Evaluating your maintenance performance leads to safer, more efficient operations.
As stated in 14 CFR 135.431, Part 135 operators who operate aircraft with at least 10 passenger seats are required to set up and maintain Continuing Analysis and Surveillance (CASS) programs. The CASS program ensures the overall effectiveness of an operator’s inspection and maintenance activities by collecting data on their performance and analyzing and correcting deficiencies. It will also help operators to identify hazards and to structure control measures to minimize risks, thereby increasing the safety of their operations.
Your CASS program should contain the following elements to ensure that your maintenance activities are carried out effectively and in full regulatory compliance:
- Gather the data necessary to evaluate the performance of your maintenance activities
- Identify deficiencies and positive or negative trends
- Facilitate in making appropriate revisions and modifications when necessary.
Inputs into a CASS program generally come from two sources: performance information from aircraft and engines, and the results of a systematic audit of maintenance activities.
Data sources for this part may include inspection forms, minimum equipment list items, pilot reports, scheduled and unscheduled component removals, service difficulty reports, engine performance data, and reports from flight-data monitoring or health and usage monitoring systems.
Problems that affect or could affect airworthiness or the safety of passengers and crew must be given top priority and the root cause determined and corrected ASAP. Put a system in place so that urgent issues are reported to the appropriate levels of management in a timely manner, and make sure everyone understands when it is appropriate to use the emergency response channel for their reports.
Nonemergency items that affect safety can be sorted into those that require short-term or long-term monitoring. They will also need to be prioritized according to their severity and likelihood, and analyzed for subsequent corrective action. Problems not related to safety can be prioritized according to scope, financial impact, convenience, or accepted as part of the cost of operation with no corrective action required.
The audit function needs to include at least the following areas: removed component condition/evaluation and follow-up, review of the administrative and supervisory aspects of the maintenance program (both internal and vendor), and ensuring regulatory and policy compliance.
It has been estimated that in 65 to 70 percent of all maintenance-related incidents and accidents, failure to follow approved policies and procedures was a major contributing factor. In addition to the potential for a serious accident to occur, failure to comply with appropriate documentation frequently places the operator and maintenance personnel in a position of regulatory noncompliance and all of the associated problems that come with it.
A good audit program is one that is structured to provide a continuous audit of the maintenance system to ensure that everyone, at all levels, who is connected with the system are in compliance with:
- All applicable government regulations
- OEM policies, procedures, and maintenance instructions
- Your customers’ required or recommended policies and procedures
- Your own company’s policies and procedures
- Industry standards.
As the Part 135 operator, you are responsible for ensuring that all external suppliers and vendors also are in compliance with all applicable government regulations. This means that your outside suppliers and vendors must be included in your audit program, as you need to gather the relevant information that substantiates their compliance.
The audit program should ensure that:
- All technical data are current and readily available to the user
- All maintenance is performed in accordance with the methods, standards, and techniques specified in the appropriate technical data
- All maintenance documentation, such as inspection forms, work orders, and so on, are regularly reviewed for completeness, accuracy, and proper entries
- All airworthiness releases are properly executed by the appropriate individuals
- All carry-over/deferred maintenance items are properly handled
- The receiving department identifies and inspects parts and materials in accordance with regulations and best practices
- All shelf-life items are properly controlled
- Procedures for the calibration and control of tools and equipment are in place and being followed
- Housekeeping requirements are being met to ensure a safe working place.
While you may not be required to run a CASS program, there can be significant benefit for operators who use 14 CFR Part 135, Subpart J, Maintenance, Preventive Maintenance, and Alterations, as a template for developing their own maintenance quality assurance program.