The UH-X utility helicopter is a military variant of the Bell 412EPI commercial helicopter. It is being developed jointly by Bell Helicopter and SUBARU to meet the requirements of the Japan Ground Self-Defense Force (JGSDF).
A prototype of the UH-X utility helicopter took to the skies for the first time in December 2018. The helicopter flew for 55 minutes before landing at the Utsunomiya Airfield in Tochigi Prefecture, Japan. It will be handed over to the Ministry of Defence (MoD) in March 2019 following the completion of the flight test programme.
Japan MoD plans to replace the JGSDF’s existing fleet of 127 UH-1J utility helicopters with 150 UH-Xs over the next 20 years. The first UH-X helicopter is scheduled to be delivered to the JGSDF in 2022.
The UH-X fleet will be deployed by the JGSDF in island defence, search-and-rescue (SAR), transport, and disaster relief missions.
Details of the UH-X programme
The UH-X (Utility Helicopter-X) programme was initiated by the Japanese MoD to replace the ageing UH-1J fleet in service with the JGSDF. Airbus Helicopters and its local partner Kawasaki Heavy Industries (KHI), as well as a consortium of Bell Helicopter and Fuji Heavy Industries (now SUBARU) submitted their proposals for the competition.
Bell-SUBARU’s UH-X design was preferred to a clean sheet design offered by Airbus Helicopters and KHI partnership.
SUBARU received a contract from the Japanese MoD to supply 150 UH-X helicopters for the JGSDF, in September 2015.
A scale model of the UH-X helicopter was on display at the Japan International Aerospace Exhibition 2016 (JA2016) held in Tokyo in October 2016.
The new helicopter will be indigenously built by SUBARU using a new production line at its Utsunomiya plant. The new production line was opened in early 2018.
UH-X design and features
The UH-X helicopter is based on the airframe of Bell 412EPI and will feature a rugged fuselage integrating a four-blade main rotor and a semi-monocoque tail boom structure fitted with a two-blade tail rotor. The under-fuselage will incorporate a skid-type landing gear.
The helicopter is designed to meet the specifications of the JGSDF, while offering superior performance, safety, and efficiency. It will support the most challenging missions and will also ensure low lifecycle costs and high availability.
SUBARU’s in-house metal surface treatment technologies and highly efficient manufacturing technologies will be used to build the helicopter’s next-generation rotorcraft.
The UH-X helicopter will be equipped with a state-of-the-art avionics suite integrating high-resolution multi-function displays, an automatic flight control system (AFCS), and sensors.
It will have an overall length of approximately 13m, a width of 3m, and an overall height of 4m. The maximum gross weight will be 5.5t, while the useful load of the rotorcraft will be more than 2t.
The helicopter will also feature a spacious cabin, which can be configured to transport personnel and cargo and serve other customer-specific missions.
Engine and performance of UH-X helicopter
The helicopter will be equipped with two Pratt & Whitney PT6T-9 engines coupled to a robust main rotor gearbox. Each engine will integrate state-of-the-art electronic engine controls (ECS) and will deliver a maximum take-off power of 1,800shp (1,342kW).
The PT6T-9 engine will deliver 15% more power than its predecessors and will also ensure a time between overhauls (TBO) of 4,000 hours. The ECS, equipped with the full hydromechanical back-up, will further reduce the workload of the pilot.
The power-plant will enable the helicopter to achieve a maximum horizontal speed of 125kt and deliver superior performance in hot and high conditions.