The purpose of a quality assurance program is to verify on a continuing basis that the maintenance policies and proce- dures in use are current and effective, and that the aircraft is consistently returned to service in an airworthy condi- tion. The quality assurance program specifically focuses on maintenance procedures, but it also should coordinate with the organization’s safety management system (SMS).
4.13.1. ReQuiRemenTs
A specific quality assurance program is not required of Part 91 operators, but it should be considered an industry stan- dard or best practice.
Specific requirements for the quality assurance program for Part 135 and Part 121 operators can be found in FAR 135.431 and FAR 121.373, which both refer to a continuing analysis and surveillance system (CASS), described fur- ther in a later section of this guide. See also FAA Advisory Circular 120-79, Developing and Implementing a Continuing Analysis and Surveillance System.
On an international basis, the fundamental requirement for a quality assurance program is derived from ICAO Annex 6: 8.7.3.2, which states: “The maintenance organization shall ensure compliance with 8.7.3.1 by either establishing an independent quality assurance system to monitor compli- ance with and adequacy of the procedures, or by providing a system of inspection to ensure that all maintenance is properly performed.” Individual countries develop their own specific regulations to ensure compliance with this rule.
4.13.2 oveRview
The ICAO definition provides two options in developing a quality assurance program:
• A system of 100-percent inspection of all work per- formed – typically found in smaller organizations where an inspector or another technician inspects the work of the technician performing the task and signs the task card as the inspector.
• For larger organizations, an internal audit system that continuously reviews the policies and procedures in place to ensure their effectiveness is most commonly used. (This method is also known as the CASS.)
From a safety perspective, having both elements in place would provide the greatest margin of safety for mainte- nance operations. Regardless of the method selected, a clearly documented procedure for quality assurance is es- sential for consistent results.
4.13.3 100-PeRcenT insPecTions
In the U.S., duplicate inspections are required for items identified as required inspection items (RII) by the aircraft manufacturer. These typically include replacement of engines and controls, flight controls, key hydraulic system
NB
AA Me
MB
er
ship elements and other items that could seriously impact the
safety of flight. Individual organizations also can add items to the list of duplicate inspection items based on their own service history.
Most manufacturers provide task forms with a space for an inspector’s signature for schedule maintenances tasks. While only required if specified in the approved inspection program, it is certainly a best practice that should be con- sidered in the development of maintenance procedures. One key to an effective duplicate inspection program begins with the organizational structure. Typically, a chief inspector reports to the maintenance manager on an equal level with the chief mechanic or whatever job title is responsible for production and scheduling of tasks. This structure is adopted to ensure that pressures to return the aircraft to service do not compromise the integrity of the work performed.
The other key to a successful 100-percent duplicate inspec- tion process is the return-to-service procedures. These pro- cedures should be documented and ensure that all forms used for scheduled and unscheduled maintenance have areas for the duplicate inspection signature. Furthermore, the process should ensure that all work performed by the various disciplines (avionics, interior, NDT, airframe, etc.) contains the inspector’s release for that area and that one signature releases the entire aircraft for service.
4.13.4 cAss oveRview
The continuous analysis and surveillance system (CASS) is essentially an internal auditing program for the maintenance department. These internal reviews usually divide all main- tenance activities into various sections and are conducted on a scheduled basis. Generally, monthly inspections are conducted so that the entire organization is reviewed on an annual basis – much like the continuous inspection program for the aircraft.
The first critical success factor is the selection of the auditor(s). The internal audits may be conducted by an individual or by teams. In either case, it is essential that the person(s) conducting the reviews be well versed in both company procedures and regulatory requirements. It also is helpful to have training in auditing techniques. Many orga- nizations have included auditor training into their training programs.
As with the 100-percent inspections, the organizational structure of CASS is another critical success factor. The person selected as the internal auditor needs to report di- rectly to the maintenance manager for all matters relating to the internal audits to ensure that the proper resources are made available for the appropriate corrective actions. Fur- thermore, the internal auditor should work with the safety manager, if in place, to ensure continuity with the safety management system.
4.13.5 cAss AudiT PRoGRAm
As mentioned above, the internal audit program first needs to be well documented. The specific checklists used will evolve continuously as regulations and conditions change, but the frequency and procedures will remain relatively con- stant. The specific areas to be reviewed will vary consider- ably from one organization to another based on the nature of tasks performed, but listed below is a brief outline of areas typically reviewed:
Maintenance Authorization – Verify that the work performed is within the scope of approvals, typically the maintenance manual and inspection program. Also, verify that any work subcontracted is performed by organizations with appropri- ate certifications (auditing of vendors).
Maintenance Control – Verify that inspections are per- formed per the approved inspection program; life-limited parts are maintained per Chapter 5; all airworthiness direc- tives and mandatory service bulletins are accomplished and other service information is properly reviewed; and all equipment is installed as alterations are maintained in accordance with instructions for continued airworthiness. Another area of maintenance control to be reviewed is that of scheduling, duty limits and other administrative polices for presence of procedures and consistency of application. Quality Assurance – Review the effectiveness of the internal audit program to ensure that procedures are used consistently; the procedures in place reflect current require- ments; and non-conformities are promptly corrected. Maintenance Records – Ensure that appropriate entries are made and the aircraft is properly released; required support- ing documentation is retained (and ideally the superseded documents are removed); listings are maintained per air- worthiness directives and service bulletins; and all records are maintained and retained in accordance with company policies.
Training – Review the training program to ensure that all elements are addressed (technical training, industrial safety, company maintenance procedures, specialized training such as NDT, welding, etc.); the training is accomplished accord- ing to the schedule in the training plan; and appropriate records are maintained.
Publications – Verify that the appropriate publications are available for all tasks performed, and there is an effective process in place to ensure that only the most current tech- nical and regulatory information is provided.
Equipment – Verify that all tooling and equipment neces- sary to properly perform the maintenance tasks are avail- able and in good working order; an effective tool calibration program that includes personal tools is in place; and effec- tive controls are used and record maintained.
Spares – Verify that the procedures in place ensure that an incoming inspection is performed; appropriate documenta-
tion is retained at acceptance of the materials; the materials are properly stored; a shelf life program is in place; appropri- ate tagging procedures are used; and unserviceable ma- terials are adequately quarantined. In addition, this review should be applied not only to components but also to all materials such as sheet metal, consumables, standard parts and so on; aircraft materials should be effectively isolated from non-aircraft materials. Finally, there should be a pro- cess in place to qualify suppliers to ensure that only quality materials are procured.
Facility – Ensure that adequate facilities and conditions such as lighting, heating, etc. are in place and consistent with hu- man factors affecting performance. Also, review the issues relating to industrial safety, environmental protection, fire prevention and aircraft fueling.
The above list is only intended as a starting point for de- veloping an effective internal audit program. The primary resource will be the procedures found in the company main- tenance procedures manual (sometimes referred to as the maintenance exposition). This document is the repository for company policies and procedures. The purpose of the internal audit program is to ensure that the procedures are current, complete and complied with.
4.13.6 cAss AudiT ResuLTs
The final critical element of the CASS system is the disposi- tion of the information obtained during the internal audits. A system needs to be in place to promptly correct any non- conformity discovered during the reviews as well as any items received from anonymous hazard-reporting mecha- nisms that may be in place.
The first step is to develop a single list of the non-confor- mities. Just as with discrepancies found on the aircraft, it is critical to ensure that all items are properly corrected within the appropriate timeframe.
The next step is the analysis of the items. Frequently, a safety team is developed to help review the non-con- formities and suggest or approve the corrective actions. Regardless of whether a team is used, it is important to have a review mechanism in place. Use of risk analysis or job hazard analysis tools is common for larger organizations, but less formal processes also can be effective.
Frequently, a hierarchy of corrective actions is developed. For a given hazard (a hole in the ground), the first choice would be engineering a permanent solution (fill the hole). The second preference would be to install adequate safe- guards (put a rope around the hole), while the third choice might be training of employees (telling everyone to avoid the hole).
Once an appropriate corrective action has been determined and implemented, a follow-up should be conducted to verify that the non-conformity has been corrected. The final step is to communicate the results of the actions to the
workgroup both to validate the effectiveness of the pro- gram and to encourage participation by all.