ETSO-2C41d

• ED Decision 2003/10/RM found in: CS-ETSO Amdt 17 - European Technical Standard Orders (Oct 2026)

#### ETSO-2C41d *ED Decision 2003/10/RM* ##### **Airborne Automatic Direction Finding (ADF) Equipment** **1 Applicability** This ETSO gives the requirements which airborne automatic direction finding equipment that is 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 EUROCAE document ED-51 (1983 rev. 1987) or RTCA DO-179 plus additions shown paragraph 3.2 below. 3.1.2 Environmental Standard See CS-ETSO Subpart A paragraph 2.1 3.1.3 Computer Software See CS-ETSO Subpart A paragraph 2.2 3.2 Specific Radio Technical Commission for Aeronautics (RTCA) Document DO-179 (1982), used in US TSO-C41d differs from EUROCAE document ED-51 as follows: — ED-51 demands tuning increments of 0.5 kHz or less to match the European NDB frequency scheme (500 Hz channels), DO-179 demands increments of 1 kHz. **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.