Heinkel HE 6

Heinkel HE 6
HE 6b with Packard engine
Type:	Long-range ocean plane
Design country:	German Empire
Manufacturer:	Heinkel
First flight:	August 2, 1927
Production time:	1927
Number of pieces:	1

The Heinkel HE 6 is one of the Heinkel aircraft works Warnemünde developed in the 1920s by German float plane , with the first nonstop - Atlantic crossing east-west direction should be conducted in. Announced in the media, the company failed with a failed start.

development

After Charles Lindbergh had succeeded for the first time in May 1927 in a solo flight across the Atlantic from North America to Europe without a stopover, increased efforts were made to cover this route in the opposite direction as well, due to the wind conditions over the sea the more difficult one was. Even Ernst Heinkel , who promised some public attention from its chief designer gave Karl Schwaerzler commissioned to develop a suitable aircraft. As donors could HAPAG - Reederei are obtained, whose department had "Aviation" very interested in recording an overseas air traffic and 180,000 for the organization and execution ℛℳ ready made. A second client, albeit in the background, was the Reichsmarine , who wanted to test radio equipment developed by Telefunken and Lorenz in this hidden way on their behalf , since the Versailles Treaty prohibited the German Reich from producing any military equipment. The suitability of the aircraft as a maritime patrol aircraft should also be tested.

Schwärzler began planning work in June 1927 and on July 4th the first construction drawings were handed over to the production department. Construction was completed only a few weeks later and on August 2nd the HE 6 with the serial number 286 took off for its first flight despite the lack of some cladding panels and without painting. A BMW VIa with 700 hp (515 kW) and a two-bladed propeller served as the drive . Since the aircraft engine developed the previous year for an Atlantic flight had not yet been sufficiently tested, it was replaced in September 1927 by a more powerful Packard engine with a four-bladed propeller, which Heinkel from Severa GmbH , a camouflaged company of the Reichsmarine, made available was asked. For a better differentiation, the two variants were referred to as HE 6a and HE 6b. In the latter version, the design was given registration D-1220 .

By changing the drive, the preparations for the Atlantic flight dragged on into October. During the first test flights it was also found that the HE 6 could only with difficulty overcome the suction effect of the water when taking off , which is why the float was changed several times and the front float struts were extended to improve the angle of attack . At the end of the tests and as an immediate flight preparation, the crew, consisting of flight captain Horst Merz, radio operator Wilhelm Bock and the on-board fitter Rohde, carried out a flight of 10:43 hours with a 1000 kg payload with the HE 6 on October 10, 1927, which was German Record meant. Two days later, the same crew started the first leg of their Atlantic flight with a delay due to problems with the radio system generator. The next stages were impaired by the radio equipment, which was still not working correctly, and additional difficulties with cooling . In addition, there were delays due to bad weather. Lisbon was not reached until October 18, the last stopover on the European mainland. The next destination was Horta in the Azores. The persistently bad weather initially led to an aborted take-off run on October 21. The flight was then completed on November 4 in 9:35 hours. The actual ocean flight finally took off on November 13th. In the process, the HE 6, which was picking up speed in the swell, either the propeller ends or the left tip of the float was torn off by the impact of the waves, which led to the immediate undercutting of the water surface. The aircraft overturned, with the left wing and float being torn off. The crew was able to free themselves from the wreck, which was later recovered. Another attempt to cross the Atlantic was not attempted by Heinkel afterwards. His competitor Junkers finally succeeded in doing this in 1928 with the W 33 "Bremen" .

construction

HE 6 is a cantilever low-wing aircraft in composite construction . The fuselage consists of a fabric-covered tubular steel frame with a square cross-section, arched back and tapering towards the stern in a cutting edge. The engine with fire bulkhead is followed by a large fuselage tank and behind it the closed cabin made of duralumin with windows made of cellon for the three-person crew, on the rear wall of which the radio is located and above it on the fuselage the ring-shaped monitoring frame. The wing frame is formed by two wooden box spars with spruce straps and frames made of plywood. Most of the cladding is made of fabric. Only the underside of the fuselage between the spars, where the two flat tanks are housed, and the front edges are made of plywood. Overall, the aircraft is equipped with three fuel tanks in the fuselage and wings with a total capacity of 4320 liters. The ailerons are made of fabric-covered steel tubing.

The HE 6 has a low-set vertical tail unit with a keel fin on the underside of the fuselage and horn compensation in the upper area. The horizontal stabilizer is supported by I-struts towards the trunk. Like the ailerons, the tail unit also consists of a tubular steel frame with fabric covering. The floating mechanism is made up of two wooden floats placed in parallel, the front underside of which is flat and keeled out, initially with one step , later with two for better detachment from the water during take-off. The floats are divided into seven compartments with floors made of duralumin and designed for 95% reserve buoyancy. The connection to the fuselage is made by N-posts and among each other by I-struts.

Technical specifications

Parameter	Data (HE 6b)
crew	3 (pilot, on-board fitter, radio operator)
length	13.18 m
span	18.20 m
height	4.47 m
Wing area	75.4 m²
V position	2 °
Empty mass	2800 kg
Payload	3200 kg
Takeoff mass	6000 kg
drive	a liquid-cooled, twelve-cylinder - four stroke - V engine
Type	Packard 3A-2500
Starting power nominal power continuous power	840 PS (618 kW) 700 PS (515 kW) 560 PS (412 kW) on the ground
Fuel volume	4320 l
Top speed	205 km / h near the ground
Cruising speed	170 km / h
Landing speed	125 km / h
Rate of climb	1.2 m / s
Rise time	14.0 min at 1000 m
Summit height	2300 m with maximum payload
Radius of action	4000 km
Flight duration	23 h

literature

• Volker Koos: Ernst Heinkel . From the biplane to the jet engine. Delius Klasing, Bielefeld 2007, ISBN 978-3-7688-1906-0 , p. 84 ff .
• Volker Koos: Ernst Heinkel Flugzeugwerke 1922–1932 . Heel, Königswinter 2006, ISBN 3-89880-502-6 , p. 26/27 .
• 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. 87 ff .

Web links

Commons : Heinkel HE 6  - Collection of pictures, videos and audio files

• The ocean plane from Warnemünde. Retrieved on October 27, 2018 (a report on the Heinkel HE 6 by Dr. Volker Koos). 

Individual evidence

1. ^ Karl Ries: Research on the German aviation role. Part 1: 1919-1934 . Dieter Hoffmann, Mainz 1977, ISBN 3-87341-022-2 , p. 91 .