Method for the synchronisation of data in a computer network, in particular for the synchronisation of traffic information, preferably air traffic information, in a computer network from traffic control centres for traffic monitoring, comprising at least one server and a number of clients in data connection with the server, - wherein on the server a central data model is kept available, which contains the data to be synchronised and which, upon arrival of a manipulation request, executes data manipulation corresponding to the manipulation request, - wherein on each of the clients a local data model corresponding to and synchronised with the central data model is kept available, - wherein on each of the clients there is a presentation program running for presenting the data to be synchronised and for interaction with a user, and wherein a control program runs on each of the clients that offers the user the possibility of manipulating the data to be synchronised, - wherein during data manipulation by the user with the control program running on a client a relevant manipulation request is created and forwarded to the local data model and the respective manipulation contained in the manipulation request is executed in the respective local data model of this client, - wherein the manipulation request, after successful execution in the local data model of the client, is transmitted to the server and the respective manipulation contained in the manipulation request is executed in the central data model of the server, and - wherein after successful execution of the manipulation of the central data model of the server the manipulation request is transmitted to all clients and the local data models of all clients are changed according to the manipulation request, characterised in that - the local data model of a client, in particular of all clients, each has two similar local data models (23, 25) corresponding to the central data model of the server, - upon corresponding activation of the control program by the user, a manipulation request is created and forwarded to the first local data model and the respective manipulation is executed in the first local data model of the client, - after successful execution of the manipulation in the first local data model of the client the manipulation request is transmitted to the server, - the client after receiving manipulation requests from the server conveys the respective manipulation requests to the second local data model, - the first and the second data model (23, 25) are compared with one another and in case of conflict the first data model is overwritten with the content of the second data model, and - for the transmission of the manipulation requests from the server to a client an asynchronous transmission or broadcast transmission is used. - wherein on the server a central data model is kept available, which contains the data to be synchronised and which, upon arrival of a manipulation request, executes data manipulation corresponding to the manipulation request, - wherein on each of the clients a local data model corresponding to and synchronised with the central data model is kept available, - wherein on each of the clients there is a presentation program running for presenting the data to be synchronised and for interaction with a user, and wherein a control program runs on each of the clients that offers the user the possibility of manipulating the data to be synchronised, - wherein during data manipulation by the user with the control program running on a client a relevant manipulation request is created and forwarded to the local data model and the respective manipulation contained in the manipulation request is executed in the respective local data model of this client, - wherein the manipulation request, after successful execution in the local data model of the client, is transmitted to the server and the respective manipulation contained in the manipulation request is executed in the central data model of the server, and - wherein after successful execution of the manipulation of the central data model of the server the manipulation request is transmitted to all clients and the local data models of all clients are changed according to the manipulation request, characterised in that - the local data model of a client, in particular of all clients, each has two similar local data models (23, 25) corresponding to the central data model of the server, - upon corresponding activation of the control program by the user, a manipulation request is created and forwarded to the first local data model and the respective manipulation is executed in the first local data model of the client, - after successful execution of the manipulation in the first local data model of the client the manipulation request is transmitted to the server, - the client after receiving manipulation requests from the server conveys the respective manipulation requests to the second local data model, - the first and the second data model (23, 25) are compared with one another and in case of conflict the first data model is overwritten with the content of the second data model, and - for the transmission of the manipulation requests from the server to a client an asynchronous transmission or broadcast transmission is used.