TheHopfner HA-11/33 was an amphibious flying boat built in Austria in 1933 to a specification by theDr. Oetker company. The result was a conventional, high-wing cantilever monoplane with a stepped flying boat hull and pontoons on struts under the wings at mid-span. The cabin was fully enclosed, and the twin engines were mounted tractor-fashion on struts above the wing.
A HA-11/33 was purchased by theAustrian Air Force, and was subsequently absorbed into the GermanLuftwaffe following theAnschluss. Deemed worthy of further development,WNF (which had absorbedHirtenberg, which itself had taken overHopfner) was tasked with developing it into a military training aircraft for flying boat pilots. DesignatedWNF Wn 11 by theRLM, testing was undertaken atTravemünde in 1940, but the type was not ordered into production. Development of a highly streamlined derivative withHirth HM 508 engines, theWNF Wn 11C was also abandoned.
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Taylor, Michael J. H. (1989).Jane's Encyclopedia of Aviation. London: Studio Editions. p. 510.
Nowarra, Heinz J. (1993).Die Deutsche Luftruestung 1933-1945 Vol.4 – Flugzeugtypen MIAG-Zeppelin (in German). Koblenz: Bernard & Graefe Verlag. p. 43.ISBN3-7637-5468-7.
