Korea Aerospace Industries (KAI) announced on July 23 that it has successfully completed the first phase of the ‘Korean Tactical Helicopter (KUH-1) Performance Upgrade Power Transmission System Development Project,’ focusing on domestically developing the core component of the main gearboxes.
This first phase of the project, supported by the Ministry of Trade, Industry and Energy, involved a total investment of approximately KRW 110.9 billion, including around KRW 80 billion of KAI’s own funds. The project primarily concentrated on detailed design and localization of the main gearboxes, which are essential components of helicopter powertrains. KAI successfully localized 33 key parts, marking a significant milestone in reducing dependence on imported technology in the power transmission sector.
The development involved the participation of over 10 domestic companies and research institutes, employing more than 200 specialized engineers. Additionally, the project validated high-precision manufacturing technology by obtaining certifications for 35 specialized production processes.
Participating companies include Urum PTS, E.M. Korea, Ilgwang-Ju Industrial, Korea Heat Treatment, Aerocotek, Samyoung M-I Tech, Samwoo Metal Industries, and Tesco. Testing partners included WS ENG, Korea Institute of Materials Science, and Ulsan Technopark.
Notably, the team successfully tested gear, shaft, and housing components made from advanced materials such as magnesium, titanium, and high-strength steels—materials known for their challenging processing requirements—thereby ensuring design reliability and structural integrity.
The power transmission device is a critical component that distributes engine high-speed rotation to the main and tail rotors in helicopters. It is regarded as one of the three core technologies for helicopter systems, alongside the automatic flight control system and rotor systems.
KAI plans to proceed with further development, including full-scale manufacturing of the gearboxes and basic performance testing, under a subsequent phase outlined in a memorandum with the Defense Technology Promotion Institute.
A KAI official stated, “This successful development demonstrates the potential for localizing helicopter power transmission units in Korea, which could substantially reduce import reliance and improve operational efficiency and maintenance cycles. The accumulated technology can be applied to the upgrade of the Surion helicopter’s performance and the next-generation medium tactical helicopter project. Moreover, it will contribute to enhancing the competitiveness of Korean aviation technology in the global market.”
