Reliability and Maintainability

Poor reliability is unacceptable. An aircraft as a system must achieve a user’s confi­dence that it will work as and when required. This entails a multidisciplinary study for an efficient and cost-effective system integration leading to better reliability and maintainability (R&M) during the operational lifespan. In the current economic cli­mate, the role of reliability, maintainability, and recyclability must be scrutinized for cost control – not only the in-house product line but also the supply chain of bought – out items. Even those systems that are perceived as reliable are only reliable due to the significant redundancy built into the system or the vast amount of corrective maintenance that keeps a system running. Despite immense efforts to predict and

improve the components used in the systems, their R&M often remain at the same levels.

The design must guarantee integrity with significant time between failures that repairs can be made in a specific downtime period. An aircraft must have more TBO than the competition, which is linked to the system reliability as a function of the operational environment and length of operational time. Although the avionic and engine suites come with a well-studied R&M status, many other aircraft com­ponents (i. e., mainly structures with many built-in redundancies) have yet to evolve to address maintenance issues at the conceptual design stage. Almost all bought – out items and subsystems have reliability figures obtained from rigorous testing. An aircraft as a system maintains a systematic log, recording failures and defects so they can be followed up with modifications to make designs more robust, for those already built and those that are yet to be built.