View source for Yakovlev Yak-11

{{Short description|Soviet military training aircraft}}
<!-- This article is a part of [[Wikipedia:WikiProject Aircraft]]. Please see [[Wikipedia:WikiProject Aircraft/page content]] for recommended layout. -->
{{Infobox aircraft
  |name = Yak-11
  |image = File:Let C-11 (Yak-11) F-AZFJ (9684468633).jpg
  |caption =Let C-11
  |type =Training aircraft
  |manufacturer =[[Yakovlev]], [[Let Kunovice|Let]]
  |designer =
  |first_flight = 10 November 1945
  |introduction = 1946
  |retired = 1962
  |status =
  |primary_user =[[Soviet Air Force]]
  |more_users =
  |produced =
  |number_built =4,566
  |unit cost =
  |developed_from =[[Yakovlev Yak-3]]
  |variants =
}}

The '''Yakovlev Yak-11''' ({{langx|ru|Яковлев Як-11}}; [[NATO reporting name]]: "'''Moose'''") is a [[trainer aircraft]] used by the [[Soviet Air Force]] and other Soviet-influenced air forces from [[1947 in aviation|1947]] until [[1962 in aviation|1962]].

==Design and development==
The [[Yakovlev|Yakovlev design bureau]] began work on an advanced trainer based on the [[Yakovlev Yak-3|Yak-3]] fighter in mid-1944, although the trainer was of low priority owing to the ongoing [[Second World War]].<ref name="GunRus p469">Gunston 1995, p. 469.</ref> The first prototype of the new trainer, designated Yak-UTI or Yak-3UTI flew in late 1945. It was based on the [[radial engine|radial]]-powered Yak-3U, but with the new [[Shvetsov ASh-21]] seven-cylinder radial replacing the [[Shvetsov ASh-82|ASh-82]] of the Yak-3U.<ref name="OKBYak p249">Gordon Komissarov and Komissarov 2005, p. 249.</ref>{{#tag:ref|The single-row ASh-21 was essentially half of the two-row, 14-cylinder ASh-82.<ref name="GunRus p469"/>|group=nb}} It used the same all-metal wings as the Yak-3U, with a  fuselage of mixed metal and wood construction. The pilot and observer sat in tandem under a long canopy with separate sliding hoods. A single [[synchronization gear|synchronised]] [[Berezin UB|UBS]] 12.7&nbsp;mm machine gun and wing racks for two 100&nbsp;kg (220&nbsp;lb) bombs comprised the aircraft's armament.<ref name="GunYak p97">Gunston and Gordon 1997, p. 97.</ref>

[[File:LET C-11 ‘1706’ (33733903654).jpg|left|thumb|Let C-11]]
An improved prototype flew in 1946, with revised cockpits and a modified engine installation with the engine mounted on shock absorbing mounts.<ref name="OKBYak p249"/> This aircraft passed state testing in October 1946, with production beginning at factories in [[Saratov]] and [[Leningrad]] in 1947.<ref name="GunYak p99">Gunston and Gordon 1997, p. 99.</ref>

Production Yak-11s were heavier than the prototypes, with later batches fitted with non-retractable tailwheels and revised propellers. A 7.62&nbsp;mm [[ShKAS machine gun]] was sometimes fitted instead of the UBS, while some were fitted with rear-view periscopes above the windscreen.<ref name="GunYak p99"/> Soviet production totalled 3,859 aircraft between 1947 and 1955, with a further  707 licence-built by [[Let Kunovice|Let]] in [[Czechoslovakia]] as the C-11.<ref name="OKBYak p250-1">Gordon Komissarov and Komissarov 2005, pp. 250–251.</ref>

=== Yak-11U ===
In 1951, Yakovlev revised the design of the Yak-11, adding a retractable [[tricycle landing gear]], with two variants proposed, the Yak-11U basic trainer and Yak-11T proficiency trainer, which carried equipment similar to contemporary jet fighters. The new aircraft had reduced fuel capacity and was unsuitable for operations on rough or snow-covered runways, and so was rejected for Soviet service, although a few units were built in Czechoslovakia as the C-11U.<ref name="OKBYak p251">Gordon Komissarov and Komissarov 2005, p. 251.</ref>

==Operational history==
[[File:Yak 11 Egyptian 1964.jpg|thumb|Egyptian Air Force Yak-11]]
The Yak-11 entered service in 1947, serving as a standard advanced trainer with the [[Soviet Air Forces]] and [[DOSAAF]].<ref name="OKBYak p250">Gordon Komissarov and Komissarov 2005, p. 250.</ref> Both the Yak-11 and C-11 were used in all [[Warsaw Pact]] countries and were exported to eighteen countries, including many African, [[Middle East]]ern and Asian countries.<ref name="GunYak p99"/>

Egyptians used the aircraft extensively during their intervention in the Yemeni Civil war. Egyptian aircraft were modified with Sakr 78mm unguided rockets and two .303in guns in the wings. and were used in the ground attack role. 

[[North Korea]]n Yak-11s were used in combat in the [[Korean War]], with one Yak-11 being the first North Korean aircraft shot down by US forces when it was destroyed by a [[North American F-82 Twin Mustang]] over [[Kimpo Airfield]] on 27 June 1950.<ref name="IAPRtwin p160-1">Thompson 2001, pp. 160–161.</ref>  [[East Germany]] used the Yak-11 to intercept American [[Espionage balloon|reconnaissance balloons]].<ref name="OKBYak p250"/>


==Surviving aircraft==
[[File:86 Yak 11 N5934 Czech Mate 2014 gold heat photo D Ramey Logan.jpg|Heavily modified Yak-11 used for air racing|thumb]]
Due to its Yak-3 lineage, the Yak-11 has recently seen widespread popularity among [[warbird]] enthusiasts. Highly modified versions of the Yak-11 are often seen at [[air race]]s. About 120 Yak-11s remain airworthy.

==Operators==
{{acopmap|Yak-11|Yak-11 operators}}
[[File:Yak-11 (NPA).JPG|thumb|Fighter/trainer aircraft Yakovlev Yak-11 ([[National People's Army]])]]
[[File:Jak-11 RB.jpg|thumb|right|Preserved Yak-11 of the [[Polish Air Force]]]]
[[File:Jak 11 D-FYAK.jpg|thumb|Yakovlev Yak-11 disguised in wartime fighter camouflage]]

;{{flag|Afghanistan|1980}}
*[[Afghan Air Force]] − Received 12 in 1955.<ref name="SIPRI">{{cite web |title=Arms transfer database |url=https://armstransfers.sipri.org/ArmsTransfer/TransferRegister |website=Stockholm International Peace Research Institute |access-date=16 May 2024}}</ref> Operated an unknown number as late as 1981{{sfn|Paxton|2016|page=66}}
;{{flag|Albania|1946}}
*[[Albanian Air Force]] − Received 6 in 1953<ref name="SIPRI" /> 
;{{DZA}}
*[[Algerian Air Force]] − 12 ex-Egyptian aircraft delivered in 1964, possibly modernized in Czechoslovakia before delivery<ref name="SIPRI" />
;{{ANG}}
*[[National Air Force of Angola]]{{citation needed|date=May 2024}}
;{{AUT}}
*[[Austrian Air Force]]{{sfn|Wragg|2011|page=63}} − 4 donated by the Soviet Union in 1955<ref name="SIPRI" />
;{{flag|Bulgaria|1948}}
*[[Bulgarian Air Force]] − 30 C-11 received in 1954<ref name="SIPRI" />
;{{CHN}}
*[[People's Liberation Army Air Force]] − 50 delivered in 1950<ref name="SIPRI" />
;{{CSK}}
*[[Czechoslovak Air Force]] − 120, produced under license<ref name="SIPRI" />
;{{DDR}}
*[[Air Forces of the National People's Army|East German Air Force]]{{sfn|Wragg|2011|page=133}}
;{{flag|Egypt|1952}}
*[[Egyptian Air Force]]{{sfn|Cooper|2017|page=12}}
;{{flag|Iraq|1963}}
*[[Iraqi Air Force]]{{sfn|Wragg|2011|page=158}}
;{{flag|Hungary|1949}}
*[[Hungarian Air Force]]{{sfn|Wragg|2011|page=145}}
;{{MLI}}
*[[Malian Air Force]] − 4, non-operational by 2011{{sfn|Wragg|2011|page=191}}
;{{flag|Mongolia|1945}}
*[[Mongolian People's Army|Mongolian People's Air Force]]{{sfn|Wragg|2011|page=196}}
;{{PRK}}
*[[North Korean Air Force]]{{sfn|Wragg|2011|page=176}}
;{{flag|Poland|1928}}
*[[Polish Air Force]] − Received 40 in 1953<ref name="SIPRI" />
;{{flag|Romania|1952}}
*[[Romanian Air Force]] − Received 20 between 1952 and 1953<ref name="SIPRI" />
;{{SOM}}
*[[Somali Air Corps]] − 20, non-operational by 1991{{sfn|Wragg|2011|page=256}}
;{{USSR}}
*[[Soviet Air Force]]
*[[DOSAAF]]
;{{SYR}}
*[[Syrian Air Force]]{{sfn|Wragg|2011|page=273}}
;{{VIE}}
*[[Vietnam People's Air Force]]{{citation needed|date=May 2024}}
;{{YEM}}
*[[Yemen Air Force#Birth of the North and South Yemeni Air Forces|North Yemen Air Force]] − 30 donated by the Soviet Union between 1957 and 1958<ref name="SIPRI" />

==Specifications (Yak-11)==
[[File:Yakolev Yak-11 3-view silhouette.jpg|thumb]]
{{Aircraft specs
    |ref                        = <!-- reference --> 
    |prime units?               = met
    <!-- imp or kts first for US aircraft, and UK aircraft pre-metrification, 
    met(ric) first for all others. You MUST choose a format, or no specifications will show -->
    <!--General characteristics-->
    |crew                   = two, student and instructor
    |capacity               = 
    |length m               = 8.20
    |length ft              = 26
    |length in              = 10.5
    |span m                 = 9.4
    |span ft                = 30
    |span in                = 10
    |height m               = 3.28
    |height ft              = 10
    |height in              = 5
    |wing area sqm          = 15.40
    |wing area sqft         = 166
    |aspect ratio           = 
    |airfoil                = 
    |empty weight kg        = 1900
    |empty weight lb        = 4189
    |gross weight kg        = 
    |gross weight lb        = 
    |max takeoff weight kg  = 2440
    |max takeoff weight lb  = 5379
    |more general           = 
    <!--Powerplant-->
    |eng1 number            = 1
    |eng1 name              = [[Shvetsov ASh-21]]
    |eng1 type              = air-cooled radial piston engine
    |eng1 kw                = <!-- prop engines --> 521
    |eng1 hp                = <!-- prop engines --> 700
    |eng1 shp               = <!-- prop engines --> 
    |eng1 kn                = <!-- jet/rocket engines --> 
    |eng1 lbf               = <!-- jet/rocket engines --> 
    |power original         = 
    |thrust original        = 
    |eng1 kn-ab             = 
    |eng1 lbf-ab            = 
    |more power             = 
    |prop name              = 
    |prop dia m             = <!-- propeller aircraft --> 
    |prop dia ft            = <!-- propeller aircraft --> 
    |prop dia in            = <!-- propeller aircraft --> 
    |rot dia m              = <!-- helicopters --> 
    |rot dia ft             = <!-- helicopters --> 
    |rot dia in             = <!-- helicopters --> 
    |rot area sqm           = <!-- helicopters --> 
    |rot area sqft          = <!-- helicopters --> 
    |rot number             = 
    <!--Performance-->
    |max speed kmh          = 460
    |max speed mph          = 289
    |max speed kts          = 248
    |max speed note         = 
    |max speed mach         = 
    |cruise speed kmh       = 370
    |cruise speed mph       = 230
    |cruise speed kts       = 
    |cruise speed note      = 
    |stall speed kmh        = 
    |stall speed mph        = 
    |stall speed kts        = 
    |stall speed note       = 
    |never exceed speed kmh = 
    |never exceed speed mph = 
    |never exceed speed kts = 
    |range km               = 1250
    |range miles            = 795
    |range nmi              = 
    |range note             = 
    |combat range km        = 
    |combat range miles     = 
    |combat range nmi       = 
    |combat range note      = 
    |ferry range km         = 
    |ferry range miles      = 
    |ferry range nmi        = 
    |ferry range note       = 
    |endurance              = <!-- if range unknown --> 
    |ceiling m              = 7100
    |ceiling ft             = 23295
    |ceiling note           = 
    |climb rate ms          = 8.1
    |climb rate ftmin       = 1600
    |climb rate note        = 
    |sink rate ms           = <!-- sailplanes --> 
    |sink rate ftmin        = <!-- sailplanes --> 
    |sink rate note         = 
    |wing loading kg/m2     = 161
    |wing loading lb/sqft   = 32.9
    |disk loading kg/m2     = 
    |disk loading lb/sqft   = 
    |power/mass             = 0.17 kW/kg (0.10&nbsp;hp/lb)
    |thrust/weight          = 
    |more performance       = 
    <!--Armament-->
    |armament = *1x nose-mounted [[machine gun]], either 12.7&nbsp;mm [[Berezin UB|UBS]] or 7.62&nbsp;mm [[ShKAS machine gun|ShKAS]]
*up to 200&nbsp;kg (440 lb) of bombs on two underwing racks<!-- add bulletted list here or if you want to use the following 
        specific parameters, remove this parameter--> 
    |guns                   = 
    |bombs                  = 
    |rockets                = 
    |missiles               = 
    |hardpoints             = 
    |hardpoint capacity     = 
    |hardpoint rockets      = 
    |hardpoint missiles     = 
    |hardpoint bombs        = 
    |hardpoint other        = 
    |avionics               = 
    }}

==See also==
{{Portal|Aviation}}
{{aircontent|
|related=
*[[Yakovlev Yak-3]]
|similar aircraft=
*[[Boulton Paul Balliol]]
*[[Fiat G.49]]
*[[North American T-6 Texan]]
*[[PZL TS-8 Bies]]
*[[Soko 522]]
*[[Valmet Vihuri]]
|sequence=
|lists=<!-- related lists -->
|see also=<!-- other relevant information -->
}}

==Notes==
{{reflist|group=nb}}

==Citations==
{{reflist}}

==References==
{{Commons category|Yakovlev Yak-11}}

* {{cite book |last1=Cooper |first1=Tom |title=Hot Skies Over Yemen, Volume 1: Aerial Warfare Over the South Arabian Peninsula, 1962-1994 |date=2017 |publisher=Helion & Company Publishing |location=Solihull, UK |isbn=978-1-912174-23-2}}
* Gordon, Yefim, Dmitry Komissarov and Sergey Komissarov. ''OKB Yakovlev: A History of the Design Bureau and its Aircraft''. Hinkley, UK: Midland Publishing, 2005. {{ISBN|1-85780-203-9}}.
* [[Bill Gunston|Gunston, Bill]].  ''The Osprey Encyclopedia of Russian Aircraft 1975–1995''. London, UK: Osprey, 1995. {{ISBN|1-85532-405-9}}.
* Gunston, Bill and Yefim Gordon. ''Yakovlev Aircraft since 1924''. London, UK: Putnam Aeronautical Books, 1997. {{ISBN|1-55750-978-6}}.
* {{cite book |editor1-last=Paxton |editor1-first=John |title=The Statesman's Year-Book 1981-82 |date=2016 |publisher=Springer |isbn=978-0-230-27110-4 |url=https://books.google.com/books?id=RfrFDQAAQBAJ |language=en}}
* Thompson, Warren. "Twin Mustang in Korea". ''International Air Power Review''. Volume 3, Winter 2001/2002. Norwalk, Connecticut, USA:AIRtime Publishing. {{ISBN|1-880588-36-6}}. {{ISSN|1473-9917}}. pp.&nbsp;156–167.
* {{cite book |last1=Wragg |first1=David |title=The World Air Power Guide |date=2011 |publisher=Casemate Publishers |isbn=978-1-84468-784-8 |url=https://books.google.com/books?id=s2PNDwAAQBAJ&q=the+world+air+power+guide |language=en}}


{{Yakovlev Yak-1 family}}
{{Yakovlev aircraft}}
{{Czech trainer aircraft}}

[[Category:Yakovlev aircraft|Yak-011]]
[[Category:Low-wing aircraft]]
[[Category:1940s Soviet military trainer aircraft]]
[[Category:Aerobatic aircraft]]
[[Category:Single-engined tractor aircraft]]
[[Category:Aircraft first flown in 1945]]
[[Category:Aircraft with retractable conventional landing gear]]
[[Category:Single-engined piston aircraft]]