Häfeli DH-1

The Häfeli DH-1 was a 1910s Swiss two-seat reconnaissance aircraft, built by the aircraft department of the Federal Construction Works (Eidgenoessische Konstruktionswerkstaette, K+W) at Thun, Switzerland.

Development and design

In 1915 K + W set up their aircraft department and employed August Häfeli as chief engineer. Häfeli had previously designed the AGO C.I and AGO C.II, German reconnaissance biplanes. His first design was the Häfeli DH-1, similar in concept to his designs for AGO Flugzeugwerke. The DH-1 was a three-bay biplane of wood and fabric construction, it had a fuselage pod with tandem seating for the two-man crew and twin booms mounting the tail. The DH-1 was powered by an Argus As II engine built under licence by Buhler Brothers Limited. Six aircraft were built.

Operational history

Six DH-1s were built during 1916 but within a year three had been destroyed in accidents. The survivors were withdrawn from service in 1919 and scrapped.

Operators

Specifications (DH-1)

Airco DH.1

The Airco DH.1 was an early military biplane of typical "Farman" pattern flown by Britain's Royal Flying Corps during World War I. By the time the powerplant for which it was designed was sufficiently plentiful it was obsolete as an operational aircraft, and apart from a few examples sent to the Middle East it served as a trainer and Home Defence fighter.

Design and development

Geoffrey de Havilland was one of the pioneering designers at the Royal Aircraft Factory and was partially or wholly responsible for most pre-war "Factory" designs. When he left to become chief designer at The Aircraft Manufacturing Company (Airco) in 1914, his first design was strongly reminiscent of the F.E.2, one of the last designs on which he had worked at the Royal Aircraft Factory.

Like the F.E.2, the DH.1 was of pusher configuration, accommodating its pilot and observer in two open tandem cockpits in the nose. The observer's cockpit was stepped down below the pilot's and equipped with a machine gun. The wings were of typical fabric-covered, two-bay, unstaggered, unswept, equal span design, while the stabiliser and rudder were carried on the end of two long, open-framework booms. The type, like the F.E.2b, was designed for the water-cooled Beardmore 120 hp (89 kW) inline engine. However, all available Beardmore engines were required for F.E.2b and R.E.5 production, so the air-cooled Renault 70 hp (52 kW) V8 engine was installed instead.

DH1

DH1 may refer to:

DH-1 (rocket)

The DH-1 is a reusable two-stage-to-orbit rocket proposed in the book The Rocket Company by Patrick J. G. Stiennon, David M. Hoerr, Doug Birkholz (AIAA, 2005). The concept is patented. The DH-1 has not (yet) been built, and its manufacturing company, AM&M, is also fictional. The book highlights and seeks to solve many problems of building a Cheap Access To Space vehicle via the DH-1 design. "The Rocket Company" is a work of fiction, but the science, engineering and politics that underlies the design of the DH-1 are described as highly-feasible. The design is notable in that it attempts to avoid new or nonexistent wonder technologies, to rely on human rather than computer control, to consider the possible economics of a very small 5,000-pound (2,300 kg) payload capacity (including pilot), to make use of a 'pop up first stage' launch profile, to market the vehicle for 'space access' rather than 'cargo delivery', and to offer a business plan whose intention is to sell the DH-1 vehicles themselves, rather than payload space on a company launch vehicle, as is currently the norm.