Mitsubishi H-60

The JMSDF chose S-70B as the successor of to the Mitsubishi HSS-2B Sea King (a licence-built version of the Sikorsky Sea King). When the SH-X (later SH-60J) project started, it was immediately after HSS-2B was put into service, so initially it was planned to integrate a mission system of HSS-2B with a bare aircraft of SH-60B, but finally a system newly developed by the TRDI was adopted. It is similar to LAMPS Mk.III in that the helicopter is equipped with a computer and connected to the mothership's combat direction system via a datalink, but it also has a dipping sonar as well as SH-60F.[3] The Defense Agency ordered two XSH-60Js from Sikorsky for $27 million. Their first flights were on 31 August and in October 1987. The Defense Agency designated the model SH-60J. They were fitted with Japanese avionics systems and tested by the JMSDF.[4]

The SH-60J is built in Japan under license from Sikorsky. It began deliveries in August 1991 and entered service thereafter. Based on a concept of the JMSDF, HQS-103 Dipping Sonar, HPS-104 active electronically scanned array Search Radar, and HLR-108 ESM System equipment of the avionics of SH-60B be different.[3] The engine is the GE/IHI T700-IHI-701C turboshaft, which Ishikawajima-Harima Heavy Industries produced under license from General Electric. It is a hybrid of the SH-60B and SH-60F, except for avionics. The crew includes a pilot, copilot and sensor operator. The copilot can concentrate on the role of tactical coordinator with the help of the Automatic Flight Management System and Inertial Navigation system.[5][6] Over 100 SH-60Js have been produced by 2007.[7]

A JMSDF SH-60K, 21st Squadron

The SH-60K is an upgraded version of the SH-60J.[8] The SH-60K anti-submarine helicopter which strengthened performance and versatility for the JMSDF. Mitsubishi began development in 1997. The SH-60K has formerly known as SH-60Kai.[9] The Director General of the Defense Agency admitted adoption in March 2005.[10]

Mitsubishi developed new main rotor blade, Ship Landing Assist System, new avionics system, and other systems. Two prototypes SH-60Ks were built by modifying SH-60Js. These prototypes were completed and delivered by June 2002. The SH-60K's cabin was expanded in length by 30 cm (11.8 in) and in height by 15 cm (5.91 in) compared to the SH-60J.[10] The larger cabin allows for the new avionics system.[11] Those and the airframe changes are compensated by the exchange of the T700-IHI-401C2 engine. The first production SH-60K was delivered to JMSDF on 10 August 2005.[10]

In December 2022, the Japanese government decided to reduce the number of SH-60Ks deployed for maritime patrols and replace some SH-60Ks with Sea Guardian unmanned aerial vehicles. The Japanese government plans to increase its defense budget from 1.24% of GDP in fiscal 2021 to around 2.0% within 10 years, a decision made as part of efforts to use the budget efficiently.[12]

XSH-60L

A further upgrade version of SH-60K has planned and in development. It will be equipped with a multi-static sonar system and a new adaptive control millimetric wave ultra-high-speed communication system (Click System) as well as improved engine transmission performance.[13][14] The first flight of the prototype, XSH-60L, was carried out on May 11, 2021.[15]

A JASDF UH-60J, Training Squadron

In 1988, the Japan Air Self-Defense Force choose the UH-60L to replace its KV-107 and Sikorsky S-62 helicopters.[16][17] The first aircraft was built by Sikorsky, with the company designation S-70A-12, and two more were assembled by Mitsubishi Heavy Industries.[2][18] Mitsubishi is producing the remaining UH-60Js under license.[19][20] The Japan Marine Self-Defense Force also chose Search and rescue, and utility helicopters to replace the S-61A in 1989.

The UH-60J is powered by T700 engines license-built by Ishikawajima-Harima Heavy Industries in Japan. It features external fuel tanks, an external rescue winch, a Japan-built radar, a FLIR turret in the nose and bubble side windows for observers.[17] The Japan Air Self-Defense Force machines were fitted with T700-IHI-701A engines, while Japan Maritime Self-Defense Force machines were fitted with marinized T700-IHI-401C engines.[18] Fuel tanks can be attached to pylons on stub wings. The UH-60Js began deliveries in 1991 and entered service in 1992.[21] A total of 40 UH-60Js were in service in 2010. The JASDF ordered 40 newer UH-60Js in December 2010 to begin replacing older UH-60Js.[22]

Mitsubishi and Sikorsky have teamed in support of the Self Defense Force's mission requirements. The UH-60J+ incorporates various upgrades for the modern SAR mission.[23] By 2006 Defense budget of Japan, UH-60Js begin addition of Refueling probe in 2009.[24] These UH-60Js completed training with the United States Air Force and widened their activity in SAR mission.[25]

A JGSDF UH-60JA, Kasumigaura Aviation School

The Japan Ground Self-Defense Force ordered a utility variant of the UH-60L designated UH-60JA in 1995.[21] The JGSDF began receiving the UH-60JA in 1997.[2] It features improved avionics, including FLIR, Color weather radar, GPS receiver, a Night Vision Goggle compatible cockpit and wire cutter.[18][21] The JGSDF plans to acquire 70.[26]

The JGSDF plan was to replace its UH-1H helicopters which had become obsolete. Due to budgetary constraints it was decided to replace the rotary wing fleet with a high-low combination of UH-60JA and UH-1J (an updated UH-1H) with the UH-60JA being the high and the UH-1J the low.[27] By 2004 the budgetary constraints have driven the JGSDF to seriously consider eliminating either the UH-60JA or the UH-1J from the fleet, and purchasing just one type of airframe for the utility mission.[28]