8. GUIDANCE FOR APPENDIX A TO PART 35, A35.2 - FORMAT.
a. The ICA should be organized and cross-referenced in a clear, logical, and usable format.
Service bulletins (SBs), as described in AC 20-114, form a different class of service document than those required for type certification; SBs are not an acceptable substitute for ICA. The SBs may be used as a vehicle for distributing information; however, temporary manual revisions are more appropriate for this purpose. Incorporating the appropriate information through temporary manual revisions is not considered an undue burden to the TC holder. However, if the TC holder decides to incorporate SBs by reference into the ICA, the TC holder should meet the following criteria:
(1) The ICA should reference the specific SB revision. The ICA should not simply specify “latest revision.”
(2) The technical content of the SB should be FAA-approved.
b. Appendix A35.4, Airworthiness Limitations Section, specifies that the ICA must contain a separate section titled “Airworthiness Limitations.”
c. The FAA has accepted a variety of formats, including the Air Transport Association (ATA) 100 Specification or ATA iSpec 2200. The documents that constitute the complete ICA should be identified as containing the ICA required under §35.4, regardless of the format.
9. GUIDANCE FOR APPENDIX A TO PART 35, A35.3 - CONTENT. The ICA is intended to be a complete document; therefore, it should be emphasized that the information should be contained in the manuals, not referenced in separate documents, such as service letters or SBs.
The ICA must be written in English; however, metric system units may be used for the technical aspects of the product in the areas of design, production, operation, or maintenance. Appendix A35.3 also specifies that the applicant provide a minimum of two distinct groupings as part of the ICA manual. These two groupings are: Propeller Maintenance Section and Propeller Overhaul Section. When the overhaul manual is not titled “Propeller Overhaul Manual,” the following sentence or a similar sentence to define an overhaul should be added: «The contents of this manual serve to document all requirements in order to accomplish a complete propeller overhaul.».
a. Guidance for A35.3(a), Propeller Maintenance Section.
(1) Paragraphs A35.3(a)(1) and (a)(2). The description of the propeller features and data and its components, systems, and installations should contain enough detail to perform propeller maintenance and preventive maintenance. This may include any necessary warnings and guidance, such as applicable metric system or U.S. Standard System requirements. This description ensures compliance with the requirements for the observation and recording of the maintenance performed and the methods, techniques, and practices used.
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(2) Paragraph A35.3(a)(3). The description of the control and operation of the propeller components and systems should also provide enough detail to perform the maintenance at the levels specified in the ICA.
(3) Paragraph A35.3(a)(4). The propeller maintenance section should also address all accessories, cover-plates, etc., that may be attached to, mounted on, or driven by the propeller, because their interfaces affect the propeller. The propeller maintenance section should have complete installation instructions for those parts and accessories that are part of the propeller type design. The instructions should include minimum interface instructions and any appropriate specifications, warnings, or cautions for those areas on which non-propeller TC accessories or parts could be installed on the propeller at a later date.
(4) Paragraph A35.3(a)(5). The instructions should include appropriate warnings to head the aircraft into the wind during the performance of rotating ground system checks such as overspeed governor checks. The manual should include any additional checks specific for the propeller.
(5) Paragraph A35.3(a)(6).
(a) The applicant does not have to provide specific scheduling information for each part, but the scheduling information provided should ensure the continued airworthiness of the entire propeller to the extent that the lack of specific scheduling information on any part would not adversely affect the continued airworthiness of the propeller. The substantiation for scheduling information should be derived from propeller certification testing, development testing, service experience of the same or similar type design propeller, or a combination of these. A general note should be added to the ICA that states that it is good maintenance practice to perform inspections on an opportunity basis whenever any component is exposed, regardless of if the component is scheduled to be serviced at that time.
(b) A single, top-level overhaul period for the propeller should be adequate when the overhaul period provides an appropriate interval to ensure the continued airworthiness of the entire propeller.
(c) An applicant should provide at least one scheduling option for the ICA. The propeller parts, components, and accessories should be monitored and serviced while installed; if not, the products should be scheduled for appropriate maintenance or overhaul to ensure their continued airworthiness. For example, this could mean soft times for each module, assembly, sub-assembly, accessory, or part of the propeller. If the propeller is taken off the aircraft, the ICA should provide maintenance or overhaul instructions to determine the propeller’s eligibility for reinstallation on an aircraft and continued service use. The disassembly of the propeller, module, or component assembly to the piece-part level may be required before returning the propeller to service if the exposure occurs after a considerable number of hours in service.
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(d) The applicant may refer to a component manufacturer as the source for the scheduling information. In that case, the manufacturer’s component manual becomes part of the ICA, and the TC holder remains responsible for the information, even though the component manufacturer provides the information in the component manual. The TC holder is responsible for providing the scheduling information in the principal ICA (for example, the propeller maintenance section) and defining when the maintenance referenced in the component manual should be performed. There may be cases in which, due to the complexity of the maintenance task, only the original equipment manufacturer (OEM) is approved to work on a part or component. In such cases, when accepted by the CMACO, the ICA should only reference the recommended scheduling periods, the manufacturer’s documents, and the manufacturer’s name and address.
(e) The ICA should identify and reference any component manuals that are part of the ICA. In such cases, the TC holder is responsible for controlling the content and changes in component manuals in accordance with the program provided to the FAA under paragraph A35.1(c). The TC holder may work with the component manufacturer to distribute changes to component manuals.
(f) The ICA should include the recommended overhaul periods.
(g) The applicant must include an inspection program in the ICA to ensure the continued airworthiness of the propeller. Certification tests, analyses, and service experience, if available, should be used to develop the inspection program for parts, assemblies, subassemblies, or modules. The Airworthiness Limitations section does not have to define the inspection program. However, the inspection program should cross-reference any airworthiness limitations that are required with the inspection program. An adequate inspection program should also include subsequent inspections (periods, frequency, and parts involved).
(6) Paragraph A35.3(a)(7). The troubleshooting information should ensure that the propeller and its modules, assemblies, sub-assemblies, and parts are able to perform their intended functions within the approved flight envelope and prevent propeller malfunctions. The troubleshooting information should address potential malfunctions and provide either procedures to rectify them or to replace the affected part or component before continued operation.
(7) Paragraph A35.3(a)(8). The applicant should provide a means to ensure configuration control during maintenance in the ICA. This configuration control should ensure that the proper parts, components, and combinations of parts and components are identified and comply with the TC.
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(8) Paragraph A35.3(a)(9). The list of tools for maintenance should be adequate for completing the work. The list may include lists located in the sections of the ICA in which the work is described. However, the list of tools and equipment should be located in a manner that facilitates locating and ordering the tools and equipment. Also, the list should include a crossreference to the section in which the method of using each tool is described. Special tools should be noted, as there is a specific regulatory requirement for the use of a special tool when performing maintenance.
b. Guidance for A35.3(b), Propeller Overhaul Section. It is not necessary to define a single overhaul period for the entire propeller, modules, or assemblies. However, experience has shown that every part of the propeller is exposed for inspection at some point during the life of the propeller. The TC holder should clearly define what level or amount of inspection and repair or replacement of parts constitutes an overhaul. The modular maintenance concept is an efficient overhaul method, even though each part may effectively be overhauled at different times.
(1) Paragraph A33.3(b)(1). The propeller overhaul manual or section should contain enough details for the disassembly, overhaul, and re-assembly of the propeller. This manual or section should also include necessary warnings and guidance.
(2) Paragraph A35.3(b)(2).
(a) Adequate inspection criteria should enable the appropriate inspection of each part of the propeller, sub-assembly, assembly, and module, as well as systems and components.
Inspections should identify the required action at each level, such as part replacement, repair, or further detailed inspection.
(b) The accuracy and reliability of inspection techniques should be consistent with the criticality of the parts being inspected and the types of defects for which the part is being inspected. The ICA should identify parts and key features or areas for which special emphasis or a higher awareness is needed to assure continued airworthiness. Cleaning could have a significant effect on the inspection, as improper cleaning could result in missing potentially hazardous defects. Therefore, the ICA should emphasize the proper cleaning methods, with the appropriate cautions when improper cleaning could impede inspection.
(3) Paragraph A35.3(b)(3). The overhaul manual should contain details for all fits and clearances for the propeller and components, structural integrity, and functionality of new and worn parts. While these fits and clearances may be identified in the manual as limits, they are not considered airworthiness limitations. However, if these limits are exceeded, the component or part may not be airworthy.
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(4) Paragraph A35.3(b)(4).
(a) This requirement ensures that worn or substandard parts that do not meet the ICA inspection limits cannot be returned to service. To make the propeller airworthy, such parts should be either replaced or repaired. While the ICA does not have to include repairs for all propeller parts, it should identify when or under what conditions parts must be replaced or repaired. If a part or component fails to meet the inspection requirements of the ICA, replacement is an acceptable alternative to repair.
(b) Repairs specified in the ICA should be complete and may include personnel training requirements. When the repair is accomplished in accordance with the ICA, the part should conform to its approved type certificate and, if safe for operation, should constitute an airworthy part.
(c) The FAA may allow and approve other repair data that is not part of the TC and is not reflected in the ICA. However, when design change data for repair or alteration constitutes a major change to the type design, the need for such repair or alteration information in the ICA should be evaluated, because the repair or alteration could introduce a new feature that does not exist in the original type design. This is particularly true for an STC. Any major change in type design, whether in support of a repair or an alteration, that is substantive enough to require significant additions to the ICA should be approved as an STC or amended TC.
(5) Paragraph A35.3(b)(5). The ICA should also contain a means to ensure configuration control during overhaul such that the proper parts, components, and any combinations that comply with the type design are identified during assembly or replacement.
(6) Paragraph A35.3(b)(6).
(a) The ICA should provide test acceptance criteria identified as limits, although not identified as airworthiness limitations. Changes to such propeller test acceptance criteria that are safety related should be considered major design changes and may be changed with appropriate FAA-approved data to substantiate the change. The ICA should provide calibration requirements (frequency, accuracy, and protocol to be used) for all testing and measurement equipment used to return the propeller and its component parts to service.
(b) The manual or section should include instructions for testing a propeller after overhaul. When applicable, this should also include any minimum testing requirements for a single overhauled component or model.
(7) Paragraph A35.3(b)(7). The manual or section should identify special containers, equipment, and tools that may be necessary to comply with the instructions for storage. The storage limits should also include any environmental restrictions, such as limits for temperature or humidity.
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(8) Paragraph A35.3(b)(8). The list of tools for overhaul should be adequate for completing the work. The list may include lists located in the sections of the ICA in which the work is described. Also, the list should include a cross-reference to the section in which the method of using each tool is described or the tools are used. Any special tools should be highlighted, because §43.13 requires the use of special tools when performing maintenance.
10. GUIDANCE FOR APPENDIX A TO PART 35, A35.4 -- AIRWORTHINESS LIMITATIONS SECTION.
a. The ICA must include an Airworthiness Limitations section. The Airworthiness Limitations section may appear in both the maintenance and overhaul sections; this is acceptable as long as both sections remain identical. The Airworthiness Limitations section should be prominently located, entitled “Airworthiness Limitations,” and identified at the beginning of the section as having been approved by the FAA.
b. The CMACO approves the Airworthiness Limitations section. Changes to mandatory inspection intervals, as well as life limits and replacement times, require CMACO approval. The addition of restrictions to an existing Airworthiness Limitations section should be accompanied by an airworthiness directive (AD).
[Original signed 11/3/03 by P.A.W.]
Peter A. White Acting Manager, Engine and Propeller Directorate Aircraft Certification Service
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