View source for Raab-Katzenstein RK-26

{{Infobox aircraft
 |name=RK-26 Tigerschwalbe
 |image=SK 10.jpg
 |caption=
 |type=Training aircraft
 |manufacturer=[[Raab-Katzenstein]]<br>[[AB Svenska Järnvägsverkstädernas Aeroplanavdelning|ASJA]]
 |designer=[[Gerhard Fieseler]]
 |first_flight=By the end of the 1920s
 |introduction=
 |retired=
 |status=retired
 |primary_user=[[Swedish Air Force]]
 |more_users=[[Finnish Air Force]]
 |produced=
 |number_built=Raab-Katzenstein: 2<br>ASJA: 25
 |unit cost=
 |developed_from=
 |variants=
}}
'''Raab-Katzenstein RK-26 Tigerschwalbe''', also known as the '''Fieseler F 1 Tigerschwalbe''', was a German twin-seat biplane trainer aircraft designed by [[Gerhard Fieseler]] by the end of the 1920s.

==Design and development==
In December 1930, Fieseler was invited by the [[Swedish Air Force]] (''Flygvapnet'') to present his aircraft for the Swedish aircraft manufacturing company [[AB Svenska Järnvägsverkstädernas Aeroplanavdelning|ASJA]]. ''Flygvapnet'' was in need for a new trainer, and the RK-26 was an interesting aircraft. Fieseler had recently won a world aerobatics championship with an RK-26. ASJA then decided to buy one aircraft. It was tested with different engine configurations by ''Flygvapnet'', who later ordered 25 aircraft from ASJA.

==Operational history==
The trainer was given the designation '''Sk 10''' by ''Flygvapnet''. It was used between 1932 and 1945, but was quite controversial during its active life. This was partly due to changes in the design, which made the aircraft 200&nbsp;kg heavier than the original, and this changed its flight characteristics drastically. The aircraft was involved in many accidents. Of the 25 delivered aircraft, 18 were written off.

One aircraft, the SE-ADK was purchased in 1934 by a civilian, L. Hemmeringer. When the [[Winter War]] began, Hemmeninger donated the aircraft to [[Finland]]. The aircraft ended up being used by the [[Swedish Voluntary Air Force (Winter War)|Swedish Voluntary Air Force]] from 9 February 1940. The aircraft was painted in Finnish colors, but was used quite sparingly, due to lack of spares and the bad condition of its engine. Most of the time it was standing at the air force base in [[Veitsiluoto]].

==Surviving craft==
One Sk 10, the only remaining ''Tigerschwalbe'', is preserved at the ''[[Flygvapenmuseum]]''.

==Operators==
;{{AUT}}:
*[[Austrian Air Force]]
;{{FIN}}:
*[[Finnish Air Force]]
;{{SWE}}:
*[[Swedish Air Force]]

==Specifications==

{{Aircraft specs
|ref=Thulinista Hornetiin<ref name=Heinonen>{{cite book |last1=Heinonen |first1=Timo |title=Thulinista Hornetiin : 75 vuotta Suomen ilmavoimien lentokoneita |date=1992 |publisher=Keski-Suomen Ilmailumuseo |location=Helsinki |isbn=951-95688-2-4 |language=Finnish}}</ref>
|prime units?=met
<!--
        General characteristics
-->
|crew=2
|length m=6.55
|length note=
|span m=8.4
|span note=
|height m=2.66
|height note=
|wing area sqm=20.2
|wing area note=
|aspect ratio=<!-- sailplanes -->
|airfoil=
|empty weight kg=782
|empty weight note=
|gross weight kg=1136
|gross weight note=
|max takeoff weight kg=1100
|max takeoff weight note=
|fuel capacity=
|more general=
<!--
        Powerplant
-->
|eng1 number=1
|eng1 name=[[Armstrong Siddeley Lynx]]
|eng1 type=7-cylinder air-cooled radial piston engine
|eng1 kw=149-160
|eng1 note=

|prop blade number=2
|prop name=fixed-pitch propeller
|prop dia m=<!-- propeller aircraft -->
|prop dia note=
<!--
        Performance
-->
|max speed kmh=190
|max speed note=
|cruise speed kmh=160
|cruise speed note=
|stall speed kmh=
|stall speed note=
|never exceed speed kmh=
|never exceed speed note=
|range km=
|range note=
|combat range km=
|combat range note=
|ferry range km=
|ferry range note=
|endurance=<!-- if range unknown -->
|ceiling m=5000
|ceiling note=
|g limits=<!-- aerobatic -->
|roll rate=<!-- aerobatic -->
|climb rate ms=
|climb rate note=
|time to altitude=
|wing loading kg/m2=
|wing loading note=
|fuel consumption kg/km=
|power/mass=
|more performance=<!--<br />
*'''Take-off run:''' {{cvt||m|0}}
*'''Take-off run to {{cvt|15|m|0}}:''' {{cvt||m|0}}
*'''Landing run:''' {{cvt||m|0}}
*'''Landing run from {{cvt|15|m|0}}:''' {{cvt||m|0}}-->

|avionics=
}}

==See also==
{{aircontent|
|related=
|similar aircraft=
|lists=
* [[List of military aircraft of Germany]]
* [[List of military aircraft of Sweden]]
|see also=
}}

==References==
{{Commons category|Raab-Katzenstein RK 26}}
{{reflist}}

{{Raab-Katzenstein aircraft}}
{{Fieseler aircraft}}
{{ASJA aircraft}}
{{Swedish military aircraft designations}}

[[Category:Raab-Katzenstein aircraft]]
[[Category:Biplanes]]
[[Category:Aerobatic aircraft]]
[[Category:Single-engined tractor aircraft]]
[[Category:1920s German military trainer aircraft]]
[[Category:Aircraft first flown in 1929]]