A wireless communication system for 2. use aboard an aircraft, said wireless communication system comprising: a router connected to an antenna (2, 2a-c), wherein the router is configured to transmit and receive wireless data communication to and from a stationary communication server outside said aircraft through at least one ground base station (6, 6a-c) via said antenna; wherein said antenna (2, 2a-c) is a directional antenna; a control unit configured to determine an attitude change of said aircraft by determining a change in at least one of a roll angle, pitch angle and/or yaw angle of said aircraft; an antenna steering unit connected to said control unit and being configured to steer an antenna beam of said directional antenna (2, 2a-c) based on the determined attitude change of said said aircraft in order to compensate for said determined attitude change, such that said antenna beam maintains a direction towards a predetermined sector (21-24, 31-34) of a ground surface below the aircraft, wherein said router is connected to a plurality of directional antennas (2, 2a-c) defining at least two groups of directional antennas, wherein each group comprises at least one directional antenna and each group is configured to radiate and/or receive radio waves towards/from a selected sector (21-24, 31-34) of a ground surface below the aircraft, the selected sectors being at least mostly non-overlapping, and preferably non-overlapping; wherein said control unit is configured to evaluate a data link quality between each group and said at least one ground base station in said selected sector, and wherein said antenna steering unit is configured to steer said antenna beam(s) to radiate and/or receive radio waves towards/from a new sector (21-24, 31-34) of the ground surface, when said data link quality is below a predefined quality threshold value; and wherein said steering unit is configured to steer the antenna beam(s) of each group sequentially such that the direction of the antenna beam(s) of at least one group is maintained towards the selected sector(s) while steering the antenna beam(s) of at least one different group to radiate and/or receive radio waves towards/from the new sector. a router connected to an antenna (2, 2a-c), wherein the router is configured to transmit and receive wireless data communication to and from a stationary communication server outside said aircraft through at least one ground base station (6, 6a-c) via said antenna; wherein said antenna (2, 2a-c) is a directional antenna; a control unit configured to determine an attitude change of said aircraft by determining a change in at least one of a roll angle, pitch angle and/or yaw angle of said aircraft; an antenna steering unit connected to said control unit and being configured to steer an antenna beam of said directional antenna (2, 2a-c) based on the determined attitude change of said said aircraft in order to compensate for said determined attitude change, such that said antenna beam maintains a direction towards a predetermined sector (21-24, 31-34) of a ground surface below the aircraft, wherein said router is connected to a plurality of directional antennas (2, 2a-c) defining at least two groups of directional antennas, wherein each group comprises at least one directional antenna and each group is configured to radiate and/or receive radio waves towards/from a selected sector (21-24, 31-34) of a ground surface below the aircraft, the selected sectors being at least mostly non-overlapping, and preferably non-overlapping; wherein said control unit is configured to evaluate a data link quality between each group and said at least one ground base station in said selected sector, and wherein said antenna steering unit is configured to steer said antenna beam(s) to radiate and/or receive radio waves towards/from a new sector (21-24, 31-34) of the ground surface, when said data link quality is below a predefined quality threshold value; and wherein said steering unit is configured to steer the antenna beam(s) of each group sequentially such that the direction of the antenna beam(s) of at least one group is maintained towards the selected sector(s) while steering the antenna beam(s) of at least one different group to radiate and/or receive radio waves towards/from the new sector.