8900.1 CHG 562

Volume 4  Aircraft Equipment and Operational Authorization

Indicates new/changed information.

chapter 14  General Operating and Flight Rules—Maintenance Issues

Section 3  Evaluate/Approve an Inspection Program Under Part 91, § 91.409(f)(4)


A.    Maintenance: 3428, 3429.

B.    Avionics: 5428, 5429.

4-1402    OBJECTIVE. This section discusses Title 14 of the Code of Federal Regulations (14 CFR) part 91 inspection programs and provides procedures for aviation safety inspectors (ASI) to evaluate, approve, or disapprove inspection programs under part 91, § 91.409(f)(4).

4-1403    INSPECTION PROGRAM. Depending on the type and size of aircraft, there are several inspection program options available for aircraft owner/operators to choose from. This section is specifically addressing approved inspection programs under § 91.409(f)(4), but more information about part 91 inspection programs in general can be found in Volume 6, Chapter 1, Section 2. Regardless of the inspection program used, persons approving or disapproving equipment for return to service after an inspection must make an entry in the record of that equipment per 14 CFR part 43, § 43.11.

A.    Approved Inspection Program Content. Each inspection program is unique and specifically designed for an individual aircraft. The program is typically a customized version of the manufacturer’s recommended inspection program. This program is used when other programs are not directly applicable to the aircraft in question, or the owner/operator desires more flexibility due to the type of operation (low utilization, unique environments, etc.). This type of program can also be used if the manufacturer did not provide an adequate inspection program. For more information on what this type of program should contain, refer to AC 91‑90, Part 91 Approved Inspection Programs.

NOTE:  We generally refer to an inspection program approved under 14 CFR part 135 as an Approved Aircraft Inspection Program, or AAIP, and an inspection program approved under § 91.409(f)(4) more generically as just an Approved Inspection Program, or AIP. They are all forms of “Approved Inspection Programs,” but the term AAIP has long been associated with part 135. So the term “AAIP” should be used when referring to an inspection program approved under part 135 and the term “AIP” should be used when referring to a program approved under any other part to reduce confusion.

B.    Tracking Programs. Tracking programs are not a part of an inspection program and should not be approved as such. They are only tools that assist operators in tracking and scheduling. Computer software companies and operators have developed computer programs designed to function as tracking programs to track items such as scheduled maintenance and inspection requirements, Airworthiness Directives (AD), and SBs. Owner/operators may have these programs in house or they may send their data to a software company to track the maintenance for them. Additionally, some manufacturers provide Web‑based programs that include the inspection task cards or forms which are then utilized to document maintenance actions. While such programs are typically comprehensive, care should be taken that they do not introduce issues with the owner/operator’s ability to maintain the actual maintenance records required per § 91.417. In addition, if digital signatures are being used, there should be security and protection measures in place to ensure the electronic signatures are not compromised. Refer to AC 120-78, Electronic Signatures, Electronic Recordkeeping, and Electronic Manuals, for more information on this subject. Using these programs to track and/or document inspection requirements can provide greater accuracy and reliability over previous methods; however, the owner/operator is still responsible for the proper accomplishment of inspections, recordkeeping, and retention. Electronic systems can be referenced and described in the inspection programs, but the systems themselves do not require Federal Aviation Administration (FAA) approval or acceptance.

4-1404    COORDINATION REQUIREMENTS. This task requires coordination between maintenance and avionics inspectors.


A.    References (current editions):

    Title 14 CFR Parts 43 and 91.

    AC 43‑9, Maintenance Records.

    AC 91-90, Part 91 Approved Inspection Programs.

    AC 120-78, Electronic Signatures, Electronic Recordkeeping, and Electronic Manuals.

    AC 120-97, Incorporation of Fuel Tank System Instructions for Continued Airworthiness into Operator Maintenance or Inspection Programs.

    AC 121-22, Maintenance Review Boards, Maintenance Type Boards, and OEM/TCH Recommended Maintenance Procedures.

B.    Forms. None.

C.    Job Aids. None.

4-1406    PROCEDURES.

A.    Approve an Inspection Program Under § 91.409(f)(4). AC 91-90 provides general guidelines for operators who wish to submit F4 programs for review and approval. Inspectors should give careful attention to the time intervals and level of detail provided with the inspection program, and should familiarize themselves with AC 91-90 before reviewing the operator’s submission.

1)     Completeness and Adequacy. Review the F4 program for completeness and adequacy. Completeness is established if the F4 covers the entire aircraft in its present configuration with all associated equipment and components being addressed in the F4 program. The program developed must include inspection of all systems, including engines, propellers, appliances, survival equipment, and emergency equipment installed on the aircraft. Adequacy is determined by verifying that the inspection program has all required elements in it, and that inspection items are clearly defined with associated intervals. Instructions for performing the inspections must be included in the program, or a reference to the manufacturer’s instructions can be used if clearly identified. AC 91-90 has more detail on this topic and what is acceptable.
2)    Evaluating Proposed Task Intervals. If the F4 program is for an aircraft that has a published manufacturer’s program, use the manufacturer’s program as a convenient reference point for evaluation of the proposed program. For simplicity, any request for intervals greater than the manufacturer’s defined intervals we refer to as “extensions,” even though under an F4 these are not actually extensions, but simply the proposed interval defined for the task, since each inspection program is unique to the aircraft in question. When considering extension of the manufacturer’s inspection intervals as part of an F4, inspectors and operators must collaborate to determine a reasonable length for the task interval. An operator should base its task interval on in-service data collected from either its own aircraft or from a representative sampling of the task from aircraft fleet data. The acceptability of fleet data is dependent on how much different operating procedures and conditions could affect the inspection items in question. When evaluating an inspection program with task intervals greater than the manufacturers, the inspector should consider the following:
a)    An operator may adjust intervals for individual tasks or for a complete inspection package. However, if an operator requests adjustment of intervals for a complete inspection package, it must provide a comprehensive justification for the interval extensions on a task-by-task basis. Justification for adjusting individual tasks or inspection package intervals requires analyzing a mutually agreed‑upon sampling of completed inspections and analyzing routine, non-routine, and teardown report findings generated during those inspections.
b)    Ensure time requirements set by regulatory requirements are not modified (including any provisions for short-term extensions) without supporting FAA approval (such as an alternative method of compliance (AMOC) for an AD). This includes items such as:

1.    The test and inspection of emergency locator transmitters (ELTs);

2.    Altimeter/altitude reporting systems;

3.     Intervals specified by ADs;

4.    Airworthiness limitation items (ALIs);

5.    Life-limited items; and

6.    Certification Maintenance Requirements (CMR).

c)    If the F4 is for an aircraft with a published manufacturer’s program, requests for intervals greater than the manufacturer’s defined intervals must be submitted with sufficient justification to support that request. There are many sources of data an operator might use in a justification request. Here are some examples:

1.    Original Equipment Manufacturer (OEM) Recommendations. Recommendations from the OEM for the aircraft, engine, propeller, component, or emergency equipment, detailing any possible task interval extensions.

2.    Manufacturer’s information. SBs, SLs, and other in-service reports/resolutions related to the task interval.

3.    Past operating experience. The maintenance history of the applicable aircraft, engines, propellers, components, or items of emergency equipment.

4.    Overhaul teardown reports. Reports from teardowns of engines, propellers, or components that show dimensional checks and condition of critical parts.

5.    Aircraft/engine utilization information. A summary of fleet-wide service experience (hours, cycles, years), time in service, and daily utilization (high, low, average).

6.    Parts replacements. Information regarding component removal and replacement activity and vendor repair maintenance records.

7.    Engine oil analysis reports. Review the operator’s oil analysis reports (if applicable) for abnormal wear and recommendations from the lab for follow-up action. Repeated abnormal wear reports may indicate a problem with the operator’s engine maintenance program.

8.    Engine trend monitoring reports. If the operator has a trend monitoring program, review the program for abnormalities that would indicate a problem with the operator’s engine maintenance program.

9.    Oil consumption history. This is the history of oil consumption throughout the engine’s operation since its last overhaul.

10.    Pilot reports and maintenance reports. Reports of mechanical irregularities and the resulting corrective actions.

11.    Routine maintenance tasks that generate no findings. Tasks that generate no findings are as important as tasks that do generate findings.

12.    Routine maintenance tasks that generate findings. Tasks which involve structures, zonal areas, and aircraft systems.

d)    When reviewing an operator’s request for extension of an inspection or individual task, the following data sources should be considered:

1.    Any information the operator provides that is relevant to the proposed task interval extension.

2.    Mechanical Interruption Summary Reports (MISRs). Review previous MISRs to detect trends or irregularities. This review may indicate problem areas in maintenance procedures, operational procedures, or the operator’s training regarding the reliability of its aircraft.

3.    Service Difficulty Reports (SDRs). Query the SDR database for information on the component the operator wants to extend. A high number of reports, failures, or other deficiencies may be a reason to reject a task interval extension.

4.    ADs. Some ADs may restrict operating an aircraft, engine, propeller, or component past a manufacturer’s recommended task interval.

5.    Type Certificate Data Sheets (TCDSs). Review TCDSs for information related to task interval extensions or references to life limits.

6.    Operator’s violation history. When analyzing the risk for a proposed task interval extension, review the operator’s current status and history for maintenance-related violations, information, and data contained in programs such as the Enforcement Information System (EIS), Voluntary Disclosure Reporting Program (VDRP), Aviation Safety Action Program (ASAP), etc.

7.    Operator’s accident, incident, and occurrence history. If the operator has a history of accidents, incidents, or occurrences related to maintenance issues, factor in these events when analyzing the proposed task interval extension.

8.    Surveillance data. Use PTRS/Safety Assurance System (SAS) to review the operator’s surveillance history for items that may indicate the operator’s safety culture and compliance with regulations. Identify the operator’s specific areas that may present a greater risk and then analyze safety-critical performance measures.

4-1407    TASK OUTCOMES.

A.    Complete the PTRS Record.

B.    Complete the Task. Successful completion of the task will result in approval of the inspection program, or providing feedback to the submitter about unacceptable items. Approval of the inspection program should be done per standard office procedures. For example, use an office stamp with date and signature of the inspector on the cover page or list of effective pages. Filing of the approved programs in the office must also be accomplished per local policy.

4-1408    FUTURE ACTIVITIES. Monitor inspection programs for compliance in accordance with Volume 6, Chapter 2, Section 1 for part 91 subpart K (91K) operators and Volume 6, Chapter 1, Section 7 for basic part 91 operators.

RESERVED. Paragraphs 4‑1409 through 4‑1425.