View source for General Aircraft Monospar ST-25

{{Use dmy dates|date=March 2017}}
{{Use British English|date=March 2017}}
{{Infobox aircraft
 |name = Monospar ST-25
 |image = Monospar.jpg
 |caption = Monospar ST-25 Jubilee of Eloy Fernández Navamuel during the Spanish Civil War<ref>Howson, 1990</ref>
 |type =
 |national_origin = United Kingdom
 |manufacturer = [[General Aircraft Limited|General Aircraft Ltd, Hanworth]]
 |designer = <!--only appropriate for single designers, not project leaders-->
 |first_flight = 19 June 1935
 |introduction = <!--date the aircraft entered military or revenue service-->
 |retired = <!--date the aircraft left military or revenue service. if vague or multiples, it probably should be skipped-->
 |status = <!--in most cases, this field is redundant; use it sparingly-->
 |primary_user =
 |more_users =
 |produced = 1935–1939
 |number_built = 60
 |unit cost =
 |developed_from = [[General Aircraft Monospar|General Aircraft Monospar ST-10]]
 |variants = <!-- variants OF the topic type -->
}}

The '''General Aircraft Monospar ST-25''' was a British 1930s light twin-engined utility aircraft.

==Design and development==
The Monospar ST-25 was a low-wing cantilever monoplane with a fabric-covered metal structure. The monospar name came from the use of a single [[spar (aviation)|spar]] in the wing structure, that had been developed by H J Stieger. The cabin was enclosed with five seats. It was based on the GAL [[Monospar ST-10]], with the addition of a folding seat for a fifth passenger, extra side windows, and the addition of a radio receiver. On 19 June 1935, the prototype (G-ADIV) made its first flight at [[Hanworth Air Park]]. It was designated Monospar ST-25 Jubilee, to honour the 25th anniversary of the reign of King George V.<ref name=jackson1973>Jackson 1973, pp. 215–220</ref>

==Operational history==
*The last flying Monospar ST-25 (ZK-AFF), of [[Henry Piet Drury van Asch|Piet Van Asch]], the owner of New Zealand Aerial Mapping Ltd, was lost in 1986 in a hangar fire.<ref>[http://www.wings.net.nz/oldwings/aerialmap.html PIET VAN ASCH – New Zealand's Aerial Mapping Pioneer at wings.net.nz] {{webarchive|url=https://web.archive.org/web/20130209215109/http://www.wings.net.nz/oldwings/aerialmap.html |date=9 February 2013 }}</ref>
*The last surviving Monospar ST-25 (OY-DAZ), an ST-25 Ambulance, was fully restored during 1989–1999, and is now displayed in ''Egeskov Veteranmuseum'' at [[Egeskov Castle]], Denmark.<ref>Ogden (2009)</ref>

==Variants==
[[File:GAL Monospar ST-25 0792.jpg|thumb|Monospar ST-25 Universal, after conversion from ST-25 De Luxe]]
[[File:Monospar ST-25.jpg|thumb|right|Monospar ST-25 Universal]]  
;Monospar ST-25 Jubilee
:(1935-1936) Single fin and rudder. 30 built.<ref name=jackson1973/>
;Monospar ST-25 De Luxe
:One Monospar ST-25 Jubilee with a large single fin and two [[Pobjoy Niagara|Niagara II]] engines, later converted to the prototype Monospar ST-25 Universal, with twin fins.<ref name=jackson1973/>
;Monospar ST-25 Ambulance
:Variants of both Monospar ST-25 Jubilee and ST-25 Universal, with a large door on the starboard side to allow a stretcher to be loaded.<ref name=jackson1973/>
;Monospar ST-25 Universal
:(1936-1939) Twin fin and twin rudder. 29 built, including the conversion of the De Luxe.<ref name=jackson1973/>
;Monospar ST-25 Freighter
:A variant of the Monospar ST-25 Universal, with a large freight door but without the passenger seating.<ref name=jackson1973/>
;GAL.26
:One modified Monospar ST-25 Jubilee, fitted with two [[Blackburn Cirrus Minor|Cirrus Minor I]] engines in 1936.<ref name=jackson1973/>
;GAL.41
:One experimental aircraft based on the Monospar ST-25 Universal. A new fuselage was built containing a pressurized section with two seats. Its purpose was to test possible pressurization systems for a proposed airliner, the GAL.40.<ref name="am1290p7346">{{harvnb|Jarrett|1990|pp=734–736}}</ref>{{#tag:ref|The [[Fairey FC1]] was selected to meet the requirement for the airliner.<ref>{{harvnb|Jarrett|1990|p=735}}</ref>|group=lower-alpha}} The GAL.41 flew for the first time on 11 May 1939,<ref>{{harvnb|Jarrett|1990|p=736}}</ref> and was grounded in 1941.<ref>[https://web.archive.org/web/20090107194501/http://www.jaapteeuwen.com/ww2aircraft/html%20pages/GENERAL%20AIRCRAFT%20MONOSPAR%20ST-25.htm General Aircraft Monopar ST-25] – British Aircraft of World War II accessed 1 July 2017]</ref>

==Operators==
;{{flag|Aden}}
*[[Arabian Airways]]<ref name="am488p238"/>
;{{AUS}}
*Adelaide Airways/[[Australian National Airways]]<ref name="am488p238">{{harvnb|Stroud|1988|p=238}}</ref>
*[[MacRobertson Miller Airlines|Airlines WA]]<ref name="am488p238"/>
;{{CAN}}
*[[Eastern Canada Air Lines]] (five ST-25 Freighters, delivered in 1936)<ref name="am488p238"/>
* Maritime Airways<ref name="am488p238"/>
;{{DEN}}
*[[Zone-Redningskorpset]] - 1 ambulance version<ref name="am488p238"/>
;{{EST}}
*ES-AXY "Vahur", in the service of the Ministry of Transport and Communications<ref>[http://www.ra.ee/fotis/index.php/et/photo/view?id=34461&_xr=6125e033631c8 Estonian National Archives Photo Database, EFA.446.0.194553]</ref>
;{{FRA}}
*Armée de l'Air (2 ST-25 in Indochine (Vietnam) in November 1945)<ref>{{cite web|title = Les Nakajima Ki-43 " Oscar " dans l’Armée de l’Air, une fausse bonne idée |language = fr|url = http://www.avionslegendaires.net/dossier/recits/nakajima-ki-43-oscar-larmee-de-lair-fausse-bonne-idee/|date = 21 February 2016}}</ref>
;{{NED}}
*Van Melle's Confectionery Works, Breskens (one Jubilee, PH-IPM "Dubbele Arend", delivered in 1935)<ref>{{cite web|url = http://www.geschiedeniszeeland.nl/tab_themas/themas/luchtvaart/rond_vliegveld/|language = nl|archive-url = https://web.archive.org/web/20140225090851/http://www.geschiedeniszeeland.nl/tab_themas/themas/luchtvaart/rond_vliegveld/|archive-date = 25 February 2014|title = Rond vliegveld}}</ref>
;{{NZL}}
*New Zealand Aerial Mapping
*[[Royal New Zealand Air Force]]
;{{ROM}}
*[[Royal Romanian Air Force]]
;{{flag|Spain|1931}}
*[[Spanish Republican Air Force]]
;{{ESP}}
*[[Spanish Air Force]]
;{{TUR}}
*[[General Command of Mapping (Turkey)]]
*Turkish Government (two ST-25 Freighters for parachute training delivered in 1937)
;{{UK}}
*Crilly Airways<ref name="am488p237">{{harvnb|Stroud|1988|p=237}}</ref>
* Utility Airways<ref name="am488p2378">{{harvnb|Stroud|1988|pp=237–238}}</ref>
*[[Royal Aircraft Establishment]] (two Jubilees used for radio development)
*[[Royal Air Force]] (impressed civil aircraft used during the second world war)

==Specifications (Monospar ST-25 Jubilee)==
{{Aircraft specs
|ref=Jackson, 1973
|prime units?=imp
<!--
        General characteristics
-->
|crew=one
|length m=8.03
|span m=12.24
|height m=2.39
|wing area sqft=217
|empty weight lb=1,680
|gross weight lb=2,875

<!--
        Powerplant
-->
|eng1 number=2
|eng1 name=[[Pobjoy Niagara]] II
|eng1 type=7-cyl. air-cooled radial piston engine
|eng1 hp=90
<!--
        Performance
-->
|max speed mph=142
|range miles=585
|ceiling ft=16,000
|climb rate ftmin=800
}}

==See also==
*[[General Aircraft ST-18 Croydon]]

==References==
===Notes===
{{reflist|group=lower-alpha}}

===Citations===
{{reflist}}

===Bibliography===
*Howson, Gerald. 1990. ''Aircraft of the Spanish Civil War 1936–39''. Putnam {{ISBN|978-0-85177-842-6}}
*Jackson, A.J. (1973). ''British Civil Aircraft since 1919'', Volume 2. Putnam. pp.&nbsp;215–220, 519–521 {{ISBN|0-370-10010-7}}
* {{cite magazine |last=Jarrett |first=Philip |author-link=Philip Jarrett |title=Nothing Ventured...No 9 |magazine=[[Aeroplane Monthly]] |date=December 1990 |volume=18 |issue=12 |pages=734–737, 775 |issn=0143-7240}}
* {{cite magazine |last1=Lumsden |first1=Alec |last2=Heffernan |first2=Terry |title=Probe Probare No 2: Monospar ST-25 |magazine=Aeroplane Monthly |date=February 1984 |volume=12 |issue=2 |pages=94–96 |issn=0143-7240}}
*Ogden, Bob (2009). ''Aviation Museums and Collections of Mainland Europe''. Air-Britain. {{ISBN|978-0-85130-418-2}}
* {{cite magazine |last=Stroud |first=John |title=Wings of Peace |magazine=Aeroplane Monthly |date=April 1988 |volume=16 |issue=4 |pages=232–238 |issn=0143-7240}} 
*{{cite magazine|last=Wright|first=Matthew|title=Mapping by Monospar|magazine=[[Air Enthusiast]]|date=1991|issue=44 |pages=6–9 |issn=0143-5450}} 
<!-- ==External links== -->

{{GAL aircraft}}
{{Spanish liaison aircraft}}

[[Category:1930s British civil utility aircraft]]
[[Category:General Aircraft Limited aircraft|ST-25]]
[[Category:Low-wing aircraft]]
[[Category:Aircraft first flown in 1935]]
[[Category:Twin piston-engined tractor aircraft]]