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{|{{Infobox aircraft begin
 | name=Horten H.II Habicht
 | image=File:Horten IIM art.jpg
 | caption=A modified H.II with a Hirth HM.60R motor in a [[Engineering:Pusher configuration|pusher configuration]] 
}}{{Infobox aircraft type
 | type=[[Engineering:Flying wing|Flying wing]] [[Engineering:Glider (sailplane)|glider]] and motorglider
 | national origin={{wipe|Germany}}
 | manufacturer=
 | designer=Walter and Reimar Horten, who also built it
 | first flight=July 1935
 | introduced=
 | retired=
 | status=
 | primary user=
 | more users= <!--Limited to three in total; separate using <br /> -->
 | produced= <!--years in production-->
 | number built=4
 | program cost= <!--Total program cost-->
 | unit cost= <!--Incremental or flyaway cost for military or retail price for commercial aircraft-->
 | developed from= 
 | variants with their own articles=
}}
|}

The '''Horten H.II Habicht''' (Hawk) was a German [[Engineering:Flying wing|flying wing]] [[Engineering:Glider (sailplane)|glider]] built in {{wipe|Germany}} in 1935. Four, including one flown mostly as a motorglider, were built. One of the gliders was used to test the [[Physics:Aerodynamics|aerodynamics]] of a prototype [[Social:World War II|World War II]] Horten jet fighter-bomber.

==Design==

The Horten brothers' first glider, the [[Engineering:Horten H.I|H.I]], was a true [[Engineering:Flying wing|flying wing]] without any vertical surfaces or [[Engineering:Fuselage|fuselage]] which had flown for seven hours at the 1934 Rhön competition on the Wasserkuppe. It had attracted much interest, gaining a DM600 "Construction Prize", but was hard to control and made only one competitive flight.  The brothers "abandoned and burned it on the Wasserkuppe". In the next nine months, helped by the prize, they built the Horten H.II which had a wing of greater span and higher [[Engineering:Aspect ratio (aeronautics)|aspect ratio]] than the shallow [[Engineering:Delta wing|delta]] of the Horten I, with sweep on the [[Engineering:Trailing edge|trailing edge]]s as well. With improved [[Physics:Flight dynamics#Aircraft|yaw]] control it flew much better, though a test report from Hanna Reitsch made it clear that more work was required.<ref name=SimonsI/>{{r|KGW|p=Section 3}}{{r|Nurf|p=p.29}}

The Habicht had a thick, [[Physics:Camber (aerodynamics)#Example – An aerofoil with reflexed camber line|reflex section]] wing, with a maximum thickness/[[Astronomy:Chord (aeronautics)|chord]] ratio of 20% at the root and 10% near the tips. It had a quarter-[[Astronomy:Chord (aeronautics)|chord]] sweep of 26°, 3° of [[Astronomy:Dihedral (aeronautics)|dihedral]] and 7° of [[Astronomy:Washout (aeronautics)|washout]].  It was in three parts with a central section, built on steel tubes, and two wooden outer panels. The latter had single [[Engineering:Spar (aeronautics)|spar]]s and [[Chemistry:Plywood|plywood]] covered leading edges, forming torsion-resisting D-boxes.{{r|KGW|p=Table 1}}

In the absence of a conventional [[Engineering:Rudder|rudder]] the Habicht had drag rudders.  These were leading edge [[Engineering:Flap (aeronautics)|flaps]] placed near the tips and formed by mounting the leading edge surfaces on a hinge so they could open upwards and downwards{{r|Nurf|p=p.53}} (those of the Horten H.I had extended downwards only).{{r|KGW|p=Section 3}}  Their differential operational controlled yaw and they served as conventional airbrakes when opened together.<ref name=Lailes1/> The whole trailing edge was occupied by control surfaces; the outer panels had [[Engineering:Elevon|elevon]]s outboard and landing [[Engineering:Flap (aeronautics)|flap]]s inboard and there were further landing flaps on the centre section.{{r|KGW|p=Section 3}} Rear control surfaces were assisted by Flettner servo tabs{{r|KGW|p=Section 3}} and were ply covered.<ref name=Lailes1/>

The seat in the Habicht was strongly reclined and positioned the pilot entirely within the {{convert|700|mm|in|abbr=on}} maximum thickness of the central wing profile.  In place of a canopy the leading edge near the cockpit was covered on each side in transparent Cellon.{{r|KGW|p=Section 3}}

The Habicht had tandem wheel landing gear; the forward wheel, fitted with a brake, was mounted on a long fork and retracted by being swung backward so it was semi-protruding from the fuselage. The fixed rear wheel was below the trailing edge, half within a large [[Engineering:Aircraft fairing|fairing]] which was rectangular ahead of the wheel and raked behind. {{r|Nurf|p=p.70}} This probably acted as a short-coupled [[Biology:Fin|fin]].{{r|KGW|p=Section 3}}

==Development==
[[File:Flying wing (2561202768).jpg|left|The landing gear (retracted) of the Horten H.IIL|thumb]]
The first Horten H.II was completed as a glider in May 1935 and flew shortly after,{{r|Nurf|p=pp.36}} too late for the 1935 Rhön contest.<ref name=SimonsI/> It was soon flying as a motorglider, designated H.IIM{{r|KGW|p=Section 3}} powered by a [[Engineering:Pusher configuration|pusher configuration]] Hirth HM 60R air-cooled, inverted, four cylinder, inline engine, mounted on top of the wing.{{r|KGW|p=Section 3}}<ref name=Lailes1/>{{r|Nurf|p=pp.36, 43}}  The engine increased the empty weight by {{convert|110|kg|lb|abbr=on}} and enabled a maximum speed in level flight of {{convert|200|km/h|mph|abbr=on}}, but increased the minimum sink rate to {{convert|0.8|m/s|ft/s|abbr=on}}.{{r|Nurf|p=pp.43-4}}  To clear the [[Engineering:Propeller (aeronautics)|propeller]], the rear wheel fairing was altered to have a squarer profile.<ref name=Lailes1/> In 1937 the borrowed engine had to be returned, ending the career of the first Habicht.{{r|Nurf|p=p.36}}

The Luftwaffe became aware of Horten's work during tests of the [[Engineering:Horten H.V|Horten H.V]], a twin engine aircraft with military potential, and ordered three more Horten II motorgliders.{{r|Nurf|p=pp.46, 51}} Designated '''Horten H.IIL''', they had slightly increased washout and a more upright seat. The pilot's head was now above the wing under a {{convert|300|mm|in|abbr=on}} high clear perspex canopy.{{r|Nurf|p=p.51}}  The alterations increased the weight by {{convert|30|kg|lb|abbr=on}}.{{r|Nurf|p=pp.43-56}} The first two of these were built in 1937 and the decision was made to enter them as gliders in the annual Rhön contest.{{r|Nurf|p=p.51}}  Their performance there were not outstanding as their [[Physics:Wing loading|wing loading]] was too low to reach the speeds necessary for rapid cross country flights between thermals.<ref name=SimonsI/>

The third Horten H.IIL was test flown in November 1938 by Hanna Reitsch, who reported that whilst comfort was "not exceptional", the "view is bad" (even with the new canopy), entry and exit were "only possible for athletes" and that the undercarriage retraction lever could only be operated by pilots with longer arms than hers.{{r|KGW|p=Section 3}} It achieved a soaring flight of {{convert|160|mi|km|abbr=on|order=flip}} in 1938.{{r|Nurf|p=p.51}}

That example was destroyed in a fatal accident in March 1939. Witnesses described how the canopy detached during a high-speed dive in aerobatics practice, hitting pilot Kurt Hiekmann.{{r|Nurf|p=p.69-70}}
 
Encouraged by the military, the Hortens concentrated on the [[Engineering:Horten H.III|Horten H.III]] as a competitor in the 1938 Rhön, where the H.IILs were used only for pilot training.{{r|Nurf|p=p.69-70}} Nonetheless, D-10-125, the first of the H.IILs, was continuously modified. One of the first changes was to the central leading edge transparencies, which were reduced to two separate panels on either side of ply skinning. Early photographs of it show a fully transparent leading edge{{r|KGW|p=Section 3}} and later images the revisions.<ref name=SimonsI/> It was much involved in the 1944 development of the Horten IX twin-jet fighter-bomber; most notably it was flown as a "wind-tunnel substitute" for the H.IX V-6, with its extended, pointed nose, dummy air-intakes and exhausts, and twin small fins.{{r|Nurf|p=p.144-5}} A photograph also exists of it with the intakes but not the pointed nose.{{r|Nurf|p=Jacket}}
D-10-125 is now on display, restored to an earlier form, in the Deutsches Technikmuseum, [[Place:Berlin|Berlin]].<ref name=Ogden/>

==Variants==

;Horten II: Original glider version from 1935, flown summer 1935.{{r|KGW|p=p.36}}

;Horten IIM: The original version modified into a motorglider with a [[Engineering:Pusher configuration|pusher configuration]] Hirth HM.60R, flown from autumn 1935 to 1937.{{r|KGW|p=p.36}}

;Horten IIL: Three built in 1937–1938 for the Luftwaffe, with canopy, upright seat and slightly increased washout.{{r|Nurf|p=pp.46, 51}}

==Aircraft on display==

*Deutsches Technikmuseum, [[Place:Berlin|Berlin]]: Horten IIL ''D-10-125''.

== Specifications (Horten IIL) ==
{{Aircraft specs
|ref=Nurflügel (2012){{r|Nurf|p=p.56}}
|prime units?=met
<!--
        General characteristics
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|genhide=

|crew=One
|capacity=
|length m=
|length note=
|span m=16.5
|span note=
|height m=
|height ft=
|height in=
|height note=
|wing area sqm=32
|wing area note=
|aspect ratio=8.5
|airfoil=
|empty weight kg=250
|gross weight lb=
|gross weight note=
|max takeoff weight kg=330
|max takeoff weight note=
|more general=

<!--
        Performance
-->
|perfhide=

|max speed kmh=
|max speed note=
|cruise speed kmh=
|cruise speed note=
|stall speed kmh=
|stall speed mph=
|stall speed kts=
|stall speed note=
|never exceed speed kmh=230
|never exceed speed mph=
|never exceed speed kts=
|never exceed speed note=
|minimum control speed kmh=
|minimum control speed mph=
|minimum control speed kts=
|minimum control speed note=
|g limits=<!-- aerobatic -->
|roll rate=<!-- aerobatic -->
|glide ratio=1:24 at {{convert|72|km/h|mph kn|abbr=on}} and {{convert|10.3|kg/m2|lb/sqft|abbr=on}} 
|sink rate ms=0.7
|sink rate note=minimum, at {{convert|72|km/h|mph kn|abbr=on}} and {{convert|10.3|kg/m2|lb/sqft|abbr=on}} 
|lift to drag=
|wing loading kg/m2=
|wing loading lb/sqft=
|wing loading note=
|more performance=

}}

==References==
{{reflist|refs=

<ref name=Ogden>{{cite book |title=Aviation Museums and Collections of Mainland Europe |last= Ogden |first=Bob  |year=2009|publisher= Air Britain (Historians) Ltd|page=212 |isbn=978 0 85130 418 2}}</ref>

<ref name=SimonsI>{{cite book |title=Sailplanes 1920-1945 |last=Simons |first=Martin |edition=2nd revised |year=2006|publisher= EQIP Werbung & Verlag GmbH|location=Königswinter |isbn=3 9806773 4 6|pages=143–5}}</ref>

<ref name=Nurf>{{cite book |title=Nurflügel |last=Horten |first=Reimar|first2=Peter F.|last2=Selinger |edition=2nd revised |year=2012|publisher= H. Weishaupt Verlag|location=Graz |isbn=978-3-900310-09-7|pages=26–55}}</ref>

<ref name=Lailes1>{{cite journal |date=25 April 1936|title=Un motoplaneur de 60 CV|journal=Les Ailes| issue=775|pages=17| url=http://gallica.bnf.fr/ark:/12148/bpt6k6555215g/f11}}</ref>

<ref name=KGW>{{cite web|url=http://www.twitt.org/Farnborough.html#top|title=The Horten tailless aircraft|author=K. G. Wilkinson|date=18 April 1946|work=ADVANCE SUMMARY for TECHNICAL INTELLIGENCE REPORTS ANALYSIS DIVISION TSNTS-2|access-date=5 April 2016|archive-url=https://web.archive.org/web/20070610230735/http://www.twitt.org/Farnborough.html#top|archive-date=10 June 2007|url-status=dead}}</ref>

}}
<!-- ==Further reading== -->
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[[Category:Glider aircraft]]
[[Category:Motor gliders]]
[[Category:Flying wings]]

{{Sourceattribution|Horten H.II}}