The T-50B is currently the only supersonic trainer jet equipped with a state of the art avionics system.
Lithuania, whose air force has only a handful of trainer jets and helicopters, has welcomed the offer, since neither it nor the other Baltic states had sufficient forces to patrol their skies.
Just last week, Lockheed agreed to license the design for a trainer jet from Aermacchi S.p.A. of Italy to use in a competition for an Air Force contract.
Pilot astronauts also train in the T-38 Talon aircraft, a supersonic trainer jet.
In 2010 and 2011, South Korea exported trainer jets and submarines to Indonesia.
One of them was the M-2 Skaut, designed by Zdeněk Rublič, who later designed the Aero L-29 Delfín trainer jet.
Iraq was negotiating the acquisition of T-50 trainer jets, having first publicly expressed official interest during the Korea-Iraq summit in Seoul on 24 February 2009.
The British are lobbying for their trainer jet, the Hawk.
In July 2008, a trainer jet missed the runway and crashed into the fence.
(See was killed in the crash of a T-38 trainer jet three months before his Gemini 9 mission.)