IRImplementing rule
ETSO-C121b
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.
- 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 '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]
IR · ETSO-C121b — CS-ETSO · ED Decision 2013/012/R · CS-ETSO Easy Access Rules · EAR revision 14 Aug 2026