Heinkel HD 43

Heinkel HD 43
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Type:	Fighter plane
Design country:	German Empire
Manufacturer:	Heinkel
First flight:	1929
Commissioning:	-
Production time:	1929/1930
Number of pieces:	4th

The Heinkel HD 43 is a fighter aircraft produced by Ernst Heinkel Flugzeugwerke in Warnemünde at the end of the 1920s .

development

The HD 43 was designed as a further development of the HD 37 from 1928. The HD 37 was commissioned by the Soviet air forces and was to become their future standard fighter. A license production was already in the planning phase when an incident occurred during testing in the USSR. During a test flight on July 20, 1928, the pilot W. O. Pissarenko got into a tailspin with the first of the two delivered prototypes , could no longer control the aircraft and had to jump off with a parachute. Although the tests were successfully completed by a pilot from Heinkel-Werke with the remaining HD 37, the final report criticized the fact that in some cases the aircraft was difficult to get out of the tailspin. As a result, a Soviet delegation headed by Jakow Alksnis traveled to Warnemünde in January 1929 and commissioned some modernizations that were supposed to improve the flight characteristics. In response, the HD 37 was revised; the changes concerned the wing profile, the area ratio of upper to lower wing and the construction of the landing gear and tail unit. Two specimens named HD 43a with the serial numbers 326 and 327 were built, which were tested in the same year by the Swedish military pilot Nils Söderberg, who had already test flown the HD 37 and was specially hired by Ernst Heinkel . The exact date of the first flight is not known, but the HD 43 was publicly demonstrated on August 3, 1929 by Walter Hagen, a pilot from the Travemünder Verprobungsstelle See , at the Warnemünder Flugtag with an aerobatic program.

The two planes were subsequently dispatched and arrived in the Soviet Union at the end of the year. The flight tests at the Research Institute of the Air Force (NII WWS) in Moscow began in January 1930 and was again carried out by W. O. Pissarenko. After it ended in the following month, the evaluation surprisingly showed that the flight characteristics had deteriorated compared to the HD 37 due to the modernization. The High Command of the Soviet Air Force therefore made the decision to reject the HD 43 and, as initially planned, to release the original model for series production instead.

Meanwhile, Heinkel produced two more aircraft designated as HD 43b with the serial numbers 344 and 345 in 1930. They were sold to Siam at a unit price of 80,000 Reichsmarks and were used as Bin Khap Lai Type 8 and later as Type 15 in its air force from 1931 .

construction

The HD 43 is a braced, single-handle double - decker in a composite construction .

hull

In contrast to the HD 37, the fuselage is slimmer and has a smaller, but also rectangular cross-section with a curved top. It consists of a tubular steel frame formed by four longitudinal spars and welded-in frames and ends in a vertical cutting edge. Struts, which are inserted diagonally in the front part, are made of tubular steel, while the rest of the fuselage is made of steel wire. From the bow to the pilot's cabin, the cladding consists of aluminum, behind it of fabric and partly of plywood. Behind the engine mount is a sheet steel fire bulkhead, behind which is the main tank with a capacity of 260 l between the engine and the pilot's cabin. The “camel hump” hull of the HD 37, which rises towards the cockpit, was kept flatter in the HD 43, as was the upper side of the fuselage that sloped behind the cockpit.

Structure

The wings of different spans are strongly staggered, slightly V-shaped, connected by N-struts and braced with profile wire. They are rectangular in shape with the same depth and curved edges at the end. The frame is formed by two wooden box spars with straps made of pine and bars made of plywood. Plywood is also used for the planking of the underside of the wing between the spars. The rest of the cladding is made of fabric. The upper wing, in which there are two additional drop tanks with 65 l each, is connected to the fuselage by a canopy , the lower wing has connections on the lower fuselage chord.

Tail unit

The tail unit and all the rudders are made from a fabric-covered tubular steel frame. The vertical fin is free-standing, the horizontal fin is braced towards the fuselage with I-handles and adjustable in flight. Ailerons are located in both the upper and lower wings.

landing gear

The main wheel landing gear is not retractable and is attached to the fuselage by V-struts. It has split axles with oil-dampened pressure rubber suspension in the front struts. There is a spring-loaded grinding spur at the rear .

Technical specifications

Parameter	Data
crew	1
span	above 10.0 m below 8.0 m
length	7.1 m
height	3.35 m
Wing area	26.56 m²
Preparation mass	1220 kg
Payload	420 kg
Takeoff mass	1640 kg
drive	a liquid-cooled twelve-cylinder four-stroke V-engine with a rigid two-bladed wooden propeller
Type	BMW VI 7.3Z
Take-off power Combat and climb power Rated power Continuous power	750 PS (552 kW) 750 PS (552 kW) on the ground / in 1000 m 650 PS (478 kW) on the ground / in 1000 m 500 PS (368 kW) in 700 m
Top speed	322 km / h near the ground
Marching speed	290 km / h
Landing speed	95 km / h
Rise time	1.12 min at 1000 m 4.54 min at 3000 m 9.24 min at 5000 m 12.0 min at 6000 m
Service ceiling	8400 m
Armament	two rigid, synchronized machine guns

literature

• Volker Koos: Ernst Heinkel Flugzeugwerke 1922–1932 . Heel, Königswinter 2006, ISBN 3-89880-502-6 , p. 103/104 .
• Dimitri Alexejewitsch Sobolew: German traces in Soviet aviation history . Mittler, Herford 2000, ISBN 3-8132-0675-0 , p. 60 ff .
• Helmut Stützer: The German Aircraft 1919–1934 . Mittler, Herford 1984, ISBN 3-8132-0184-8 , pp. 78, 144 and 209 .

Individual evidence

1. ^ Lennart Andersson: German-Swedish secret projects between 1921 and 1935 . In: Flieger Revue Extra . No. 18 , 2007, p. 17/18 .
2. ↑ Volker Koos: Aviation between the Baltic Sea and Breitling . Transpress, Berlin 1990, ISBN 3-344-00480-8 , pp. 121 .