AIRCRAFT RELIABILITY AND MAINTENANCE

Aircraft Reliability and Maintenance

Aircraft Reliability and Maintenance

1. Introduction

World of IATA (International Air Transport Association) was 800 million three years (1990-1992) and American International scheduled services to 115 billion dollars in losses, the airlines. This represents more than 14 yuan per passenger (Milne, 1993) subsidies. We must maintain a military aircraft, the aircraft cost 160 million dollars per year. According to a statistical one for each type of aircraft 11 percent of total operating costs for maintenance. For the most do not want the business activities of any aircraft, whether military or civilian, is unscheduled maintenance. However, until now, no reliability or maintenance of measures to try to measure or quantify the unscheduled maintenance. The average over the past five years [operating] time between failure (MTBF) has been widely used in many commercial and defense industrial measurement reliability. Maintenance programs are in use MTBF many difficulties. One of the most important, it did not engineer to solve maintenance problems. Crocker and Kumar (1999) discussed the reliability of the center in the planning difficulties, as long as the MTBF values ??that separate maintenance. Use has been obtained from the MTBF (Knowles, 1995; Mitchell, 1998), many researchers are several criticisms. MTBF has several drawbacks. These measures include: Although it can be predicted from the field failure data • MTBF, which is almost impossible to predict from the test data, the system time to failure distribution is exponential mean time between failures, resulting in a new design of the main problems the project. • The average time to failure using the exponential failure distribution limit, it can not be used to simulate the use of the relevant failure analysis. Most of the Defense standard (DoD, 1991a, 1991b), who meet MIL - HDBK - 217 and MIL - STD - 1388 is based on the exponential distribution, now abandoned, a new reliability index of the search has been in a The main areas of reliability engineering. Recently, in the UK commercial and military aircraft operators of maintenance free operating period for future generations of aircraft reliability (MFOP) concept. According to Sydney (1999), British Airways, Airbus has studied the application of the concept MFOP Airbus aircraft to meet the growing demand for independent operation. He also pointed out that this concept can be used in civilian and military aircraft, Airbus Military has recently led the company as its new military transport aircraft as part of a formal proposal, including MFOP. Bottomley (1999) pointed out that the ultra-reliable aircraft project by the Association of British Aerospace Companies (SBAC) is to identify the purpose of achieving the elimination of unscheduled maintenance, and "guaranteed" period of operation, the feasibility of free repairs.

Three Spool Turbofan

Rolls-Royce for their choice of three large commercial turbofan engine spool configuration (ie, the RB211 and Trent family), in which the pressure (IP) compressor is a single (IP) shaft , run concentric with the LP and HP shaft and by a single IP ...