Heinkel HD 29

Heinkel HD 29
Type:	Trainer aircraft
Design country:	German Empire
Manufacturer:	Heinkel
First flight:	1925
Production time:	1925
Number of pieces:	1

The Heinkel HD 29 was a German trainer aircraft produced by the Ernst Heinkel Flugzeugwerke . The abbreviation HD stands for "Heinkel Doppeldecker".

development

The HD 29 was created in 1925 as a further development of the HD 21 training aircraft . Practically identical in structure, it was only visually distinguishable from the fuselage by the modified strut bracket that connected the upper wing to the fuselage. The Allied Aviation Guarantee Committee , which was responsible for compliance with the restrictions imposed on aircraft construction in Germany after the First World War, confirmed the civilian design of the aircraft on May 28, 1925. In the same year, a sample copy with the work number 227 was built at the Heinkel plant in Warnemünde. It received the civil registration D-689 and took part in the German round flight of 1925 together with six HD 21s , whereby the HD 29 was also reported as HD 21 due to the small differences.

A public demonstration of a total of four Heinkel types - in addition to the HD 21 and HD 29, their successor models, the HD 32 and the HD 35 - took place on December 16, 1925 at the Berlin-Tempelhof airfield . In addition to the press, domestic and foreign representatives of state authorities were also invited, who were given the opportunity to test the models on site in flight. Serial production of the sample did not result in this presentation.

construction

The HD 29 is a single-legged, tensioned and strongly positively staggered double-decker in wood construction with a tail landing gear .

Fuselage: The fuselage consists of plywood frames crossed out with steel wires and four longitudinal spars clad with plywood, which form a square cross-section with a curvature on the upper side and end in a vertical tail edge. Behind the engine, the paneling up to the fire bulkhead in front of the first cabin is made of aluminum sheet. The aircraft is equipped with three cabins, the front of which - if not required for a passenger - can be covered and alternatively used as luggage storage space.

Structure : The wings are in two parts and consist of a wooden frame with two box spars and plywood ribs. The lower wing has a slight V-position of 2 °, while the upper wing is straight. The undersides are planked with plywood between the individual stiles, the rest of the area is covered with fabric. 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 connection consists of I-posts. Only the upper wing has ailerons; It also houses the fuel tanks with a volume of 150 liters.

Tail unit: The tail unit has a normal design, the vertical fin is made of a wooden frame with plywood planking and the horizontal fin is made of a tubular steel frame with fabric covering. The elevator is aerodynamically balanced and supported on the fuselage with two struts. All oars are made of tubular steel covered with fabric.

Landing gear: The HD 29 has a rigid main landing gear with a continuous axle and rubber rope suspension . There is a grinding spur at the rear.

Technical specifications

Parameter	Data
crew	2-3
span	above 10.5 m below 9.0 m
length	7.20 m
height	3.07 m
Wing area	27.7 m²
Preparation mass	680 kg
Payload	270 kg
Takeoff mass	950 kg
drive	a liquid-cooled six - cylinder four-stroke in - line engine
Type	Mercedes DI
fuel	150 l
Starting power	110 hp (81 kW)
rated capacity	100 hp (74 kW)
Top speed	135 km / h
Cruising speed	120 km / h
Landing speed	70 km / h
Rate of climb	1.8 m / s
Rise time	9 min, 30 s at 1000 m altitude 25 min at 2000 m altitude
Range	565 km 154 km with 2–3 people
Service ceiling	3100 m

literature

• Volker Koos: Ernst Heinkel Flugzeugwerke 1922–1932 . Heel, Königswinter 2006, ISBN 3-89880-502-6 , p. 74/75 .
• 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. 63 ff .
• Helmut Stützer: The German military aircraft 1919–1934 . E. S. Mittler & Sohn, Herford 1984, ISBN 3-8132-0184-8 , p. 36, 140 and 183 .