PART 35--AIRWORTHINESS STANDARDS: PROPELLERS Subpart A--General Sec. 35.1 Applicability. 35.3 Instruction manual for installing and operating the propeller. 35.4 Instructions for continued airworthiness. 35.5 Propeller operating limitations. Subpart B--Design and Construction 35.11 Applicability. 35.13 General. 35.15 Design features. 35.17 Materials. 35.19 Durability. 35.21 Reversible propellers. 35.23 Pitch control and indication. Subpart C--Tests and Inspections 35.31 Applicability. 35.33 General. 35.35 Blade retention test. 35.37 Fatigue limit tests. 35.39 Endurance test. 35.41 Functional test. 35.42 Blade pitch control system component test. 35.43 Special tests. 35.45 Teardown inspection. 35.47 Propeller adjustments and parts replacements. Appendix A--Instructions for Continued Airworthiness Authority: Secs. 313, 601, 603, 72 Stat. 752, 775; 49 U.S.C. 1354, 1421, 1423. Source: Docket No. 2095, 29 FR 7458, June 10, 1964, unless otherwise noted. Subpart A--General Sec. 35.1 Applicability. (a) This part prescribes airworthiness standards for the issue of type certificates and changes to those certificates, for propellers. (b) Each person who applies under Part 21 for such a certificate or change must show compliance with the applicable requirements of this part. [Amdt. 35-3, 41 FR 55475, Dec. 20, 1976] Sec. 35.3 Instruction manual for installing and operating the propeller. Each applicant must prepare and make available an approved manual or manuals containing instructions for installing and operating the propeller. [Amdt. 35-5, 45 FR 60181, Sept. 11, 1980] Sec. 35.4 Instructions for continued airworthiness. The applicant must prepare Instructions for Continued Airworthiness in accordance with Appendix A to this part that are acceptable to the Administrator. The instructions may be incomplete at type certification if a program exists to ensure their completion prior to delivery of the first aircraft with the propeller installed, or upon issuance of a standard certificate of airworthiness for an aircraft with the propeller installed, whichever occurs later. [Amdt. 35-5, 45 FR 60181, Sept. 11, 1980] Sec. 35.5 Propeller operating limitations. Propeller operating limitations are established by the Administrator, are included in the propeller type certificate data sheet specified in Sec. 21.41 of this chapter, and include limitations based on the operating conditions demonstrated during the tests required by this part and any other information found necessary for the safe operation of the propeller. [Amdt. 35-5, 45 FR 60182, Sept. 11, 1980] Subpart B--Design and Construction Sec. 35.11 Applicability. This subpart prescribes the design and construction requirements for propellers. Sec. 35.13 General. Each applicant must show that the propeller concerned meets the design and construction requirements of this subpart. Sec. 35.15 Design features. The propeller may not have design features that experience has shown to be hazardous or unreliable. The suitability of each questionable design detail or part must be established by tests. Sec. 35.17 Materials. The suitability and durability of materials used in the propeller must-- (a) Be established on the basis of experience or tests; and (b) Conform to approved specifications (such as industry or military specifications, or Technical Standard Orders) that ensure their having the strength and other properties assumed in the design data. (Secs. 313(a), 601, and 603, 72 Stat. 752, 775, 49 U.S.C. 1354(a), 1421, and 1423; sec. 6(c), 49 U.S.C. 1655(c)) [Amdt. 35-4, 42 FR 15047, Mar. 17, 1977] Sec. 35.19 Durability. Each part of the propeller must be designed and constructed to minimize the development of any unsafe condition of the propeller between overhaul periods. Sec. 35.21 Reversible propellers. A reversible propeller must be adaptable for use with a reversing system in an airplane so that no single failure or malfunction in that system during normal or emergency operation will result in unwanted travel of the propeller blades to a position substantially below the normal flight low-pitch stop. Failure of structural elements need not be considered if the occurrence of such a failure is expected to be extremely remote. For the purposes of this section the term "reversing system" means that part of the complete reversing system that is in the propeller itself and those other parts that are supplied by the applicant for installation in the aircraft. Sec. 35.23 Pitch control and indication. (a) No loss of normal propeller pitch control may cause hazardous overspeeding of the propeller under intended operating conditions. (b) Each pitch control system that is within the propeller, or supplied with the propeller, and that uses engine oil for feathering, must incorporate means to override or bypass the normally operative hydraulic system components so as to allow feathering if those components fail or malfunction. (c) Each propeller approved for installation on a turbopropeller engine must incorporate a provision for an indicator to indicate when the propeller blade angle is below the flight low pitch position. The provision must directly sense the blade position and be arranged to cause an indicator to indicate that the blade angle is below the flight low pitch position before the blade moves more than 8 deg. below the flight low pitch stop. [Amdt. 35-2, 32 FR 3737, Mar. 4, 1967, as amended by Amdt. 35--5, 45 FR 60182, Sept. 11, 1980] Subpart C--Tests and Inspections Sec. 35.31 Applicability. This subpart prescribes the tests and inspections for propellers and their essential accessories. Sec. 35.33 General. (a) Each applicant must show that the propeller concerned and its essential accessories complete the tests and inspections of this subpart without evidence of failure or malfunction. (b) Each applicant must furnish testing facilities, including equipment, and competent personnel, to conduct the required tests. Sec. 35.35 Blade retention test. The hub and blade retention arrangement of propellers with detachable blades must be subjected to a centrifugal load of twice the maximum centrifugal force to which the propeller would be subjected during operations within the limitations established for the propeller. This may be done by either a whirl test or a static pull test. (Secs. 313(a), 601, and 603, 72 Stat. 752, 775, 49 U.S.C. 1354(a), 1421, and 1423; sec. 6(c), 49 U.S.C. 1655(c)) [Amdt. 35-4, 42 FR 15047, Mar. 17, 1977] Sec. 35.37 Fatigue limit tests. A fatigue evalution must be made and the fatigue limits determined for each metallic hub and blade, and each primary load carrying metal component of nonmetallic blades. The fatigue evaluation must include consideration of all reasonably foreseeable vibration load patterns. The fatigue limits must account for the permissible service deteriortion (such as nicks, grooves, galling, bearing wear, and variations in material properties). [Amdt. 35-5, 45 FR 60182, Sept. 11, 1980] Sec. 35.39 Endurance test. (a) Fixed-pitch wood propellers. Fixed-pitch wood propellers must be subjected to one of the following tests: (1) A 10-hour endurance block test on an engine with a propeller of the greatest pitch and diameter for which certification is sought at the rated rotational speed. (2) A 50-hour flight test in level flight or in climb. At least five hours of this flight test must be with the propeller operated at the rated rotational speed, and the remainder of the 50 hours must be with the propeller operated at not less than 90 percent of the rated rotational speed. This test must be conducted on a propeller of the greatest diameter for which certification is requested. (3) A 50-hour endurance block test on an engine at the power and propeller rotational speed for which certification is sought. This test must be conducted on a propeller of the greatest diameter for which certification is requested. (b) Fixed-pitch metal propellers and ground adjustable-pitch propellers. Each fixed-pitch metal propeller or ground adjustable-pitch propeller must be subjected to the test prescribed in either paragraph (a)(2) or (a)(3) of this section. (c) Variable-pitch propellers. Compliance with this paragraph must be shown for a propeller of the greatest diameter for which certification is requested. Each variable-pitch propeller (a propeller the pitch setting of which can be changed by the flight crew or by automatic means while the propeller is rotating) must be subjected to one of the following tests: (1) A 100-hour test on a representative engine with the same or higher power and rotational speed and the same or more severe vibration characteristics as the engine with which the propeller is to be used. Each test must be made at the maximum continuous rotational speed and power rating of the propeller. If a takeoff rating greater than the maximum continuous rating is to be established, and additional 10-hour block test must be made at the maximum power and rotational speed for the takeoff rating. (2) Operation of the propeller throughout the engine endurance tests prescribed in Part 33 of this subchapter. [Doc. No. 2095, 29 FR 7458, June 10, 1964, as amended by Amdt. 35-2, 32 FR 3737, Mar. 4, 1967; Amdt. 35-3, 41 FR 55475, Dec. 20, 1976] Sec. 35.41 Functional test. (a) Each variable-pitch propeller must be subjected to the applicable functional tests of this section. The same propeller used in the endurance test must be used in the functional tests and must be driven by an engine on a test stand or on an aircraft. (b) Manually controllable propellers. 500 complete cycles of control must be made throughout the pitch and rotational speed ranges. (c) Automatically controllable propellers. 1,500 complete cycles of control must be made throughout the pitch and rotational speed ranges. (d) Feathering propellers. 50 cycles of feathering operation must be made. (e) Reversible-pitch propellers. Two hundred complete cycles of control must be made from lowest normal pitch to maximum reverse pitch, and, while in maximum reverse pitch, during each cycle, the propeller must be run for 30 seconds at the maximum power and rotational speed selected by the applicant for maximum reverse pitch. [Doc. No. 2095, 29 FR 7458, June 10, 1964, as amended by Amdt. 35-3, 41 FR 55475, Dec. 20, 1976] Sec. 35.42 Blade pitch control system component test. The following durability requirements apply to propeller blade pitch control system components: (a) Except as provided in paragraph (b) of this section, each propeller blade pitch control system component, including governors, pitch change assemblies, pitch locks, mechanical stops, and feathering system components, must be subjected in tests to cyclic loadings that simulate the frequency and amplitude those to which the component would be subjected during 1,000 hours of propeller operation. (b) Compliance with paragraph (a) of this section may be shown by a rational analysis based on the results of tests on similar components. [Amdt. 35-5, 45 FR 60182, Sept. 11, 1980] Sec. 35.43 Special tests. The Administrator may require any additional tests he finds necessary to substantiate the use of any unconventional features of design, material, or construction. Sec. 35.45 Teardown inspection. (a) After completion of the tests prescribed in this subpart, the propeller must be completely disassembled and a detailed inspection must be made of the propeller parts for cracks, wear, distortion, and any other unusual conditions. (b) After the inspection the applicant must make any changes to the design or any additional tests that the Administrator finds necessary to establish the airworthiness of the propeller. [Doc. No. 3095, 29 FR 7458, June 10, 1964, as amended by Amdt. 35-3, 41 FR 55475, Dec. 20, 1976] Sec. 35.47 Propeller adjustments and parts replacements. The applicant may service and make minor repairs to the propeller during the tests. If major repairs or replacement of parts are found necessary during the tests or in the teardown inspection, the parts in question must be subjected to any additional tests the Administrator finds necessary. Appendix A--Instructions for Continued Airworthiness A35.1 GENERAL (a) This appendix specifies requirements for the preparation of Instructions for Continued Airworthiness as required by Sec. 35.4. (b) The Instructions for Continued Airworthiness for each propeller must include the Instructions for Continued Airworthiness for all propeller parts. If Instructions for Continued Airworthiness are not supplied by the propeller part manufacturer for a propeller part, the Instructions for Continued Airworthiness for the propeller must include the information essential to the continued airworthiness of the propeller. (c) The applicant must submit to the FAA a program to show how changes to the Instructions for Continued Airworthiness made by the applicant or by the manufacturers of propeller parts will be distributed. A35.2 FORMAT (a) The Instructions for Continued Airworthiness must be in the form of a manual or manuals as appropriate for the quantity of data to be provided. (b) The format of the manual or manuals must provide for a practical arrangement. A35.3 CONTENT The contents of the manual must be prepared in the English language. The Instructions for Continued Airworthiness must contain the following sections and information: (a) Propeller Maintenance Section. (1) Introduction information that includes an explanation of the propeller's features and data to the extent necessary for maintenance or preventive maintenance. (2) A detailed description of the propeller and its systems and installations. (3) Basic control and operation information describing how the propeller components and systems are controlled and how they operate, including any special procedures that apply. (4) Instructions for uncrating, acceptance checking, lifting, and installing the propeller. (5) Instructions for propeller operational checks. (6) Scheduling information for each part of the propeller that provides the recommended periods at which it should be cleaned, adjusted, and tested, the applicable wear tolerances, and the degree of work recommended at these periods. However, the applicant may refer to an accessory, instrument, or equipment manufacturer as the source of this information if it 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-references to the Airworthiness Limitations section of the manual must also be included. In addition, the applicant must include an inspection program that includes the frequency and extent of the inspections necessary to provide for the continued airworthiness of the propeller. (7) Troubleshooting information describing probable malfunctions, how to recognize those malfunctions, and the remedial action for those malfunctions. (8) Information describing the order and method of removing and replacing propeller parts with any necessary precautions to be taken. (9) A list of the special tools needed for maintenance other than for overhauls. (b) Propeller Overhaul Section. (1) Disassembly information including the order and method of disassembly for overhaul. (2) Cleaning and inspection instructions that cover the materials and apparatus to be used and methods and precautions to be taken during overhaul. Methods of overhaul inspection must also be included. (3) Details of all fits and clearances relevant to overhaul. (4) Details of repair methods for worn or otherwise substandard parts and components along with information necessary to determine when replacement is necessary. (5) The order and method of assembly at overhaul. (6) Instructions for testing after overhaul. (7) Instructions for storage preparation including any storage limits. (8) A list of tools needed for overhaul. A35.4 AIRWORTHINESS LIMITATIONS SECTION The Instructions for Continued Airworthiness must contain a section titled Airworthiness Limitations that is segregated and clearly distinguishable from the rest of the document. This section must set forth each mandatory replacement time, inspection interval, and related procedure required for type certification. This section must contain a legible statement in a prominent location that reads: "The Airworthiness Limitations section is FAA approved and specifies maintenance required under Secs. 43.16 and 91.403 of the Federal Aviation Regulations unless an alternative program has been FAA approved." [Amdt. 35-5, 45 FR 60182, Sept. 11, 1980, as amended by Amdt. 35-6, 54 FR 34330, Aug. 18, 1989] Effective Date Note: At 54 FR 34330, Aug. 18, 1989, Sec. A35.4 in Appendix A, Part 35 was amended by changing the cross reference "Sec. 91.163" to "Sec. 91.403", effective August 18, 1990.