CHAPTER 4. CASS IN YOUR ORGANIZATION
4-1. CASS DOCUMENTATION. You should describe your CASS policy and procedures in writing. You can produce these documents in a paper or electronic form, or another comparable record. For example, you could put them in a detailed chapter or section within your general maintenance manual or you could put them in a separate CASS manual associated with your general maintenance manual. In all cases, your policy and procedures should be written and not simply be verbal understandings.
4-2. WRITTEN POLICY AND PROCEDURES. Your CASS policy and procedures should:
a. Recognize CASS as a Coordinated System. You should recognize and treat your CASS as a coordinated system rather than just audit and data collection activities dispersed within your maintenance program. You do not have to contain your CASS personnel within a single department or office. However, your policy and procedures should identify all functions related to your CASS. You should not assume that because an audit or data collection function exists somewhere within your organization, it automatically satisfies your CASS requirement with no further coordination necessary.
b. Identify Major Programs. It should identify any programs, such as an optional reliability program, that you use to satisfy a major portion of your CASS. Your CASS documentation may refer to the documentation for that other program rather than restate the documentation again in another manual. The relationship/interfaces between the CASS and that other program should be clear and address responsibility and feedback issues to ensure that the other program meets CASS objectives.
c. Address Communication and Coordination Needs. It should address the need for fluid communications and coordination among the individuals who you have assigned authority, responsibility, and duties related to your CASS.
d. Address Principles of System Safety. You should base it on principles of system safety.
e. Identify Positions of Authority and Responsibility. It should clearly identify the positions within your maintenance organization with authority and responsibility for the CASS.
Remember that authority means permission and responsibility means obligation. Consistent with the system safety attributes, you must identify a position that has autonomous decision-making authority for your overall CASS process. There also must be a position that has, or positions that have, direct responsibility for carrying out the various functions of your CASS. If you have a larger organization, you may have a number of positions that have direct responsibility for carrying out functions of your CASS. However, there should be only one position that has the autonomous decision-making authority to authorize change for any of the CASS procedures for the CASS activities or functions.
(1) Authority. For purposes of this AC, “authority,” with regard to a CASS, means the power to create or modify fundamental policies or procedures without higher level review or approval. The individual with authority for the CASS may design or change the CASS without Par 4-1 Page 13
Page 14 Par 4-2 having to seek approval from a higher level of management. The CASS procedures should include how to modify the CASS.
(2) Responsibility. For purposes of this AC, “responsibility,” with regard to a CASS, means an obligation, with the expected accountability, for ensuring that others successfully accomplish tasks and functions in accordance with applicable policies, procedures, and standards. The person with direct responsibility may directly accomplish this work, or you may delegate the work. The individual with overall responsibility for your CASS has the obligation to carry out the functions of the CASS, including overseeing and managing any personnel to whom you have delegated CASS functions and duties. If your organization is smaller where personnel share duties and only carry out CASS functions part-time, this oversight and management responsibility relates only to those part-time tasks.
(a) You should designate a single person or position within your organization with the overall authority for your CASS, and you should designate an individual, position, or management committee within your organization with overall responsibility for managing and implementing your CASS. If you are a small certificate holder, an individual may have both authority and responsibility for CASS activities. That individual might also have responsibility for other functions as well as the CASS. It would be common for the person with overall responsibility for CASS functions to delegate some or much of this work to others within your organization, depending on the size and staffing of the certificate holder. The FAA expects you to assign clear responsibility for your CASS activities so that you do not end up with a fragmented system with a high risk of confusion over who is responsible for a given task.
(b) You should ensure that personnel with CASS responsibilities and duties are as independent as possible from the day-to-day operations of your maintenance program. Ideally, personnel conducting audits would work in separate departments from the departments performing your actual maintenance activities. However, if you are a small certificate holder, this may not necessarily be feasible. If you are a small certificate holder, personnel performing your CASS functions, particularly audits, may consist of one or more of the following:
1. “Borrowed” personnel from other shops or departments. Your procedures should include ways to avoid having these individuals assigned to audit areas where they normally work.
2. The company owner or chief executive officer (CEO), particularly if there are no other employees and the CASS audits focus on outside vendors and maintenance providers because maintenance providers accomplish all or most of your actual maintenance work.
3. Outside resources that you make arrangements with to perform audits and analysis for you.
4. Others that you have determined are qualified to provide independent audit, operational data collection, and analysis services that fulfill the requirements of a CASS as described in this AC.
CHAPTER 5. MAJOR CASS ACTIVITIES
5-1. SUMMARY OF A CASS. The regulations require that your CASS accomplish surveillance and analysis of all elements of your maintenance program from two perspectives:
verifying performance and verifying effectiveness. There are four activities in the CASS process:
surveillance, analysis, corrective action, and followup. You can carry out the first two activities (surveillance and analysis) in two different ways. One audit-based, and the other is operational data and collection and analysis-based. The results of the two types of surveillance and analysis feed into the third and fourth major CASS activities: corrective action and followup. Figure 5-1 summarizes the flow of the four basic activities of CASS, which paragraphs 5-2 through 5-5 describe in further detail.
FIGURE 5-1. THE FOUR BASIC CASS ACTIVITIES:
SURVEILLANCE, ANALYSIS, CORRECTIVE ACTION, FOLLOWUP Verify Performance of Maintenance Program Verify Effectiveness of Maintenance Program 1a. Surveillance: Audit process.
- Create an audit plan based on risk assessment.
- Perform work-in-progress audits.
- Perform transaction audits.
- Perform systems audits.
- Identify hazards.
1b. Surveillance: Data collection process.
- Select data sets.
- Collect operational data.
- Collect failure data.
- Identify trends, anomalies, and potential hazards.
2a. Analysis: Identify hazards and accomplish risk analysis and assessment.
2b. Analysis: Identify hazards, investigate adverse indicators, and accomplish risk analysis and assessment.
3. Corrective Action: Accomplish Root Cause Analysis (RCA); develop, implement, and monitor a corrective action plan, as appropriate.
4. Followup (Performance Measurement): Verify the corrective action is effective, and initiate risk-based followup surveillance planning, as appropriate.
a. Risk Management in CASS.
(1) In concert with the attributes of a good organization, you should prioritize personnel and resources for CASS as part of the overall risk management process. Risk management facilitates the balancing act between assessed risks and practical risk mitigation.
(2) Risk management serves to focus safety efforts on those hazards posing the greatest risks. Essentially, any methodology used to prioritize surveillance personnel and resources (as well as to formulate corrective action decisions later in the process) involves principles of risk management.
(3) A formal risk management process is composed of the following elements:
identifying hazards, analyzing risk, assessing risk, and controlling risk. This process, embedded within the processes used to provide the product/service; it is not a separate process. The flow Par 5-1 Page 15
Page 16 Par 5-1 chart in Figure 5-2 summarizes an overview of the risk management process. The elements of a risk management process encompass the four major CASS activities (Figure 5-1).
FIGURE 5-2. RISK MANAGEMENT PROCESS
5-2. VERIFYING PERFORMANCE OF YOUR MAINTENANCE PROGRAM.
a. Surveillance of the Performance of Your Maintenance Program.
(1) Definition of a CASS “Audit.” Your main tool for assessing whether you are properly performing (executing) your maintenance program is audits, particularly work-in-progress audits. Work-in-progress audits are consistent with the plain language meaning of “performance” found in 14 CFR part 121, § 121.373 and 14 CFR part 135, § 135.431. The main direction of your audits should address your maintenance program objectives found at §§ 121.367 or 135.425, as appropriate. For purposes of CASS, a CASS audit is a formal examination of the activities of a department or area of your maintenance program based on an established standard such as the regulations or your manual. The intention of work-in-progress
audits is to ensure that your maintenance personnel, as well as your maintenance providers, comply with your manual, program, and all other requirements.
(2) Audit Procedures. You should have written procedures to guide your auditing process, including the scheduling of audits. The CASS addresses both internal audits and external audits. Internal audits are audits that you conduct within your organization. External audits are audits that you conduct of vendors who supply parts and services to you. Your CASS procedures should include a methodology for determining priorities and for establishing and adjusting audit cycles (for example, 12, 18, 24, 36-month cycles) so that you focus your resources on the most pressing issues. This is a risk assessment and risk management process.
(See paragraph 5-2(a)(3) for further explanation of risk assessment and risk management.)
(a) Although the majority of the generated inputs to this process are internal, one additional input may be the result of outside audits conducted by entities other than yourself or your maintenance providers. For example, the results of audits or inspections conducted by the FAA or the Department of Defense (DOD) may be useful by providing you with:
• Specific findings requiring RCA and possible corrective action (activities discussed later in this AC), and
• Information useful in focusing your own audits and operational data collection.
(b) You may approach this initial scheduling task in many different ways, ranging from resource allocation based on company experience and very basic analysis to the use of a sophisticated, software-supported risk analysis process. Within this range of possible methodologies, your CASS procedures should contain a process to systematically make those decisions that are compatible with the size and complexity of your operations. The FAA encourages you to make this process as structured as possible. You should place priority first on safety and regulatory compliance, and second on issues of operational efficiency. However, if your CASS is effective, you will meet all three of these objectives.
(3) Prioritizing Surveillance Resources. Essentially, any methodology that you select to prioritize your surveillance resources (as well as to formulate corrective action decisions later in the process) involves principles of risk assessment. Risk assessment is a concept applicable in many aspects of an aviation operation. (See FAA Order 8040.4, Safety Risk Management, for additional information.) Order 8040.4 is an example and is not the only source of risk assessment procedures. However, it provides insight into FAA expectations. The FAA encourages operators to incorporate the principles of this systematic process to:
• Establish a plan, including the scope of the process and priorities (for example, detect and prevent noncompliance);
• Specify the areas of concern for surveillance and analysis (personnel, the maintenance program and organization, operations, aircraft, facilities, and systems);
• Identify hazards or potential threats to the operation;
• Determine how likely the consequences of a hazard will occur and actually cause harm;
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• Determine the severity of the consequences, for a realized hazard;
• Express a combination of the likelihood and severity of harm as “risk;” and
• Evaluate the appropriate response to the identified risk.
(a) Your CASS should take into account four principal potential sources of hazards:
1. Personnel (hiring, capabilities, competence, interaction, and human factors),
2. Equipment (design, maintenance, logistics, and technology),
3. Workplace (environment, sanitation, and user friendly), and
4. Organization (safety culture, authority, responsibility, standards, procedures, and controls).
(b) There are a number of quantitative and graphical tools that exist to help you determine the gradations of a risk (high, medium, low) based on the likelihood of an unwanted event occurring and the severity of the consequences if it does occur. In the initial steps of your CASS process, the appropriate response involves setting surveillance priorities based on risk assessments aimed at maintaining compliance and safety in maintenance activities. Your CASS risk assessment, through the feedback loop, helps you to set the audit and data collection priorities that enhance the focus of surveillance. An interdisciplinary team, guided by your CASS management but involving representatives from relevant technical areas, can best accomplish this process.
(c) To identify the areas to audit and in order to set priorities, you should consider factors in outside reports. These could include results of inspections, reports, special studies, or audits conducted by outside entities such as the FAA, DOD, Department of Transportation (DOT), DOT Office of the Inspector General (OIG), or National Transportation Safety Board (NTSB). Outside reports may address:
• Information specific to you or your maintenance providers,
• Information related to the industry as a whole and of interest to you, or
• Relevant information about an accident, incident, or equipment type.
(4) Audit Materials. You should provide your CASS auditors with checklists to ensure consistency and completeness of audits. However, you should permit your auditors that flexibility necessary to ask questions not contained on the checklist if he or she finds an area that requires further investigation.
(5) Areas Requiring Auditing. The CASS monitors all 10 elements of your maintenance program. The following are examples of some, but not all, of the areas within each element of your maintenance program that the CASS looks at. You should note that all of these items are predisposed to surveillance of the maintenance program performance function of the CASS, accomplished through audits.
(a) Airworthiness Responsibility.
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1. As an air carrier, you are primarily responsible for the airworthiness of your aircraft as well as the performance of maintenance, including work done by maintenance providers, on your aircraft. You must ensure that all completed maintenance, including work done by outside persons, is in accordance with your maintenance program and maintenance manual.
2. Your air carrier certificate makes you a maintenance entity. Each person who accomplishes maintenance on your aircraft does so as an agent on your behalf. Consistent with the privileges and limitations of your air carrier certificate, you must, through your maintenance organization, execute operational control over any maintenance activities anyone accomplishes on your aircraft or any of its component parts. Such activities include determining when maintenance is required, what maintenance is required, accomplishing the maintenance, determining if the maintenance was done satisfactorily, and approving your aircraft for RTS.
Consistent with the regulations, you may not delegate this responsibility to anyone else, including persons that you use for any of your maintenance, preventive maintenance, or alterations.
(b) Manuals.
1. The content of all your manuals, including maintenance manuals and technical content, is your responsibility. You may base your manuals on the Original Equipment Manufacturer (OEM) manuals or other information, but regulations require you to use your own manual, not the OEM manuals.
2. You should ensure that all of your manuals, publications, and forms are useable, current, correct, and readily available to all personnel required to use them.
3. You should ensure that each person who is required to comply with your manual must have access to it during performance of normal duties.
(c) Maintenance Organization.
1. Consistent with the responsibility described above, you must have a maintenance organization that is able to effectively exercise and maintain operational control over all persons performing, supervising, managing, and amending your maintenance program.
Your maintenance organization must be able to manage and guide your maintenance personnel and provide the direction necessary to achieve your overall maintenance program objectives.
2. The individual with overall maintenance program authority and responsibility is your Director of Maintenance (DOM), who should function as the accountable manager for the maintenance program. Your organization must clearly identify this individual, and he or she must be qualified in accordance with 14 CFR part 119, §§ 119.65 and 119.67(c) or §§ 119.69 and 119.71(e), as appropriate. While retaining overall authority and responsibility, your accountable manager may delegate direct responsibility for elements of the program as appropriate for the size and structure of your maintenance organization.
3. Your air carrier manual must contain a chart or a description of your maintenance organization showing clear authority and responsibility, including delegated Par 5-2 Page 19
responsibility, for the overall maintenance program and all of its elements and functions. The regulations also require you to include a description in your maintenance manual of the duties and responsibilities for each position in your maintenance organization so that you do not end up with a fragmented organizational system with high risk of confusion over who is responsible for a given task.
4. In order to be effective, an adequate maintenance organization must be able to demonstrate the following four organizational obligations:
• The obligation to define the environment within which individuals conduct their tasks,
• The obligation to define the policies and procedures that individuals must follow and respect,
• The obligation to allocate the resources that individuals need in order to achieve your safety and production goals, and
• The obligation to investigate system failures and take all needed remedial action to avoid a repetition.
5. Your maintenance organization will be predisposed to failure if you permit the following failures to occur:
• Failure to understand the effect of people on the safety and reliability of aircraft maintenance operations,
• Failure to organize your employees’ work,
• Failure to monitor your employees’ work effectively, and
• Failure to implement appropriate and effective corrective actions.
6. You must organizationally separate the performance of your RII function(s) from the performance of your other maintenance (including inspection), preventive maintenance, and alteration functions. This organizational separation must be below the level of the individual who has primary responsibility for your RII function, as well as your other maintenance, preventive maintenance, and alterations functions. In simple terms, this means that the part of the maintenance organization that accomplishes your maintenance, preventive maintenance, and alterations functions cannot be the same part of your maintenance organization that accomplishes your RII function. When implementing the organizational separation, do not confuse your maintenance department with your maintenance organization. Your maintenance department and your inspection department are both a part of your maintenance organization. The organizational separation has to occur below the individual in your organization who has primary responsibility for both the maintenance function and the required inspection function. This individual must be qualified to make an airworthiness determination.
(d) Maintenance Schedule. Your maintenance schedule sets out the item, task, and interval of your scheduled maintenance effort. You should ensure that you accomplish your maintenance schedule as stated. The maintenance schedule should be task-based and appropriately modified in accordance with the CASS data collection and analysis findings. Your audits should find that your initial selection and the continuous validation of each scheduled maintenance task and its associated interval is accomplished according to well-defined criteria Page 20 Par 5-2
throughout the service life of the item, system, or structure. Your maintenance schedule should be primarily proactive and designed to permit the item, system, or structure to do what it is designed to do.
(e) RIIs.
1. You must have specific procedures, standards, and limits necessary for the acceptance or rejection of each your RIIs and for periodic inspection and calibration of precision tools, measuring devices, and test equipment. You should note that the OEM’s manuals and procedures do not contain RII procedures, standards, and limits. You must develop and document these aspects yourself.
2. You must ensure that anyone who you authorize to accomplish RII inspections is properly trained and qualified for each RII task that you authorize him or her to perform.
3. You must ensure that any RII inspector understands that if he or she performs an item of work, he or she may not perform a required inspection on that item.
4. You must ensure that the structure of your maintenance organization is designed to organizationally separate the accomplishment of the required inspection function from the accomplishment of the other maintenance, including other inspection, preventive maintenance, and alteration functions.
5. You must ensure that your manual contains procedures to ensure that only supervisory personnel of an inspection unit or the individual who has overall responsibility for the RII function as well as the other maintenance, preventive maintenance, and alteration functions may countermand the decision of any RII inspector regarding an RII.
(f) Maintenance Providers. You must ensure that all of your maintenance providers and your suppliers are qualified and provide services and products according to your maintenance program and manual. Other than location, there should be no difference between the way your own employees and any of your maintenance providers complete work. Before you identify any maintenance provider in your maintenance provider listing as an essential maintenance provider, you should conduct an onsite audit that will permit you to determine that each proposed essential maintenance provider has an adequate organization and provides competent personnel and adequate facilities and equipment for the essential maintenance intended.
(g) Personnel Training.
1. You must have means that you can use to determine that all of your maintenance personnel, including maintenance provider personnel, are competent to accomplish their duties.
2. You must have a training program for maintenance personnel (including inspection personnel and maintenance provider personnel) who determine the adequacy of accomplished maintenance.
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3. Part of your maintenance program should ensure that your maintenance personnel are competent to perform their duties.
(h) Accomplishment and Approval of Maintenance.
1. All of your maintenance facilities and equipment, including base and line stations as well as all of your maintenance providers’ facilities and equipment, are adequate to perform the maintenance. Other than scope and location, there should be no difference in the standards for facilities and equipment between you and your maintenance providers.
• You properly store, dispense, identify, and handle parts and components.
• You and your maintenance provider properly calibrate your tools and equipment.
• You identify requirements for specialized tools or training and provide the tools and training.
2. You or your maintenance provider perform(s) maintenance and alterations according to the methods, standards, and techniques specified in your manuals.
3. If you use an onsite representative to monitor work at a maintenance provider, you should ensure that you have clear procedures for this individual to report and document deviations from your manual or any of your methods, standards, and techniques specified in your manuals.
4. You or other persons properly document work interruptions and deferred maintenance in shift turnover records and accomplish them according to applicable procedures.
5. Major repairs and major alterations are properly classified, consistent with the 14 CFR part 1, § 1.1 meaning of major alteration or repair, and accomplished in accordance with FAA-approved technical data.
NOTE: During 1953, the Civil Aeronautics Authority (CAA) published a list of repairs to specific parts, as well as specific types of repairs that were considered major repairs in Civil Aeronautics Manual 18. This major repair list was later adopted, unchanged, as part of 14 CFR part 43 appendix A. If you rely exclusively on this standardized list of major repairs to make your major/minor classification, you will end up classifying some minor repairs as major and some major repairs as minor simply because the list has not been updated to include evolving airplane design and construction techniques such as composite structures, damage tolerant design, and the high speed pressurized jet transport that did not exist in 1953.
6. Appropriately certificated mechanics or repairmen whom you have authorized to do so, execute log entries and Airworthiness Release Forms.
7. You, or those you have authorized to do so, complete log entries and Airworthiness Release Forms according to your written policies and procedures.
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(i) Maintenance Recordkeeping System.
1. You or other persons generate and retain maintenance records and current status records in accordance with your manual procedures.
2. Maintenance records and current status records are complete and correct.
3. You or other persons appropriately evaluate, accomplish, and track Airworthiness Directives (AD).
4. ADs with an alternative method of compliance (AMOC) and ADs that have been reconfigured (undone) are appropriately evaluated for accomplishment and for other modifications in the affected area (Supplemental Type Certificate (STC), major repairs, and alterations), documentation, and tracked.
NOTE: The current edition of AC 39-9, Airworthiness Directives Management Processes, provides you with additional information and guidance on developing a management process to help you comply with part 39, Airworthiness Directives.
5. The maintenance recordkeeping system identifies life-limited parts and tracks the current status time in service.
(j) CASS.
1. Your CASS ensures that you or other persons properly execute all elements of your maintenance program and that they are consistently effective by design rather than by chance.
2. Senior management reviews CASS issues on a regularly scheduled basis.
They hold meetings of CASS or maintenance management committees or boards on a regular basis to discuss findings, analysis, and the progress of corrective actions. These meetings may address events, as well as statistical data and trends.
(6) Objective of CASS Audits. Most of your CASS audits should be primarily proactive, searching out potential problem areas in program execution before they result in undesirable events. However, your CASS procedures may also be reactive when they address how to direct audits in response to events or a series of events. For example, an analysis of rejected takeoffs, unscheduled landings, in-flight shutdowns, or accidents or incidents may indicate the need for special audits or surveillance. One of the activities of a CASS identifies indications of program weaknesses or deficiencies through an analysis of trends. For example, your CASS auditors would not necessarily investigate a single maintenance-related rejected takeoff. A CASS would, however, consider whether that instance, coupled with other instances, indicated a need to focus audits on a particular issue.
(7) Informal Communications Within a CASS. Your auditors and analysts should maintain informal lines of communication with your personnel in the various maintenance departments, so that your maintenance personnel can discuss concerns they may have. Through Par 5-2 Page 23
this informal communications process, you can learn about potential hazards in your system. For example, you may learn about an event that might have occurred but, because of some intervention, did not. Your shop personnel know of this event, but it is otherwise difficult or impossible to detect in routine audits. If you keep informal lines of communication open to your shop personnel, your CASS may detect this near event. The FAA suggests that your CASS procedures address how to encourage this type of communication and interaction.
b. Analysis of Audits.
(1) RCA. A risk assessment process tells you where to allocate resources and helps you to understand what it finds. Your audit results should undergo risk assessment and preliminary RCA to identify a deficiency or potential deficiency in any element of your maintenance program. This preliminary analysis helps your CASS personnel determine the priority level that the issue merits and what type of additional technical expertise it may need to complete the RCA and to evaluate corrective action options.
(a) RCA treats errors as defects in the system rather than in an individual. RCA looks beyond the symptom to find the organizational defect that permitted an error to occur. The more thorough the analysis, the greater the likelihood you will uncover why the system deficiency could occur, and how your organization can respond definitively. The RCA process starts during the early part of an audit, as your auditors must collect information conducive to later analysis. If your CASS is to uncover a procedural weakness, for example, your auditors must collect information about the procedure. This should be factual and objective information, not premature judgment about root cause. RCA is key to any complete CASS, even though procedures may vary in complexity from certificate holder to certificate holder.
(b) An effective RCA can be as simple as asking and answering a question (five times) about why something happened. For example, if there is a human error in a maintenance process, the scenario could be as follows:
Question Answer Why was the error made? The individual involved was not competent to do the work.
Why? The training department did not identify a training need for this individual.
Why? The training needs identification process is very weak.
Why? The company has not identified the weakness in the training needs process.
Why? The training department lost two experienced analysts last year and has not replaced them.
(c) The above RCA leads to a training department workload problem. A superficial analysis might have lead to disciplinary action against one individual, which is indicative of a blame culture, and would, most likely, lead to a recurrence of the same error by a different individual.
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