- Hanwha Aerospace will begin ground testing of its 5,500-pound-class indigenous turbofan engine for Korean Air’s stealth wingman drone in January 2026.
- The new engine will replace the Ukrainian-made AI-222 currently used on the prototype and is being developed jointly with South Korea’s Agency for Defense Development.
South Korea is preparing to take a key step toward propulsion self-reliance, as Hanwha Aerospace begins ground testing of a homegrown engine for Korean Air’s Low Observable Unmanned Wingman System (LOWUS) stealth drone in January 2026.
According to Energy Economy News, the new 5,500-pound-class turbofan engine, developed jointly by Hanwha Aerospace and the Agency for Defense Development (ADD), will undergo its first full ground verification and performance evaluation early next year. The test aims to confirm the engine’s readiness to replace the Ukrainian-made AI-222 currently powering the LOWUS prototype.
Industry officials familiar with the program said the Ukrainian engine, produced by Ivchenko-Progress in Zaporizhzhia, has served as a stopgap solution for flight testing.
“Korean Air’s stealth unmanned wingman is currently flying with a Ukrainian AI-222 engine, but will be switched to Hanwha’s 5,500-pound-class engine,” one official said.
The AI-222’s low-bypass design and digital control system demonstrate the wingman drone’s mission profile—flying alongside the KF-21 Boramae fighter at high subsonic speeds. The new Hanwha engine will match its thrust output while incorporating design improvements to meet South Korea’s military reliability standards.
ADD and Hanwha Aerospace intend to complete development ahead of the LOWUS production phase in the mid-2030s. A prototype of the engine was publicly displayed at ADEX 2025 in Seoul, signaling that the program is advancing on schedule.
The transition from a Ukrainian to a domestic engine has broader strategic value. Defense officials cited the need to eliminate exposure to supply chain disruptions stemming from the ongoing war in Eastern Europe and to reduce dependence on foreign components governed by ITAR restrictions. By establishing an indigenous engine line, Seoul also aims to enhance its defense export competitiveness.
An ADD researcher, Lee Seung-yeol, said, “We are developing a turbofan engine equivalent in power to the one currently installed on Korean Air’s stealth drone. Once development is completed, it will serve as the power source for future systems.”
The engine program—initiated in 2013 with a ₩153.1 billion ($106 million) investment—has focused on developing the core fan, high-pressure compressor, and combustion technologies. Hanwha Aerospace says the design offers a long service life, operating for over 1,000 hours between overhauls, meeting global military engine standards.
The company’s 5,500-pound engine is part of a larger roadmap to achieve full engine independence across Korea’s military aviation portfolio. Other programs under development include a 1,400-horsepower turboprop for medium-altitude drones, a 10,000-pound-class turbofan for large UAVs and UCAVs, and a 16,000-pound-class engine for the KF-21 Block III fighter.
Ground integration testing of the LOWUS powertrain—covering intake performance, vibration, and system reliability—is expected to validate not just propulsion, but system interoperability and airworthiness. This process, the ADD explained, is essential before the aircraft’s next flight test phase.
The LOWUS stealth wingman drone is designed to operate in tandem with the KF-21 fighter, conducting high-risk missions and enabling swarm or “mosaic warfare” tactics at a reduced cost. Analysts estimate the drone’s target unit price at roughly $700,000, achievable only through mass production using domestic engines.