---
title: "ETSO-C7d — CS-ETSO · Avioverse"
description: "Direction Instrument, Magnetic Non-stabilized Type (Magnetic Compass) 1 Applicability This ETSO gives the requirements which new models of direction…"
url: "https://avioverse.aero/regulations/easa/cs-etso/subpart-b/etso-c7d"
---

# ETSO-C7d

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

IR Implementing rule

## ETSO-C7d

Direction Instrument, Magnetic Non-stabilized Type (Magnetic Compass)

1 Applicability

This ETSO gives the requirements which new models of direction instruments, magnetic non- stabilized type (magnetic compass) 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 Aerospace Standard (AS) document: AS 398A „Direction Instrument, Magnetic Non-Stabilized Type (Magnetic Compass)“, dated July 15, 1958 „reaffirmed October 1984“ (if TSO) except as amended and supplemented by this ETSO:

(i) Conformance with the following paragraphs of AS 398A is not required: 3.1; 3.1.1; 3.1.2; 3.2.

(ii) Substitute the following for paragraph 7 of AS 398A:

„Performance tests: the following tests in addition to any others deemed necessary by the manufacturers, shall be the basis for determining compliance with the performance requirements of this standard.“

3.1.2 Environmental Standard

The environmental conditions and test procedures in SAE AS 398A are to be used.

3.1.3 Computer Software

None

3.2 Specific

None

4 Marking

4.1 General

Marking is detailed in CS-ETSO Subpart A.

4.2 Specific

None.

5 Availability of Referenced Document

See CS-ETSO Subpart A paragraph 3.

IR · ETSO-C7d — CS-ETSO · ED Decision 2003/10/RM · 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.