Heinkel HD 35

Heinkel HD 35
Sk 5 in the Swedish Flygvapenmuseum
Type:	Trainer aircraft
Design country:	German Empire
Manufacturer:	Heinkel
First flight:	1925
Commissioning:	1926
Production time:	1925, 1928
Number of pieces:	2

Heinkel HD 35, 1926

The Heinkel HD 35 was a German beginner's training aircraft from the Ernst Heinkel Flugzeugwerke . The abbreviation HD stands for "Heinkel Doppeldecker".

development

The prototype of the HD 35 with the serial number 235 was built in 1925 in the Warnemünder Heinkel works as the successor to the HD 29 training aircraft . The Allied Aviation Guarantee Committee responsible for enforcing the benchmarks set in the Paris Agreement of 1922 for aircraft built in Germany then checked the draft and on September 29th confirmed the civilian orientation of the construction. On December 16, 1925, the model was presented to the public together with other Heinkel constructions at Berlin-Tempelhof Airport in the presence of press and domestic and foreign representatives on the ground and, despite bad weather conditions, also in the air, with pilots also present from the Availed themselves of the opportunity to fly the models presented, and thus the HD 35, for test purposes. The Swedish military showed interest and purchased the aircraft in April 1926. A month later it arrived in Sweden and was used as Sk 5 (Sk for Skolflygplan, training aircraft) with fuselage number 66 . From July 1927 it flew with the number 020 before it was removed from the Swedish Air Force on June 14, 1929 . From 1930 it was in the hands of various private owners, most recently with the civil license plate SE – SAM , which was issued on May 5, 1931. The flying career of the Sk 5 ended in October 1940 with the final deletion from the aviation register. The further whereabouts of the pattern remained in the dark for almost two decades until it reappeared in a private museum near Falkenberg in the 1960s . From 1989 it underwent an extensive restoration and can be viewed in the Swedish Air Force Museum ever since .

Only one more copy of the HD 35 was made with the serial number 236, which received the registration D-1319 in December 1928 and was owned by Akaflieg Hannover .

construction

The HD 35 is a einstieliger, braced biplane in wood construction .

Fuselage: The fuselage consists of four longitudinal spars clad with plywood, which form a square cross-section with a curvature on the top and end in a vertical stern cutting edge. The aircraft is equipped with a total of three cabins, but the front crew compartment behind the firewall can be covered and used as a luggage compartment, as is the case with the example on display in the Swedish Air Force Museum (see photo in the info box).

Structure : The wings consist of a wooden frame with two box spars and internal bracing. They form a slight V-position, which is 2 ° for the upper wing and 3 ° for the lower wing. The underside is planked with plywood between the individual stiles, the remaining part has a fabric covering. The wing nose is also made of plywood. The wings are connected to one another with N-struts and braced, with the upper wing being staggered forward . The canopy is formed by two inverted V-shaped struts. Both surfaces are equipped with ailerons connected by I-bars.

Tail unit: The tail unit has a normal construction, the vertical fin is made of a wooden frame and the horizontal fin is made of a tubular steel frame. Both are covered with fabric. The elevator is balanced and adjustable during flight.

Landing gear: The HD 35 has a rigid main landing gear with a continuous axle and rubber rope suspension . There is a grinding spur at the rear .

Technical specifications

HD 35, picture from 1926

Parameter	Data
crew	2-3
span	above 11.0 m below 9.84 m
length	7.5 m
height	3.1 m
Wing area	32.4 m²
Preparation mass	760 kg
Payload	300 kg
Takeoff mass	1060 kg
drive	a liquid-cooled six - cylinder in - line engine
Type	Mercedes D II
Starting power nominal power continuous power	129 PS (95 kW) 120 PS (88 kW) on the ground 105 PS (77 kW) on the ground
Fuel volume	160 l
Top speed	138 km / h near the ground
Cruising speed	120 km / h
Landing speed	71 km / h
Rise time	9.2 min at 1000 m altitude 22.6 min at 2000 m altitude
Range	250 km
Service ceiling	3300 m

literature

• Volker Koos: Ernst Heinkel Flugzeugwerke 1922–1932 . Heel, Königswinter 2006, ISBN 3-89880-502-6 , p. 86/87 .
• 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. 64 ff .

Web links

Commons : Heinkel HD 35  - collection of pictures, videos and audio files

Individual evidence

1. ^ Helmut Stützer: The German military aircraft 1919–1934 . E. S. Mittler & Sohn, Herford 1984, ISBN 3-8132-0184-8 , p. 187 .