Research on IMA Common Mode Analysis for Powerplant System in aircraft

Abstract:
According to the requirement of CCAR25.1309 (b), the system design must provide fail-safe capability to prevent single failure propagation in order to prevent catastrophic condition. Moreover, the common mode failure that influences single part and fail-safe conditions are not allowed. Common Cause Analysis is the compliance method used in CCAR25.1309 (b), and Common Mode Analysis is part of Common Cause Analysis. Common Cause Analysis is used to check the independence of function/system meet the requirement. The critical function implemented with redundant components, channels and IMA devices is easily influenced by common design error. The independence between components is hard to prove and belongs to single failure category. The independence between components needs to be analyzed through Common Mode Analysis. The Common Mode Analysis of SWITCH and GPM is studied. In the analysis, loss of IMA single component, erroneous IMA single component and the similar IMA components all erroneous are analyzed. This research supports the closure of CCAR25.1309 (b).