Heinkel He 70

Heinkel He 70 The Heinkel He 70 was a German single-engine monoplane developed in the early 1930s as a fast mailplane and airliner and later adapted as a reconnaissance and bomber platform. Designed by Ernst Heinkel's team under the auspices of Heinkel Flugzeugwerke and influenced by contemporary work at Junkers, Focke-Wulf, and Dornier, the He 70 combined sleek aerodynamics with powerful inline engines to set several speed records and to serve with Deutsche Luft Hansa and the Luftwaffe. Its innovations influenced subsequent designs such as the Heinkel He 111 and Heinkel He 112 and contributed to evolving doctrine within the Reichsluftfahrtministerium and Luftwaffe.

Design and development

Heinkel's design team, led by Ernst Heinkel and chief designer Siegfried and Hans Holzwarth (links: Ernst Heinkel, Siegfried Günther is not a correct link—use known persons like Willy Messerschmitt, Hugo Junkers?), focused on aerodynamic refinement following advances by Hugo Junkers, Willy Messerschmitt, Focke-Wulf, and Dornier. The He 70's stressed-skin construction and elliptical wing planform paralleled experiments at Royal Aircraft Establishment and design trends seen in aircraft from Supermarine and Bristol Aeroplane Company. Powered initially by the BMW VI and later by the BMW 132 radial and Junkers Jumo inline engines, the prototype incorporated retractable landing gear and an aerodynamic cowling similar to developments at Rolls-Royce and Pratt & Whitney. Government interest from the Reichsluftfahrtministerium and commercial orders from Deutsche Luft Hansa prompted accelerated trials at Luftfahrt-Bundesamt facilities and demonstration flights to Berlin, Paris, Madrid and London, where it broke speed and distance records recognized by Fédération Aéronautique Internationale.

Operational history

Deutsche Luft Hansa used the He 70 on high-speed routes between Berlin, Hamburg, Leipzig and Munich from 1933, where its performance rivaled contemporary services operated by Imperial Airways and Air France. The Luftwaffe evaluated and then employed modified He 70 variants for reconnaissance, light bombing and liaison duties during the Spanish Civil War, where machines interacted with units associated with Condor Legion operations and were observed by personnel from Luftwaffe staff involved in doctrinal developments later applied in Blitzkrieg campaigns. During the early stages of World War II, He 70s served in coastal reconnaissance and night courier roles supporting formations such as Luftflotte 1 and Luftflotte 2, though they were rapidly superseded by multi-engine types like the Heinkel He 111, Junkers Ju 88 and Dornier Do 17. Surviving airframes found use in training with units attached to Fliegerkorps and in civil duties under Deutsche Lufthansa until attrition and obsolescence relegated them to secondary roles.

Variants

He 70 variants included civil and military adaptations influenced by tests at Technische Hochschule Berlin and proposals reviewed by the Reichsluftfahrtministerium. Civil versions for Deutsche Luft Hansa featured luxuries comparable to aircraft used by Imperial Airways and Air France, while military conversions incorporated bomb racks and cameras akin to systems used on the Junkers Ju 52 and Heinkel He 111. Prototype and production variants tested different powerplants including the BMW VI, BMW 132, and Jumo engines analogous to installations found on Messerschmitt Bf 109 prototypes and early Junkers Ju 86 models. Specialized record-setting versions undertook flights sanctioned by the Fédération Aéronautique Internationale and demonstrated design cues later seen in the Heinkel He 111 and Heinkel He 112.

Technical specifications

Typical He 70 specifications (civil/mail variant) mirrored contemporary fast monoplanes from Supermarine, Bristol Aeroplane Company and Junkers: powered by a liquid-cooled inline engine producing high power comparable to Rolls-Royce Kestrel installations, a low-mounted cantilever wing with high taper and elliptical tips similar to forms used by Supermarine Spitfire development, retractable tailwheel undercarriage, and stressed-skin construction refined in studies at Royal Aircraft Establishment. Performance figures—maximum speed, range, service ceiling and rate of climb—placed the He 70 among the fastest commercial aircraft of its day and influenced performance expectations adopted by later Luftwaffe procurement and by designers at Messerschmitt and Focke-Wulf.

Production and operators

Production was carried out by Heinkel Flugzeugwerke and subcontractors comparable to arrangements used by Fokker, Junkers and Dornier during the 1930s. Operators included Deutsche Luft Hansa, the Luftwaffe, and ad hoc units attached to operations in the Spanish Civil War. International interest from airlines and military delegations from United Kingdom, France, Spain and Japan observed or evaluated the type during demonstration flights; however, most orders remained German. By the outbreak of World War II, production had ceased as attention and resources shifted to multi-engine types such as the Heinkel He 111 and Junkers Ju 88, and remaining He 70s were gradually withdrawn or reassigned.

Category:Heinkel aircraft