The Häfeli DH-3 was a 1910

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two-seat reconnaissance aircraft, built by the aircraft department of the Federal Construction Works (''

Eidgenoessische Konstruktionswerkstaette ''Eidgenössische Konstruktionswerkstätte'' English: "Federal Constructions Works", short K+W, was a Swiss state-owned enterprise, with the aim of making the Swiss military independent of foreign sources for its equipment needs. It was establishe ...

'', (K+W)) at Thun, Switzerland.

Development and design

Following the poor performance of the DH-2, August Häfeli designed an improved version the Häfeli DH-3. It was basically the same airframe as the DH-2, the upper wing had a cutout to give a greater field of fire for the pivoting machine gun. It was a two-bay aircraft of wood and fabric construction, powered by a 120 hp (89 kW)

Argus As II The Argus As II was a six-cylinder, in-line, water-cooled, aircraft engine produced in Germany by Argus Motoren in 1914. The Argus As II produced at 1,350 rpm.Der Argus Flugmotor, 1916 Design and development The Argus As II was a major re ...

water-cooled inline engine. Initial problems with the landing gear and the engine cooling system led to modifications. Further developments were the re-engined and improved DH-3a, and the DH-3b used for engine trials. Following successful trials with an installation of the

Handley Page Handley Page Limited was a British aerospace manufacturer. Founded by Frederick Handley Page (later Sir Frederick) in 1909, it was the United Kingdom's first publicly traded aircraft manufacturing company. It went into voluntary liquidation a ...

slats all surviving DH-3as were modified in 1932.

Operational history

On 8 January 1919 a DH-3 inaugurated the first Swiss air mail service between Zurich and Berne. A DH-3 aircraft failed a structural test in 1923 which caused the DH-3 to be withdrawn from service. The DH-3a, following modification, remained in service until 1939.

Variants

;DH-3 :Initial production version with

engine, 24 built. ;DH-3a :Improved version with

Hispano-Suiza HS-41 8Aa Hispano-Suiza () is a Spanish automotive–engineering company. It was founded in 1904 by Marc Birkigt and Damian Mateu as an automobile manufacturer and eventually had several factories in Spain and France that produced luxury cars, aircraft en ...

engines, four aircraft ordered in 1919. A second order for 30 aircraft was placed in 1919 with license-built engines, a third order for 49 aircraft being placed in 1925. Survivors were modified at Thun in 1932 with Handley Page slats and changes to allow crew to wear parachutes. ;DH-3b :Three aircraft powered by the indigenous 150 hp (112 kW) LFW 0 engine developed by the Swiss Locomotive and Machine Works were built in 1918.

Operators

; *

Swiss Air Force The Swiss Air Force (german: Schweizer Luftwaffe; french: Forces aériennes suisses; it, Forze aeree svizzere; rm, Aviatica militara svizra) is the air component of the Swiss Armed Forces, established on 31 July 1914 as a part of the army and ...

Specifications (DH-3a)

References

External links

* ETH-Bibliothek Zürich, Bildarchiv
Häfeli DH-3 (M III) No 530, Argus As II engineviewer
* ETH-Bibliothek Zürich, Bildarchiv
Häfeli DH-3 M IIIb, Argus As II engineviewer
* ETH-Bibliothek Zürich, Bildarchiv
Häfeli DH-3 aircraft, Argus As II engineviewer

Konstruktion Häfeli DH-3 in Thun
{{DEFAULTSORT:Hafeli Dh-3 1910s Swiss military reconnaissance aircraft Biplanes Single-engined tractor aircraft Aircraft first flown in 1917