Appendix 1 to ETSO-C139a A1 -- Correction to RTCA DO-214A, 'Audio Systems Characteristics and Minimum Performance Standards for Aircraft Audio Systems and Equipment'

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

###### Appendix 1 to ETSO-C139a A1 — Correction to RTCA DO-214A, ‘Audio Systems Characteristics and Minimum Performance Standards for Aircraft Audio Systems and Equipment’ *ED Decision 2022/018/R* **A1.1 Introduction** This Appendix corrects RTCA DO‑214A, ‘Audio Systems Characteristics and Minimum Performance Standards for Aircraft Audio Systems and Equipment’, regarding an optical character recognition error in the value of a test capacitor in a test procedure not detected during the peer review process. The value was ‘1E‑14 F (0.01 pF)’ instead of the required ‘1E-8 F (0.01 µF)’, so it was six orders of magnitude too low for interphone channels. In addition, this Appendix clarifies RTCA DO-214A, ‘Audio Systems Characteristics and Minimum Performance Standards for Aircraft Audio Systems and Equipment’, regarding an ambiguous requirement for the HOT microphone feature in Section 1.4.5. **A1.2 Correction** In Section 2.8.2.9 of RTCA DO-214A, ‘Audio Systems Characteristics and Minimum Performance Standards for Aircraft Audio Systems and Equipment’, ‘0.01 pF’ is replaced by ‘10 nF’. [Amdt ETSO/17]