South Korean defense firm Korea Aerospace Industries (KAI) Ltd. said Thursday it has completed the delivery of six additional T-50i advanced trainer jets to Indonesia. KAI signed a contract to supply T-50i aircraft to the Indonesian Air Force in 2021 and began deliveries in February. The aircraft manufacturer first inked a deal to supply 16 T-50 trainer jets to Indonesia in 2011, and has now delivered 22 aircraft. Indonesia was the first overseas customer for the T-50i, the export variant of South Korea's first homegrown supersonic jet trainer. The Southeast Asian country has acquired 42 South Korean-made aircraft, including 20 KT-1 trainer jets. The two countries have expanded cooperation in the defense sector, with Indonesia taking part in a joint development project of South Korea's indigenous KF-21 fighter jet.