View source for 1st Air Fleet

{{Short description|Imperial Japanese Navy unit during the Pacific War}}
{{Use dmy dates|date=March 2025}}
{{Infobox military unit
| unit_name                   = 1st Air Fleet (IJNAS)
| native_name                 = {{nihongo|第一航空艦隊|Daiichi Kōkū Kantai}}
| image                       = Naval ensign of the Empire of Japan.svg
| image_size                  = 200px
| caption                     = [[Rising Sun Flag]]
| dates                       = 10 April 1941 – 14 July 1942<br> 1 June 1943 – 15 June 1945
| country                     = {{flag|Empire of Japan}}
| allegiance                  = {{flagicon image|Flag of the Japanese Emperor.svg}} [[Emperor of Japan]]
| branch                      = {{navy|Empire of Japan}}
| type                        = [[Air force|Naval Air Fleet]] (''Kantai'')
| role                        = 
| size                        = 
| command_structure           = 
| garrison                    = 
| nickname                    = 
| patron                      = 
| motto                       = 
| colors                      = 
| march                       = 
| mascot                      = 
| anniversaries               = 
| battles                     = {{Tree list}}
* [[Pacific War]]
** [[Attack on Pearl Harbor|Pearl Harbor]]
** [[Battle of Wake Island|Wake Island]]
** [[Battle of Rabaul (1942)|Rabaul]]
** [[Bombing of Darwin|Darwin]]
** [[Indian Ocean raid|Indian Ocean]]
** [[Battle of the Coral Sea|Coral Sea]]
** [[Battle of Midway|Midway]]
** [[Battle of the Eastern Solomons|Eastern Solomons]]
** [[Battle of the Santa Cruz Islands|Santa Cruz]]
** [[Battle of the Philippine Sea|Philippine Sea]]
** [[Battle of Leyte Gulf|Leyte Gulf]]
{{Tree list/end}}
| notable_commanders          = [[Chūichi Nagumo]]
<!-- Insignia -->
| identification_symbol       = [[File:Roundel of Japan.svg|100px]]
| identification_symbol_label = Roundel
}}
The {{nihongo|'''1st Air Fleet'''|第一航空艦隊|Daiichi Kōkū Kantai}}, also known as the '''''Kidō Butai''''' ("Mobile Force"), was a combined [[carrier battle group]] comprising most of the [[aircraft carrier]]s and [[carrier air group]]s of the [[Imperial Japanese Navy]] (IJN) during the first eight months of the [[Pacific War]].

At the time of its best-known operation, the [[attack on Pearl Harbor]], in December 1941, the 1st Air Fleet was the world's largest fleet of aircraft carriers.

In its second generation, 1st Air Fleet was a land-based fleet of "kichi kōkūtai" (base air unit(s)).

==Origins==
[[File:Wakamiya.jpg|thumb|left|Japanese seaplane carrier ''Wakamiya''.]]
In 1912, the British [[Royal Navy]] had established its own flying branch, the [[Royal Naval Air Service]] (RNAS). The IJN was modeled on the Royal Navy and the IJN Admiralty sought establishment of their own Naval Air Service. The IJN had also observed technical developments in other countries and saw military potential of the airplane. In 1913, the [[Japanese seaplane carrier Wakamiya|IJN seaplane carrier ''Wakamiya'']] was converted into a [[seaplane tender]] and aircraft were purchased. The 1st and 2nd Air Fleet were to be the primary attack force of the [[IJNAS]].

The Japanese carriers' experiences off China had helped further develop the IJN's carrier doctrine. One lesson learned in China was the importance of [[force concentration]] and mass in projecting naval air power ashore. Therefore, in April 1941 the IJN formed the 1st Air Fleet to combine all of its fleet carriers under a single command. The IJN centered its doctrine on air strikes that combined the air groups within carrier divisions, rather than each individual carrier. When more than one carrier division was operating together, the divisions' air groups were combined with each other.  This doctrine of combined, massed, carrier air attack groups was the most advanced of its kind of all the world's navies.  The IJN, however, remained concerned that concentrating all of its carriers together would render them vulnerable to being wiped out all at once by a massive enemy air or surface strike. Thus, the IJN developed a compromise solution in which the fleet carriers would operate closely together within their carrier divisions but the divisions themselves would operate in loose rectangular formations, with approximately {{convert|7000|m|yd}} separating the carriers from each other.<ref>Parshall and Tully, pp. 82, 86, 137–138, and 416; Peattie, pp. 124–25, 147–53; Tully; Stille, pp. 13–14</ref><ref group=Note>According to Parshall and Tully, pp. 86–87, the Japanese would not usually launch their entire carrier air groups into a single massed attack. Instead, each carrier would launch a "deckload strike" of all its aircraft that could be spotted at one time on each flight deck. Subsequent attack waves consisted of the next deckload of aircraft. Thus, 1st Air Fleet air attacks would often consist of at least two, massed waves of aircraft. Peattie (p. 152) and [[Jisaburō Ozawa]] (Goldstein, pp. 78–80) emphasize that the First Air Fleet was ''not'' the IJN's primary strategic striking force. The IJN still considered the First Air Fleet an integral component in the Combined Fleet's decisive battle task force centered on battleships.</ref>

Although the concentration of so many fleet carriers into a single unit was a new and revolutionary offensive strategic concept, the First Air Fleet suffered from several defensive deficiencies which gave it, in [[Mark Peattie]]'s words, a {{" '}}[[wikt:glass jaw|glass jaw]]':  it could throw a punch but couldn't take one."<ref>Peattie, p. 159</ref> Japanese carrier [[Anti-aircraft warfare|anti-aircraft guns]] and associated fire control systems had several design and configuration deficiencies which limited their effectiveness. The IJN's fleet [[combat air patrol]] (CAP) consisted of too few fighter aircraft and was hampered by an inadequate early warning system, including a lack of [[radar]]. Poor radio communications with the fighter aircraft inhibited effective command and control of the CAP. The carriers' escorting warships were deployed as visual scouts in a ring at long range, not as close anti-aircraft escorts, as they lacked training, doctrine, and sufficient anti-aircraft guns. These deficiencies would eventually doom ''Kaga'' and other First Air Fleet carriers.<ref>Parshall and Tully, pp. 85 and 136–145; Peattie, pp. 155–59: Stille, pp. 14–15, 50–51</ref>

==Organization==

===As a Carrier-Based Fleet===
{{external links|section|date=March 2025}}
The First Air Fleet ''(Dai-ichi Kōkū Kantai)'' was a major component of the [[Combined Fleet]] ''(Rengō Kantai)''. When created on 10 April 1941, it had three kōkū sentai (air flotillas; in the case of aircraft carriers, carrier divisions): On that date, First Kōkū Sentai consisted of {{ship|Japanese aircraft carrier|Akagi||2}} and {{ship|Japanese aircraft carrier|Kaga||2}} and their aircraft units. Later that spring, a number of destroyers were added. On 10 April 1941, Second Kōkū Sentai comprised {{ship|Japanese aircraft carrier|Sōryū||2}}, {{ship|Japanese aircraft carrier|Hiryū||2}} and the 23rd Kuchikutai (Destroyer Unit). Fourth Kōkū Sentai consisted solely of [[Light aircraft carrier|light carrier]] {{ship|Japanese aircraft carrier|Ryūjō||2}} and her aircraft unit, until two destroyers were added in August. (At its inception, First Air Fleet did not include Third Kōkū Sentai<ref>Prange, Gordon W. in collaboration with Goldstein, Donald M. and Dillon, Katherine V. (1981) At Dawn We Slept: The Untold Story of Pearl Harbor, Penguin Books, Ltd., p. 101 {{ISBN|0-14-00-6455-9}}</ref> and it did not include it on 7 December 1941. Third Kōkū Sentai (3rd Carrier Division, see table below) was attached to First Fleet, as distinct from First Air Fleet.<ref>Thorpe, Donald W. (1977) Japanese Naval Air Force Camouflage and Markings World War II, Aero Publishers, Inc., p. 116 {{ISBN|0-8168-6587-6}}</ref> On 1 April 1942, Third Kōkū Sentai was disbanded.[http://www.combinedfleet.com/Zuiho.htm Imperial Flattops]) See the table titled "Transition", below.

When formed on 10 April 1941, First Air Fleet was a naval battlegroup with the single most powerful concentration of carrier-based aircraft in the world at the time.<ref>[http://www.combinedfleet.com/cvlist.htm Tully, Anthony, "Stories and Battle Histories of the IJN's Carrier Fleet"], Retrieved 8 September 2010.</ref> Military historian [[Gordon Prange]] called it "a revolutionary and potentially formidable instrument of sea power."<ref>Prange, Gordon W. in collaboration with Goldstein, Donald M. and Dillon, Katherine V. (1981). ''At Dawn We Slept: The Untold Story of Pearl Harbor'', Penguin Books, Ltd., p. 107 {{ISBN|0-14-00-6455-9}}</ref>

Fifth Kōkū Sentai (5th Carrier Division) was created on 1 September 1941 and was added to First Air Fleet [http://hush.gooside.com/Order/GF/SqF1941.html#anchor593961 The Naval Data Base:航空戦隊.]. When the new aircraft carrier {{ship|Japanese aircraft carrier|Zuikaku||2}} was added to Fifth Kōkū Sentai, First Air Fleet consisted of ''Akagi'', ''Kaga'', ''Sōryū'', ''Hiryū'', ''Ryūjō'', ''Kasuga Maru'' (renamed {{ship|Japanese aircraft carrier|Taiyō||2}} ca. 31 August 1942), {{ship|Japanese aircraft carrier|Shōkaku||2}} and ''Zuikaku'',<ref>{{Cite web|url=http://www.combinedfleet.com/Akagi.htm|title=Imperial lattops|website=www.combinedfleet.com}}</ref><ref>{{Cite web|url=http://www.combinedfleet.com/kaga.htm|title=Imperial lattops|website=www.combinedfleet.com}}</ref><ref>{{Cite web|url=http://www.combinedfleet.com/soryu.htm|title=Soryu Tabular Record of Movement &#124; Imperial Flattops &#124; Nihon Kaigun|website=www.combinedfleet.com}}</ref><ref>{{Cite web|url=http://www.combinedfleet.com/hiryu.htm|title=Hiryu Tabular Record of Movement &#124; Imperial Flattops &#124; Nihon Kaigun|website=www.combinedfleet.com}}</ref><ref>http://www.combinedfleet.com/ryujo.htm</ref><ref>{{Cite web|url=http://www.combinedfleet.com/taiyo.htm|title=Imperial Flattops|website=www.combinedfleet.com}}</ref><ref>{{Cite web|url=http://www.combinedfleet.com/shokaku.htm|title=Imperial Flattops|website=www.combinedfleet.com}}</ref><ref>{{Cite web|url=http://www.combinedfleet.com/Zuikak.htm|title=Imperial Flattops|website=www.combinedfleet.com}}</ref> along with their aircraft units and a number of destroyers.[http://hush.gooside.com/Order/GF/SqF1941.html#anchor593961 The Naval Data Base:航空戦隊.] On 25 September 1941, ''Kasuga Maru'' was transferred from Fifth Kōkū Sentai to Fourth Kōkū Sentai.[http://www.combinedfleet.com/taiyo.htm Imperial Flattops] (''Kasuga Maru'' was used to ferry aircraft to distant Japanese bases and should not be considered a front-line aircraft carrier. The status of any aircraft unit that she may have had is unclear.[http://www.combinedfleet.com/taiyo.htm Imperial Flattops]) Light carrier {{ship|Japanese aircraft carrier|Shōhō||2}} was added to Fourth Kōkū Sentai on 22 December 1941.[http://www.combinedfleet.com/shoho.htm Imperial lattops] She was destroyed on 7 May 1942 in the [[Battle of the Coral Sea]].[http://www.combinedfleet.com/shoho.htm Imperial lattops] ''Akagi'', ''Kaga'', ''Sōryū'', and ''Hiryū'' were lost in the [[Battle of Midway]].<ref>Morison, Samuel Eliot (1963). ''The Two-Ocean War'', Little, Brown & Co., ff. 156–161</ref>

Each Kōkū Sentai of First Air Fleet tended to include a pair of aircraft carriers, and each included the respective hikōkitai/hikōtai (aircraft/aviation unit(s)) of each aircraft carrier.<ref>Hata, Ikuhiko; Izawa, Yasuho and Shores, Christopher (2011). ''Japanese Naval Air Force Fighter Units and Their Aces 1932–1945'', Grub Street, ff. 128–159, {{ISBN|978-1-906502-84-3}}</ref><ref>Thorpe, Donald W., (1977). ''Japanese Naval Air Force Camouflage and Markings World War II'', Aero Publishers, Inc., {{ISBN|0-8168-6587-6}}</ref> Each Kōkū Sentai of First Air Fleet was a tactical unit that could be deployed separately or combined with other Kōkū Sentai of First Air Fleet, depending on the mission. For example, for operations against [[New Britain]] and [[New Guinea]] in January 1942, First Kōkū Sentai and Fifth Kōkū Sentai participated.<ref>Hata, Ikuhiko; Izawa, Yasuho and Shores, Christopher (2011). ''Japanese Naval Air Force Fighter Units and Their Aces 1932–1945'', Grub Street, p. 21, {{ISBN|978-1-906502-84-3}}</ref>

The number (from approximately two dozen up to approximately 80 aircraft) and type of aircraft varied, based on the capacity of the aircraft carrier.<ref>[http://navalhistory.flixco.info/H/106050x67747/259869/a0.htm IJN 1st Air Fleet] Retrieved 8 September 2010.</ref> The large [[fleet carrier]]s had three types of aircraft; [[Fighter aircraft|fighters]], [[torpedo bomber|level/torpedo bomber]]s, and [[dive bomber]]s. The smaller carriers tended to have only two types of aircraft, fighters and torpedo bombers.

At the beginning of the Pacific War, First Air Fleet included six [[fleet carrier]]s: ''Akagi'', ''Kaga'', ''Sōryū'', ''Hiryū'', ''Shōkaku'', and ''Zuikaku'', and two [[light carrier]]s: ''Ryūjō'' and ''Kasuga Maru'' (later renamed ''Taiyō''), as shown in the table below.

On 14 July 1942, First Air Fleet was converted into Third Fleet (第三艦隊) and Eighth Fleet (第八艦隊), and 2nd Carrier Division (first generation) and 5th Carrier Division were disbanded.<ref>Nairei (Internal Order) No. 1241, 14 July 1942, amending Nairei No. 1226 of 1941, JACAR (アジア歴史資料センター Asia Historical Materials Center) Ref.C12070164100, page 9 of 50.</ref> On the same date, the Japanese Navy's front-line aircraft carriers and their aircraft units came under the command of the [[IJN 3rd Fleet|3rd Fleet]], which was created in its sixth generation on that date.<ref>戦史叢書80巻463-465頁「空母部隊の再建と新戦法」(Senshi Sōsho Vol. 80, ff.463-465; "Rebuilding Carrier Units and New Tactics".</ref>

====Kidō Butai====
The '''''Kidō Butai''''' (機動部隊, "Mobile Strike Force") was the [[Combined Fleet]]'s tactical designation for its combined [[carrier battle group]]s.<ref name="Klemen">{{cite web|last=Klemen |first=L |url=https://warfare.gq/dutcheastindies/nagumo.html |title=Vice-Admiral Chuichi Nagumo |work=Forgotten Campaign: The Dutch East Indies Campaign 1941–1942 |url-status=live |archiveurl=https://web.archive.org/web/20120630044158/http://www.dutcheastindies.webs.com/nagumo.html |archivedate=2012-06-30 }}</ref>  The title was used as a term of convenience; it was not a formal name for the organization.  It consisted of Japan's six largest carriers, carrying the 1st Air Fleet. This mobile task force was created for the [[attack on Pearl Harbor]] under Vice-Admiral [[Chūichi Nagumo]] in 1941.<ref>Parshall and Tully, pp. 6 & 535.</ref> For the attack, the ''Kidō Butai'' consisted of six aircraft carriers (commanded by Chūichi Nagumo, [[Tamon Yamaguchi]] and [[Chūichi Hara]]) with 414 airplanes, two [[Battleship|battleships]], three [[Cruiser|cruisers]], nine destroyers, eight [[Tanker (ship)|tankers]], 23 [[Submarine|submarines]], and four [[Midget submarine|midget submarines]]. However, these escort ships were borrowed from other fleets and squadrons. It was the single most powerful naval fleet until four of the six aircraft carriers of the unit were destroyed in the disastrous [[Battle of Midway]].

{| class="wikitable" 
|-
!style="color: white; height: 5px; background: navy;"| ''Carriers of the Kidō Butai, 1941'' !! style="color: white; height: 5px; background: navy;"|
|-
! [[1st Carrier Division]]
|-
| align=center | {{ship|Japanese aircraft carrier|Akagi||2}} || align=center | [[File:Japanese.aircraft.carrier.akagi.jpg|50px]]
|-
| align=center | {{ship|Japanese aircraft carrier|Kaga||2}} || align=center | [[File:Japanese Navy Aircraft Carrier Kaga.jpg|50px]]
|-
! [[2nd Carrier Division]]
|-
| align=center | {{ship|Japanese aircraft carrier|Sōryū||2}} || align=center | [[File:Japanese aircraft carrier Soryu.jpg|50px]]
|-
| align=center | {{ship|Japanese aircraft carrier|Hiryū||2}} || align=center | [[File:Japanese aircraft carrier hiryu.jpg|50px]]
|-
! [[Third Carrier Division|3rd Carrier Division]]
|-
| align=center | {{ship|Japanese aircraft carrier|Zuihō||2}} || align=center | [[File:Japanese aircraft carrier Zuihō.jpg|50px]]
|-
| align=center | {{ship|Japanese aircraft carrier|Hōshō||2}} || align=center | [[File:Japanese aircraft carrier Hosho cropped.jpg|50px]]
|-
! [[Fourth Carrier Division|4th Carrier Division]]
|-
| align=center | {{ship|Japanese aircraft carrier|Ryūjō||2}} || align=center | [[File:RyujoFlightdeck.jpg|50px]]
|-
| align=center | {{ship|Japanese aircraft carrier|Taiyō||2}} || align=center | [[File:Japanese aircraft carrier Taiyō cropped.JPG|50px]]
|-
! [[5th Carrier Division]]
|-
| align=center | {{ship|Japanese aircraft carrier|Shōkaku||2}} || align=center | [[File:Aircraft carrier shokaku h73066.jpg|50px]]
|-
| align=center | {{ship|Japanese aircraft carrier|Zuikaku||2}} || align=center | [[File:japanese.aircraft.carrier.zuikaku.jpg|50px]]
|}

====Transition (extract)====
{| class="wikitable" 
|-
! Date || Lower units || Lowest units and ships 
|-
| rowspan="5"| 10 April 1941 (original) || rowspan="2"| [[First Carrier Division|1st Carrier Division]] || {{ship|Japanese aircraft carrier|Akagi||2}}, {{ship|Japanese aircraft carrier|Kaga||2}} 
|-
| Destroyer Division 7: {{ship|Japanese destroyer|Akebono|1930|2}}, {{ship|Japanese destroyer|Ushio|1930|2}} 
|-
| rowspan="2"| [[Second Carrier Division|2nd Carrier Division]] || {{ship|Japanese aircraft carrier|Sōryū||2}}, {{ship|Japanese aircraft carrier|Hiryū||2}}
|-
| Destroyer Division 23: {{ship|Japanese destroyer|Kikuzuki|1926|2}}, {{ship|Japanese destroyer|Uzuki|1925|2}} 
|-
| [[Fourth Carrier Division|4th Carrier Division]] || {{ship|Japanese aircraft carrier|Ryūjō||2}} 
|-
| rowspan="7"| 10 December 1941 || rowspan="2"| 1st Carrier Division || ''Akagi'', ''Kaga'' 
|-
| Destroyer Division 7: ''Akebono'', ''Ushio'' 
|-
| rowspan="2"| 2nd Carrier Division || ''Sōryū'', ''Hiryū''  
|-
| Destroyer Division 23: ''Kikuzuki'', ''Uzuki'' 
|-
| rowspan="2"| 4th Carrier Division || ''Ryūjō'', {{ship|Japanese aircraft carrier|Taiyō||2}} 
|-
| Destroyer Division 3: {{ship|Japanese destroyer|Shiokaze||2}}, {{ship|Japanese destroyer|Hokaze||2}} 
|-
| [[Fifth Carrier Division|5th Carrier Division]] || {{ship|Japanese aircraft carrier|Shōkaku||2}}, {{ship|Japanese aircraft carrier|Zuikaku||2}}, {{ship|Japanese destroyer|Oboro|1930|2}}, {{ship|Japanese destroyer|Akigumo|1941|2}} 
|-
| rowspan="8"| 10 April 1942 || 1st Carrier Division || ''Akagi'', ''Kaga'' 
|-
| 2nd Carrier Division || ''Hiryū'', ''Sōryū'' 
|-
| 4th Carrier Division || ''Ryūjō'', {{ship|Japanese aircraft carrier|Shōhō||2}} 
|-
| 5th Carrier Division || ''Shōkaku'', ''Zuikaku'' 
|-
| rowspan="4"| 10th Cruiser-Destroyer Squadron || {{ship|Japanese cruiser|Nagara||2}} 
|-
| Destroyer Division 4: {{ship|Japanese destroyer|Nowaki|1940|2}}, {{ship|Japanese destroyer|Arashi||2}}, {{ship|Japanese destroyer|Hagikaze||2}}, {{ship|Japanese destroyer|Maikaze||2}} 
|-
| Destroyer Division 10: {{ship|Japanese destroyer|Kazagumo||2}}, {{ship|Japanese destroyer|Makigumo|1941|2}}, {{ship|Japanese destroyer|Yūgumo|1941|2}}, ''Akigumo'' 
|-
| Destroyer Division 17: {{ship|Japanese destroyer|Urakaze|1940|2}}, {{ship|Japanese destroyer|Isokaze|1939|2}}, {{ship|Japanese destroyer|Tanikaze|1940|2}}, {{ship|Japanese destroyer|Hamakaze|1940|2}} 
|-
| 14 July 1942 || colspan="2"|disbanded 
|}

====Commanders====

;Commander-in-Chief
{{Officeholder table start
| showorder          = y
| showimage          = y
| image_title        = Portrait
| officeholder_title = Commander-in-Chief
| showtermlenght     = y
| showparty          = n
| showdefencebranch  = n
}}
{{Officeholder table
| order             = 1
| image             = Chuichi Nagumo.jpg
| military_rank     = Vice Admiral
| officeholder      = [[Chūichi Nagumo]]<br>南雲 忠一
| officeholder_sort = Nagumo, Chūichi
| born_year         = 1887
| died_year         = 1944
| term_start        = 10 April 1941
| term_end          = 14 July 1942
| timeinoffice      = {{ayd|1941|04|10|1942|07|14}}
}}
{{Officeholder table end}}

;Chief of Staff
{{Officeholder table start
| showorder          = y
| showimage          = y
| image_title        = Portrait
| officeholder_title = Chief of Staff
| showtermlenght     = y
| showparty          = n
| showdefencebranch  = n
}}
{{Officeholder table
| order             = 1
| image             = RyunosukeKusaka.jpg
| military_rank     = Rear Admiral
| officeholder      = [[Ryūnosuke Kusaka]]<br>草鹿 龍之介
| officeholder_sort = Kusaka, Ryūnosuke
| born_year         = 1893
| died_year         = 1971
| term_start        = 10 April 1941
| term_end          = 14 July 1942
| timeinoffice      = {{ayd|1941|04|10|1942|07|14}}
}}
{{Officeholder table end}}

===As a Land-Based Air Fleet===
On 1 July 1943, the 1st Air Fleet was recreated<ref>Nairei (Internal Order) No. 1331, 1 July 1943, JACAR (アジア歴史資料センター Asia Historical Materials Center) Ref. C12070178900.c1060b00002.0hourei_11_006.1493_01.pdf at p. 47 of 50</ref> as an exclusively land-based air fleet. It was intended to consist of nearly 1,600 aircraft when completed,<ref>citing Senshi Sōsho, Vol. 39 at 178-181; Vol. 71 at 204</ref> but the war situation prevented it from reaching that figure, and the second generation of this fleet began with only two Kōkūtai: Dai 261 Kaigun Kōkūtai (a one-month-old Zerosen unit)<ref>Hata, Ikuhiko; Izawa, Yasuho; Shores, Christopher (2011). ''Japanese Naval Air Force Fighter Units and Their Aces 1932–1945'', Grub Street, p.209, {{ISBN|978-1-90650284-3}}</ref> and Dai 761 Kaigun Kōkūtai (a bomber unit that was created on the same day as this fleet was<ref>The Maru Mechanic, Vol. 46, Ushio Shobō K.K., 1984, at 121</ref>).  On 30 September 1943, a cabinet meeting planned the {{nihongo|'''Absolute National Defense Zone'''|絶対国防圏|Zettai Kokubōken}} strategy.<ref>http://www.ndl.go.jp/horei_jp/kakugi/txt/txt00504.htm (今後採ルヘキ戦争指導ノ大綱) by National Diet Library. Accessed 2009-05-28. [https://web.archive.org/web/20080616140444/http://www.ndl.go.jp/horei_jp/kakugi/txt/txt00504.htm Archived] 2009-05-30.</ref> The plan intended the [[Kuril Islands]], [[Bonin Islands]], [[Mariana Islands]], [[Caroline Islands]], [[Biak]], [[Sunda Islands]] and [[Burma]] to be [[unsinkable aircraft carrier]]s. The 1st Air Fleet became the main force of this plan. However, it was soundly beaten in the [[Battle of the Philippine Sea]]. The IJN then moved the air fleet to the [[Philippines]] to regroup. However, due partly to the aircrews' lack of combat experience, the air fleet suffered severe losses in the [[Formosa Air Battle]]. After the battle it had only 41 aircraft.{{citation needed|date=January 2019}} The only tactic left for them was the [[Kamikaze|kamikaze attack]].

====Transition (extract)====
{| class="wikitable" 
|-
! Date !! Higher unit !! Lower units !! Lowest units 
|-
| 1 July 1943 || [[Imperial General Headquarters]] || 261st [[Kōkūtai|NAG (Naval Air Group or Naval Aviation Group)]]., 761st NAG 
|-
| 1 January 1944 || Imperial General Headquarters || 121st NAG, 261st NAG, 263rd NAG, 265th NAG, 321st NAG,<br/>341st NAG, 344th NAG, 521st NAG, 523rd NAG, 1021st NAG 
|-
| rowspan="2"| 15 February 1944 || rowspan="2"| [[Combined Fleet]] || [[61st Air Flotilla]] || 121st NAG, 261st NAG, 263rd NAG, 321st NAG, 341st NAG,<br> 343rd NAG, 521st NAG, 523rd NAG, 761st NAG, 1021st NAG  
|-
|| [[62nd Air Flotilla]] || 141st NAG, 262nd NAG, 265th NAG, 322nd NAG, 345th NAG,<br/>361st NAG, 522nd NAG, 524th NAG, 541st NAG, 762nd NAG  
|-
| rowspan="3"| 5 May 1944 || rowspan="3"| Combined Fleet || [[22nd Air Flotilla]] || 151st NAG, 202nd NAG, 251st NAG, 253rd NAG, 301st NAG,<br> 503rd NAG, 551st NAG, 755th NAG 
|-
| [[26th Air Flotilla]] || 201st NAG, 501st NAG, 751st NAG 
|-
| 61st Air Flotilla || 121st NAG, 261st NAG, 263rd NAG, 321st NAG, 341st NAG,<br/>343rd NAG, 521st NAG, 523rd NAG, 763rd NAG, 1021st NAG 
|-
| rowspan="5"| 7 August 1944 || rowspan="5"| [[Southwest Area Fleet]] || 22nd Air Flotilla || Higashi-Caroline NAG 
|-
| [[23rd Air Flotilla]] || Gōhoku NAG 
|-
| 26th Air Flotilla || Hitō NAG 
|-
| 61st Air Flotilla || Mariana NAG, Nishi-Caroline NAG 
|-
| 153rd NAG, 201st NAG, 761st NAG, 1021st NAG 
|-
| rowspan="3"| 15 December 1944 || rowspan="3"| Southwest Area Fleet || 23rd Air Flotilla || Gōhoku NAG 
|-
| 26th Air Flotilla || Hokuhi NAG, Chūhi NAG, Nanpi NAG 
|-
| 153rd NAG, 201st NAG, 761st NAG, 1021st NAG 
|-
| rowspan="2"| 1 March 1945 || rowspan="2"| Southwest Area Fleet || 26th Air Flotilla || Hokuhi NAG, Chūhi NAG, Nanpi NAG, 141st NAG, 153rd NAG,<br> 201st NAG, 221st NAG, 341st NAG, 761st NAG, 763rd NAG 
|-
| Taiwan NAG, 132nd NAG, 133rd NAG, 165th NAG, 634th NAG,<br/>765th NAG, 1021st NAG 
|-
| 8 May 1945 || Combined Fleet || 132nd NAG, 133rd NAG, 205th NAG, 765th NAG || 
|-
| 15 June 1945 || colspan="3"| disbanded 
|}

====Commanders====

;Commanders-in-Chief
{{Officeholder table start
| showorder          = y
| showimage          = y
| image_title        = Portrait
| officeholder_title = Commander-in-Chief
| showtermlenght     = y
| showparty          = n
| showdefencebranch  = n
}}
{{Officeholder table
| order             = 1
| image             = KakujiKakuta.jpg
| military_rank     = Vice Admiral
| officeholder      = [[Kakuji Kakuta]]<br>角田 覚治
| officeholder_sort = Kakuta, Kakuji
| born_year         = 1890
| died_year         = 1944
| died              = y
| term_start        = 1 July 1943
| term_end          = 2 August 1944
| timeinoffice      = {{ayd|1943|07|01|1944|08|02}}
}}
{{Officeholder table
| order             = 2
| image             = Kinpei Teraoka.jpg
| military_rank     = Vice Admiral
| officeholder      = {{ill|Kinpei Teraoka|ja|寺岡謹平}}<br>寺岡謹平
| officeholder_sort = Teraoka, Kinpei
| born_year         = 1891
| died_year         = 1984
| term_start        = 7 August 1944
| term_end          = 20 October 1944
| timeinoffice      = {{ayd|1944|08|07|1944|10|20}}
}}
{{Officeholder table
| order             = 3
| image             = Takijiro Onishi.jpg
| military_rank     = Vice Admiral
| officeholder      = [[Takijirō Ōnishi]]<br>大西 瀧治郎
| officeholder_sort = Ōnishi, Takijirō
| born_year         = 1891
| died_year         = 1945
| term_start        = 20 October 1944
| term_end          = 10 May 1945
| timeinoffice      = {{ayd|1944|10|20|1945|05|10}}
}}
{{Officeholder table
| order             = 4
| image             = Shima Kiyohide.jpg
| military_rank     = Vice Admiral
| officeholder      = [[Kiyohide Shima]]<br>志摩 清英
| officeholder_sort = Shima, Kiyohide
| born_year         = 1890
| died_year         = 1973
| term_start        = 10 May 1945
| term_end          = 15 June 1945
| timeinoffice      = {{ayd|1945|05|10|1945|06|15}}
}}
{{Officeholder table end}}

;Chiefs of Staff
{{Officeholder table start
| showorder          = y
| showimage          = y
| image_title        = Portrait
| officeholder_title = Chief of Staff
| showtermlenght     = y
| showparty          = n
| showdefencebranch  = n
}}
{{Officeholder table
| order             = 1
| image             = Miwa Yoshitake.jpg
| military_rank     = [[Captain (naval)|Captain]] / Rear Admiral
| officeholder      = {{ill|Yoshitake Miwa|ja|三和義勇}}<br>三和義勇
| officeholder_sort = Miwa, Yoshitake
| born_year         = 1899
| died_year         = 1944
| died              = y
| term_start        = 1 July 1943
| term_end          = 2 August 1944
| timeinoffice      = {{ayd|1943|07|01|1944|08|02}}
}}
{{Officeholder table
| order             = 2
| image             = 
| military_rank     = Captain
| officeholder      = {{ill|Toshihiko Odawara|ja|小田原俊彦}}<br>小田原俊彦
| officeholder_sort = Odawara, Toshihiko
| born_year         = 1899
| died_year         = 1945
| term_start        = 7 August 1944
| term_end          = 1 January 1945
| timeinoffice      = {{ayd|1944|08|07|1945|01|01}}
}}
{{Officeholder table
| order             = 3
| image             = Tomozō Kikuchi.jpg
| military_rank     = Rear Admiral
| officeholder      = {{ill|Tomozō Kikuchi|ja|菊池朝三}}<br>菊池朝三
| officeholder_sort = Kikuchi, Tomozō
| born_year         = 1896
| died_year         = 1988
| term_start        = 1 January 1945
| term_end          = 10 May 1945
| timeinoffice      = {{ayd|1945|01|01|1945|05|10}}
}}
{{Officeholder table
| order             = 4
| image             = Tasuku Nakazawa.jpg
| military_rank     = Rear Admiral
| officeholder      = {{ill|Tasuku Nakazawa|ja|中澤佑}}<br>中澤佑
| officeholder_sort = Nakazawa, Tasuku
| born_year         = 1894
| died_year         = 1977
| term_start        = 10 May 1945
| term_end          = 15 June 1945
| timeinoffice      = {{ayd|1945|05|10|1945|06|15}}
}}
{{Officeholder table end}}

{{center|'''Some of the commanders of the ''Kidō Butai'''''}}
<gallery class="center">
File:Chuichi Nagumo.jpg|[[Admiral]] [[Chūichi Nagumo]] (Commander-in-Chief, 1st Carrier Division)
File:TamonYamaguchi.jpg|[[Vice Admiral]] [[Tamon Yamaguchi]] (2nd Carrier Division)
File:KakujiKakuta.jpg|Vice Admiral [[Kakuji Kakuta]] (4th Carrier Division - from 1941)
File:Gunichi Mikawa.jpg|Vice Admiral [[Gunichi Mikawa]] (3rd Battleship Division)
File:SentaroOmori.jpg|Vice Admiral [[Sentarō Ōmori]] (1st Destroyer Squadron)
File:ShigeyoskiMiwa.jpg|Vice Admiral [[Shigeyoshi Miwa]] (3rd Submarine Squadron)
File:RyunosukeKusaka.jpg|Vice Admiral [[Ryūnosuke Kusaka]] (Chief of staff, 1st Air Fleet)
File:Kaku Tomeo.jpg|[[Rear Admiral]] {{ill|Tomeo Kaku|ja|加来止男}} (2nd Carrier Division: Hiryu)
File:Yanagimoto Ryusaku.jpg|Rear Admiral [[Ryusaku Yanagimoto]] (2nd Carrier Division: Soryu)
</gallery>

==Operations==
[[File:Aboard a Japanese carrier before the attack on Pearl Harbor.jpg|thumb|right|150px|Planes taking off]]
[[File:Japanese planes preparing-Pearl Harbor.jpg|thumb|right|150px|1st Air Fleet Aichi [[dive bomber]]s preparing to bomb American naval base in Pearl Harbor, Hawaii]]
[[File:Carrier shokaku.jpg|thumb|right|150px|Carrier {{ship|Japanese aircraft carrier|Shokaku||2}} preparing to launch the [[attack on Pearl Harbor]].]]
[[File:Shoho g17026.jpg|thumb|right|150px|Japanese aircraft carrier {{ship|Japanese aircraft carrier|Shōhō||2}} being hit by bombs and torpedoes at the [[Battle of the Coral Sea]].]]
[[File:Aircraft prepare to launch from Japanese carrier Shōkaku during Battle of the Santa Cruz Islands, 26 October 1942 (80-G-176150).jpg|thumb|right|150px|Japanese aircraft at the [[Battle of the Santa Cruz Islands]].]]
[[File:Lowering the flag on Zuikaku.jpg|thumb|right|150px|{{ship|Japanese aircraft carrier|Zuikaku||2}} sinking after being hit at the [[Battle of Leyte Gulf]].]]

===Pearl Harbor===
{{main|Attack on Pearl Harbor|Attack on Pearl Harbor order of battle}}
The ''Kidō Butai'' (also known as the ''Carrier Striking Task Force'') set sail from [[Kasatka Bay|Hitokappu Bay]], Japan under [[Vice Admiral]] [[Chūichi Nagumo]] on 26 November 1941, arriving in Hawaiian waters on Sunday, 7 December 1941 Hawaiian time. At around 8am, the first wave began its attack on the [[US Pacific Fleet]] based at [[Pearl Harbor]] and on outlying airfields. By the end of the day, 21 American [[List of United States Navy ships present at Pearl Harbor, December 7, 1941|ships were either sunk or crippled]], 188 aircraft were destroyed, and almost 2,500 Americans were killed. Japan was now formally at war with the United States.

For the [[attack on Pearl Harbor]], this fleet had a strength of 103 [[level bomber]]s, 128 [[dive bomber]]s, 40 [[torpedo bomber]]s, 88 fighter planes, plus 91 planes for a total of 441 planes.

===Bombing of Darwin===
{{main|Bombing of Darwin}}
The Bombing of Darwin on 19&nbsp;February 1942 was the largest single attack ever mounted by a foreign power on Australia. On that day, 242 Japanese aircraft, in two separate raids, attacked the town, ships in [[Darwin, Northern Territory|Darwin's]] harbour and the town's two airfields in an attempt to prevent the [[Allies of World War II|Allies]] from using them as bases to contest the [[Battle of Timor|invasion of Timor]] and [[Battle of Java (1942)|Java]]. The town was only lightly defended and the Japanese inflicted heavy losses upon the Allied forces at little cost to themselves. The urban areas of Darwin also suffered some damage from the raids and there were a number of civilian casualties.

===Indian Ocean Raid===
{{main|Indian Ocean raid}}
Between 31 March and 10 April 1942 the Japanese conducted a naval sortie against Allied naval forces in the [[Indian Ocean]]. The Fast Carrier Task Force (''Kidō Butai''), consisting of six carriers commanded by Admiral [[Chūichi Nagumo]], inflicted heavy losses on the British fleet, with the sinking of 1 carrier, 2 cruisers, 2 destroyers, and 23 merchant ships for the loss of 20 aircraft. [[Easter Sunday Raid|Attacks on the island]] of [[Ceylon]] were also carried out.

===Battle of the Coral Sea===
{{main|Battle of the Coral Sea}}
The 1st Air Fleet dispatched the [[Fifth Carrier Division]] in the [[Coral Sea]] during the return from the Indian Ocean. On May 7 the USN sighted the Port Moresby invasion force and mistook it for the main carrier force. Admiral [[Frank Jack Fletcher|Fletcher]] sent an aircraft strike which sank the IJN light carrier ''Shōhō''. After this loss of air cover, the Port Moresby invasion force abandoned its mission and retreated north. On the same day the IJN sighted and sank USN destroyer {{USS|Sims|DD-409|2}} and [[Replenishment oiler|oiler]] {{USS|Neosho|AO-23|2}}. The primary action took place on 8 May. Both carrier forces sighted and attacked each other. As a result, {{USS|Lexington|CV-2|2}} was sunk and {{USS|Yorktown|CV-5|2}} was damaged by a Japanese air strike. USN aircraft managed to damage ''Shōkaku'', while ''Zuikaku'' was undamaged in the battle but sustained severe losses in aircraft and aircrew, so both Japanese carriers had to return to Japan for repair and replenishment and were unable to participate in the following operation. The remaining fleet returned to Japan to prepare for the Midway invasion (Operation MI).

===Battle of Midway===
{{main|Battle of Midway}}
Admiral [[Isoroku Yamamoto]] planned to lure and destroy USN carriers by attacking the Midway Islands in June 1942. The Japanese were unaware that the United States had broken [[Japanese naval codes|their naval code]]. As a result of this, USN carriers were already in the area when the Japanese attacked Midway. On 3 June US land-based bombers from Midway attacked the Japanese fleet but scored no hits. On 4 June, due to the poor reconnaissance efforts and tactical mistakes of Vice Admiral [[Chūichi Nagumo]], USN dive bombers were able to surprise the Japanese carrier force and destroyed three carriers (''Akagi'', ''Kaga'' and ''Sōryū''). At the time of the attack the Japanese carriers were in the process of preparing to launch an air strike against the US carriers and their hangars were full of loaded aircraft, bombs and aviation fuel which decisively contributed to their destruction. Carrier ''Hiryū'' managed to survive the attack and Rear Admiral [[Tamon Yamaguchi]] launched a strike against ''Yorktown''. Aircraft from ''Hiryū'' managed to cripple ''Yorktown'', which was later sunk by {{Jsub|I-168||6}}. In response, the US launched a strike against ''Hiryū'' and sank her. That day the Japanese lost four aircraft carriers and much of their experienced aircrew.

===Battle of the Philippine Sea===
{{main|Battle of the Philippine Sea}}
The US Navy's attack on the Japanese base at [[Chuuk Lagoon|Truk]] (Chuuk) on 17 February 1944 ([[Operation Hailstone]]) surprised the Japanese military. In response, the Japanese Navy ordered all of the 61st Air Flotilla to the [[Mariana Islands]].<ref>Hata, Ikuhiko; Izawa, Yasuho and Shores, Christopher (2011). ''Japanese Naval Air Force Fighter Units and Their Aces 1932–1945'', Grub Street, p. 86, {{ISBN|9781906502843}}</ref> Its Number 261 Kaigun Kōkūtai (fighter) advanced to Saipan circa 19–24 February 1944, but attrition in air combats and illness weakened the unit greatly and it played only a minor role in the Battle of the Philippine Sea.<ref>Hata, Ikuhiko; Izawa, Yasuho and Shores, Christopher (2011). ''Japanese Naval Air Force Fighter Units and Their Aces 1932–1945'', Grub Street, ff. 209–210, {{ISBN|9781906502843}}</ref> Elements of No. 263 Kaigun Kōkūtai (fighter) of the 61st Air Flotilla were stationed on Guam from 15 June 1944 and participated in the battle.<ref>Hata, Ikuhiko; Izawa, Yasuho and Shores, Christopher (2011). ''Japanese Naval Air Force Fighter Units and Their Aces 1932–1945'', Grub Street, p. 212, {{ISBN|9781906502843}}</ref>

===Battle of Leyte Gulf===
{{main|Battle of Leyte Gulf}}
After disastrous losses at the [[Battle of the Philippine Sea]], the Japanese carrier force was again practically without aircrew and aircraft. This meant that at the [[Battle of Leyte Gulf]] the IJN carrier force was only used as a decoy force where it was ultimately destroyed, the battle that saw the last ''Kidō Butai'' survivor, ''Zuikaku'', along with ''Zuiho'', ''Chiyoda'' and ''Chitose'' succumbing to US air attacks of Admiral [[William F. Halsey]]'s [[Task Force 38]].

==References==
{{reflist|group=Note}}

==Citations==
{{reflist|20em}}

==Bibliography==
* Hata, Ikuhiko; Izawa, Yasuho and Shores, Christopher, (2011). ''Japanese Naval Air Force Fighter Units and Their Aces 1932–1945'', Grub Street, {{ISBN|978-1-906502-84-3}}
* {{cite book | last=Parshall | first=Jonathan | first2=Anthony | last2=Tully | year=2005 | title=Shattered Sword: The Untold Story of the Battle of Midway | publisher=Potomac Books | location=Dulles, Virginia | isbn=1-57488-923-0 | url-access=registration | url=https://archive.org/details/shatteredswordun0000pars }}
* Prange, Gordon W. in collaboration with Goldstein, Donald M. and Dillon, Katherine V. (1981). ''At Dawn We Slept: The Untold Story of Pearl Harbor'', Penguin Books, Ltd., {{ISBN|0-14-00-6455-9}}
* Thorpe, Donald W. (1977). ''Japanese Naval Air Force Camouflage and Markings World War II''. Fallbrook, CA: Aero Publishers, 1977. {{ISBN|0-8168-6583-3}} (hardcover; paperback {{ISBN|0-8168-6587-6}}).
* "Monthly the Maru" series, and "The Maru Special" series, {{cite web|url=http://www.kojinsha.co.jp/ |title=Ushio Shobō |archiveurl=https://web.archive.org/web/20090606143807/http://www.kojinsha.co.jp/ |archivedate=2009-06-06 |url-status=live }} (Japan)
* "Monthly Ships of the World" series, {{cite web|url=http://www.ships-net.co.jp/ |title=Kaijinsha |archiveurl=https://web.archive.org/web/20090531032538/http://www.ships-net.co.jp/ |archivedate=2009-05-31 |url-status=live }} (Japan)
* "Famous Airplanes of the World" series and "Monthly Kōku Fan" series, Bunrindō (Japan)

==External links==
* [http://www.combinedfleet.com/cvlist.htm ''Kidō Butai at Combined Fleet.com'']

{{Imperial Japanese Navy air units}}

{{DEFAULTSORT:1st Air Fleet Of The Imperial Japanese Navy}}
[[Category:Fleets of the Imperial Japanese Navy]]
[[Category:Units of the Imperial Japanese Navy Air Service]]
[[Category:Military units and formations established in 1941]]
[[Category:Military units and formations disestablished in 1942]]
[[Category:Military units and formations established in 1943]]
[[Category:Military units and formations disestablished in 1945]]
[[Category:1945 disestablishments in Japan]]