Abstract: A method and system for propagating data such as entertainment data in an airline system is disclosed. The entertainment data may comprise video, audio and games data. A computer server device is provided at an airline terminal, and a mobile computer is provided in an aircraft with a hard disk array for storage of the digital data. The data can be propagated in the system to aircraft and to further airline terminals by an automatic software function which occurs when an aircraft mobile computer electrically connects with the server computer at the terminal. Such connection is made between the aircraft and an aerobridge at the airline terminal. The software provides checking to see if the mobile computer is an authorized computer, and also to determine whether the data in the mobile computer is more recent than the data in the computer server or vice versa and then a data exchange occurs to replace the old data with new data.