OBS_VALUE: Precise licensing and authorization fees were not found in the cited sources. The HCAA website states that: An Operator to be involved in commercial air transport must be the holder of a valid Air Operator Certificate (AOC) issued by the Hellenic Civil Aviation Authority and a valid Commercial Operating License. This AOC is issued by the HCAA according to Commission Regulation (EU) No 1139/2018 as amended and its implementing Rules. The Commercial operating license is also issued by the HCAA under the Regulation (EC) No 1008/2008 as amended.