CS-25 H25 Instructions for Continued Airworthiness

(See AMC to Appendix H) H25.1 General (a) This Appendix specifies requirements for the preparation of Instructions for Continued Airworthiness as required by CS 25.1529 and CS 25.1729 (b) The Instructions for Continued Airworthiness for each aeroplane must include the Instructions for Continued Airworthiness for each engine and propeller (hereinafter designated ‘products’), for each appliance required by this CS-25 and any required information relating to the interface of those appliances and products with the aeroplane. If Instructions for Continued Airworthiness are not supplied by the manufacturer of an appliance or product installed in the aeroplane, the Instructions for Continued Airworthiness for the aeroplane must include the information essential to the continued airworthiness of the aeroplane. (c) The applicant must consider the effect of ageing structures in the Instructions for Continued Airworthiness (see AMC 20-20). H25.2 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. H25.3 Content The contents of the manual or manuals must be prepared in a language acceptable to the Agency. The Instructions for Continued Airworthiness must contain the following manuals or sections, as appropriate, and information: (a) Aeroplane maintenance manual or section (1) Introduction information that includes an explanation of the aeroplane’s features and data to the extent necessary for maintenance or preventive maintenance. (2) A description of the aeroplane and its systems and installations including its engines, propellers, and appliances. (3) Basic control and operation information describing how the aeroplane components and systems are controlled and how they operate, including any special procedures and limitations that apply. (4) Servicing information that covers details regarding servicing points, capacities of tanks, reservoirs, types of fluids to be used, pressures applicable to the various systems, location of access panels for inspection and servicing, locations of lubrication points, lubricants to be used, equipment required for servicing, tow instructions and limitations, mooring, jacking, and levelling information. (b) Maintenance Instructions (1) Scheduling information for each part of the aeroplane and its engines, auxiliary power units, propellers, accessories, instruments, and equipment that provides the recommended periods at which they should be cleaned, inspected, adjusted, tested, and lubricated, and the degree of inspection, the applicable wear tolerances, and work recommended at these periods. However, reference may be made to information from an accessory, instrument or equipment manufacturer as the source of this information if it is shown 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, an inspection programme that includes the frequency and extent of the inspections necessary to provide for the continued airworthiness of the aeroplane must be included. (2) Troubleshooting information describing probable malfunctions, how to recognise those malfunctions, and the remedial action for those malfunctions. (3) Information describing the order and method of removing and replacing products and parts with any necessary precautions to be taken. (4) Other general procedural instructions including procedures for system testing during ground running, symmetry checks, weighing and determining the centre of gravity, lifting and shoring, and storage limitations. (c) Diagrams of structural access plates and information needed to gain access for inspections when access plates are not provided. (d) Details for the application of special inspection techniques including radiographic and ultrasonic testing where such processes are specified. (e) Information needed to apply protective treatments to the structure after inspection. (f) All data relative to structural fasteners such as identification, discard recommendations, and torque values. (g) A list of special tools needed. H25.4 Airworthiness Limitations Section (a) 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 - (1) Each mandatory modification time, replacement time, structural inspection interval, and related structural inspection procedure approved under CS 25.571; (2) Each mandatory replacement time, inspection interval, related inspection procedure, and all the critical design configuration control limitations approved under CS 25.981 for the fuel tank system. (3) Any mandatory replacement time of EWIS components as defined in CS 25.1701 (see AMC Appendix H 25.4(a)(3)). (4) A limit of validity (LOV) of the engineering data that supports the structural maintenance programme, stated as a total number of accumulated flight cycles or flight hours or both, approved under CS 25.571. Until the full-scale fatigue testing is completed and the LOV is approved, the Airworthiness Limitations Section must specify an interim limitation restricting aircraft operation to not more than half the number of the cycles accumulated on the fatigue test article. (5) Each Certification Maintenance Requirement established to comply with any of the applicable requirements of CS-25 (see AMC 25-19). (6) Each mandatory replacement time, inspection interval, and related inspection and test procedure, and each critical design configuration control limitation for each lightning protection feature approved under CS 25.954. (b) If the Instructions for Continued Airworthiness consist of multiple documents, the section required by this paragraph must be included in the principal manual. This section must contain a legible statement in a prominent location that reads: ‘The Airworthiness Limitations Section is approved and variations must also be approved’. H25.5 Electrical Wiring Interconnection System Instructions for Continued Airworthiness The applicant must prepare Instructions for Continued Airworthiness applicable to Electrical Wiring Interconnection System as defined in CS 25.1701. (see AMC Appendix H 25.5) H25.6 Information system security Instructions for Continued Airworthiness The applicant must prepare Instructions for Continued Airworthiness (ICA) that are applicable to aircraft information system security protection as required by CS 25.1319 (see AMC 20-42 Section 9).