The was a combat aviation unit of the Imperial Japanese Navy

Imperial Japanese Navy

The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...

 (IJN) during the Pacific Campaign

Pacific War

The Pacific War, also sometimes called the Asia-Pacific War refers broadly to the parts of World War II that took place in the Pacific Ocean, its islands, and in East Asia, then called the Far East...

 of World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. The flotilla, mainly consisting of land-based bombers, fighters, and reconnaissance aircraft, reported to the IJN's 11th Air Fleet. As originally organized, the flotilla's core units were the 4th Naval Air Group

4th Air Group

was a land-based bomber aircraft unit of the Imperial Japanese Navy Air Service during the Pacific campaign of World War II. The unit was formed on 10 February 1942 and flew the Mitsubishi G4M Rikko Navy Type 1 Attack Bomber aircraft...

, Tainan Naval Air Group

Tainan Air Group

was a fighter aircraft and airbase garrison unit of the Imperial Japanese Navy during the Pacific campaign of World War II. The flying portion of the unit was heavily involved in many of the major campaigns and battles of the first year of the war...

, and Yokohama Naval Air Group

Yokohama Air Group

was an aircraft and airbase garrison unit of the Imperial Japanese Navy Air Service during the Pacific campaign of World War II.-History:The Yokohama Air Group was formed in Yokohama, Japan on October 1, 1936 as a patrol unit equipped with six Navy Type 91 Hiro H4H flying boats...

. The 4th flew bombers, the Tainan fighters, and the Yokohama reconnaissance aircraft.

The 25th Air Flotilla, under the command of Rear Admiral Sadayoshi Yamada

Sadayoshi Yamada

- Notes :...

, was deployed to Rabaul, New Britain on 29 March 1942. From this location, the unit supported Japanese military operations in the New Guinea

New Guinea campaign

The New Guinea campaign was one of the major military campaigns of World War II.Before the war, the island of New Guinea was split between:...

 and Solomon Islands

Solomon Islands campaign

The Solomon Islands campaign was a major campaign of the Pacific War of World War II. The campaign began with Japanese landings and occupation of several areas in the British Solomon Islands and Bougainville, in the Territory of New Guinea, during the first six months of 1942...

 Campaigns. During these campaigns, the unit was augmented by aircraft from other flotillas. The operational title for this hybrid organization was the 5th Air Attack Force. The organization took heavy losses in air combat over Guadalcanal

Guadalcanal campaign

The Guadalcanal Campaign, also known as the Battle of Guadalcanal and codenamed Operation Watchtower by Allied forces, was a military campaign fought between August 7, 1942 and February 9, 1943 on and around the island of Guadalcanal in the Pacific theatre of World War II...

.

Organization

{| class="wikitable"
! Date|| Higher unit || Aviation units and vessels
|-
| 1 April 1942 (original) || rowspan="8"|11th Air Fleet || 4th Naval Air Group, Tainan Naval Air Group, Yokohama Naval Air Group, MV Mogamigawa Maru
|-
| 29 April 1942 || 4th Naval Air Group

4th Air Group

was a land-based bomber aircraft unit of the Imperial Japanese Navy Air Service during the Pacific campaign of World War II. The unit was formed on 10 February 1942 and flew the Mitsubishi G4M Rikko Navy Type 1 Attack Bomber aircraft...

, Tainan Naval Air Group

Tainan Air Group

was a fighter aircraft and airbase garrison unit of the Imperial Japanese Navy during the Pacific campaign of World War II. The flying portion of the unit was heavily involved in many of the major campaigns and battles of the first year of the war...

, Yokohama Naval Air Group

Yokohama Air Group

was an aircraft and airbase garrison unit of the Imperial Japanese Navy Air Service during the Pacific campaign of World War II.-History:The Yokohama Air Group was formed in Yokohama, Japan on October 1, 1936 as a patrol unit equipped with six Navy Type 91 Hiro H4H flying boats...

, Akitsushima

Japanese seaplane tender Akitsushima

The was a seaplane tender of the Imperial Japanese Navy, serving during the World War II from 1942 until being sunk in September 1944.-Design:In 1938, the IJN wanted to use their large-sized flying boats more effectively, because the Kawanishi H6K was the only aircraft able to hit the Pearl Harbor...

, MV Mogamigawa Maru
|-
| 1 November 1942 || 251st Naval Air Group, 702nd Naval Air Group, 801st Naval Air Group
|-
| 18 May 1943 || 251st Naval Air Group, 702nd Naval Air Group
|-
| 1 July 1943 || 251st Naval Air Group, 501st Naval Air Group, 702nd Naval Air Group
|-
| 1 September 1943 || 251st Naval Air Group, 253rd Naval Air Group, 702nd Naval Air Group, 705th Naval Air Group, 751st Naval Air Group
|-
| 1 December 1943 || 251st Naval Air Group, 253rd Naval Air Group, 751st Naval Air Group
|-
| 1 February 1944 || 251st Naval Air Group, 582nd Naval Air Group, 751st Naval Air Group
|-
| 5 May 1944 || colspan="2"|dissolved
|-
| 10 July 1944 || rowspan="2"|2nd Air Fleet || Nansei-Shotō Naval Air Group
|-
| 15 November 1944 || 203rd Naval Air Group, 701st Naval Air Group, Nansei-Shotō Naval Air Group
|-
| 15 December 1944 || 3rd Air Fleet || 203rd Naval Air Group, 701st Naval Air Group
|-
| 10 February 1945 || colspan="2"|dissolved

Commanding officers

{| class=wikitable
! !! Rank !! Name !! Date !! Note
|-
|1|| Rear-Admiral || Sadayoshi Yamada

Sadayoshi Yamada

- Notes :...

 || 1 April 1942 ||
|-
|2|| Rear-Admiral || Keizō Ueno || 17 November 1942 ||
|-
|x|| || dissolved || 5 May 1944 ||
|-
|3|| Captain

Captain (naval)

Captain is the name most often given in English-speaking navies to the rank corresponding to command of the largest ships. The NATO rank code is OF-5, equivalent to an army full colonel....

 / Rear-Admiral || Tomozō Kikuchi || 10 July 1944 || Rear-Admiral on 15 October 1944.
|-
|4|| Captain || Toshiyuki Yokoi || 24 October 1944 ||
|-
|x|| || dissolved || 10 February 1945 ||