Korea Aerospace Industries Co. (KAI), South Korea's sole aircraft manufacturer, said Monday it has signed a preliminary deal with a Thai firm for the maintenance of T-50TH trainer jets.KAI has exported 14 T-50TH trainer jets to Thailand, and Thai Aviation Industries (TAI) has handled maintenance services for the planes with technology support from KAI."The company expects the partnership with TAI will help win additional trainer jet orders in the country," a company spokesperson said over the phone.Source: Yonhap News Agency