Software Maintenance on the Airbus Family

For computers under AEROSPATIALE responsibility, two technologies are used in parallel to ease software changes on- board the Airbus Family. In one technology, all computers with a data base have tele-loading capability from a Multipurpose Disk Drive Unit (MDDU). The best known is the FMS but other ones have been designed in the same way; configuration management is performed through the Multipurpose Control and Display Unit (MCDU) in this case. Tele-loading is monitored by the on-board computers. In the second technology, there is extensive use of the On Board Replaceable Module (OBRM) to implement operational programs of all computers on which changes are expected. These modules are in accordance with ARINC 607 and their installation in the computer builds the part number, solving automatically the configuration control problem; special techniques are used to check compatibility between OBRMs of a given set and between this set and the computer hardware.