Par 302 Page 9
(c) These high load events typically have detailed inspection instructions specified in Original Equipment Manufacturer (OEM) maintenance manuals. The objective of these instructions is to detect aircraft damage following an in-service flight or ground event. These instructions are typically referred to as Unscheduled Maintenance or Special Inspections. While there are many conditions that can result in high loads on the airframe and subsequent structural damage, the use of flight data in your inspection process is considered particularly beneficial for the events identified above.
(d) Your processes for evaluating these events should address 1) appropriate indication that an event has occurred, 2) evaluation of the severity of the event, and 3) coordination with the manufacturer, as appropriate. Your special inspection procedures for high load events should be robust enough to:
• Identify that a very high load event had occurred,
• Assure that indications of structural damage would be found in an initial inspection,
• Involve the OEM if necessary,
• Provide a process for additional inspections that would identify all of the structural damage, and
• Provide a process for approval for return to service.
(3) Technical Data that Describe Maintenance Standards, Methods, Techniques, and Procedures. This section of your manual concerns detailed procedures for accomplishing specific tasks. You should describe methods, techniques, technical standards, measurements, calibration standards, operational tests, structural repairs, and the like in this section. You should also include procedures for aircraft weight and balance, jacking, lifting, and shoring, storage, cold weather operations, towing, aircraft taxi, and aircraft cleaning. You can derive your maintenance manual contents from the manufacturer’s publications. However, based on your particular service experience, organization, and operating context, the FAA expects you to continuously modify and customize your maintenance manual as necessary for the continuing success of your maintenance program. This is one of the desired outcomes of a well-functioning CASS, which is explained in more detail in chapter 11 of this AC and in AC 120-79.
b. Work Cards. Work cards, while not a regulatory requirement, have evolved as a best practice. Work cards are considered part of your air carrier manual and the air carrier maintenance program. They are the “what to do” and the “how to do it” part of your airworthiness responsibility. Work cards are used as a simple means of complying with regulations for performing maintenance, as well as maintenance recordkeeping. Work cards provide detailed, concise procedural instructions that organize and control your maintenance activities while providing a means to ensure that your maintenance activities comply with your air carrier maintenance manual. It is an easy way to make sure maintenance, as well as other personnel are following your procedures. The second primary function is to document your maintenance activities, providing a means to comply with your air carrier maintenance
Page 10 Par 302 recordkeeping requirements. Work cards may also document the results of inspections, checks, and tests for data collection and analysis. Your work-in-progress audits of work card activity that you conduct under your CASS ensures that each person who accomplishes work on your aircraft is following your manual.
Par 400 Page 11 CHAPTER 4. AIR CARRIER MAINTENANCE ORGANIZATION
400. MAINTENANCE ORGANIZATION—GENERAL. You are required to have a maintenance organization that is able to perform, supervise, manage, and amend your program;
manage and guide your maintenance personnel; and provide the direction necessary to achieve your maintenance program objectives. You are required to include a chart or a description of your maintenance organization in your manual. You can read about maintenance organization requirements in part 121, subpart L, part 135, subpart J and portions of part 119, subpart C.
These organizational regulations apply to your organization, as well as any other organization that provides maintenance services for you. A chart is a good way to show your assignment of overall and direct authorities and responsibilities.
401. REQUIRED MAINTENANCE ORGANIZATION MANAGEMENT POSITIONS.
14 CFR § 119.65 includes specific requirements for maintenance management positions for operations under part 121. These are a Director of Maintenance (DOM) and a chief inspector, or equivalent positions. These are management positions required by the regulations; however, they are not all of the management positions that you will need to administer and manage your maintenance organization.
a. For operations conducted under part 121, § 119.65 requires you to have qualified individuals serving full-time in the DOM and chief inspector, or equivalent, positions. If necessary for your operation, you can ask the FAA for a deviation from the types and numbers of required part 121 or 135 management positions.
b. For operations that you conduct under part 135, § 119.69 requires you to have a qualified individual serving in the DOM management position; however, there is no regulatory requirement for a part 135 chief inspector management position. However, in a practical sense, you will have an individual in your part 135 maintenance organization who has direct responsibility for the RII function, as well as those other duties, responsibilities, and functions normally associated with a part 121 chief inspector.
c. In your manual, you are required to list the names and addresses, and to state the duties, responsibilities, and authority of each of your required management personnel. You should state in your manual who has overall authority and/or responsibility, and who has direct authority and/or responsibility for a given process. Also, you are required to notify the FAA when you make changes in your required management personnel or when you have a vacancy. In addition to these requirements for the part 119 required management personnel, you are also required to list the duties and responsibilities of all of your management personnel.
NOTE: Authority means the power to design or change fundamental policy or procedures without having to seek higher level approval. Authority is permission; it is a right coupled with an autonomous power to accomplish certain acts or order others to act. Often one person grants another authority to act, such as an employer to an employee, a corporation to its officers, or a governmental empowerment to perform certain functions.
Page 12 Par 401 NOTE: Responsibility means the obligation to ensure a task or function is successfully carried out. Responsibility includes accountability for the action to carry out a task or function.
402. REQUIRED AIR CARRIER MAINTENANCE ORGANIZATIONAL STRUCTURE.
a. The regulations defining an air carrier maintenance organization are necessarily broad given the different types and sizes of air carriers. A single means of compliance or a single organizational chart that would apply to all air carrier organizations is not possible.
b. You must designate a single person or position as the accountable manager with the authority and the overall responsibility for managing and implementing your entire maintenance program, including all inspection functions. The inspection functions and the required inspection functions are part of your maintenance program. The FAA expects you to designate your DOM as the accountable manager for your maintenance program.
c. The FAA expects your maintenance organization to have three general organizational functions to ensure all operations are conducted to the highest possible degree of safety. If you are a larger organization, you may have different departments for each level, while in the smallest organizations these functions may be carried out by one or two individuals. Generally, these three organizational functional levels include:
(1) Mechanics and/or inspectors performing the work at the first level (operations);
(2) Middle managers and supervisors at the second level (tactics); and
(3) The maintenance program accountable manager at the third level (strategy).
d. The FAA expects to see clear authority and responsibility in your maintenance organization, including delegated responsibility, for the overall maintenance program and all of its elements and functions. You should include a description of each individual’s duties and responsibilities in your manual so that there is not a fragmented organizational system with a high risk for confusion over who is responsible for a given element, process, or task.
403. ORGANIZATIONAL SEPARATION OF THE INSPECTION AND MAINTENANCE DEPARTMENTS.
a. There is a clear regulatory requirement for a maintenance organization at §§ 121.365 and 135.423. Because inspection is an integral part of your maintenance organization, there is no regulatory requirement for an inspection organization. There is no regulatory requirement to separate your inspection department, if you have one, from the rest of your maintenance organization, because inspection is integral to maintenance. The FAA has defined maintenance in § 1.1 as “inspection, overhaul, repair, preservation, and the replacement of parts, but excludes preventive maintenance.” If you choose to have an inspection department, you must organize it as an integral part of your maintenance organization.
b. Regulations require you to organize the performance of all maintenance functions, including inspection, repair, overhaul, and the replacement of parts, to separate the function of
Par 403 Page 13 required inspections from the function of the other maintenance, preventive maintenance, and alteration activities. This organizational separation must be below the level of administrative control where overall responsibility for the required inspection functions as well as the other maintenance, preventive maintenance, and alteration functions is exercised. Consistent with paragraph 402(b) of this AC, your DOM exercises overall authority and responsibility over the required inspection functions, as well as the other maintenance (including inspection), preventive maintenance, and alteration functions. See Figure 4-1 for a representative organizational chart
Page 14 Par 403 FIGURE 4-1. TYPICAL ORGANIZATIONAL CHART SHOWING THE
ORGANIZATIONAL SEPARATION OF THE RII FUNCTION AND THE OTHER
MAINTENANCE, PREVENTIVE MAINTENANCE, AND ALTERATION FUNCTION
OVERALL AUTHORITY
AND RESPONSIBILTY
FOR BOTH RII AND
OTHER MAINTENANCE
AND ALTERATION
FUNCTIONS
PART 119 DIRECTOR
OF MAINTENANCE
DIRECT RESPONSIBILITY
FOR OTHER
MAINTENANCE AND
ALTERATION
FUNCTIONS
MANAGER OF
MAINTENANCE
DIRECT RESPONSIBILITY
FOR RII FUNCTIONS
PART 119 CHIEF
INSPECTOR
Par 500 Page 15 CHAPTER 5. ACCOMPLISHMENT AND APPROVAL OF MAINTENANCE AND
ALTERATIONS
500. ACCOMPLISHMENT OF MAINTENANCE.
a. As a maintenance entity, you are authorized under 14 CFR §§ 43.3(f), 43.7(e), 121.379, and 135.437 to perform maintenance on your own air carrier aircraft and to approve them for return to service without obtaining any other maintenance certification. In addition, §§ 121.379 and 135.437 provide clear authority for you, under your air carrier certificate, to perform maintenance on behalf of other air carriers who conduct operations under the same part as you do. You may also perform maintenance for an air carrier or other operator conducting operations under a different part than you are. However, this maintenance is not included in your air carrier maintenance authority; therefore, any maintenance that you perform under this circumstance must be separated and independent of your authority and certification as an air carrier.
b. Each individual who makes an airworthiness determination on your behalf must hold an appropriate airman’s certificate. Sections 121.378 and 135.435 require that any individual who you put directly in charge of performing maintenance hold an appropriate airman certificate, such as a mechanic certificate with ratings appropriate to the work being performed.
Section 121.371 requires that any individual that you authorize to perform RII for you hold an appropriate airman certificate. Section 121.709 requires that anyone who you authorize to issue an approval for return to service hold an appropriate airman’s certificate. Your DOM and chief inspector must hold an airman’s certificate with airframe and powerplant ratings. These certificate requirements are air carrier qualification requirements, not requirements for an airman certificate that are needed or exercised to do maintenance. All maintenance on your aircraft and approval for return to service is accomplished under your air carrier certificate by your maintenance organization or persons authorized by you, not by any individual or organization under their certificate. One exception to the individual airman certificate requirement occurs if you arrange for a certificated repair station located outside the United States to perform maintenance. At such repair stations, individuals directly in charge of performing maintenance or required inspections are not required to hold FAA airman certificates.
501. MAJOR REPAIRS AND ALTERATIONS. Under §§ 121.379(b) and 135.437(b), major repairs and alterations must be done in accordance with technical data approved by the FAA.
Appendix A to part 43 contains a list of repairs and alterations that are considered to be major.
However, you should note that the Civil Aeronautics Agency published a list of repairs and alterations to specific parts, as well as specific types of repairs that were considered major repairs during 1953. This major repair and alteration list was later adopted, unchanged, as part of appendix A of part 43. Exclusive reliance on the part 43, appendix A list of major repairs and alterations to make the major/minor classification will result in the classification of some minor repairs as major and classification of some major repairs as minor simply because the appendix A list has not been updated to include evolving airplane design and construction techniques such as composite structures and the high speed, high altitude pressurized jet transport that did not exist when the list was developed. You should have detailed major/minor classification procedures in your manual to evaluate each repair or alteration on a case-by-case basis using such factors as the certification basis of the aircraft, classification of the structure as primary,
Page 16 Par 501 secondary, or a primary structural element, or classification as a fail-safe, safe-life, or damagetolerant structure.
502. AIRWORTHINESS RELEASE FORM OR AIRCRAFT LOG ENTRY AND APPROVAL FOR RETURN TO SERVICE. After performing any maintenance on your airplane, you must approve it for return to service before you may operate it. As an air carrier, you must issue an approval for return to service under §§ 121.709 or 135.443 as appropriate.
You can read additional, more detailed information about approving your airplanes for return to service in chapter 8 of this AC.
503. SCOPE OF MAINTENANCE. You must provide instructions in your maintenance program and maintenance manual for maintenance and alterations encompassing the four areas of “what to do,” “when to do it,” how to do it,” and “was it done properly” in at least three major areas: scheduled maintenance, unscheduled maintenance, and specific maintenance requirements for major components of the aircraft.
a. Scheduled Maintenance. Scheduled maintenance consists of all the individual maintenance tasks performed according to the maintenance time limitations (maintenance schedule). Your scheduled maintenance activities should include procedural instructions for the maintenance tasks and requirements to record the results of the inspections, checks, tests, and other maintenance.
b. Unscheduled Maintenance.
(1) Unscheduled maintenance includes procedures, instructions, and standards for maintenance that occurs on an unscheduled or unforeseen basis. A need for unscheduled maintenance may result from scheduled maintenance tasks, pilot reports, or unforeseen events, such as high-load events, hard or overweight landings, tail strikes, ground damage, lightning strikes, or an engine over-temperature. In your maintenance manual, you should include instructions and standards for the accomplishment and recording of unscheduled maintenance and detailed procedures for recording all types of unscheduled maintenance.
(2) You should include a comprehensive process in the unscheduled maintenance portion of your manual that addresses those rare, very high-load events that occur to aircraft.
These very high load events may result in structural damage, but unless you have comprehensive procedures to identify and evaluate such damage, you may not identify this damage before you approve your aircraft for return to service. Your manual should include very high load event special inspection procedures that address at least these four objectives:
(a) Identify that a very high load event has/has not occurred,
(b) Assure that indications of structural damage are found in an initial inspection,
(c) Involve the OEM if necessary, and
(d) Provide a process for additional inspections that would identify all of the structural damage.
Par 503 Page 17 (and 18)
c. Specific Maintenance Requirements for Major Aircraft Components.
(1) Engine Maintenance Program. Your engine maintenance program should cover the maintenance of installed engines and off-wing engines for each engine model you operate. If your aircraft has auxiliary power units (APU), you may want to include APU maintenance as part of your engine maintenance program. Usually, the installed engine or APU requirements will be contained in the maintenance time limitations. In addition to procedural information, the off-wing program described in your maintenance manual should provide shop scheduling information or intervals for cleaning, adjusting, inspecting, testing, and lubricating each part of the engine or APU requiring that maintenance. You should include in your maintenance manual the degree of inspection, the applicable wear tolerances, and the work required when the engine or APU is in the shop.
(2) Propeller Maintenance Program. If applicable, your propeller maintenance program should cover the maintenance of installed propellers and off-wing propellers for each model you operate. Usually, the installed propeller system scheduled maintenance requirements will be contained in the maintenance time limitations. In addition to procedural information, the off-wing program described in your manual should provide shop scheduling information or intervals for cleaning, inspecting, adjusting, testing, and lubricating each part of the propeller system requiring that maintenance. You should include in your maintenance manual the degree of inspection, the applicable wear tolerances, and the work required at these periods. Some modern propellers are constructed of composite materials and, therefore, may require unique tools, repair procedures, and specialized training for your maintenance personnel.
504. PARTS AND APPLIANCES MAINTENANCE PROGRAM. For the most part, this component of your maintenance program covers shop operations, which may include both scheduled and unscheduled tasks. You may conduct these shop operations at some location other than where you perform maintenance on your aircraft. Your parts and appliance maintenance program should cover both installed parts and appliances and off-wing maintenance for each part and appliance model that you operate. Usually, the installed part and appliance scheduled maintenance requirements will be contained in the maintenance time limitations. In addition to procedural information, the off-wing program described in your maintenance manual should provide shop scheduling information or intervals for cleaning, adjusting, inspecting, testing, and lubricating each component of the part and appliance requiring that maintenance. Include in your maintenance manual the degree of inspection, the applicable wear tolerances, and the work required when the part or appliance is in the shop.
Par 600 Page 19 CHAPTER 6. MAINTENANCE SCHEDULE
600. THE MAINTENANCE SCHEDULE. Sections 119.49 and 121.135(b) require you to have maintenance time limitations, also called a maintenance schedule. These same rules permit you to make standards for determining your maintenance time limitations. This language is the regulatory basis of FAA-approved reliability programs that were developed in the 1960s. The maintenance time limitations set out the what, how, and when of your scheduled maintenance effort. Although in the past the schedule included only basic overhaul limits and other general requirements, today it includes a specific list of each individual maintenance task and its associated time limit. The regulations are broad enough to permit you to organize all of these individual tasks into a series of integrated scheduled work packages of your own design that provide a continuous succession of necessary or desirable scheduled maintenance tasks for your entire airplane.
601. THE FAA’s ROLE IN RELATION TO THE MAINTENANCE SCHEDULE. The FAA authorizes your maintenance schedule through your OpSpecs, and your CASS monitors that schedule to verify its effectiveness, i.e., producing the desired results. Your CASS will be your principal source of information that might indicate a needed change to your maintenance schedule. (CASS is described in chapter 11 of this AC and in much more detail in AC 120-79.)
The FAA expects you to correct any deficiencies in your maintenance schedule. Under §§ 121.373(b) and 135.431(b), if you do not make needed changes, the FAA can require you to change your maintenance schedule or any other element of your maintenance program found deficient.
602. MAINTENANCE SCHEDULE CONTENTS.
a. Your maintenance schedule should contain at least the following information:
(1) What (Unique Identifier). This is the item that you are going to maintain. Your identifier should be specific enough to allow the item to be easily and accurately identified by the individual assigned to do the scheduled maintenance task.
(2) How (Task). How to maintain the item; the scheduled maintenance task to be done.
A scheduled maintenance task is a maintenance action that you perform at regular, scheduled intervals so that you can ensure the item can continue to perform its intended function within its operating context, or so you can discover a hidden failure, or to ensure that a hidden function is available. You should not use terms such as hard time, on-condition, or condition monitored in your maintenance schedule. These terms represent obsolete 1960s methodology, are vague, and do not describe the maintenance task you are performing. If your maintenance schedule contains these terms, there is a risk that the scheduled maintenance you want and need may not be the maintenance that is being performed.
(3) When (Frequency). The time-in-service interval between the times when you accomplish a scheduled maintenance task. Your intervals are measured in time in service and may be measured by calendar time, operational hours, flight cycles, or any other appropriate parameter. In addition, for task management, inventory, and audit purposes, you should identify, on the maintenance schedule, the task or work card associated with each scheduled maintenance
Page 20 Par 602 task. This way, you can ensure that all of your scheduled maintenance tasks are being accomplished according to your schedule.
b. Your overall maintenance schedule objective is to correctly do the correct tasks at the correct interval. Keep in mind that more maintenance is not always a good idea, so if you decide to decrease intervals or add tasks, you should go through the same justification process as any other change to the maintenance schedule.
603. STANDARDS FOR DETERMINING MAINTENANCE TIME LIMITATIONS.
a. As we mentioned in paragraph 600 earlier, §§ 119.49 and 121.135 permit you to have standards for determining your maintenance time limitations. In the past, this language was used as the regulatory basis for FAA-approved reliability programs that evolved during the 1960s.
These programs were based on the Air Transport Association of America’s (ATA) now obsolete process-based Maintenance Steering Group – 2nd Task Force (MSG–2) decision logic that focused on failure rates and maintaining individual parts of the aircraft. Consistent with the continuous evolution of aviation, MSG–2 became obsolete in 1980 with the advent of ATA’s task-based Maintenance Steering Group – 3rd Task Force (MSG–3) decision logic. MSG–3 focused on aircraft systems and a loss of function rather than an individual part failure. In any case, the management of these MSG–2 process-based programs was actuarial analysis. Air carriers used the failure rates of a part to determine, through a probability process, the likelihood that the part would have a similar failure rate in the future. The standard was the acceptable failure rate. Air carriers used a failure rate alert program with upper control limits (UCL) and lower control limits (LCL) to track part failure rates. The air carrier was obliged to take action only when the failure rate deviated from the probability-based prediction, i.e., exceeded the UCL or the LCL. If the part did not respond, the air carrier was authorized to move the UCL or LCL to make the failure rate within the alert program limits.
b. During the 1970s, after collecting a large amount of operational data over time, the industry came to the realization that using failure rates and alert programs was not the most effective way of managing scheduled maintenance. Using the vast amount of operational data that was available, United Airlines developed and published a report during 1978 under a U.S.
Department of Defense contract entitled “Reliability Centered Maintenance (RCM).” This very significant document was in stark contrast to the previous part failure rate focus. RCM focused on the loss of function of an aircraft system. RCM determined that everything doesn’t fail the same way; failures occur according to six different failure patterns. RCM also determined that everything doesn’t require the same type of maintenance; there are four different types of scheduled maintenance. RCM also took into account the different consequences (safety, operational, and economic) of a loss of function, as well as system functional redundancy and inherent design safety when determining if scheduled maintenance was required. In some cases, RCM determined that no scheduled maintenance was required. This resulted in doing only required maintenance, and a much lower maintenance burden.
c. The RCM document was the major basis for the ATA’s development of the MSG–3 decision logic in 1980. Since then, most aircraft manufacturers have used the Air Transport Association’s MSG–3 decision logic to help them develop scheduled maintenance requirements for their new products. Besides providing organization and flow to the deliberative process, the