In the field of aircraft maintenance, ensuring the reliability of maintenance programs is essential for maintaining aircraft airworthiness and operational safety. As civil aircraft log increasing flight hours and cycles, combined with insights from failures and operational issues, there is a continual need for updates to maintenance programs. Task transfer within these programs is crucial for broadening maintenance capabilities, reducing risks, and enhancing efficiency. However, the traditional Maintenance Steering Group-3 (MSG-3) methodology, commonly employed to shape maintenance program development, only offers qualitative guidelines for task transfers. It falls short of providing strong theoretical backing and quantitative risk evaluation methods for these processes. This deficiency can result in subjective evaluations of task transfers, which may jeopardize both safety and efficiency in maintenance operations.
To tackle this concern, a research team from the Civil Aviation University of China conducted a study titled “Risk Evaluation for the Task Transfer of an Aircraft Maintenance Program Based on a Multielement Connection Number.” This research emphasizes the quantitative assessment of risks associated with aircraft maintenance task transfers. The study introduces a comprehensive risk evaluation framework rooted in the principles of MSG-3.
The framework begins with the development of an all-encompassing risk assessment index system that encompasses four key dimensions: Density (such as the number of components and the difficulty of inspections), Importance (including safety implications and economic consequences), Exposure Degree (like temperature, vibration, and potential damage from external objects), and Manpower/Personnel (considering inspection intervals and worker proficiency). Subsequently, the Analytic Network Process (ANP) is utilized to assign weights to these interconnected index factors, incorporating expert subjective assessments to navigate the complexities of these interdependencies, a known limitation of the traditional Analytic Hierarchy Process (AHP).
Moreover, the study presents an evaluation model based on multielement connection numbers, which effectively characterizes decision data and allows for the quantification of task transfer risks through set-pair potential analysis. The researchers also performed temporal risk trend analysis using partial connection numbers of varying orders to identify both static risk conditions and the dynamic evolution of risks.
To assess the framework”s applicability, an empirical case study was conducted on the maintenance program of the Boeing 737NG, focusing specifically on the transfer of maintenance responsibilities for the landing gear damping strut from the system/powerplant program to the zonal inspection program. Expert evaluations involving airline maintenance engineers, engineering managers, and academic scholars, alongside the use of Super Decision software, were employed to determine index weights and reliability levels.
The findings indicated that the overall task transfer risk for the evaluated zonal inspection item (Task 32-800-00) was categorized as “same potential level 7,” suggesting a low risk and high reliability. The calculated risk probability stood at 5.85 × 10^{-5}, meeting the acceptable risk standards set by the U.S. Federal Aviation Administration (FAA) and the European Union Aviation Safety Agency (EASA). Sensitivity analysis further revealed that the “Importance” factor significantly influenced transfer risk; an excessive weighting of this factor could heighten overall risk, while “Density” and “Manpower/Personnel” had a lesser effect.
The research paper “Risk Evaluation for the Task Transfer of an Aircraft Maintenance Program Based on a Multielement Connection Number” is authored by Tao LIU, Zhibo SHI, Huifen DONG, Jie BAI, and Yu YAN. The complete text is accessible at: https://doi.org/10.1007/s42524-023-0282-0.
