ETSO-C121b

• ED Decision 2013/012/R found in: CS-ETSO Amdt 17 - European Technical Standard Orders (Oct 2026)

#### ETSO-C121b *ED Decision 2013/012/R* ##### **Underwater Locating Device (Acoustic) (Self-powered)** **1 Applicability** This ETSO gives the requirements which Underwater Locating Device (Acoustic) (Self-Powered) that are 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 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 Standards set forth in the SAE AS8045A, Minimum Performance Standard for Underwater Locating Devices (Acoustic) (Self-Powered), dated August 2011. 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 The battery used in the underwater locating device authorized under this ETSO must be appropriate for the intended operational environment, not pose a hazard to the aircraft and meet the requirements of acceptable battery standards. If non-rechargeable lithium batteries are used to power the underwater locating device, [ETSO-C142a](#_DxCrossRefBm920220844) “Lithium Batteries” provides MPS for such lithium batteries. Demonstrate the saltwater immersion tests in SAE Document AS8045A, section 5.13, using a seawater solution meeting the requirements of ASTM D1141-98, Standard Practice for the Preparation of Substitute Ocean Water, dated 2008. 3.2.1 Failure condition classification See CS-ETSO, Subpart A, paragraph 2.4. Failure or loss of the function defined in paragraph 3.1.1 of this ETSO has been determined to be a minor failure condition. **4 Marking** 4.1 General Marking is detailed in CS-ETSO, Subpart A, paragraph 1.2. 4.2 Specific None. **5 Availability of referenced document** See CS-ETSO, Subpart A, paragraph 3. [Amdt ETSO/3] [Amdt ETSO/8]