Heinkel HD 34

Heinkel HD 34
Type:	Bomb and reconnaissance aircraft
Design country:	German Empire
Manufacturer:	Heinkel
First flight:	1928
Commissioning:	-
Production time:	1927/1928
Number of pieces:	1

The Heinkel HD 34 was a German bomb and reconnaissance aircraft produced by Ernst Heinkel Flugzeugwerke in Warnemünde in the second half of the 1920s. The abbreviation HD stands for Heinkel Doppeldecker .

history

As part of the first secret air armaments program initiated by the Reichswehr in 1927, Captain Kurt Student , who was employed at the WaPrüf 6 F department of the Army Armed Forces Office , approached Heinkel in August of that year and placed the order for the development of a twin-engine bomber and long-range reconnaissance aircraft. For reasons of concealment, the Reich Ministry of Transport acted as the client for the design, which was officially designated as a “land multi-purpose aircraft”. Heinkel completed a full-size dummy in 1927 , which was used to study the room layout and the accommodation of equipment and instruments . In 1928 a model aircraft with the serial number 287 was manufactured. Construction was completed in the first half of the year and the model designated as the HD 34 completed its maiden flight in early summer. Longer tests could not be carried out with the aircraft, however, because on June 25, 1928 Heinkel's chief pilot Stephan von Prondzynski had to make an emergency landing of the HD 34 west of the Breitling near the Arado aircraft factory after an engine failure , even before registration and the assignment of a license plate. it was irreparably damaged; the pilot suffered only minor injuries. The program was discontinued after this incident.

construction

The HD 34 was a braced and single-leg braced double-decker in a composite construction . The fuselage consisted of a welded tubular steel frame crossed with wire with a rectangular cross-section, arched back of the fuselage and ending in a vertical cutting edge. The pilot and observer sat one behind the other in two separate, open cabins. A series image device consisting of three cameras and an FT device with a retractable towed antenna were housed in the observer's stand. As armament, the pilot was supposed to use two permanently installed machine guns with drum magazines placed on the back of the fuselage in front of him; a rotating ring mount with a movable twin machine-gun was provided for the observer .

The wings consisted of two wooden box spars , ribs and straps made of spruce and webs made of plywood . The front edges were covered with plywood, the rest of the frame was covered with fabric. The upper wing had a greater span and depth than the lower. Both were connected by N-struts in one plane and had ailerons , with only the lower ones being controlled directly by the pilot, who transmitted the movement to the upper ailerons through bumpers.

The tail unit was of normal construction and comprised fins and rudders made of fabric-covered tubular steel frames. The horizontal stabilizer was braced towards the fuselage. Both side and elevators were aerodynamically balanced. The HD 34 was equipped with a rigid chassis with main wheels on a two-part axle and front struts with compression rubber. There was a rubber-sprung abrasive spur at the stern .

Technical specifications

Parameter	Data
crew	2
span	18.0 m
length	11.73 m
height	4.84 m
Wing area	85.4 m²
Preparation mass	3000 m
Payload	1500 kg
Takeoff mass	4500 kg
drive	two water-cooled twelve-cylinder - four cycle - V-engines , each with a rigid wooden propeller (diameter 3.25 m, 2.3 m) ${\displaystyle m}$
Type	BMW VI 7.3Z
Starting power nominal power continuous power	750 PS (552 kW) at 1650 rpm 650 PS (478 kW) at 1575 rpm 500 PS (368 kW) at 1530 rpm at an altitude of 700 m
Top speed	266 km / h
Rate of climb	9.3 m / s
Landing speed	86 km / h
Rise time	1.48 min at 1000 m altitude
Service ceiling	7600 m
Armament (projected)	two fixed machine-guns, each 1000 rounds a movable twin machine-gun, each 1000 rounds
Drop ammunition (projected)	40 12 kg bombs

literature

• Volker Koos: Ernst Heinkel Flugzeugwerke 1922–1932. Heel, Königswinter 2006, ISBN 3-89880-502-6 , pp. 84/85.
• Volker Koos: Aviation between the Baltic Sea and Breitling. Warnemünde sea and land airfield 1914–1945. Transpress, Berlin 1990, ISBN 3-344-00480-8 , pp. 96 and 127.
• Helmut Stützer: The German military aircraft 1919–1934. E. S. Mittler & Sohn, Herford 1984, ISBN 3-8132-0184-8 , pp. 63, 142/143 and 197.