South Korea is probing an alleged theft of technical information related to the developmental Korea Aerospace Industries KF-21 fighter.
The investigation, conducted by South Korean counterintelligence officials, centres on Indonesian engineers allegedly downloading KF-21 information to a USB drive, according to a report by South Korea’s official Yonhap news agency, citing “multiple” sources.
“An investigation is currently under way to figure out whether the stored data contains strategic technologies,” Yonhap reports a source as saying.
The reports suggest that the investigation’s subjects have been forbidden from leaving South Korea.
FlightGlobal has contacted South Korea’s Defense Acquisition Program Administration, which overseas the KF-21 programme, about the reports. An Indonesian official declined to comment.
Indonesia is a junior partner in the KF-21 programme, responsible for 20% of its W8.8 trillion ($6.6 billion) development costs. For some years, Jakarta has been tardy on payments. Yonhap reports that it has paid just W278 billion, well below the W1 trillion it owes.
Indonesian engineers are based in South Korea to support the programme, which also aims to produce a variant for Indonesian service, sometimes designated I-FX.
FlightGlobal understands that Jakarta, eager to build up its aerospace sector, is displeased with the level of technology transfer taking place through the KF-21 programme. There is a view that the KF-21 absorbs Indonesian taxpayer funds without materially improving the nation’s technical capabilities.
Nonetheless, senior Indonesian officials have periodically underlined their commitment to the programme. In February 2023, Indonesian deputy defence minister Wamenhan Herinda stated that Jakarta has a “big commitment” to the KF-21, as it offered an opportunity to “master high technology in the defence industry”.
Whatever the merits of the South Korean allegations, the episode is likely to further strain relations between Jakarta and Seoul.
Also raising questions about Jakarta’s commitment to the KF-21 is its order for 48 Dassault Rafale fighters, as well as a memorandum of understanding to acquire up to 24 Boeing F-15EXs.
South Korea is expected to operate 120 KF-21s and Indonesia 50. The type is powered by two GE Aerospace F414 engines.
Six KF-21 prototypes are involved in the aircraft’s test campaign. Mass production is set to start this year, with deliveries to the Republic of Korea Air Force to start in the second half of 2026.
