251st Air Group

251st Air Group
吉田一 Hajime Yoshida · Public domain · source
Unit name	251st Air Group
Dates	1944–1945
Country	Empire of Japan
Allegiance	Imperial Japanese Navy
Branch	Imperial Japanese Navy Air Service
Type	Naval aviation
Role	Fighter and interceptor operations
Size	Air group
Command structure	11th Air Fleet; 13th Air Fleet
Garrison	Taiwan (Formosa); Philippines
Notable commanders	Nobuo Fujita; Shigetoshi Miyazaki

251st Air Group was an Imperial Japanese Navy aviation unit formed in 1944 during the Pacific campaign of World War II. It operated from bases in Taiwan (Formosa), the Philippines, and various contested islands, engaging United States Navy and United States Army Air Forces formations during the Battle of Leyte Gulf, the Philippine campaign (1944–45), and related engagements. The unit was part of larger formations including the 11th Air Fleet and elements assigned to the 13th Air Fleet and suffered heavy losses during operations against Task Force 38 and Task Force 58 carrier raids.

Formation and Organization

The air group was formed as the IJN reorganized air assets after the losses at the Guadalcanal Campaign and the Solomon Islands campaign, drawing pilots from veteran units that had fought in the Battle of Midway and the Guadalcanal Campaign (1942–43). Its establishment followed doctrinal shifts seen after the Battle of the Philippine Sea and the Marianas Turkey Shoot, when the Imperial Japanese Navy Air Service attempted to consolidate remaining fighter and bomber strength into numbered air groups under the command of fleet-level staff such as the Combined Fleet and the Naval General Staff (Japan). Organizationally, the group comprised fighter squadrons equipped with types standardized in late-war IJN tables similar to those of the 331st Air Group and other contemporaneous units.

Operational History

Assigned initially to defend Formosa and the Ryukyu Islands against escalating Allied air raids, the unit took part in interceptor missions against raids by B-29 Superfortress escorts and B-24 Liberator formations operating from China and Guam. During the Battle of Leyte Gulf, elements of the group were tasked with supporting surface units of the Imperial Japanese Navy and attempted strike operations against Task Force 38 carrier groups operating from the Philippine Sea. The group conducted sorties against USS Enterprise (CV-6), USS Essex (CV-9), and other carriers during repeated air-sea battles around Leyte Gulf and Samar, often clashing with aces and veteran pilots from the United States Navy Fighter Squadrons such as VF-17 and VF-1. Losses increased during the Philippine campaign (1944–45) as logistical constraints, fuel shortages, and replacement pilot experience declined, mirroring attrition trends seen in the Battle of Okinawa and the Battle of Iwo Jima campaigns. Surviving elements surrendered following the Surrender of Japan and were disbanded during the postwar demobilization overseen by occupation authorities including Supreme Commander for the Allied Powers staff.

Aircraft and Equipment

The group's primary fighters included late-war models fielded by the Imperial Japanese Navy Air Service such as the Mitsubishi A6M Zero variants adapted from earlier A6M5c versions and, in some detachments, the J2M Raiden interceptors for high-altitude defense against B-29 Superfortress raids. Some flights operated twin-engined types comparable to the Nakajima J1N for night fighting and reconnaissance tasks; training and replacement aircraft were influenced by production limitations at plants like Mitsubishi Heavy Industries and Nakajima Aircraft Company. Armament typically mirrored IJN standard loads with 20 mm cannons and 7.7 mm machine guns, and the group occasionally employed limited numbers of air-to-surface ordnance during anti-shipping sorties targeting units of the United States Seventh Fleet and United States Third Fleet.

Command and Personnel

Commanding officers were drawn from experienced IJN aviators with service records including deployments to theaters such as China Burma India Theater and the Central Pacific Area. Notable leaders associated with comparable air groups included figures who had served under senior commanders in the Combined Fleet and had trained at facilities like Kasumigaura Naval Air Station and Genzan Air Station. Personnel shortages in 1944–45 forced rapid promotion of junior officers and reliance on pilots who had seen earlier action in the Dutch East Indies campaign, the Malayan campaign, and the Aleutian Islands Campaign. Ground crew and maintenance personnel faced challenges due to Allied submarine interdiction of supply lines connecting Formosa to the Japanese home islands, complicating aircraft servicing and sortie generation.

Bases and Deployments

The group operated from airfields on Formosa including Taichung Airfield and Tainan Airfield, staging through forward bases in the Philippines such as Clark Field and auxiliary strips on Leyte Gulf islands. It also utilized temporary detachments on outlying atolls and islands threatened by United States Navy carrier strikes, relocating between garrisons under pressure from operations like Operation Hailstone and carrier raids originating in the Central Pacific Campaign. As Allied forces advanced during the Philippine campaign (1944–45), surviving elements withdrew toward the Japanese home islands and surrendered in the aftermath of the Surrender of Japan.

Category:Units of the Imperial Japanese Navy Air Service Category:Military units and formations established in 1944 Category:Military units and formations disestablished in 1945