---
title: "ETSO-C154c — CS-ETSO · Avioverse"
description: "Universal Access Transceiver (UAT) Automatic Dependent Surveillance - Broadcast (ADS-B) Equipment Operating on the Frequency of 978 MHz 1 Applicability…"
url: "https://avioverse.aero/regulations/easa/cs-etso/subpart-b/etso-c154c"
---

# ETSO-C154c

European Technical Standard Orders (CS-ETSO) · CS-ETSO · EAR revision 1 Oct 2026

IR Implementing rule

## ETSO-C154c

Universal Access Transceiver (UAT) Automatic Dependent Surveillance - Broadcast (ADS-B) Equipment Operating on the Frequency of 978 MHz 1 Applicability

This ETSO gives the requirements which Universal Access Transceiver (UAT) Automatic Dependent Surveillance - Broadcast (ADS-B) Equipment Operating on the Frequency of 978 MHz 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 Radio Technical Commission for Aeronautics (RTCA) Document DO-282B, Minimum Operational Performance Standards for Universal Access Transceiver (UAT) Automatic Dependent Surveillance Broadcast (ADS-B), dated 02/12/2009.

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.

3.1.4 Electronic Hardware Qualification

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.

Failure of the function defined in paragraph 3.1.1 of this ETSO has been determined to be a major failure condition.

4 Marking

4.1 General

Marking as detailed in CS-ETSO Subpart A paragraph 1.2.

4.2 Specific

Transmitting and receiving components must be permanently and legibly marked. The following table explains how to mark components. Find the equipment class in RTCA/DO-282B, Section 2.1.11.

| If component can:                                                          | Mark it with:                                                                                                                                                                                                                  | Sample marking pattern:              |
| -------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------ |
| Transmit and receive                                                       | Equipment class it supports                                                                                                                                                                                                    | Class A1H or Class A3                |
| Transmit, but not receive                                                  | Equipment class it supports                                                                                                                                                                                                    | Class B1 or Class A3 - Transmit Only |
| Receive, but not transmit                                                  | Equipment class it supports                                                                                                                                                                                                    | Class A2 - Receive Only              |
| Perform the optional frequency diplexer function developed under this ETSO | The words “UAT Diplexer,” Maximum amplitude attenuation between the antenna port (A) and UAT port (U) of the diplexer, and Maximum amplitude attenuation between the antenna port (A) and transponder port (T) of the diplexer | UAT Diplexer A/U -0.x dB A/T -0.x dB |

5 Availability of Referenced Document

See CS-ETSO Subpart A paragraph 3.

\[Amdt ETSO/7]

IR · ETSO-C154c — CS-ETSO · ED Decision 2012/009/R · CS-ETSO Easy Access Rules · EAR revision 1 Oct 2026

[All rules in SUBPART B – LIST OF ETSOs](https://avioverse.aero/regulations/easa/cs-etso/subpart-b)

Consolidated from the EASA Easy Access Rules (revision 1 Oct 2026, extracted 13 Oct 2026) for convenience. Not the official publication — verify against the Official Journal of the European Union and the EASA publications before operational use.