AC 27-1B

Change 1-9

Advisory circular · Certification of Normal Category Rotorcraft

Approved
June 23, 2023
Last reviewed
June 29, 2023
Cancels
AC27-1B Change 8
Family
AC 27-1 · 10 versions
Revision
B, Change 9
14 CFR parts
27
Cited by
1 AD

Guidance, not mandatory unless a rule or AD requires it. DRS record last changed October 23, 2026.

Show pages 1137–1148
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AC 27-1B, Chg 1 2/12/03 (MANUAL IDENTIFICATION)

REQUIREMENTS (Continued)

b. Types of lubricants to be used.

Reference Appendix A, A27.3 (a)(4). This is required when applicant determines the rotorcraft and its engine(s), rotor(s), and appliances will require lubrication. The information is normally included in chapters that address lubrication and in Chapter 12.

10. EQUIPMENT REQUIRED FOR SERVICING Equipment required for servicing and lubricating. Reference Appendix A, A27.3 (a) (4). This is required when applicant determines equipment will be required for servicing and lubricating the rotorcraft and its engine(s), rotor(s), and appliances. The information is normally included in chapters addressing equipment for servicing or lubrication and in Chapter 12. In addition, the equipment required for servicing and lubricating should be listed in the List of Special Tools contained in Chapter 1.

11. RECOMMENDED PERIODS The recommended period at which each part of the rotorcraft and its engine(s), auxiliary power unit, rotor(s), accessories, instruments, and equipment should be:

a. Cleaned.

b. Inspected.

c. Adjusted.

d. Tested.

e. Lubricated.

Reference Appendix A, A27.3 (b)(1). This is always required as applicable.

f. There is not a specific format for the recommended periods, however the ICA should include the time and/or interval the above items are to be accomplished.

12. DEGREE OF THE INSPECTION The degree (scope) of the inspection for each part of the rotorcraft and its engine(s), auxiliary power unit, rotor(s), accessories, instruments and equipment. Reference Appendix A, A27.3

(b)(1). It is required for each part of the rotorcraft and its engine(s), auxiliary power unit, rotor(s), accessories, instruments, and equipment which is required to be inspected. This information is normally contained in the chapters of the item being inspected and Chapter 5.

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(MANUAL IDENTIFICATION)

REQUIREMENTS (Continued)

13. WORK RECOMMENDED The work recommended at these periods when each path of the rotorcraft was cleaned, inspected, adjusted, tested, and lubricated. Reference Appendix A, A27.3 (b)(I). This is required when applicant determines that work will be recommended for that part of the rotorcraft at that period. When maintenance tasks are associated with cleaning, inspecting, adjusting, testing or lubrication of each part of the rotorcraft and its engine(s), auxiliary power unit, rotor(s), accessories, instruments and equipment, then those tasks should be included in the ICA. This information is normally contained in the chapters that the work is required.

14. APPLICABLE WEAR TOLERANCES The applicable wear tolerances. Reference Appendix A, A27.3 (b)(1). This is required when applicant determines that wear tolerances will be required for the rotorcraft, its engine(s), rotor(s), and appliances. When a procedure requires maintenance personnel to determine whether the item being inspected or maintained meets a standard, the ICA should include the standard and specify how much wear is acceptable. The tolerances are normally contained in the chapter addressing the tolerance.

15. TROUBLESHOOTING Troubleshooting information describing:

a. Probable malfunctions.

b. How to recognize those malfunctions. (Probable Cause). Some malfunctions could be identified on the basis of a baseline vibration signature provided as follows in the maintenance manual:

The baseline vibration characteristics of the basic aircraft configuration to be used for maintenance or trouble shooting purposes should be provided as the vibratory aircraft reference in the maintenance manual. These characteristics should be given for specified loading and flight conditions (speed, altitude) with vibration pickups at specified airframe locations decided by the manufacturer. The characteristics should be given as a typical range of vibration levels at these locations and for the most representative frequencies and directions for the rotorcraft concerned (N omega main rotor and n omega tail rotor...). The manufacturers and operators should keep the basic vibration data updated from field/service experience.

c. The remedial (corrective) action for those malfunctions.

Reference Appendix A, A27.3 (b)(2). This is required when applicant determines the rotorcraft, its engine(s), rotor(s), and appliances require troubleshooting.

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AC 27-1B, Chg 1 2/12/03 (MANUAL IDENTIFICATION)

REQUIREMENTS (Continued)

d. The use of a table is recommended. A sample is shown below Malfunction Probable Cause Corrective Action Describe the malfunction. List all probable causes of the Provide a corrective action for malfunction. all probable causes.

e. Troubleshooting information is normally contained in the chapters where troubleshooting is required.

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(MANUAL IDENTIFICATION)

REQUIREMENTS (Continued)

16. ORDER AND METHOD OF REMOVAL Information describing the order and method of removal of products and parts with any necessary precautions to be taken. Reference Appendix A, A27.3 (b)(3). This is required when products and parts can be removed as part of maintenance. This includes the removal of products and parts in conjunction with a repair.

a. The order is a step-by-step procedure: what is the first thing you do, then what is next, until the product or part is removed.

b. The method is the procedure or process used to remove the product or part. If the removal of a product or part could result in injury to personnel or damage to the rotorcraft if not done correctly, the ICA should include precaution. See Chapter1, Paragraph 13.

c. The information is normally contained in the chapters requiring removal of the product or part.

17. ORDER AND METHOD OF REPLACING Information describing the order and method of replacing products and parts with any necessary precautions to be taken. Reference Appendix A, A27.3 (b)(3). This is required when products and parts can be replaced.

a. The order is a step by step procedure, what is the first thing you do, then what is next until the product or part is replaced (reinstalled).

b. The method is the procedure or process used to replace (reinstall) the product or part. If the replacement of a product or part could result in injury to personnel or damage to the rotorcraft if not done correctly, the ICA should include precaution. See Chapter 1 Paragraph 13.

c. The use of the phrase "Install in reverse order" does not meet the requirements of the FAR/JAR and should not be used in the ICA.

d. The information is normally contained in the chapters requiring replacement of the part.

18. GENERAL PROCEDURAL INSTRUCTIONS -TESTING General procedural instructions including procedures for system testing during ground run.

Reference Appendix A, A27.3 (b)(4). This is required when system testing during ground run is specified. The information is normally contained in the chapters requiring the test, or applicant may have a section for special inspections, tests, and checks.

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AC 27-1B, Chg 1 2/12/03 (MANUAL IDENTIFICATION) REQUIREMENTS (continued)

19. GENERAL PROCEDURAL INSTRUCTIONS - CHECKS General procedural instructions including procedures for symmetry checks. Reference Appendix A, A27.3 (b)(4). This is required when applicant specifies that symmetry checks are required. The information is normally contained in the chapters addressing the symmetry checks, or applicant may have a section for special inspections, tests, and checks.

20. STORAGE LIMITATIONS Storage Limitations. Reference Appendix A, A27.3 (b)(3). This is required when the rotorcraft, engine, appliance manufacturer, or consumable materials manufacturer determines there is a storage limitation.

a. There are various storage limitations. The applicant needs to identify those storage limitations, provide procedure for storage and a means to ensure the storage limitations are not exceeded.

b. The information is normally contained in the chapter specifying the storage.

21. SPECIAL INSPECTION TECHNIQUES. Details for the application of special inspection techniques including radiographic and ultrasonic testing where such processes are required.

Reference Appendix A, A27.3 (d). This is required when applicant specifies special inspection techniques will be required.

a. The ICA should include the equipment required for the special inspection.

b. The ICA should include the procedure for conducting tests, including any precautions. See Chapter 1, Paragraph 13.

c. The information is normally contained in the chapters requiring special inspection techniques, or the applicant may have a section for special inspections, tests, and checks.

22. PROTECTIVE TREATMENT Information needed to apply protective treatment to a structure after inspection. Reference Appendix A, A27.3 (e). This is required when applicant determines protective treatment will be required for structure.

a. The ICA should include procedures for applying protective treatment.

b. The ICA should specify type of materials to be used.

c. The ICA should include the precautions associated with the protective treatment.

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(MANUAL IDENTIFICATION) REQUIREMENTS (continued)

d. The information is normally contained in the chapters that require the treatment.

23. STRUCTURAL FASTENERS Information relative to structural fasteners such as identification of structural fasteners, structural fasteners discard recommendations, and torque values. Reference Appendix A,

127.3 (f). This is required when structural fasteners are used and torque values are required.

a. The ICA should identify all structural fasteners i.e. rivets, screws, bolts or others.

b. The ICA should specify the requirements for discarding structural fasteners

c. When a structural fastener is required to be torqued, the ICA should contain those specific torques and the procedure to torque the structural fastener.

d. Torque values must be specific and in United States or Metric Standards .

e. Ihe information is normally contained in the chapters specifying structural fasteners and torque values.

24. SPECIAL TOOLS A List of Special Tools. Reference Appendix A, A27.3 (g). This is required when special tools or equipment are specified in the chapters of the ICA.

a. When a procedure in the ICA requires the use of a special tool(s) that tool should be listed in the List of Special Tools.

b. The List of Special Tools is normally contained in the Introduction.

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AC 27-1B, Chg 1 2/12/03 (MANUAL IDENTIFICATION) ATTACHMENT 1 PART 27 REQUIREMENTS The following is a breakdown of Appendix A to FAR/JAR Part 27 and is intended to provide guidance to assist an applicant for a Type Design Change under a Type Certificate (TC), Supplemental Type Certificate (STC), or Field Approval (FA) requiring Instructions for Continued Airworthiness (ICA). This breakdown is intended to provide guidance to assist an applicant in understanding the ICA requirements of § 27.1529. An applicant may use the guidance to prepare the ICA. Completion of this appendix will provide information needed for the evaluation and will reduce the time required for evaluation of the proposed ICA. The open parentheses ( ) in the Requirement Column indicates the status of ICA Requirements: Y = applicable; N/A = non-applicable. In the Location Column, list the page number in the Applicant's ICA that contains the information.

Project Numbers) ACO/FSDO Project Engineer Applicant Make Model Date Requirement Regulation Location ) ICA for each engine A27.1(b) ( ) ICA for each rotor A27.1(b) () ICA for each appliance required by this chapter A27.1(b) ( ) Any required information relating to the interface of the A27.1(b) ( ) appliances, ( ) engines and ( ) rotors with the rotorcraft.

( ) If ICA are not supplied by the manufacturer of an ( ) A27.1 appliance, ( ) engine or ( ) rotor installed in the rotorcraft, the ICA for the rotorcraft must include ( ) the information essential to the continued airworthiness of the rotorcraft.

) A program showing how changes to the applicant's ICA will be A27.1(c) distributed.

() A program showing how changes to the ICA of the A27.1(c) manufacture of the engine(s), rotor(s) and appliances installed in the rotorcraft will be distributed, if referenced in applicant's ICA () ICA that must be in a form of a manual or manuals as A27.2(a) appropriate for the quantity of data.

( ) A format of the manual or manuals which must provide for a 427.2(b) practical arrangement.

( Content prepared in the English language. A27.3 ( ) Introduction information that includes ( ) an explanation of A27.3(a) (1) the rotorcraft's features and ( ) data to the extent necessary for maintenance and preventive maintenance.

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(MANUAL IDENTIFICATION) ATTACHMENT 1 PART 27 REQUIREMENTS Requirement Regulation Location ( ) A description of the ( ) rotorcraft and its systems and A27.3(a) (2) installations, ( ) engines and its systems and installations, () rotors and its systems and installations, and ) appliances and its systems and installations.

( ) Basic control and operating information describing ( ) how A27.3(a) (3) the rotorcraft components and systems are controlled and ( ) how the rotorcraft components and systems are operated including ( ) any special procedure and limitations.

( ) Servicing information that covers details regarding ( ) A27.3 (a) (4) servicing points, ( ) capacities of tanks, ( ) capacities of reservoirs, ( ) types of fluids to be used, and ( ) pressures applicable to the various systems.

( ) Location of access panels for ( ) inspection and ( ) A27.3 (a) (4) servicing.

( ) Servicing information that covers details regarding ( ) A27.3(a) (4) locations of lubrication points, and ( ) the lubricant to be used.

) Equipment required for servicing. A27.3(a) (4) ) Tow instructions and limitations. A27.3(a) (4) ) Mooring information A27.3(a) (4) ) Jacking information A27.3(a) (4) Leveling information A27.3(a)(4) ( ) Scheduling information for each part of the ( ) rotorcraft A27.3(b)(1) that, provides the recommended periods at which they should be f ) cleaned, ( ) inspected, ( ) adjusted, ( ) tested, lubricated and ( ) the work recommended at these periods.

) Scheduling information for the ( ) rotorcraft's engine(s) that A27.3(b)(1) provides the recommended periods at which they should be ( ) cleaned, ( ) inspected, ( ) adjusted, ( ) tested, lubricated and ( ) the work recommended at these periods.

NOTE: This information may be in the FAA AUTHORITY-accepted engine ICA.

( ) Scheduling information for the ( ) rotorcraft's auxiliary A27.3(b) (1) power unit(s) (APU) that provides the recommended periods at which they should be ( ) cleaned, ( ) inspected, ) adjusted, ( ) tested, ( ) lubricated, and ( ) the work recommended at these periods.

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AC 27-1B, Chg 1 2/12/03 (MANUAL IDENTIFICATION) ATTACHMENT 1 PART 27 REQUIREMENTS Requirement Regulation Location ( ) Scheduling information for the ( ) rotorcraft's rotor(s) that A27.3(b)(1) provides the recommended periods at which they should be ( ) cleaned, ( ) inspected, ( ) adjusted, ( ) tested, ( lubricated, and ) the work recommended at these periods.

( ) Scheduling information for the ( ) rotorcraft's accessories A27.3(b)(1) that provides the recommended periods at which they should be ( ) cleaned, ( ) inspected, ( ) adjusted, ( ) tested, ( ) lubricated, and the work recommended at these periods.

( ) Scheduling information for the ( ) rotorcraft's instruments A27.3(b)(1) that provides the recommended periods at which they should be ( ) cleaned, ( ) inspected, ( ) adjusted, ( ) tested, ( ) lubricated, and ( ) the work recommended at these periods.

( ) Scheduling information for the ( ) rotorcraft's equipment A27.3(b)(1) that provides the recommended periods at which they should ( ) cleaned, ( ) inspected, ( ) aajusted, ( ) testea, ( ) lubricated, and () the work recommended at these periods.

( ) The degree of inspection for each part of the ( ) rotorcraft A27.3(b)(1) and its ( ) engine(s), ( ) auxiliary power unit, ( ) rotor(s), ( ) accessories, ( ) Instruments, and ( ) equipment.

() The applicable wear tolerances A27.3(b)(1) The applicant may refer to an ( accessory, ( ) instrument, or A27.3(b)(1) ( ) equipment manufacturer as the source of this information if the applicant shows ( ) that the item has an exceptionally high degree of complexity requiring specialized maintenance techniques, test equipment, or expertise.

( ) The recommended overhaul periods and necessary cross A27.3(b)(1) references to the Airworthiness Limitation Section.

( ) An inspection program that includes ( ) the frequency and ( A27.3(b)(1) ) extent of the inspection necessary to provide for the continued airworthiness of the rotorcraft.

( ) Troubleshooting information describing ( ) problem A27.3(b)(2) malfunctions, ( ) how to recognize those malfunctions, and ) the remedial action for those malfunctions.

) Information describing the order and method of A27.3(b)(3) ) removing and ( ) replacing engine(s) with any necessary precautions to be taken.

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(MANUAL IDENTIFICATION) ATTACHMENT 1 PART 27 REQUIREMENTS Requirement Regulation Location () Information describing the order and method of A27.3(b) (3) ) removing and ( ) replacing rotor(s) with any necessary precautions to be taken.

( ) Information describing the order and method of A27.3(b)(3) ) removing and ( ) replacing parts with any necessary precautions to be taken.

( ) Other general procedural instructions including A27.3(b)(4) ) storage limitations and procedures for ( ) testing system during ground running, ( ) making symmetry checks, () weighing and determining the center of gravity, ( ) lifting, and ( ) shoring.

( ) Diagrams of structural access plates and information needed to A27.3(c) gain access for inspections when access plates are not provided.

( ) Details for the application of special inspection techniques A27.3 (a) including radiographic and ultrasonic testing where such processes are specified.

() Information needed to apply projective treatment to structure A27.3(e) after inspection.

) All data relative to structural fasteners such as A27.3(f) ) identification, ( ) discarded recommendations, and torque values.

() A list of special tools needed A27.3(g) ( ) The Instructions for Continued Airworthiness must contain a A27.4 section, titled Airworthiness Limitations that is segregated and ( ) clearly distinguishable from the rest of the document. NOTE: The Airworthiness Limitations Section in the applicant's ICA will be evaluated by the appropriate FAA/AUTHORTY.

( ) The Airworthiness Limitations Section must set forth each A27.4 mandatory replacement time, structural inspection procedure approved under § 27.571.

( ) If the Instructions for Continued Airworthiness consist of A27.4 multiple documents, the Airworthiness Limitations Section required by this paragraph must include in the principal manual.

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AC 27-1B, Chg 1 2/12/03 (MANUAL IDENTIFICATION) ATTACHMENT 1 PART 27 REQUIREMENTS Requirement Regulation Location ( ) The Airworthiness Limitations Section must contain a legible A27.4 statement in a prominent location indicating that the Airworthiness Limitations Section is FAA/AUTHORITY-approved and specifies required maintenance and/or inspections. The exact, required wording of this statement is found in the FAR/JAR.

Figure 1 (continued) NOTE: The Airworthiness Limitations Section (ALS) is evaluated and approved by the FAA/AUTHORITY. The applicant's proposed ICA is submitted to the FAA/AUTHORITY.

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(MANUAL IDENTIFICATION)

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