Why Maintenance Errors and Weak SMS Still Appear in U.S. Aviation Accident Reports — Evidence and Regulatory Response
Even with one of the largest and most sophisticated aviation systems in the world, the United States continues to record aircraft accidents and incidents that involve maintenance errors and deficiencies in safety processes. Investigative authorities such as the National Transportation Safety Board (NTSB) and regulatory agencies such as the Federal Aviation Administration (FAA) publish reports and safety recommendations that help explain these issues. (ntsb.gov)
🔎 “Improper Maintenance” in NTSB Reports
The NTSB is the independent federal agency responsible for investigating civil aviation accidents and identifying probable causes and contributing factors. In many investigations, the NTSB identifies maintenance errors, inadequate inspections, or incorrect reassembly of components as key elements in the accident sequence.
Recent Example of Improper Maintenance
In March 2024, the NTSB released a preliminary report regarding an American Airlines Boeing 737 runway excursion. The investigation identified that hydraulic lines were improperly reconnected after brake replacement maintenance, and other related components were installed incorrectly — a maintenance error that directly contributed to the aircraft’s compromised ground handling. (apnews.com)
This type of finding underscores the importance of precise maintenance execution and effective post-maintenance inspection, especially for complex systems such as hydraulics, which directly affect braking and ground control.
Historical Accidents Linked to Maintenance
Another well-documented case is Alaska Airlines Flight 261 (2000), where a failure in a jackscrew assembly led to loss of pitch control and the fatal crash of the MD‑83. The NTSB determined that inadequate lubrication and maintenance of the jackscrew assembly caused its deterioration over time. (en.wikipedia.org)
These findings are not isolated; multiple NTSB reports identify maintenance-related issues as significant factors in various accidents and serious incidents.
🧠 The Role of Safety Management Systems (SMS)
A Safety Management System (SMS) is a structured framework of policies, procedures, and practices intended to proactively identify hazards, manage risk, and prevent accidents rather than solely reacting to failures. (faa.gov)
FAA and NTSB Perspective
The FAA describes SMS as an essential mechanism for operators and maintenance organizations to systematically identify and mitigate hazards, assess risk, and monitor controls to improve safety performance over time. (faa.gov)
The NTSB, in turn, has consistently recommended the adoption and robust implementation of SMS, noting that accidents involving Part 135 operators and other sectors could be prevented or mitigated with more effective safety management practices. (ntsb.gov)
📉 Safety Culture and Operational Gaps
Regulatory bodies recognize that implementing an SMS is only part of the solution; the organizational safety culture must embrace SMS principles for the system to be effective. In the 2019 B‑17 Flying Fortress accident, NTSB findings revealed that the operator lacked an effective safety culture — despite having an SMS requirement for commercial sightseeing flights. (en.wikipedia.org)
Following the investigation, the FAA revoked the operator’s exemption for paid flights, citing serious safety and oversight deficiencies. The crash demonstrated that SMS cannot exist solely on paper; it must be integrated into daily operational decision-making and reinforced culturally to be effective. (en.wikipedia.org)
🇺🇸 Why These Issues Persist in the U.S.
Interestingly, factors that make the U.S. aviation system robust also contribute to continued challenges in maintenance and safety culture:
🛠️ Industry Fragmentation
The U.S. general aviation sector includes:
- Tens of thousands of small repair stations and independent mechanics
- A broad range of operators from major air carriers to small charter operators
This diversity creates challenges in achieving uniform SMS implementation, quality control, and inspection rigor across the industry, especially outside large Part 121 operators.
⏱️ Operational and Economic Pressures
Maintenance organizations often operate under intense pressure to:
- Minimize aircraft downtime
- Control labor and operating costs
- Maintain tight maintenance schedules
Without a robust SMS and reinforced safety culture, such pressures can result in:
- Compressed inspection intervals
- Reduced redundancy in checks
- Normalization of procedural deviations
These conditions can increase the likelihood that maintenance errors go undetected until they contribute to an incident or accident.
📈 Regulatory and Industry Actions to Mitigate the Risk
In recent years, the FAA has taken steps to expand SMS requirements beyond major air carriers to include:
- Part 135 charter operators
- Regional airlines
- Helicopter operators
- Certain aircraft manufacturers
The FAA’s expanded SMS mandate aims to institutionalize hazard reporting, risk assessment, and mitigations across a larger segment of the aviation industry, emphasizing not just compliance but performance and cultural integration of safety practices. (reuters.com)
The NTSB has publicly supported these regulatory advances, stating that broader SMS adoption is a significant step toward enhancing aviation safety and preventing accidents before they occur. (ntsb.gov)
✈️ Conclusion
The recurrence of themes such as “improper maintenance” and weak safety culture in NTSB accident reports does not indicate a lack of technology or regulation. Rather, it underscores the complexity of aviation safety, where systems, organizational culture, and human factors interact.
The expanded regulatory emphasis on SMS and risk management, supported by investigative findings, reflects an ongoing effort to strengthen safety performance across the U.S. aviation system. By proactively identifying hazards, managing risk, and fostering a culture of safety, the industry continues to move toward fewer incidents and even safer skies.
📌 Sources
Below are the key sources referenced in this article:
- NTSB — Safety Management Systems (SMS) advocacy and accident investigation database:
https://www.ntsb.gov/advocacy/SafetyIssues/Pages/Implement-Safety-Management-Systems-in-Aviation.aspx - FAA — Safety Management System (SMS) initiative overview:
https://www.faa.gov/about/initiatives/sms - AP News — American Airlines Boeing 737 runway excursion preliminary report:
https://apnews.com/article/21fb8a4e3797636129057a809e2ad87c - Reuters — FAA expands SMS requirements to charter and manufacturers:
https://www.reuters.com/business/aerospace-defense/us-faa-mandate-use-safety-tool-by-charter-airlines-manufacturers-2024-04-22/ - NTSB Press Release supporting broader SMS adoption:
https://www.ntsb.gov/news/press-releases/Pages/NR20240423A.aspx - Wikipedia entries (for general historical context):
• Alaska Airlines Flight 261 — https://en.wikipedia.org/wiki/Alaska_Airlines_Flight_261
• 2019 B‑17 Flying Fortress crash — https://en.wikipedia.org/wiki/2019_Boeing_B-17_Flying_Fortress_crash
