Development of fault detection and reporting for non-central maintenance aircraft

This paper describes how real-time faults can be automatically detected in Boeing 737 airplanes without significant hardware or software modifications, or potentially expensive system re-certification by employing a novel approach to Airplane Conditioning and Monitoring System (ACMS) usage. The ACMS is a function of the Digital Flight Data Acquisition Unit (DFDAU), which also collects aircraft parameters and transmits them to the Flight Data Recorder (FDR). The DFDAU receives digital and analog data from various airplane subsystems, which is also available to the ACMS. Exploiting customized ACMS software allows airline operators to specify collection and processing of various aircraft parameters for flight data monitoring, maintenance, and operational efficiency trending. Employing a rigorous systems engineering approach with detailed signal analysis, fault detection algorithms are created for software implementation within the ACMS to support ground-based reporting systems. To date, over 160 algorithms are in development based upon the existing Fault Reporting and Fault Isolation Manual (FRM/FIM) structure and availability of system signals for individual faults. Following successful field-testing and implementation, 737 airplane customers have access to a state of fault detection automation not previously available on aircraft without central maintenance monitoring.