Focke-Wulf W 7

Focke-Wulf W 7
	f2
Type:	Maritime patrol
Design country:	German Empire
Manufacturer:	Focke-Wulf
First flight:	1932
Commissioning:	no
Production time:	1931/32
Number of pieces:	1

The Focke-Wulf W 7 was a single aircraft type from Focke-Wulf Werke for an on-board sea reconnaissance aircraft .

development

The Ministry of Defense (RWM) and the Ministry of Transport (RVM) set at the turn of 1928/29 considerations for a catapult-performance, single-engine reconnaissance board. Due to limited monetary leeway in the 1929–1933 households, the design should also be able to be used as a light bomber and for liaison and school assignments. In the Reichsmarineamt , the RWM / RVM studies for this single-engine seaplane were then supplemented by a mission-related catalog of requirements:

Top speed 235 km / h
Range 1100 km
Flight duration 5 hours
Reaching 3000 m altitude in 10 minutes
Seaworthiness up to swell 4–5
Two-seater (pilot and observer)

Ernst Heinkel Flugzeugwerke in Rostock-Warnemünde reacted to the catalog of demands . The central design department under Dipl. Ing.Reinhold Mewes reduced the design of the twin-engine multi-purpose aircraft Heinkel HD 59 and created a single-engine model with a liquid-cooled inline twelve-cylinder BMW VI 6.0 ZU with 660 hp / 486 kW take-off power: the Heinkel HD 60 (later: He 60 ).

The Focke-Wulf-Flugzeugwerke submitted another draft , although Henrich Focke was not very interested in the tender. Shortly before the tender arrived in Bremen, the engineer Hans Herrmann had switched from Udet Flugzeugbau to Focke-Wulf. Focke reluctantly entrusted the new man with the work. Hans Herrmann convinced the construction department in Bremen of a conventional double-decker with a floating mechanism. The special feature of the on-board reconnaissance aircraft Focke-Wulf W 7 were the spring-loaded rear float struts to absorb the impacts on the airframe when rolling in the water. This should be able to fly up to sea state 5. The imponderables of this revolutionary idea and the fact that Heinkel simply downsized an existing design in order to save time had a negative effect on Focke-Wulf. The shock absorber had to be developed first. A stroke of luck for Heinkel: in August 1930 the HD 60 (W.Nr. 380, D-2157), three months later the HD 60 a (W.Nr. 381, D-2176) went to the E -stelle (See) in Travemünde in testing. It is true that Karl Wiborg crashed fatally on December 16, 1931 with the HD 60 a on the apron at Travemünde, and in the summer of 1932 the gearbox of the BMW VI engine on the HD 60 broke. Up until these events, however, the Heinkel had presented itself convincingly overall.

In the summer of 1932, the first flight of the Focke-Wulf W 7 (serial number 116, D-2216) under Hans Herrmann was also successful. It ended in a disappointment: the control around all axes remained inadequate due to the control cables used. Focke-Wulf had to make improvements, the transfer of the W 7 to the See trial site was delayed. Although the W 7 used the same engine as the HD 60 or the HD 60 a, Focke-Wulf decided on a higher compression ratio and installed the BMW VI 6.3 ZU instead of the BMW VI 6.0 ZU. This drove a wooden four-blade propeller. The W 7 shared the top speed of approx. 240 km / h and the landing speed of 90 km / h with its competitors. The dimensions of the W 7: length 11.50 m, wingspan 13.00 m, the maximum take-off weight was 3400 kg. The design was unarmed, the installation of machine guns sMG 08/15 from the Reichswehr as a rigid firearm for the pilot or as a movable weapon for the observer was considered in the planning but not implemented.

When the W 7 was finally ready for handover, so much time had passed that the sample was in fact already outside the tender. Heinkel's third test model He 60 b (W.Nr. 418, D-2325) had made its first flight in August 1932 and was handed over to the E -stelle (lake) in September 1932. The drafts by Focke-Wulf and Heinkel both flew at the E -stelle for a short time before the E -stelle concluded the tests and spoke out in favor of purchasing the He 60.

Web links

Technical data on histaviation.com (English)

Individual evidence

^ Christian König: "First at the enemy" - aircraft and coastal reconnaissance aircraft Heinkel He 60 . Helios, Aachen 2017, ISBN 978-3-86933-187-4 , pp. 13 .
^ Christian König: "First at the enemy" - aircraft and coastal reconnaissance aircraft Heinkel He 60 . Helios, Aachen 2017, ISBN 978-3-86933-187-4 .
^ ^A ^b Hans-Jürgen Becker: Seaplanes - flying boats, amphibians, float planes . In: German aviation . tape 21 . Bernard & Graefe, Koblenz 1994, ISBN 3-7637-6106-3 , p. 177 f .
↑ Christian König: The better loses - Focke Wulf W 7 aircraft . In: Cast off! German Navy Federation, Kiel May 2018, p. 29-30 .
^ Christian König: "First at the enemy" - aircraft and coastal reconnaissance aircraft Heinkel He 60 . Helios, Aachen 2017, ISBN 978-3-86933-187-4 , pp. 14 .

[1] Christian König: "First at the enemy" - aircraft and coastal reconnaissance aircraft Heinkel He 60 . Helios, Aachen 2017, ISBN 978-3-86933-187-4 , pp. 13 .

[2] Christian König: "First at the enemy" - aircraft and coastal reconnaissance aircraft Heinkel He 60 . Helios, Aachen 2017, ISBN 978-3-86933-187-4 .

[Becker-3] A ^b Hans-Jürgen Becker: Seaplanes - flying boats, amphibians, float planes . In: German aviation . tape 21 . Bernard & Graefe, Koblenz 1994, ISBN 3-7637-6106-3 , p. 177 f .

[4] Christian König: The better loses - Focke Wulf W 7 aircraft . In: Cast off! German Navy Federation, Kiel May 2018, p. 29-30 .

[5] Christian König: "First at the enemy" - aircraft and coastal reconnaissance aircraft Heinkel He 60 . Helios, Aachen 2017, ISBN 978-3-86933-187-4 , pp. 14 .