Introduction
During a recent visit to assist a smaller international airline with their maintenance reliability program, the head of engineering—new to the role—asked me an interesting question: „How should I approach investigating these reliability alerts?” It’s not an uncommon query. Understanding where to begin and how to navigate the complexity of reliability investigations can be a daunting task for those less experienced in the field. Although finding the right answer is not always straightforward, there are clear processes that can guide this kind of analysis. In this article, we’ll explore the essentials of reliability investigation, review best practices, and outline the steps to perform both preliminary and in-depth investigations.
Understanding Reliability Programs
A reliability program serves as the backbone of a maintenance operation, ensuring continuous oversight of system performance and maintenance efficiency. These programs are essential for tracking maintenance intervals, inspection schedules, and overall equipment performance. For larger operators with more than 10 aircraft, a statistically driven reliability program is typically used. Statistical methods help identify trends, alert thresholds, and potential issues.
However, smaller airlines with fewer aircraft don’t have the same volume of data to rely on. For them, investigating individual events—such as specific malfunctions or part removals—becomes a key focus. This type of approach is referred to as event-based reliability, where every event is scrutinized for insights.
In both cases, a systematic approach is necessary. Every alert generated from a reliability program must be carefully examined. These investigations are usually handled by the engineering department, and each investigation may lead to corrective actions such as adjusting maintenance intervals, modifying equipment, or providing additional training for maintenance teams.
The Role of Cross-Functional Collaboration
Addressing a reliability alert is never the responsibility of a single department. It requires input and coordination from multiple departments within maintenance and engineering. The process involves several stages—from collecting data and analyzing it, to developing a corrective action plan and ensuring its implementation. Various units within the maintenance organization, such as line mechanics, engineering, and quality assurance, must work together to assess the problem and develop the best solution.
Identifying the Problem: The Initial Investigation
When an alert is triggered, the first step is to narrow down the scope of the issue. This can be as simple as reviewing the reliability data to determine whether the problem is isolated to a specific system or more widespread. For example, if an alert is related to lighting (ATA Chapter 33), the analysis might show whether the issue concerns a single type of light (such as landing lights or strobe lights) or affects all lighting systems.
Once the data is reviewed, engineers can determine whether the problem is isolated to a specific component or more generalized across multiple systems. If a particular aircraft or engine model shows a higher failure rate than others, the investigation would naturally focus on those areas. Each case will require a different approach based on where the failures are occurring.
Digging Deeper: The Detailed Investigation
A detailed investigation requires a methodical approach to find the root cause. At this stage, the engineering team conducts an in-depth analysis, using both troubleshooting techniques and past maintenance data. Understanding the maintenance history of a specific component, reviewing technical documentation, and assessing how previous repairs were handled can provide valuable insights into recurring issues.
The investigation should also explore whether current maintenance procedures are sufficient. If the procedures appear to be unclear or ineffective, rewriting or updating them may be necessary. It may also involve providing additional training for mechanics, particularly if human error is contributing to the issue.
Common Problem Areas
Most problems identified during a reliability alert investigation fall into one of several categories, such as:
- People (Training and Skills): Mechanics may not be following proper procedures or might require additional training.
- Procedures: Maintenance or troubleshooting processes could be outdated, unclear, or ineffective.
- Parts: Faulty or incorrectly specified parts may have been used, or supply chain issues could be contributing to recurring failures.
- Maintenance Program: The established maintenance intervals or procedures might need to be revised based on real-world performance data.
- Environmental Factors: Extreme operating conditions (such as temperature, dust, or corrosion) can have a significant impact on equipment performance.
- Interference: Mechanical or electromagnetic interference can affect system performance, especially in modern aircraft with complex electronic systems.
Solutions: Determining Corrective Actions
Once the root cause has been identified, it’s time to implement corrective actions. These might include adjusting maintenance intervals, modifying equipment, or retraining personnel. The engineering department drafts a corrective action plan, which is then reviewed by a Maintenance Program Review Board (MPRB) to ensure the solution is practical and comprehensive.
Once approved, the corrective action plan is put into place. After all the necessary adjustments and repairs have been made, the reliability team monitors the system to ensure that the issue has been resolved.
The Importance of Continuous Monitoring
Even after corrective actions are implemented, the process doesn’t end there. Continuous monitoring of the affected systems is essential to ensure the problem has been fully addressed and doesn’t reoccur. If the event rate remains high despite the initial corrective measures, the investigation process begins again, adjusting the approach as needed.
Conclusion
Investigating reliability alerts in aircraft maintenance is a multi-step, cross-functional process that requires both technical expertise and coordination across departments. While no two problems are identical, following a structured approach to investigating issues helps ensure that root causes are accurately identified and corrected. With a proactive approach to maintenance and a focus on continuous improvement, reliability programs can help operators minimize downtime, reduce costs, and improve overall safety.