ETSO-C139a A1

• ED Decision 2022/018/R found in: CS-ETSO Amdt 17 - European Technical Standard Orders (Oct 2026)

#### ETSO-C139a A1 *ED Decision 2022/018/R* ##### Audio Systems and Equipment **1 Applicability** This ETSO provides the requirements that Audio Systems and Equipment that are designed and manufactured on or after the date of this ETSO must meet in order to be identified with the applicable ETSO marking. **2 Procedures** 2.1 General The applicable procedures are detailed in CS-ETSO, [Subpart A](#_DxCrossRefBm920220672). 2.2 Specific None. **3 Technical Conditions** 3.1 Basic 3.1.1 Minimum Performance Standard The applicable standard is that provided in RTCA DO‑214A, ‘Audio Systems Characteristics and Minimum Performance Standards for Aircraft Audio Systems and Equipment’, dated 18 December 2013 as modified by Appendix 1 to this ETSO. 3.1.2 Environmental Standard See CS-ETSO, Subpart A, paragraph 2.1. 3.1.3 Software See CS-ETSO, Subpart A, paragraph 2.2. 3.1.4 Airborne Electronic Hardware See CS-ETSO, Subpart A, paragraph 2.3. 3.2 Specific 3.2.1 Failure Condition Classification See CS-ETSO, Subpart A, paragraph 2.4. **4 Marking** 4.1 General See CS-ETSO, Subpart A, paragraph 1.2. 4.2 Specific None. **5 Availability of Referenced Documents** See CS-ETSO, Subpart A, paragraph 3. [Amdt ETSO/11] [Amdt ETSO/17]