View source for Mitsubishi Ki-51

{{Short description|Japanese light bomber/dive bomber}}
<!-- This article is a part of [[Wikipedia:WikiProject Aircraft]]. Please see [[Wikipedia:WikiProject Aircraft/page content]] for recommended layout. -->
{{Infobox aircraft
| name = Ki-51
| image = File:Mitsubishi Ki-51-1.jpg
| caption = Mitsubishi Ki-51
| type = [[Light bomber]]/[[dive bomber]]
| manufacturer = [[Mitsubishi Aircraft Company|Mitsubishi Jukogyo KK]]
| designer = <!--only appropriate for individuals, not for project leaders or a company or corporation-->
| first_flight = mid-1939
| introduction = <!--date the aircraft will enter military or revenue service, if the aircraft is still in development -->
| 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 = [[Imperial Japanese Army Air Service]]
| more_users = 
| number_built = 2,385<ref>{{cite book|last=Angelucci|first=Enzo|title=Combat aircraft of World War II|year=1988|page=26|isbn=0-517-64179-8}}</ref>
| unit cost = 
| developed_from = 
| variants = <!-- variants OF the topic type -->
}}

The '''Mitsubishi Ki-51''' (Army designation "'''Type 99 Assault Plane'''"; [[World War II Allied names for Japanese aircraft|Allied reporting name]] "'''Sonia'''") was a [[light bomber]]/[[dive bomber]] in service with the [[Imperial Japanese Army]] during [[World War II]]. It first flew in mid-1939. Initially deployed against Chinese forces, it proved to be too slow to hold up against the [[fighter aircraft]] of the other [[Allies of World War II|Allied]] powers. However, it performed a useful [[Ground-attack aircraft|ground-attack]] role in the [[China Burma India Theater|China-Burma-India theater]], notably from airfields too rough for many other aircraft. As the war drew to a close, the Japanese began using them in ''[[kamikaze]]'' attacks. Total production was around 2,385 units.

On the day [[Atomic bombings of Hiroshima and Nagasaki|Hiroshima was destroyed by an atomic bomb]], a single Ki-51 was responsible for the last Japanese sinking of a US warship, sinking {{USS|Bullhead|SS-332}} with all hands.

==Variants==
* '''Prototypes''': two built
* '''Service trials''': 11 built
* '''Ki-51''': 2,372 built (Manufacturers: Mitsubishi (1,462), Tachikawa Army Air Arsenal (913)) until March 1944
* '''Ki-51A''': reconnaissance version.
* '''Ki-51B''': assault version with armor and bomb racks to carry {{cvt|441|lb|kg|order=flip}} of bombs. It could also be fitted with an aerial camera.
* '''Mansyu Ki-71''': three prototypes built by [[Manshū Aircraft Company|Mansyu]] with retractable landing gear, did not enter production.<ref name="Francillon1979p180">{{harvnb|Francillon|1979|p=180.}}</ref>

==Operators==
;{{JPN}}
* [[Imperial Japanese Army Air Force]]
;{{flag|Republic of China}}
;{{CHN}}
* Communist Chinese (captured): The last 4 of around 100 Ki-51s were retired in 1953.
;{{flag|France}}
* [[French Air Force]] - At least two Ki-51 was used by French Air Force in Indochina during [[First Indochina War]].<ref>{{cite web |url=https://hedgehoghollow.com/awoic/japan.html |title=Japanese Aircraft used by the French |website=hedgehoghollow.com |access-date=1 October 2024 }}</ref>
;{{flag|Indonesia}}
* [[Indonesian Air Force]] - In late 1945, the Indonesian [[People's Security Army]] (TKR) captured some aircraft at former Japanese bases, including [[Abdul Rachman Saleh Airport|Bugis Air Base]] in [[Malang]]. Most aircraft were destroyed during the [[Indonesian National Revolution]] of 1945–1949. Two [[Yokosuka K5Y]] "Cureng" and a Ki-51 "Guntei" carried out a bombing operation against the Dutch on 29 July 1947.
;{{DPRK}}
* Following independence, transferred from the Soviet Union.
;{{ROK}}
* Used by South Korean Airforce during Korean War

==Surviving aircraft==
[[File:Guntei.jpg|thumb|Indonesian Air Force Ki-51 "Guntei" at [[Dirgantara Mandala Museum]]]]
The only complete survivor of Ki-51 is part of the collection of the [[Dirgantara Mandala Museum]] in Indonesia. The aircraft was found abandoned at the [[Babo Airfield]] in [[West Papua (province)|West Papua province]]. The aircraft was likely stripped for spare parts and later abandoned. Before the aircraft was recovered, its propeller blade was cut off, with its engine cowling and cockpit canopy was missing. The aircraft was recovered from Babo airfield in 1987, was restored and then displayed with Indonesian Air Force markings at the Dirgantara Mandala Museum.<ref>{{cite web |url=https://pacificwrecks.com/aircraft/ki-51/iafm.html |title=Ki 51 Sonia (Babo Airfield / Indonesian Air Force Museum) |website=pacificwrecks.com |date=9 November 2019 |access-date=1 October 2024 }}</ref><ref>{{cite web |url=https://j-aircraft.com/walk/other/ki51.htm |title=Yogyakarta Ki-51 "Sonia" |website=j-aircraft.com |access-date=1 October 2024 }}</ref>

==Specifications (Ki-51)==
[[File:Mitsubishi Ki-51 3-view line drawing.png|thumb|3-view drawing of the Mitsubishi Ki-51]]
{{Aircraft specs
|ref=''Japanese Aircraft of the Pacific War''<ref name="Francillon1979p181">{{harvnb|Francillon|1979|p=181.}}</ref> 
|prime units?=met
<!--
        General characteristics
-->
|crew=2
|length m=9.21
|length note=
|span m=12.1
|span note=
|height m=2.73
|height note=
|wing area sqm=24
|wing area note=
|aspect ratio=<!-- sailplanes -->
|airfoil=
|empty weight kg=1873
|empty weight note=
|gross weight kg=2798
|gross weight note=
|max takeoff weight kg=2920
|max takeoff weight note=
|fuel capacity=
|more general=
<!--
        Powerplant
-->
|eng1 number=1
|eng1 name= [[Mitsubishi Ha-26-II]]
|eng1 type=14-cylinder air-cooled radial piston engine
|eng1 hp=950
|eng1 note=

|prop blade number=3
|prop name=variable-pitch propeller
|prop dia m=<!-- propeller aircraft -->
|prop dia note=
<!--
        Performance
-->
|max speed kmh=424
|max speed note=at {{cvt|3000|m}}
|cruise speed kmh=
|cruise speed note=
|stall speed kmh=
|stall speed note=
|never exceed speed kmh=
|never exceed speed note=
|range km=1060
|range note=
|combat range km=
|combat range note=
|ferry range km=
|ferry range note=
|endurance=<!-- if range unknown -->
|ceiling m=8270
|ceiling note=
|g limits=<!-- aerobatic -->
|roll rate=<!-- aerobatic -->
|climb rate ms=
|climb rate note=
|time to altitude={{cvt|5000|m}} in 9 minutes 55 seconds
|wing loading kg/m2=117
|wing loading note=
|fuel consumption kg/km=
|power/mass={{cvt|0.24|kW/kg|hp/lb}}
|more performance=
<!--
        Armament
-->
|guns=<br>
** 2× fixed, forward-firing 7.7 mm (.303 in) [[Type 89 machine gun]]s (replaced with 2× 12.7 mm (.5 in) [[Ho-103 machine gun]]s in later models)
** 1× 7.7 mm (.303 in) [[Type 89 machine gun|Te-4 Machine gun]] rearward-firing machine gun.
|bombs= 200 kg (441 lb) bombs (normal operations); 250 kg (551 lb) for suicide operations<ref name="Francillon1979p181"/>

|avionics=
}}

==See also==
{{aircontent
|related=
|similar aircraft=
* [[Aichi D3A]]
* [[Douglas SBD Dauntless]]
* [[Ilyushin Il-2]]
* [[Junkers Ju 87|Junkers Ju 87D]]
* [[Kawasaki Ki-32]]
* [[Mitsubishi Ki-30]]
|lists=
* [[List of military aircraft of Japan]]
}}

==Notes==
{{reflist}}

==Bibliography==
* {{Cite book|last=Francillon|first=René J.|url=https://www.worldcat.org/oclc/6124909|title=Japanese aircraft of the Pacific War|date=1979|publisher=Putnam|isbn=0-370-30251-6|location=London|oclc=6124909}} (new edition 1987 by Putnam Aeronautical Books, {{ISBN|0-85177-801-1}}.)
*{{cite journal |last1=Green|first1=William|last2=Swanborough|first2=Gordon|name-list-style=amp |title=Pentagon Over the Islands: The Thirty-Year History of Indonesian Military Aviation|journal=Air Enthusiast Quarterly |date=n.d. |issue=2 |pages=154–162 |issn=0143-5450}}
*{{cite journal |last1=Soumille|first1=Jean-Claude|title=Les avions japonais aux couleurs françaises |journal=Avions: Toute l'Aéronautique et Son Histoire |date=September 1999 |issue=78 |pages=6–17 |trans-title=Japanese Aircraft in French Colors|language=French |issn=1243-8650}}

==External links==
{{commons category|Mitsubishi Ki-51}}
* [http://www.warbirdsresourcegroup.org/IJARG/mitsubishiki51.html Mitsubishi Ki 51 Sonia at Warbirds Resource Group]
* [http://www.pilotfriend.com/photo_albums/timeline/ww2/Mitsubishi%20Ki%2051%20Sonia.htm Mitsubishi Ki 51 Sonia at Pilotfriend]
* [http://ndlsearch.ndl.go.jp/books/R100000002-I024881861 Manual for Operating Type 99 Army Reconnaissance and Type 99 Army Assault Plane – National Diet Library]

{{Mitsubishi aircraft}}
{{Tachikawa aircraft}}
{{Mansyu aircraft}}
{{Japanese Army Aircraft Designation System}}
{{Allied reporting names}}

[[Category:Mitsubishi aircraft|Ki-051]]
[[Category:1930s Japanese attack aircraft]]
[[Category:Single-engined tractor aircraft]]
[[Category:Low-wing aircraft]]
[[Category:World War II Japanese dive bombers|Ki-51, Mitsubishi]]
[[Category:Aircraft first flown in 1939]]