Air travel is one of humanity’s greatest achievements. People sometimes forget that the first human flight was in 1903. In the span of one hundred years, people went from never flying before to air travel being mundane. However, the path to safe air travel was not without mistakes and accidents. Safety continues to improve considerably, though mistakes still happen.
Accidents caused by mechanical failure have been decreasing steadily for years, with most modern accidents attributable to human error. Part of the reason for this is the novel approach that the Federal Aviation Administration (FAA) uses for maintenance regulation. Air travel is understandably a highly regulated industry, and one would think that maintenance programs are similarly restrictive. However, the primary maintenance programs used by airplanes are actually based almost entirely on performance.
Preventive maintenance is defined by the FAA as “simple or minor preservation operations and the replacement of small standard parts not involving complex assembly operations.” In other words, preventive maintenance is the servicing and inspections airplanes regularly receive at scheduled intervals, often overnight or between flights. Examples of preventive maintenance include pre-flight checks and monitoring component sensors, as well as more advanced sensor systems and other checks. These practices help prevent minor issues from escalating into major repairs. It also reduces downstream effects on consumers, the most direct being long delays or cancelled flights.
Airlines must obtain regulatory approval before implementing predictive maintenance programs, which involves extensive testing and validation by the FAA. Preventive maintenance systems must comply with AC 120-16G. A maintenance program must utilize CASS, or the Continuing Analysis and Surveillance System, which is a tool to determine the safety and effectiveness of a proposed program. CASS monitors ten elements of a maintenance program.
Additionally, a maintenance program must meet six attributes of system safety: Clear authority, Clear responsibility, Specific written procedures, Effective controls, performance measures, and well-defined interfaces. AC 120-16G is a performance-based regulation, allowing carriers to develop and implement maintenance programs based on operational data rather than rigid scheduling of part inspection and replacement. This flexibility allows airlines to tailor maintenance schedules and procedures to their specific fleet and operational needs. By allowing the aviation industry to innovate freely while still ensuring that new technology meets stringent safety standards, the FAA has fostered an effective regulatory environment that is beneficial for airliners and passenger safety. Notably, even minor improvements in servicing efficiency can have massive impacts on airline costs.
From an operations perspective, the average cost of maintenance per flight hour for a two engine wide-body commercial jet is approximately $1,200. In 2011, commercial jet airplanes were in the air for 50 million hours. This translates into a $60 billion annual maintenance bill. Engine maintenance alone accounts for 43% of the total, or $25 billion. This means that commercial jet engine maintenance costs can be reduced by $250 million for every 1% improvement in engine maintenance efficiency due to predictive maintenance.
Preventive maintenance is improving rapidly due to improvements in data collection and analysis, as well as the introduction of AI. Despite initially adding more work for pilots and technicians, preventive maintenance decreases aircraft downtime overall. The development of increasingly advanced sensors has given aviation engineers access to more data than ever, and predictive algorithms paired with preventive maintenance can improve efficiency significantly. Improved maintenance efficiency will ultimately reduce downtime, minimize delays, and enhance overall safety.
Advances in predictive analytics and data monitoring allow airlines to address mechanical issues before they become major disruptions. As these technologies evolve, changes in commercial aviation policy and training must keep up. As the airline industry currently has a shortage of technicians, it is imperative that airlines invest in training workers to work efficiently alongside these new innovative technologies. Equally important is the refinement of predictive analytics to reduce false positive and streamline operations further. With constant innovation and integration with AI and other technology, preventive maintenance will continue to improve reliability, safety, and convenience. To ensure this is done successfully and to continue to protect the flying public and build upon consumer confidence, the federal government may need to advance new guidelines.
AC 120-16G has been a massive success in improving safety and decreasing maintenance delays. The performance-based nature of the regulation combined with the rigorous testing and validation should be a model for other agencies and sectors. COVID-19 severely damaged the aviation industry, but air travel has come back stronger than ever. Constantly improving technology combined with a set of regulations that promotes innovation, air travel remains destined for continued success.
Written by Owen Rogers, Public Policy Associate
The Alliance for Innovation and Infrastructure (Aii) is an independent, national research and educational organization working to advance innovation across industry and public policy. The only nationwide public policy think tank dedicated to infrastructure, Aii explores the intersection of economics, law, and public policy in the areas of climate, damage prevention, eminent domain, energy, infrastructure, innovation, technology, and transportation.