Focke-Wulf W 4

Focke-Wulf W 4
Type:	Airborne sea ​​reconnaissance aircraft
Design country:	German Empire
Manufacturer:	Focke-Wulf
First flight:	1927
Commissioning:	-
Number of pieces:	1

The Focke-Wulf W 4 was an airborne reconnaissance aircraft and the first military aircraft to be built by the Bremen-based Focke-Wulf AG

development

The W 4 was created due to a request from the Reichsmarine within a secret armaments program from 1927 for a catapultable naval scout, the synonym for airborne reconnaissance, in direct competition with the HD 30 of the Ernst Heinkel Flugzeugwerke . Its structure was based on the land-based reconnaissance aircraft K 23 Buchfink . This was launched in about the same period, but not completed and destroyed in a major fire in the Focke-Wulf workshops on the night of September 11, 1929. The W 4 was declared as a civil aircraft due to the Versailles regulations, which did not allow the construction of a military model, which, as shown in an advertising brochure, is primarily intended for the transport of mail and for the courier service over sea routes . For the same reason, the Heinkel parallel draft HD 30 was called a "Sea Ambulance Airplane".

Not much is known about the testing of the W 4. It is said to have flown for the first time in 1927, the year in which the order was placed, but was only approved as D-1730 for the German Aviation Research Institute in August 1928 , which speaks for any problems and repair work that might have occurred during testing. For the actual suitability tests for future military use, the aircraft, like the HD 30, was handed over to the See test site in Travemünde. The launch attempts with the Heinkel K 1 catapult installed on a floating dock also took place there, but it is not known to what extent the W 4 was involved, because with a launch mass of 2985 kg, the model was well above the upper limit of only up to 2500 kg laid out catapult. The French Gnome-Rhône-Jupiter engine that was used also proved to be too weak for an aircraft of this weight class and so the aircraft was classified as unsuitable for military use. Focke-Wulf subsequently offered the model to the civilian sector, but without success. Finally, the only W 4 built was revoked in January 1932.

construction

The W 4 is a cantilever double-decker in composite construction .

hull

The fuselage consists of a tubular steel framework with a semi-oval cross-section with a flat bottom, which ends in a vertical cutting edge towards the stern. The front part is braced in the diagonal with additional steel tubes, the remaining part is braced with steel wire. The engine area up to the fire bulkhead is planked with sheet metal made of duralumin, the rest of the hull is covered with fabric. A luggage compartment is located behind the bulkhead, behind which are the separate crew cabins. In order to create additional storage space in the rear cabin, the observer's seat is designed to be foldable. The aircraft is controlled from the front cabin; This is also possible from the rear cabin thanks to an insertable auxiliary control.

Structure

The upper and lower wings are self-supporting and not connected to each other. The upper wing is designed in one piece and is connected to the fuselage by a canopy , the lower one is connected to the lower edge of the fuselage and has continuous spars. The wings can be quickly dismantled for transport by loosening eight bolts. They consist of two spars and ribs made of plywood and are covered with fabric except for the leading edge of the wing, which is also made of plywood.

Tail unit

The horizontal and vertical fin have no compensation and are designed in a three-spar box design. The horizontal stabilizer is adjustable in flight and supported with I-struts towards the fuselage. All rudders, which also include non-interconnected ailerons in the upper and lower wings, consist of a wooden frame covered with fabric.

Floating mechanism

The floating mechanism consists of two parallel single-stage, non-keeled wooden floats that are connected to the hull by a frame made of tubular steel struts.

Technical specifications

Two-sided view

Parameter	Data
crew	2
span	12.35 m
length	11.87 m
height	4.97 m
Wing area	49.8 m²
Preparation mass	2402 kg
Payload	583 kg
Takeoff mass	2985 kg
drive	an air-cooled nine-cylinder four-stroke radial engine with a rigid two-bladed wooden propeller
Type	Gnome et Rhône Jupiter VI 9 Ak
Take-off power Combat and climb power Rated power Continuous power	520 PS (382 kW) 500 PS (368 kW) on the ground 475 PS (349 kW) on the ground 444 PS (327 kW)
Top speed	204 km / h near the ground
Marching speed	190 km / h
Landing speed	92 km / h
Rise time	5.0 min at 1000 m
Service ceiling	5000 m
Range	600 km
Take-off run	215 m
Armament (provided)	a fixed and a movable machine gun

literature

• Hans-Jürgen Becker: Seaplanes - flying boats, amphibians, float planes . In: German aviation . tape 21 . Bernard & Graefe, Bonn 1994, ISBN 3-7637-6106-3 , pp. 156/157 .
• Helmut Stützer: The German military aircraft 1919–1934 . E. S. Mittler & Sohn, Herford 1984, ISBN 3-8132-0184-8 , p. 52, 127 and 191 .
• Reinhold Thiel: Focke-Wulf aircraft construction . Hauschild, Bremen 2011, ISBN 978-3-89757-489-2 , pp. 36/37 .

Web links

Commons : Focke-Wulf W 4  - Collection of images, videos and audio files

Individual evidence

1. ^ Volker Koos: Ernst Heinkel . From the biplane to the jet engine. Delius Klasing, Bielefeld 2007, ISBN 978-3-7688-1906-0 , p. 76 .
2. ↑ Thiel, p. 36