Configuring an on-board maintenance information system in an aircraft, the information system comprising a first communication interface and a second communication interface, a protected domain, an open domain, a first maintenance application module of the protected domain, a second maintenance application module of the open domain, a first data filtering module, and a second data filtering module. After having determined a mode of connection for a mobile maintenance terminal to the information system, the second data filtering module is configured to filter data exchanged between the first communication interface and the maintenance application module of the open domain if the terminal is directly connected to the information system via the second interface. If the terminal is connected to the information system via an information system on the ground and via the first communication interface, the second data filtering module is configured to filter data exchanged between maintenance application modules of the protected and open domains.