Some low-cost airlines in South Korea saw problems with booking or issuing air tickets Friday, an industry source said, in an apparent IT disruption that affected the global airline and financial sectors.The cyber outage affected the airport ticketing of Jeju Air Co., Eastar Jet Co. and Air Premia Inc., according to the source.Currently, employees of the three airlines are conducting check-ins by hand, the source said.The three airlines have used computer systems based on Microsoft's cloud service, according to the source.Source: Yonhap News Agency