Aircraft Maintenance Planning and Control PDF

Aircraft Maintenance Planning and Control Maintenance Scheduling - Process of organizing all tasks to improve efficiency, speed of work, cost-cutting, and prevention of problem - Maximizes the number of hours available, based on resources, and maximizes internal labor, which cu...

Aircraft Maintenance Planning and Control Maintenance Scheduling - Process of organizing all tasks to improve efficiency, speed of work, cost-cutting, and prevention of problem - Maximizes the number of hours available, based on resources, and maximizes internal labor, which cuts costs and speeds up tasks. - Implementation of preventive maintenance to minimize downtime and increase efficiency - Maintenance scheduling is different from maintenance planning. - Maintenance Scheduling - planned work including the 4 W’s of tasks (who, what, when, where) - Maintenance Planning - process of identifying and solving potential problems before they occur Maintenance Intervals - Hard time maintenance (fixed intervals) - Preventative process in which known deterioration of parts are limited to acceptable level by maintenance actions - Carried out periodically in relation to time-in-service - On-condition maintenance (inspection-based) - Preventative process in which parts are inspected/tested at specified periods to determine its serviceability - Inspections/tests determines the need for maintenance actions - The primary purpose of on-condition maintenance is to remove parts before its service failure - Condition monitoring (predictive maintenance) - Information on parts gained from monitoring is collected, analyzed, and interpreted on continuing basis to decide on implementing corrective procedures - Condition monitoring is automated and is part of the aircraft’s on-board health management system Units for Maintenance Intervals - Flight hours (FH) - total time an aircraft spends in flight (key metric in aviation) - Flight Cycles (FC) - operation of an engine from the time an aircraft leaves the ground (take-off) until it touches the ground at the end of a flight (landing) - Calendar Time (Cal) - passage of time in days, months, or years, usually used in A, B, C, and D checks Types of Maintenance Checks - Breakdown of A, B, C, and D checks: - - A-check: Light maintenance conducted frequently (every 400-600 flight hours). - This type of maintenance check is usually conducted every 200 to 300 flights or 400 to 600 flight hours. This type of maintenance check is considered to be relatively light as it only involves simple procedures such as lubrication of key systems, changing filters, and inspecting emergency equipment such as emergency lights.  - This type of maintenance check is essential for preventative maintenance as it is carried out in pursuit of mainly determining damages, corrosions, and even missing parts to ensure the airworthiness of the aircraft. - B-check: Involves deeper inspection of aircraft systems and components. - This type of maintenance check is usually conducted every 6 to 8 months. The process takes about 160 to 180 man-hours depending on the aircraft type, and is usually completed within 1 to 3 days. - This type of maintenance typically involves inspections of component alignments, inspecting the landing gear wheel’s condition, and torquing of the nose landing gear spotlight. - In pursuit of reducing the downtime of aircrafts, B-Check procedures have been absorbed into A-Check procedures which is why B-Check tasks nowadays are completed during the A-Check phase. - C-check: Extensive maintenance requiring the aircraft to be grounded for a longer period. - This type of maintenance check is usually conducted every 20 to 24 months. It may also be performed every specific number of flight hours depending on the manufacturer’s instructions, and may last 1 to 2 weeks. - Since this type of maintenance involves extensive tasks, it requires the presence of an aviation maintenance technician for deeper inspections for the majority of the aircraft’s parts. Considering the heavy workload, the C-Check would require the aircraft to be in a maintenance facility for the necessary tools and equipment, and may require up to 6000 maintenance hours to finish. - This type of maintenance involves assessing structures for corrosion and damage, examining the operation of the DC bus tie control unit, and an in-depth lubrication of fittings and cables. - D-check: The most thorough inspection, often referred to as a "heavy check," conducted every 6-10 years. - This type of maintenance check is considered to be a “heavy maintenance visit” as it involves comprehensive inspections and repairs for the entire aircraft which may require stripping down the entire aircraft. - Considering the workload it encompasses, this maintenance check may occur once every 6 to 10 years and may take upwards of 30,000 to 50,000 labor hours which leads to the aircraft having a downtime of 4 to 6 weeks. Short- and Long-term Planning - Daily and weekly maintenance tasks - A maintenance procedures that keep the aircraft airworthy and done consistently in intervals (e.g. daily or weekly) - These maintenance tasks includes: - Inspection of exteriors, landing gear, brakes, engine oil levels, and hydraulic systems - lubrication - cleaning - troubleshootings - minor repairs and replacements - Daily and weekly maintenance can be also called as routine or line maintenance - Long- term planning - Scheduled major overhauls - A mandatory inspection, disassembly, repair, replacement, reassembly, and testing of a system (e.g. engine or landing gear system) after operating in a certain amount of time or usage regardless of condition. The amount of operating hours or usage is given by the manufacturer. - Aircraft retirement - In deciding if an aircraft should be retired there are factors for considerations: - Ever evolving market - development of new and efficient aircrafts with better performance is more beneficial than using older aircrafts  - Maintenance cost - aircraft that fulfilled its lifespan are required to undergo major checks and repair which can be costly and time consuming - Global factors - by retiring aircraft airline companies can reduce fuel consumption and meet sustainability goals by reducing gas emissions - Aircraft’s end of life options - Storage and Preservation - aircraft will be put in to storage to be preserve for potential reactivation - Dismantling and Recycling - disassembled for parts to be recycled and waste to be properly disposed - Conversion for Non-Aviation Purposes - repurposing for training, education or research use. - Computerized maintenance management systems (CMMS) - A software tool used by mechanics and maintenance planners in order to manage maintenance activities. By having all the data be in the single system, where work orders, checklists, and work status can be seen in one place. - Some of its benefits are: - Improved Maintenance Planning and Execution - Enhanced Safety and Compliance - Inventory Management and Cost Control - Data-Driven Decision Making - Regulatory Reporting and Documentations Resources and Manpower - Manpower Planning - Also known as Human Resource Planning - Act of putting qualified number and kind of people at the right place and time - Qualified people should do their jobs in which they are suited to - Resource Planning - Plays an important role in resolving work requests, preventing equipment malfunctions, allowing better responsiveness and traceability of work and equipment maintenance, and speeding up troubleshooting efficiency - Coordination between various departments (engineering, supply chain, operations). - Engineers in supply chain management execute projects and work on the production of goods and services with the help of their technical skills and knowledge - To work with competitiveness, companies must provide quality products and services with the lowest/best price available. This cost-minimization is effective in the supply chain management as it improves relationship between the company and its customers - Operations management and supply chain management works together to support more efficient processes and drive better revenue. Supply chain management controls the process of production, while operations management oversees the production. Maintenance Budgeting and Cost Control - Maintenance Budgeting - Process of planning and allocating financial resources for asset and facility maintenance - Involves forecasting of maintenance costs in repairs, replacements, and preventive maintenance - Cost Management - Maintenance, repair, and operations (MRO) costs include expenses from labor, spare parts and materials, energy and utilities, and general overhead. One firm must budget these costs as it can affect productivity - Using Key Performance Indicator (KPI) will track maintenance costs and benchmarks that are crucial for maintenance cost and management planning. KPI include Mean Time Between Failures (MTBF) and Overall Equipment Effectiveness (OEE)  - Balancing cost-efficiency with high safety standards. - Lean Principles - Focuses on reducing waste and improving workflow, while minimizing costs and investing to the enhancement of safety measures - Material Choices - Selecting right materials is crucial in balancing cost against safety. Using innovative design techniques allows the use of less expensive materials without sacrificing safety (e.g. honeycomb structure) - Automation Tech - Automation technology might seem costly, but it is a long-term investment in cost efficiency and safety as automated systems reduce human error and enhance precision in maintenance, which leads to fewer accidents. - Regulatory Compliance - Applying safety regulations while achieving cost-efficiency requires research and development that will comply with safety laws while reducing costs. - Quality Control - By conducting testings and quality checks, safety issues may be addressed early while costs are still low. - Continuous Training - By training employees well, they are more likely to follow best practices, correct usage of equipment, and may identify potential safety hazards. Regulatory Compliance - Approval of Maintenance Programs by Aviation Authorities - Maintenance programs are essential for ensuring the airworthiness and operational safety of aircraft. It is a regulatory requirement that all maintenance programs undergo thorough evaluation and approval by relevant aviation authorities, such as the Federal Aviation Administration (FAA) in the United States or the European Union Aviation Safety Agency (EASA) in Europe. These authorities assess the technical aspects of the maintenance programs, ensuring that they meet the prescribed standards for safe aircraft operation. - Once approved, maintenance programs must be strictly adhered to, with any modifications or updates requiring further approval to ensure continued compliance with evolving regulatory requirements. Maintenance Program Requirements (According to ICAO) - EASA Part M M.A.302 requires all applicable aircraft to be maintained in accordance with an approved Maintenance Program. The Maintenance Program and any subsequent amendments shall be approved by the competent authority. (M.A.302) - EASA Certification Specifications (25.1529 Appendix H for large aircraft) - Air Navigation Order article 25 - Audits and Inspections by Regulatory Bodies - In addition to initial approval, aviation maintenance programs are subject to continuous oversight through regular audits and inspections conducted by regulatory bodies. These audits are designed to verify compliance with the approved maintenance procedures and to ensure that maintenance organizations and operators are following best practices. Function of Regulatory Bodies - Identifying aviation safety risks - Developing mitigations which may include a regulatory response, advice and guidance where a regulatory response is considered appropriate - Drafting rules - Issuing approvals - Monitoring compliance - Taking enforcement action Audits and inspections focus on several key areas, including: - Adherence to scheduled maintenance: Ensuring that all required maintenance tasks are performed in accordance with the approved program.  - Proper documentation: Verifying that accurate records are kept for all maintenance activities, including repairs, inspections, and modifications. - Personnel qualifications: Ensuring that the staff performing maintenance activities are properly trained and certified. - Facility and tool inspection: Evaluating whether the tools, equipment, and facilities used for maintenance meet regulatory standards. - Any findings during these audits must be addressed promptly, and failure to comply can result in penalties or grounding of aircraft until corrective actions are taken. - Maintenance Reliability Programs (MRP) - Maintenance Reliability Program is a system of data collection, statistical analysis and reporting of the events related to the technical status of the fleet during the operation of the aircraft/aircraft type in an operator’s fleet. - Since the operation widely varies between operators, reliability program is carried on by each operator on it’s fleet with the aim to analyze his specific operation. - Primary purpose of the Reliability Program is to provide information that is needed to adjust and improve operator’s Aircraft Maintenance Program for the aircraft/aircraft type operated in it’s fleet - Continuously running the Reliability Program, it is possible to detect negative and positive trends related to the reliability of the aircraft, its systems and components Basic Flow of Reliability Program References https://eptura.com/discover-more/blog/what-is-maintenance-scheduling/ https://skybrary.aero/articles/maintenance-programme https://www.globeair.com/g/flight-hours#:~:text=Flight%20Hours%20represent%20the%20total,maintena nce%20needs%20and%20pilot%20experience. https://www.lawinsider.com/dictionary/flight-cycle#:~:text=Flight%20Cycle%20means%20the%20operat ion,considered%20as%20a%20Flight%20Cycle. https://www.naa.edu/types-of-aviation-maintenance-checks/ https://www.managementstudyguide.com/manpower-planning.htm https://www.carl-software.com/resource-planning-the-key-issue-in-maintenance/#:~:text=The%20importa nce%20of%20maintenance%20resource%20planning&text=Resource%20planning%20allows%20better %20responsiveness,essential%20in%20any%20maintenance%20service. https://www.enggpro.com/blogs/engineering-and-the-importance-of-supply-chain-management/#:~:text= Supply%20chain%20engineering%20deals%20with,of%20their%20skills%20and%20knowledge. https://www.floridatechonline.com/blog/process-improvement/supply-chain-management-vs-operations- management/#:~:text=Operations%20management%20focuses%20on%20running,but%20how%20it%20i s%20developed. https://www.getmaintainx.com/learning-center/what-is-cost-management-for-maintenance https://www.linkedin.com/advice/1/striving-cost-efficiency-safety-automotive-hkhoe https://pilot-protection-services.aopa.org/news/2020/march/01/tbo-or-not-tbo https://www.sysmatech.com/blog/the-role-of-cmms-in-airlines-and-aviation-industry/ https://www.sap.com/sea/products/scm/asset-management-eam/what-is-cmms.html https://blog.sourceonespares.com/exploring-aircraft-lifespans-and-retirement-decisions https://simpleflying.com/the-factors-that-airlines-consider-when-retiring-aircraft/ https://www.easa.europa.eu/en/light/topics/sustainability-end-life-phase-aircraft https://www.jaars.org/updates/a-scheduled-overhaul/