Yokohama Air Group

The Yokohama Air Group was an Imperial Japanese Navy Air Service aviation unit formed at Yokohama on October 1, 1936. It was established as a patrol formation and initially operated six Navy Type 91 Hiro H4H flying boats. Unlike a commercial brand, the group was a military organization responsible for maritime patrol, reconnaissance, bombing, seaplane-fighter defense, and the operation and garrisoning of advanced air facilities. Before the Pacific War, the unit's principal capability was long-range maritime patrol using flying boats. On December 1, 1941, shortly before and during the opening phase of Japan's Pacific offensive, it was re-equipped with 24 Navy Type 97 Kawanishi H6K flying boats. The group was assigned to support Imperial Japanese Navy Fourth Fleet operations in the central Pacific as part of the 24th Air Flotilla. Its aircraft subsequently operated from dispersed island bases, reflecting the Japanese naval-air strategy of using seaplanes for reconnaissance, long-distance bombing, and local air defense in areas where conventional airfields were limited. The unit took part in Japanese operations against Wake Island immediately after the attack on Pearl Harbor. From forward bases including Majuro and Wotje, its Kawanishi H6K flying boats conducted several reconnaissance and bombing sorties between December 12 and December 18, 1941. The missions imposed pressure on the island's defenders, although the first raid suffered the loss of one aircraft to Marine fighter fire and later attacks were affected by mechanical problems and poor visibility. Wake Island fell to Japanese forces on December 23. In February 1942, a seven-aircraft detachment was sent to Rabaul in New Britain and transferred to the 25th Air Flotilla. From there, Yokohama aircraft supported Japanese operations in New Guinea and the Solomon Islands through reconnaissance and bombing missions. In April, the group also received twelve Navy Type 2 Nakajima A6M2-N fighter seaplanes. These aircraft provided air defense for Japanese positions and operated from a network of detachments at Buin, the Shortland Islands, and Tulagi. The seaplane fighters engaged Allied bombers over the Southwest Pacific during July 1942, with the unit reporting actions against USAAF B-24 Liberator and B-17 Flying Fortress aircraft. The fighting intensified around Guadalcanal and the lower Solomon Islands. On August 7, aircraft from the American carrier USS Wasp attacked Japanese installations at Tulagi, Gavutu, Tanambogo, and Florida Island, destroying 15 Yokohama seaplanes in their anchorages. Many aircraft were caught while preparing for takeoff, and aircrews and ground personnel were among the casualties. Survivors under Captain Shigetoshi Miyazaki joined the 3rd Kure Special Naval Landing Force detachment as infantry and were ultimately destroyed in the fighting. The portion of the organization that had not been committed to Tulagi returned to Japan in October 1942. On October 1 it was re-equipped with 16 Navy Type 2 Kawanishi H8K flying boats. One month later, on November 1, 1942, the flying unit was redesignated the 801 Air Group. The Yokohama Air Group therefore ceased to exist under its original designation, while its personnel and operational lineage continued within the Imperial Japanese Navy's later air-group structure.

The Yokohama Air Group was created at Yokohama on October 1, 1936, as a patrol unit of the Imperial Japanese Navy Air Service. Its original equipment consisted of six Navy Type 91 Hiro H4H flying boats, aircraft suited to maritime reconnaissance and patrol over waters beyond the range of land-based aircraft. The unit's role placed it within Japan's broader effort to develop naval aviation formations able to operate from island bases and anchorages across the western Pacific. On December 1, 1941, the group received 24 Navy Type 97 Kawanishi H6K flying boats and was assigned to Fourth Fleet operations in the central Pacific through the 24th Air Flotilla. After the outbreak of the Pacific War, the unit participated in the Japanese campaign against Wake Island. Two aircraft flew a reconnaissance and bombing mission from Majuro on December 12, but one was shot down by a United States Marine Corps Grumman F4F Wildcat. A larger night operation followed from Wotje; mechanical failures reduced the force before arrival, and the surviving aircraft delivered a limited bombing attack. Further sorties on December 15 and December 18 reached Wake with fewer losses and contributed to the sustained Japanese attack before the island surrendered on December 23. The group expanded its operations into the Southwest Pacific in 1942. On February 14, seven H6K flying boats were detached to Rabaul, New Britain, where they joined the 25th Air Flotilla. Their missions included reconnaissance and bombing in support of Japanese advances in Papua New Guinea and the Solomon Islands. On April 1, the organization acquired twelve Navy Type 2 Nakajima A6M2-N fighter seaplanes. These aircraft gave the group a local air-defense role in addition to its flying-boat missions. Detachments operated from Buin, the Shortland Islands, and Tulagi, with Tulagi becoming a major forward concentration. The fighter seaplanes engaged Allied aircraft during July 1942. On July 9, they intercepted two USAAF B-24 Liberators and claimed one destroyed. On July 17 and July 23, the unit was involved in further engagements with B-17 Flying Fortresses, although one of its own fighter seaplanes was lost in the July 23 action. On August 1, six A6M2-Ns met seven B-17s and damaged several aircraft without achieving a confirmed kill. The next day brought a series of separate air engagements, with claims by both sides that were not fully verified. The decisive blow came during the Allied landings and attacks around Tulagi and Gavutu–Tanambogo on August 7, 1942. Aircraft from USS Wasp struck Japanese facilities and destroyed 15 Yokohama seaplanes in the anchorages around the islands. The attack also killed aircrew and maintenance personnel. The surviving members of the Tulagi detachment, led by Captain Shigetoshi Miyazaki, joined Japanese naval landing-force personnel in ground combat and were eventually annihilated. The remaining elements returned to Japan on October 1, 1942, and exchanged their earlier aircraft for 16 Navy Type 2 Kawanishi H8K flying boats. On November 1, the flying unit was redesignated the 801 Air Group. This redesignation ended the Yokohama Air Group's separate identity and marked its transition into the numbered air-group system used by the Imperial Japanese Navy during the later war.

• 1942

  Deployment to Rabaul

  [1]Yokohama Air Groupen.wikipedia.org

  A seven-aircraft detachment moved to Rabaul on February 14 and supported Japanese operations in New Guinea and the Solomon Islands.

• 1942

  Addition of fighter seaplanes

  [1]Yokohama Air Groupen.wikipedia.org

  On April 1, the group received twelve Navy Type 2 Nakajima A6M2-N fighter seaplanes for defense of Japanese bases.

• 1942

  Tulagi destruction and ground combat

  [1]Yokohama Air Groupen.wikipedia.org

  On August 7, American carrier aircraft destroyed 15 Yokohama seaplanes at forward bases around Tulagi and nearby islands. Survivors fought as infantry and were later annihilated.

• 1942

  Redesignation as the 801 Air Group

  [1]Yokohama Air Groupen.wikipedia.org

  After returning to Japan and receiving 16 Navy Type 2 Kawanishi H8K flying boats, the unit was redesignated the 801 Air Group on November 1.

• 1941

  Re-equipment for Pacific operations

  [1]Yokohama Air Groupen.wikipedia.org

  On December 1, the unit received 24 Navy Type 97 Kawanishi H6K flying boats and was assigned to Fourth Fleet operations through the 24th Air Flotilla.

• 1941

  Wake Island operations

  [1]Yokohama Air Groupen.wikipedia.org

  Yokohama flying boats conducted reconnaissance and bombing sorties against Wake Island between December 12 and December 18 before the island surrendered on December 23.

• 1936

  Formation at Yokohama

  [1]Yokohama Air Groupen.wikipedia.org

  The Yokohama Air Group was established on October 1 as an Imperial Japanese Navy patrol unit equipped with six Navy Type 91 Hiro H4H flying boats.

A maritime patrol, reconnaissance, bombing, and seaplane-fighter formation organized for Imperial Japanese Navy operations across widely dispersed Pacific island bases.

• Patrol flying boat

  Navy Type 91 Hiro H4H

  The Yokohama Air Group's initial aircraft. Six H4H flying boats equipped the unit when it was formed in 1936 and provided its original maritime-patrol capability.

• Long-range flying boat

  Navy Type 97 Kawanishi H6K

  The H6K became the group's principal aircraft during the opening phase of the Pacific War. Twenty-four were assigned in December 1941 for long-range reconnaissance and bombing, including operations against Wake Island and from Rabaul.

• Fighter seaplane

  Navy Type 2 Nakajima A6M2-N

  Twelve A6M2-N fighter seaplanes joined the group in April 1942. They were used to defend Japanese bases and engaged USAAF bombers over the Southwest Pacific during July and August.

• Long-range flying boat

  Navy Type 2 Kawanishi H8K

  Sixteen H8K flying boats replaced the group's earlier aircraft after the surviving elements returned to Japan in October 1942, shortly before the unit became the 801 Air Group.

• 1942Rabaul and Southwest Pacific operations

  Rabaul · New Guinea · Solomon Islands

  A seven-aircraft detachment supported Japanese offensives with reconnaissance and bombing missions after arriving at Rabaul in February. The group later used seaplane detachments and fighter seaplanes to defend Japanese positions in the region.

  Outcome. The detachment operated under the 25th Air Flotilla until the group's forward elements were heavily damaged or destroyed during the Allied offensive in the Solomon Islands.

  Source
• 1942Tulagi and Gavutu–Tanambogo

  Tulagi · Gavutu · Tanambogo · Florida Island

  Carrier aircraft from USS Wasp attacked Japanese seaplane installations on August 7, destroying 15 Yokohama aircraft in their anchorages and killing many aircrew and support personnel. Survivors joined Japanese ground forces under Captain Shigetoshi Miyazaki.

  Outcome. The forward detachment was effectively destroyed; its surviving personnel were later annihilated in ground combat.

  Source
• 1941Wake Island operations

  Wake Island · Central Pacific

  Kawanishi H6K aircraft from the group conducted reconnaissance and bombing missions from Majuro and Wotje against the United States Marine Corps garrison on Wake Island. Several sorties were affected by mechanical problems, poor visibility, and fighter opposition. Wake surrendered to Japan on December 23.

  Outcome. Japanese capture of Wake Island; the unit suffered at least one aircraft loss during the operations.

  Source

• 1942

  Expansion into seaplane fighter defenseStrategy

  Background

  Japanese forward bases in the Southwest Pacific faced increasing Allied bomber attacks and required local air defense.

  Action taken

  The group received twelve Navy Type 2 Nakajima A6M2-N fighter seaplanes and established detachments at several forward bases.

  Aftermath

  The fighters engaged Allied bombers, but the Tulagi detachment and much of its aircraft were destroyed during the August 7 Allied attacks.

  Source

• 1942

  Replacement with Kawanishi H8K flying boatsGeneration change

  Background

  After the loss of the Tulagi detachment, the surviving portion of the organization returned to Japan for re-equipment.

  Action taken

  On October 1, the unit received 16 Navy Type 2 Kawanishi H8K flying boats.

  Aftermath

  The flying unit was redesignated the 801 Air Group on November 1, ending the Yokohama Air Group designation.

  Source

• 1941

  Assignment to central Pacific fleet operationsStrategy

  Background

  The Imperial Japanese Navy required a long-range maritime-air capability to support Fourth Fleet operations across widely separated Pacific bases.

  Action taken

  The group was re-equipped with 24 Kawanishi H6K flying boats and placed under the 24th Air Flotilla.

  Aftermath

  The aircraft were used in the Wake Island campaign and subsequently in wider Pacific reconnaissance and bombing operations.

  Source

1. 1Yokohama Air Groupen.wikipedia.org
2. 2Japanese Army Operations in the South Pacific Area: New Britain and Papua Campaigns, 1942–43awm.gov.au
3. 3Sunburst: The Rise of Japanese Naval Air Power 1909–1941usni.org