Heinkel HD 44

Heinkel HD 44
Type:	Experimental airplane
Design country:	German Empire
Manufacturer:	Heinkel
First flight:	1929
Number of pieces:	1

The Heinkel HD 44 is a German experimental aircraft that was developed by Ernst Heinkel Flugzeugwerke in Warnemünde in the 1920s and remained a one-off. The abbreviation HD stands for "Heinkel Doppeldecker".

development

The HD 44 was commissioned by the DVL in Berlin-Adlershof and was intended to serve as a test vehicle for aircraft engines. The only built example with the serial number 332 was developed and completed in 1929. It was designated as HD 44a and registered with the license plate in May 1930 D–1762. Not much is known about its subsequent use as an "engine test aircraft"; According to information in the print media of that time, drives from 300 to 1200 HP, both air -cooled and liquid-cooled, are said to have been tested. After upgrading the measuring equipment, the HD 44 could also be used as a transport aircraft for smaller goods.

construction

The HD 44 is a braced double - decker in composite construction . The fuselage consists of a welded tubular steel frame, from the engine to the pilot's cabin planked with light metal and covered with fabric in the remaining part. Behind the fire bulkhead is the cargo hold, 2.7 m long and 1.8 m high, to accommodate the measuring devices and the operating personnel. Behind it is the crew cabin, under which there is an additional small cargo hold. The structure is made up of the strongly staggered upper and lower wings of different spans, which are connected with N-struts. The wings consist of a wooden frame with two box spars, between which there are plywood sliding plates. The leading edge of the wing is made of plywood, the rest is covered with fabric. All wings have ailerons connected by bumpers. The normal stabilizer consists of a metal frame covered with fabric, the horizontal stabilizer is supported towards the fuselage with I-struts and adjustable in flight, the vertical fin only on the ground. The undercarriage is not retractable and consists of the main wheels with a large track width connected to one another by an axle with rubber rope suspension and a grinding spur at the rear.

Technical specifications

Parameter	Data
crew	2
Passengers	2-6
length	12.20 m
span	above 17.60 m below 15.15 m
height	4.6 m
Wing area	75.5 m²
V position	above 2.2 ° below 4.4 °
Empty mass	2050 kg
Payload	1070 kg as a test aircraft 1570 kg as a cargo aircraft
Takeoff mass	3120 kg as a test aircraft 3620 kg as a cargo aircraft
drive	a liquid-cooled, twelve-cylinder - four stroke - V engine
Type	BMW VI 5.5 ZU
Starting power nominal power continuous power	650 PS (478 kW) 610 PS (449 kW) on the ground 500 PS (368 kW) at an altitude of 700 m
Fuel volume	550 l
Top speed	206 km / h near the ground
Cruising speed	180 km / h
Landing speed	77 km / h
Rate of climb	6.0 m / s
Rise time	2.8 min at 1000 m 6.2 min at 2000 m 10.5 min at 3000 m 16.4 min at 4000 m
Summit height	5500 m
Range	1040 km (optimal)

literature

• Volker Koos: Ernst Heinkel Flugzeugwerke 1922–1932 . Heel, Königswinter 2006, ISBN 3-89880-502-6 , p. 106/107 .