The present invention is directed towards an onboard central maintenance computer system integrated into an aircraft system and a system for collecting and analyzing complete maintenance information. The central maintenance computer system (CMCS) collects, consolidates, and reports LRU faults data in order to aid flight crew and maintenance personnel in maintenance procedures. An aircraft system in which the CMCS is used includes a plurality of line replaceable units (LRU), a communication system through which the LRUs can transmit LRU fault data and receiver test initiation commands, and an operator interface device for receiving input commands, displaying data, and communicating with other systems. The central maintenance computer system includes a data transfer system, an input/output processor, a memory device, and a control processing system. During flight, the control processing system controls the collection of complete LRU fault data; generates an isolated fault from the LRU fault data; associates the isolated fault with one of the maintenance messages stored in the memory device; and causes the associated maintenance message to be stored as an active maintenance message in fault history.