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.
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.
The A-1 differed from the A-0 only slightly. 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. 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. 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).
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. 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.
Ju 87 V1: W. Nr 4921. Flown on 17 September 1935
- Ju 87 V2: W.Nr 4922, registration D-IDQR. Flown on 25 February 1936. Flown again as registration D-UHUH on 4 June 1937
- Ju 87 V3: W.Nr 4923. Flown on 27 March 1936
- Ju 87 V4: W.Nr 4924. Flown on 20 June 1936
- Ju 87 V5: W.Nr 4925. Flown on 14 August 1936
- Ju 87 A-0: Ten pre-production aircraft, powered by a 640 PS (471 kW, 631 hp) Jumo 210C engine
- Ju 87 A-1: Initial production version.
- Ju 87 A-2: Production version fitted with an improved 680 PS (500 kW, 671 hp) Jumo 210E engine.
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. 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. The B-1 was also fitted with “Jericho trumpets”, essentially propeller-driven sirens with a diameter of 0.7 m (2.3 ft) 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.
The trumpets were a suggestion from Generaloberst Ernst Udet (but some authors say the idea originated from Adolf Hitler). 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), 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.
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. 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.
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). 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.
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. 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). 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 towrope. The R-4 differed from the R-2 in the Jumo 211J powerplant.
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.
- Ju 87 V6: W.Nr 0870027. Flown on 14 June 1937 (A-0 to B-0 conversion)
- Ju 87 V7: W.Nr 0870028. Prototype of the Ju 87B, powered by a 1,000 PS (735 kW
986 hp) Jumo 211A. Flown on 23 August 1937 (A-0 to B-0 conversion)
- Ju 87 V8: W.Nr 4926. Flown on 11 November 1937
- Ju 87 V9: W.Nr 4927. Flown on 16 February 1938 as D-IELZ. Flown again as WL
IELZ on 16 October 1939
- Ju 87 V15: W.Nr 0870321. Registration D-IGDK. Destroyed in a crash in 1942.
- Ju 87 V16: W.Nr 0870279. Stammkennzeichen code of GT+AX.
- Ju 87 V17 and Ju 87 V18 may never have been built.
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. 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. Owing to delays, the V10 was not completed until March 1938. It first flew on 17 March and was designated Ju 87 C-1. 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). 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.
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. 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.
- Ju 87 V10: Registration D-IHFH (changed to Stammkennzeichen of TK+HD). W
- First flown 17 March 1938
- Ju 87 V11: Stammkennzeichen of TV+OV. W.Nr 4929. First flown 12 May 1938