1.1 本规程为金属结构的损伤容限评估提供了一般指导。此信息可与规范结合使用 3115英尺/3115米 以证明足够的结构耐久性。某些级别的飞机需要进行损伤容限评估，而其他级别则可选择进行损伤容量评估；见规范 3115英尺/3115米 对于这些要求。该材料是通过国际通用航空专家的公开共识开发的。内容可能更广泛地适用；申请人有责任证明更广泛的适用性是一种具体的合规手段。 1.2 有意将此信息作为设计批准的合规手段的申请人必须就其可接受的使用和应用向其各自的监督机构寻求指导（例如，适用民航当局或CAA发布的指导）。 有关哪些监督机构已接受本标准（全部或部分）作为其监管要求（以下简称“规则”）的可接受合规手段的信息，请参阅ASTM委员会F44网页（www.ASTM.org/COMMITTE/F44.htm）。 1.3 单位-- 这种做法可以用国际单位制、英制工程单位或两者同时表示信息；每个系统中所述的值可能不是完全等效的。每个系统应独立使用；合并两个系统的值可能会导致不符合标准。 1.4 本标准并不旨在解决与其使用相关的所有安全问题（如果有的话）。 本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 1.5 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 =====意义和用途====== 4.1 本规程为损伤容限评估提供了一般指导，可与规范结合使用 3115英尺/3115米 以证明金属结构具有足够的结构耐久性。本实践的用户必须向其CAA寻求指导，以了解本文所提供的指导材料的适用性和接受程度，作为合规的一种方式。 4.1.1 4级飞机和最大运行高度大于41000英尺[12497米]的加压飞机需要进行损伤容限评估。 4.1.2 对于1级、2级或3级飞机，当申请人选择损伤容限作为认证依据时，其损伤容限评估的范围，包括对广泛疲劳损伤的评估，可以根据其相关CAA的指导来确定。

1.1 This practice provides general guidance for damage tolerance evaluation of metallic structures. This information can be used in conjunction with Specification F3115/F3115M to demonstrate adequate structural durability. Damage tolerance evaluation is required for some aircraft levels and is available as an option for other levels; see Specification F3115/F3115M for those requirements. The material was developed through open consensus of international experts in general aviation. The content may be more broadly applicable; it is the responsibility of the applicant to substantiate broader applicability as a specific means of compliance. 1.2 An applicant intending to propose this information as Means of Compliance for a design approval must seek guidance from their respective oversight authority (for example, published guidance from applicable civil aviation authorities, or CAAs) concerning the acceptable use and application thereof. For information on which oversight authorities have accepted this standard (whole or in part) as an acceptable Means of Compliance to their regulatory requirements (hereinafter “the Rules”), refer to the ASTM Committee F44 web page (www.astm.org/COMMITTEE/F44.htm). 1.3 Units— This practice may present information in either SI units, English Engineering units, or both; the values stated in each system may not be exact equivalents. Each system shall be used independently of the other; combining values from the two systems may result in nonconformance with the standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 4.1 This practice provides general guidance for damage tolerance evaluation that can be used in conjunction with Specification F3115/F3115M to demonstrate adequate structural durability of metallic structures. Users of this practice must seek guidance from their CAAs for applicability and acceptance on guidance materials presented herein as one means of compliance. 4.1.1 Damage tolerance evaluation is required for Level 4 aeroplanes, and for pressurized aeroplanes with maximum operating altitude greater than 41 000 feet [12 497 meters]. 4.1.2 For Levels 1, 2, or 3 aeroplanes when an applicant selects damage tolerance as certification basis, the scope of their damage tolerance evaluation, including assessment for widespread fatigue damage, can be defined in accordance with the guidance from their relevant CAA.