IRImplementing rule
ETSO-C219a
AIRBORNE COLLISION AVOIDANCE SYSTEM (ACAS) XA/XO
1 Applicability
This ETSO provides the requirements that ACAS Xa/Xo equipment that is 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
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 EUROCAE ED-256 Revision A, ‘Minimum Operational Performance Standards for Airborne Collision Avoidance System X (ACAS X) (ACAS Xa and ACAS Xo)’, dated 28 June 2023.
3.1.2 Environmental Standard
See CS-ETSO, Subpart A, paragraph 2.1, and EUROCAE ED-256 Revision A, Section 2.3.
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.
3.2.1.1 Failure of the function defined in paragraph 3.1.1 of this ETSO that results in misleading information is:
(a)a hazardous failure condition for un-annunciated failures that could either generate an incorrect RA or result in a missing RA;
(b)a major failure condition for un-annunciated failures that could generate a false RA. 3.2.1.2 Failure of the function defined in paragraph 3.1.1 of this ETSO that results in the loss of the function (annunciated) is a minor failure condition.
Note: As used in this paragraph:
— an incorrect RA is when an RA condition exists and an RA is issued but the RA provides incorrect guidance;
— a missing RA is when an RA condition exists but an RA is not issued;
— a false RA is when an RA is issued but an RA condition does not exist.
4 Marking
4.1 General
See 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/18]
IR · ETSO-C219a — CS-ETSO · CS-ETSO Easy Access Rules · EAR revision 1 Oct 2026