On Reliability Theory of Time Limited Dispatch Analysis in Engine Control Systems

Affiliation of Author(s):民航学院

Journal:Tuijin Jishu

Abstract:To facilitate the type certification of civil aircraft and commercial aircraft engines, reliability the-oretical issues of Time Limited Dispatch(TLD)analysis for engine control systems are studied. Based on the open and closed Markov models of TLD analysis, the definition of the average integrity level of engine control systems is derived by using the theory of the time continuous Markov process. It is concluded that the accurate definition of the average integrity level is the Loss of Thrust Control(LOTC)frequency with negligible maintenance time. The Markov models of the single fault and multiple-fault TLD analysis are constructed respectively; and the characteristics of both models are analyzed based on the models. It is showed that the multiple-fault TLD model has three characteristics including the time varying instantaneous LOTC rate, the existence of no-dispatch (ND)states, and the multiple maintenance strategies of the multiple-fault state compared with the single fault TLD model. To the periodic inspection approach, the formula of the mean time to failure is derived by using the conditional life distribution in the case that faults are observed in the periodic inspection; and then, the formula of the average fault exposure time is derived. Finally, a case is given to illustrate the application of our proposed theories via a practical type of FADEC system. © 2018, Editorial Department of Journal of Propulsion Technology. All right reserved.

ISSN No.:1001-4055

Translation or Not:no

Date of Publication:2018-03-01

Co-author:Li, Nai-Xin,Zhou, Jia,Zhang, Yan-Jun

Correspondence Author:LU Zhong

Date of Publication:2018-03-01