AMC 25.605(a) Fabrication methods -- Approved process specifications

• ED Decision 2021/015/R found in: CS-25 Amdt 27 - Large Aeroplanes (Jan 2023)

AMC 25.605(a) Fabrication methods — Approved process specifications ED Decision 2021/015/R Examples of fabrication method processes that may require close control to consistently produce safe parts include the following: — castings, — composite resin transfer methods, — bonding, — welding, — heat-treating, or — additive manufacturing methods. Fabrication method process specifications should include all critical inspection steps and/or process controlled steps, and should be substantiated (they may require re-evaluation and new substantiation, if modified later). All the inherent part characteristics that result from the fabrication method and affect the material strength and other properties should be closely correlated with non‑destructive inspection (NDI) and/or process control variables. Furthermore, the applicant should show that the equipment used to support the process-critical manufacturing steps (particularly those steps that are not directly supported and controlled through inspection) is under appropriate process control, to ensure the consistent production of safe parts. Note 1: ‘safe parts’ must comply with [CS 25.603](#_DxCrossRefBm1709821059) and [CS 25.605](#_DxCrossRefBm1709821066) to ensure safety by maintaining the appropriate ‘material strength and other properties’ that are assumed in the design data. Therefore, applicants are reminded that, beyond the consideration of airframe strength, these CSs are also applicable to other applications for which safety relies on strength or stiffness, e.g. system structures. Furthermore, the reference to ‘other properties’ is intended to ensure that safety is also maintained for applications for which safety relies on ‘other properties’ (for example, safe interior cabin parts that rely upon suitable flammability properties). Note 2: approved fabrication process specifications and approved material specifications can be, for example, industry or military specifications, or European Technical Standard Orders (ETSOs). [Amdt No: 25/27]