Aviation of World War II
When creating this aircraft, the Junkers designers initially provided for the possibility of using it as a 10-seat passenger aircraft or a medium bomber. In accordance with this, the export passenger version had the designation Ju 86Z (Zivil - civilian), and the bomber Ju 86K (Krieg - military). The aircraft made its first flight in the bomber version. This happened on November 4, 1934. In 1935, the aircraft was adopted by the Luftwaffe, in February 1936, the first thirty pre-serpentine Ju 86A-0 bombers entered the combat squadron 153 "Gindenburg", which was soon completed by the production Ju 86A-T.
The Ju 86 bomber was an all-metal twin-engine bomber with a retractable landing gear in flight and a spaced tail.
The fuselage of the oval cross-section had a semi-monocoque design. Both the elements of the fuselage set and the skin were made of duralumin, the wing and tail unit were made of the same metal. In front of the fuselage in the glazed cockpit was the place of the navigator-scorer, then there was also a closed cockpit, and behind it - the bomb bay, the cockpit of the gunner-radio operator half-closed with a visor and the retractable turret of the lower gunner. The bomb bay was equipped with two cassettes, in which bombs of up to 50 kg caliber were suspended in a vertical position with the tail plumage down. One of these cassettes was in front of the center section spar, and the other was between the first and second spars. The bomb bay was closed with folding hatches.
The wing of the Ju 86 consisted of a center section and two removable parts. Engine nacelles were attached along the edges of the center section, in the lower part of the center section there were niches for retracting the landing gear. The wing structure is multi-spar. its skin was made of smooth sheets of duralumin. The wing is equipped with sectional flaps of the Junkers type, suspended ailerons with weight compensation were strengthened along its trailing edge.
For the aircraft, a two-keel spaced tail was chosen, which provides better conditions for firing in the rear hemisphere than that of a single-fin tail. The rudders are equipped with trimmers, the stabilizer was supported by two V-shaped struts.
The undercarriage retractable in flight had an unusual layout for a twin-engine aircraft - its struts retracted into the wing outward from the fuselage. Retracting the chassis was carried out using an electric drive. Shields were fixed on the chassis stacks and wheels equipped with low-pressure pneumatics, which, in the retracted position of the chassis, covered the cutouts in the lower surface of the center section. The rear wheel did not retract in flight. Initially, the aircraft was equipped with 600 hp Jumo 205 diesel engines. from. as a result, he is rightfully considered the first German bomber with a diesel power plant. The advantage of these engines was high efficiency and fire safety, however, due to the large weight and, as a combat test in Spain showed, insufficient power, the diesels had to be replaced by an 845-horsepower radial piston air-cooled BMW 152 engine (Hornet engines from Pratt-Whitney, produced in Germany under license). In 1939, when it was necessary to ensure the maximum flight range of the newly created reconnaissance modification Ju 86P, diesels were again installed on the aircraft, however, an improved high-altitude model Jumo 20 "A with a power of 680 hp. With these engines, the maximum flight altitude was 12,100 m. and at an altitude of 10,000 m, the aircraft could fly for 2.5 hours, while the Ju 86P was beyond the reach of all fighters of that time.
The engines were equipped with three-bladed metal propellers with variable pitch in flight of the Hamilton or Junkers type. Engine installations were covered with NACA hoods with adjustable air outlet slots. Coolant radiators were located under the engines.
Only defensive armament was installed on the aircraft - three 7.92-mm machine guns MG 15. One machine gun was installed in the machine gun turret in the cockpit of the navigator-scorer, the other machine gun was mounted on a pivot mount in the cockpit of the gunner-radio operator. To protect against attacks from below, a machine gun was used, mounted in the lower retractable turret. In a non-combat position, the turret was semi-recessed in the fuselage and did not have an adverse effect on the aerodynamics of the aircraft; if necessary, the turret moved down along with the gunner. However, at the same time, the aerodynamic drag of the aircraft sharply increased, its speed dropped and, accordingly, the chances of surviving in battle decreased.
If the export models of the Ju.86 had a good success, then things were not going well in the service of the Luftwaffe. Despite the great advertising created by German propaganda for him, Junkers was never able to solve the problems with Jumo-205C diesel engines. As a result, the combat readiness of the Ju.86D in units was low. Piston seizure and exhaust pipe welding corrosion were two of these problems.
The Ju.86-V9, converted from the Ju.86D-1 to the BMW-132F, was tested in the spring of 1937 and proved much more reliable than the diesel version. Junkers was asked to switch production to the Ju.86 from the BMW-132F.
With these engines, the bomber received the designation Ju.86E-1. Deliveries began in the late summer of 1937. The BMW-132F developed 810 hp on takeoff. and 650 hp at an altitude of 4500 m. Its installation made it possible to increase the fuel supply to 1500 liters. The reliability of the machine has increased - this was the main goal of modernization, and the characteristics remained almost unchanged. However, the aircraft was intended only for loading assembly lines before preparing equipment for the production of He.111. The Ju.86E-1 was assembled in parallel with the export versions of the Ju-86K bomber: the "Hungarian" Ju.86K-2, the Swedish Ju.86K-4 and K-6 for Portugal and Chile. A total of 30 Ju.86E-1s were produced with BMW-132F engines and a little more with BMW-132Ns with a takeoff power of 865 hp. and 665 hp at an altitude of 4500 m. The last model was called Ju.86E-2. They were also ordered by Austria.
The following modifications of the aircraft were developed: civil transport and Ju-86Z, training bomber Ju-86G.
Ju.86G series. One of the drawbacks of the Ju.86 was the pilot's poor visibility during takeoff until the tail was off the ground. To solve the problem, the cockpit was moved forward and the entire bow was fully glazed. The MG-15 machine gun was installed in the right front panel. The new nose was tested on the E-1 in early 1938. The aircraft was designated Ju.86-V10. According to its model, 40 last production aircraft were modernized, which, in addition to the new nose and equipment for blind flights, were identical to the Ju.86E-2. Under the designation Ju.86G-1, this aircraft left the assembly line in Dessau in late spring - early summer 1938, after which the production of this type was discontinued. A total of 390 aircraft were delivered (including transport aircraft and those assembled in Sweden, but without license production).
In the late autumn of 1938, the number of Ju.86s in the Luftwaffe reached its peak. On September 19, 1938, the Air Force headquarters included 235 bombers of all modifications in the bomber squadron, of which 200 were combat-ready. Of these, 159 were Ju.86A-Ds, 43 Ju.86Es and 33 Ju.86Gs. From that moment on, Ju.86 began to be withdrawn from the units of the first line. This process accelerated in early 1939. When the fighting began in September, only one group still had these bombers in IV/KG.1, 30 Ju.86G-1s. Soon after the Polish company, they were dismissed.
Diesel-powered aircraft were quickly withdrawn from service, and most of the VMW-132 engines were handed over to bomber flight schools and other training units. At the end of 1942, Ju.86s were sent to transport groups K.Gr.z.b.V.21 and 22, hastily formed to supply the Stalingrad pocket. From December they entered into action with 58 aircraft. Acting from Tatsinskaya, they proved to be completely unsuitable. Both groups lost 42 aircraft by the end of January. The groups themselves were disbanded in March, and the 16 remaining Ju.86s were returned to training units, but in 1943-44 several Ju.86s from flight schools were used against partisans in the Balkans.