Investigations were underway to determine the cause of the crash of the T-50 aircraft, a spokesman said.
It was the second crash in less than a year involving a T-50, South Korea's first indigenous supersonic aircraft jointly developed by Korea Aerospace Industries and Lockheed Martin.
A T-50B aircraft crashed into a mountain in the northeast last November, killing a pilot.
Indonesia in 2011 ordered 16 T-50s and Seoul is pursuing other contracts from the Philippines and Iraq.