The other model was designed by Seoul's Agency for Defense Development, who became a competitor to KAI when they judged the ADD design for a twin-engine plane requiring more domestic systems development as too ambitious.
Model lainnya dirancang oleh Seoul's Agency for Defense Development (ADD) yang menjadi pesaing KAI, mereka menilai desain ADD untuk pesawat bermesin ganda akan membutuhkan lebih banyak pengembangan sistem domestik yang dinilai terlalu ambisius.