Studies on Historical Evolution of FAR Part 33 Associated with Development of Civil High Bypass Ratio Turbofan Engine

Abstract

Federal Aviation Regulations (FAR) Part 33 is airworthiness standard of aircraft engine and it is under constant changing to adapt the new safety demands of airworthiness certification. In this paper, starting from the historical amendments, the evolution of Part 33 is studied with development of civil high bypass ratio turbofan engine by statistics analysis and the revised reason is summarized by investigation the proposals of amendments. For analysis, a conception of restriction boundary of regulation is introduced and the influence produced by each revised reason is researched between restriction boundary and safety boundary. Results show that the changed of Part 33 has four cycles, with significant revision every 10-12 years. And interestingly, the civil high bypass ratio turbofan engine has the same development stages and good corresponding relationship with significant revision period of Part 33. Under the contradiction between safety demand of FAA and technology demand of manufacturer, the revised reason of regulation is generalized into five aspects: the development of technology, the hazardous accident, the overly strict rules or vice versa, the unclear definition or explanation, the international uniformity. Therefore, the appeared new aircraft engine can promote the update of regulations and the revised regulations guide the development of next generation engine. Basing on these obtained laws, the next significance amendment of airworthiness regulation Part 33 can be predicated.