. The crews were confident that they could sink it as the flight deck had an area of about 6,500 square metres.[111] On 10 January 1941, the Stuka crews were told that four direct hits with 500 kg (1,100 lb) bombs would be enough to sink the carrier. The Ju 87s delivered six and three damaging near-misses but the ship's engines were untouched and she made for the besieged harbour of Malta.[112]
The Italian Regia Aeronautica was equipped for a while with the Stukas.[113] In 1939, the Italian government asked the RLM to supply 100 Ju 87s. Italian pilots were sent to Graz in Austria to be trained for dive-bombing aircraft. In the summer of 1940, about 100 Ju 87 B-1s, some of them ex-Luftwaffe machines, were delivered to 96° Gruppo Bombardamento a Tuffo. The Italian Stuka, renamed Picchiatello, was in turn assigned to Gruppi 97°, 101° and 102°. The Picchiatelli were used against Malta, Allied convoys in Mediterranean and in North Africa (where they took part in conquering Tobruk). They were used by the Regia Aeronautica up to 1942.[113] Some of the Picchiatelli saw action in the opening phase of the Italian invasion of Greece in October 1940. Their numbers were low and ineffective. The Italian forces were quickly pushed back. By early 1941, the Greeks had pushed into Italian occupied Albania. Once again, Hitler decided to send military aid to his ally.[114]
In March, the pro-German Yugoslav government was toppled. A furious Hitler ordered the attack to be expanded to include Yugoslavia. Operation Marita commenced on 7 April. The Luftwaffe committed StG 1, 2 and 77 to the campaign.[115] The Stuka once again spearheaded the air assault, with a front line strength of 300 machines, against minimal Yugoslav resistance in the air, allowing the Stukas to develop a fearsome reputation in this region. Operating unmolested, they took a heavy toll of ground forces, suffering only light losses to ground fire. The effectiveness of the dive bombers helped bring about Yugoslav capitulation in just ten days. The Stukas also took a peripheral part in Operation Punishment - Hitler's retribution bombing of Belgrade. The dive bombers were to attack airfields and anti-aircraft gun positions whilst the level bombers struck civilian targets. Belgrade was badly damaged, with 2,271 people reported killed and 12,000 injured.[116]
In Greece, despite British aid, little air opposition was encountered. As the Allies withdrew and resistance collapsed, the Allies began evacuating to Crete. The Stukas inflicted severe damage on Allied shipping. On 22 April, the 1,389 ton destroyers Psara and Ydra were sunk. In the next two days, the Greek naval base at Piraeus lost 23 vessels to Stuka attack.[117]
During the Battle of Crete, the Ju 87s also played a significant role. On 21–22 May 1941, the Germans attempted to send in reinforcements to Crete by sea but lost 10 vessels to "Force D" under the command of Rear-Admiral Glennie. The force, consisting of the cruisers HMS Dido, Orion and Ajax, forced the remaining German ships to retreat. The Stukas were called upon to deal with the British naval threat.[118] On 21 May, the destroyer HMS Juno was sunk and the next day the battleship HMS Warspite was damaged and the cruiser HMS Gloucester was sunk, with the loss of 45 officers and 648 ratings. The Ju 87s also crippled the cruiser HMS Fiji that morning, (she was later finished off by Bf 109 fighter bombers) while sinking the destroyer HMS Greyhound with one hit.[119] As the Battle of Crete drew to a close, the Allies began yet another withdrawal. On 23 May, the Royal Navy lost the destroyers HMS Kashmir and Kelly, followed by HMS Hereward on 26 May; Orion and Dido were also severely damaged.[120] Orion had been evacuating 1,100 soldiers to North Africa; 260 of them were killed and another 280 wounded.[121]
The Sturzkampfgeschwader supported Generalfeldmarschall Erwin Rommel's Deutsches Afrikakorps (DAK) in its two year campaign in North Africa; its other main task was attacking Allied shipping.[122] In 1941, Ju 87 operations in North Africa were dominated by the Siege of Tobruk, which lasted for over seven months.[123] It served during the Battle of Gazala and the First Battle of El Alamein, as well as the decisive Second Battle of El Alamein, which drove Rommel back to Tunisia. As the tide turned and Allied air power grew in the autumn of 1942, the Ju 87 became very vulnerable and losses were heavy. The entry of the Americans into North Africa during Operation Torch made the situation far worse; the Stuka was obsolete in what was now a fighter-bomber's war. The Bf 109 and Fw 190 could at least fight enemy fighters on equal terms after dropping their ordnance but the Stuka could not. The Junkers's vulnerability was demonstrated on 11 November 1942, when 15 Ju 87 Ds were shot down by United States Army Air Forces (USAAF) Curtiss P-40Fs in minutes.[124]
By 1943, the Allies enjoyed air supremacy in North Africa. The Ju 87s ventured out in Rotte strength only, often jettisoning their bombs at the first sight of enemy aircraft.[125] Adding to this trouble, the German fighters had only enough fuel to cover the Ju 87s on take off, their most vulnerable point. After that, the Stukas were on their own.[126]
The dive bombers continued operations in southern Europe; after the Italian surrender in September 1943, the Ju 87 participated in the last campaign-sized victory over the Western Allies, the Dodecanese Campaign. The Greek Dodecanese Islands had been occupied by the British; the Luftwaffe committed 75 Stukas of StG 3 based in Megara and Rhodos, to recover the islands. With the RAF bases some 500 kilometres (310 mi) away, the Ju 87 helped the German landing forces rapidly conquer the islands.[127]
On 22 June 1941, the Wehrmacht commenced Operation Barbarossa, the invasion of the Soviet Union. The Luftwaffe order of battle of 22 June 1941 contained four Sturzkampfgeschwader. VIII. Fliegerkorps under the command of General der Flieger Wolfram von Richthofen was equipped with units Stab, II. and III./StG 1. Also included were Stab, I., II. and III. of Sturzkampfgeschwader 2 Immelmann. Attached to II. Fliegerkorps, under the command of General der Flieger Bruno Loerzer, were Stab, I., II. and III. of StG 77. Luftflotte 5, under the command of Generaloberst Hans-Jürgen Stumpff, operating from Norway's Arctic Circle, were allotted IV. Gruppe (St)/Lehrgeschwader 1 (LG 1).[128]
The first Stuka loss on the Soviet-German front occurred early at 03:40–03:47 in the morning of the 22 June. While being escorted by Bf 109s from JG 51 to attack Brest Fortress, Oberleutnant Karl Führing of StG 77 was shot down by a I-153.[129] The Sturzkampfgeschwader suffered only two losses on the opening day of Barbarossa. As a result of the Luftwaffe's attention, the Soviet Air Force in the western Soviet Union was nearly destroyed. The official report claimed 1,489 Soviet aircraft destroyed. Göring ordered this checked. After picking their way through the wreckage across the front, Luftwaffe officers found that the tally exceeded 2,000.[130] In the next two days, the Soviets reported the loss of another 1,922 aircraft.[131] Soviet aerial resistance continued but ceased to be effective and the Luftwaffe maintained air superiority until the end of the year.
The Ju 87 took a huge toll on Soviet ground forces, helping to break up counterattacks of Soviet armour, eliminating strongpoints and disrupting the enemy supply lines. A demonstration of the Stuka's effectiveness occurred on 5 July, when StG 77 knocked out 18 trains and 500 vehicles.[132] As the 1st and 2nd Panzer Groups forced bridgeheads across the Dnieper river and closed in on Kiev, the Ju 87s again rendered invaluable support. On 13 September, Stukas from StG 1 destroyed the rail network in the vicinity as well as inflicting heavy casualties on escaping Red Army columns, for the loss of just one Ju 87.[133] On 23 September, Hans-Ulrich Rudel (who was to become the most decorated serviceman in the Wehrmacht) of StG 2, sank the Soviet battleship Marat, during an air attack on Kronstadt harbor near Leningrad, with a hit to the bow with a single 1,000 kg (2,200 lb) bomb.[134]
Also during this action, Leutnant Egbert Jaeckel sank the destroyer Minsk, while the destroyer Steregushchiy and submarine M-74 were also sunk. The Stukas also crippled the battleship Oktyabrskaya Revolutsiya and the destroyers Silnyy and Grozyashchiy in exchange for two Ju 87s shot down.[135]
Elsewhere on the Eastern front, the Junkers assisted Army Group Centre in its drive toward Moscow. From 13–22 December, 420 vehicles and 23 tanks were destroyed by StG 77, greatly improving the morale of the German infantry, who were by now on the defensive.[136] StG 77 finished the campaign as the most effective Sturzkampfgeschwader. It had destroyed 2,401 vehicles, 234 tanks, 92 artillery batteries and 21 trains for the loss of 25 Ju 87s to hostile action.[137]
At the end of Barbarossa, StG 1 had lost 60 Stukas in aerial combat and one on the ground. StG 2 lost 39 Ju 87s in the air and two on the ground, StG 77 lost 29 of their dive-bombers in the air and three on the ground (25 to enemy action). IV.(St)/LG1, operating from Norway, lost 24 Ju 87s, all in aerial combat.[138]
In early 1942, the Ju 87s were to give the Germany Army (Heer) yet more valuable support. On 29 December 1941, the Soviet 44th Army landed on the Kerch Peninsula. The Luftwaffe was only able to dispatch meager reinforcements of four Kampfgruppen (bomber group. Note: not Kampfgeschwader, meaning bomber wing) and two Sturzkampfgruppen, (dive bomber groups) belonging to StG 77. With air superiority, the Ju 87s operated with impunity. In the first 10 days of the Battle of the Kerch Peninsula, half the landing force was destroyed, while sea lanes were blocked by the Stukas inflicting heavy losses on Soviet shipping. The Ju 87's effectiveness against Soviet armour was not yet potent. Later versions of the T-34 tank could withstand Stuka attack in general, unless a direct hit was scored but the Soviet 44th Army had only obsolescent types with thin armour which were nearly all destroyed.[139]
During the Battle of Sevastopol, the Stukas repeatedly bombed the trapped Soviet forces. Some Ju 87 pilots flew up to 300 sorties against the Soviet defenders. Luftflotte 4's StG 77 flew 7,708 combat sorties dropping 3,537 tonnes of bombs on the city. Their efforts help secure the capitulation of Soviet forces on 4 July.[140]
For the German summer offensive, Fall Blau, the Luftwaffe had concentrated 1,800 aircraft into Luftflotte 4 making it the largest and most powerful air command in the world.[141] The Stukawaffe strength stood at 151.[142] During the Battle of Stalingrad, Stukas flew thousands of sorties against Soviet positions in the city. StG 1, 2 and 77 flew 320 sorties on 14 October 1942. As the German Sixth Army pushed the Soviets into a 1,000 metre enclave on the west bank of the Volga River, 1,208 Stuka sorties were flown against this small strip of land. The intense air attack, though causing horrific losses on Soviet units, failed to destroy them.[143] The Luftwaffe's Sturzkampfgeschwader made a maximum effort during this phase of the war. They flew an average of 500 sorties per day and caused heavy losses among Soviet forces, losing an average of only one Stuka per day.[144]
The Battle of Stalingrad marked the high point in the fortunes of the Junkers Ju 87 Stuka. As the strength of the Soviet Air Forces grew, they gradually wrested control of the skies from the Luftwaffe. From this point onward, Stuka losses increased.
The Stuka was also heavily involved in Operation Citadel, the Battle of Kursk. The Luftwaffe committed I, II, III./St.G 1 and III./StG 3 under the command of Luftflotte 6. I., II, III. of StGs 2 and 3 were committed under the command of Hans Seidemann's Fliegerkorps VIII.[145] Hauptmann Rudel's cannon-equipped Ju 87 Gs had a devastating effect on Soviet armour at Orel and Belgorod. The Ju 87s participated in a huge aerial counter-offensive lasting from 16–31 July against a Soviet offensive at Khotynets and saved two German armies from encirclement, reducing the attacking Soviet 11th Guards Army to just 33 tanks by 20 July. The Soviet offensive had been completely halted from the air.[146]
Losses were considerable, however. Fliegerkorps VIII lost eight Ju 87s on 8 July, six on 9 July, six on 10 July and another eight on 11 July. The Stuka arm also lost eight of their Knight's Cross of the Iron Cross holders. StG 77 lost 24 Ju 87s in the period 5–31 July (StG had lost 23 in July–December 1942), while StG 2 lost another 30 aircraft in the same period. In September 1943, three of the Stuka units were re-equipped with the Fw 190F and G (ground attack versions) and began to be re-named as Schlachtgeschwader (attack wings).[147] In the face of overwhelming air opposition, the dive-bomber required heavy protection from German fighters to counter Soviet fighters. Some units like SG 2 Immelmann continued to operate with great success throughout 1943-45, operating the Ju 87 G variants equipped with 37 mm cannons, which became tank killers, although in increasingly small numbers.[148]
In the wake of the defeat at Kursk, Ju 87s played a vital defensive role on the southern wing of the Eastern Front. To combat the Luftwaffe, the Soviets could deploy some 3,000 fighter aircraft. As a result, the Stukas suffered heavily. SG 77 lost 30 Ju 87s in August 1943 as did SG 2 Immelmann, which also reported the loss of 30 aircraft in combat operations.[149] Despite these losses, Ju 87s helped the XXIX Army Corps break out of an encirclement near the Sea of Azov.[150] The Battle of Kiev also included substantial use of the Ju 87 units, although again, unsuccessful in stemming the advances. Stuka units were with the loss of air superiority, becoming vulnerable on the ground as well. Some Stuka aces were lost this way.[151] In the aftermath of Kursk, Stuka strength fell to 184 aircraft in total. This was well below 50 percent of the required strength.[152] On 18 October 1943, StG 1, 2, 3, 5 and 77 were renamed Schlachtgeschwader (abbreviated as "SG") wings, reflecting their ground-attack role, as these combat wings were now also using ground-attack aircraft, such as the Fw 190F-series aircraft. The Luftwaffe's dive-bomber units had ceased to exist.[153]
Towards the end of the war, as the Allies gained air supremacy, the Stuka was being replaced by ground-attack versions of the Fw 190.[30] By early 1944, the number of Ju 87 units and operational aircraft terminally declined. For the Soviet summer offensive, Operation Bagration, 12 Ju 87 Gruppen and five mixed Gruppen (including Fw 190s) were on the Luftwaffe's order of battle on 26 June 1944.[154]Gefechtsverband Kuhlmey, a mixed aircraft unit, which included large numbers of Stuka dive bombers, was rushed to the Finnish front in the summer of 1944 and was instrumental in halting the Soviet fourth strategic offensive. The unit claimed 200 Soviet tanks and 150 Soviet aircraft destroyed for 41 losses.[155] By this juncture, the Luftwaffe continued to resist Soviet air attacks but it had little impact on the ground war.
By 31 January 1945, only 104 Ju 87s remained operational with their units. The other mixed Schlacht units contained a further 70 Ju 87s and Fw 190s between them. Chronic fuel shortages kept the Stukas grounded and sorties decreased until the end of the war in May 1945.[156]
Two intact Ju 87s survive:
Other aircraft survive as wreckage, recovered from crash sites.
Data from Ju 87 B-2 Betriebsanleitung, Juni 1940 (D.(Luft) T.2335/1)
General characteristics
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