Availability Confidence Limits for Passenger Aircraft with Exponential Operation Time and Repair Time

Availability is an important performance measurement of repairable system which represents the capability whether a system is operating satisfactorily at any point in time. However, aircraft availability had been seldom addressed in literatures. In this article we discussed passenger aircraft availability with exponential operation time and repair time distribution. First analyzed the airplane operation process by integrating maintenance problems. Then passenger aircraft classical availability estimates were given according to practical engineering background. Considering there were history information for a similar type of aircraft fleet, and assuming the exponential shape parameters had gamma prior distribution, we made various statistical inferences about the steady state system availability that includes point and interval estimates. A numerical example proved the effectiveness of this method using the reliability data of an aircraft fleet from a Chinese airline from 2002 to 2009. Additionally, by adopting computer simulation, the effect of introducing historical information was discussed.