ETSO CS-ETSO (Amendment 16)

eRules

Easy Access Rules for European Technical Standard Orders (CS-ETSO) (Amendment 16)

EASA eRules: aviation rules for the 21st century

Rules and regulations are the core of the European Union civil aviation system. The aim of the EASA eRules project is to make them accessible in an efficient and reliable way to stakeholders.

EASA eRules will be a comprehensive, single system for the drafting, sharing and storing of rules. It will be the single source for all aviation safety rules applicable to European airspace users. It will offer easy (online) access to all rules and regulations as well as new and innovative applications such as rulemaking process automation, stakeholder consultation, cross-referencing, and comparison with ICAO and third countries' standards.

To achieve these ambitious objectives, the EASA eRules project is structured in ten modules to cover all aviation rules and innovative functionalities.

The EASA eRules system is developed and implemented in close cooperation with Member States and aviation industry to ensure that all its capabilities are relevant and effective.

Published June 2026 1

1 The published date represents the date when the consolidated version of the document was generated.

DISCLAIMER

This version is issued by the European Aviation Safety Agency (EASA) in order to provide its stakeholders with an updated and easy-to-read publication. It has been prepared by putting together all applicable certification specifications (CS). However, this is not an official publication and EASA accepts no liability for damage of any kind resulting from the risks inherent in the use of this document.

NOTE FROM THE EDITOR

CS paragraph titles are colour-coded and can be identified according to the illustration below. The EASA Executive Director (ED) decision through which the paragraph was introduced or last amended is indicated below the paragraph title(s) in italics .

Certification specification

ED decision

The format of this document has been adjusted to make it user-friendly and for reference purposes. Any comments should be sent to erules@easa.europa.eu.

INCORPORATED AMENDMENTS

CS (ED DECISIONS)

Note: To access the official versions, please click on the hyperlinks provided above.

1 This is the main applicability date defined in the ED Decision. However, the decision allowed that this CS was not applied to applications received until 31 December 2012, if so requested by the applicant and providing that in such a case the applicant could demonstrate that the process of development of the relevant part or appliance started before the entry into force of the ED Decision (5 July 2012), in accordance with the specifications applicable at that time.

2 This is the main applicability date defined in the ED Decision. However, the decision allowed that this CS was not applied to applications received until 31 December 2013, if so requested by the applicant and providing that in such a case the applicant could demonstrate that the process of development of the relevant part or appliance started before the entry into force of the ED Decision (15 July 2013), in accordance with the specifications applicable at that time.

3 This is the main applicability date defined in the ED Decision. However, the decision allowed that this CS was not applied to applications received before 1 July 2018, if so requested by the applicant and providing that in such a case the applicant could demonstrate that the process of development of the relevant part or appliance started before the entry into force of the ED Decision (20 February 2018), in accordance with the specifications applicable at that time.

4 This is the main applicability date defined in the ED Decision. However, this decision shall not apply to applications received by EASA 6 months after the date of entry into force of this Decision, if so requested by the applicant, and provided that in such a case the applicant can demonstrate that the process of development of the relevant part or appliance started before the date of entry into force of this decision and is in accordance with the specifications applicable at that time.

TABLE OF CONTENTS

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PREAMBLE

Amendment 16

The following is a list of paragraphs affected by this amendment:

ED Decision 2020/011/R

Amendment 15

The following is a list of paragraphs affected by this amendment:

ED Decision 2018/008/R

Amendment 14

The following is a list of paragraphs affected by this amendment:

ED Decision 2018/002/R

Amendment 13

The following is a list of paragraphs affected by this amendment:

ED Decision 2020/006/R

Amendment 12

The following is a list of paragraphs affected by this amendment:

ED Decision 2016/013/R

Amendment 11

The following is a list of paragraphs affected by this amendment:

ED Decision 2016/029/R

ED Decision 2016/006/R

Amendment 10

The following is a list of paragraphs affected by this amendment:

ED Decision 2014/010/R

Amendment 9

The following is a list of paragraphs affected by this amendment:

ED Decision 2013/012/R

Amendment 8

The following is a list of paragraphs affected by this amendment:

ED Decision 2012/009/R

Amendment 7

The following is a list of paragraphs affected by this amendment:

Amendment 6

The following is a list of paragraphs affected by this amendment:

ED Decision 2009/015/R

Amendment 5

The following is a list of paragraphs affected by this amendment:

ED Decision 2009/014/R

Amendment 4

The following is a list of paragraphs affected by this amendment:

ED Decision 2010/010/R

Amendment 3

The following is a list of paragraphs affected by this amendment:

ED Decision 2007/017/R

Amendment 2

The following is a list of paragraphs affected by this amendment:

ED Decision 2006/004/R

Amendment 1

The following is a list of paragraphs affected by this amendment:

ED Decision 2008/012/R

1.APPLICABILITY

- 1.1 Requirements for the issue of European Technical Standard Order (ETSO) authorisations are found in Part 21, Section A, Subpart O.

- 1.2 Marking requirements for the issue of European Technical Standard Order (ETSO) authorisations are found in Part 21, Section A, Subpart Q.

2.STANDARDS TO MEET TECHNICAL CONDITIONS

2.1 Environmental standards

Unless otherwise stated in paragraph 3.1.2 of the specific ETSO, the applicable environmental standards are contained in EUROCAE/RTCA document ED-14D, Change 3/DO 160D 'Environmental Conditions and Test Procedures for Airborne Equipment', Change 3, dated December 2002, ED 14E/DO -160E dated March 2005, ED-14F/DO-160F dated March 2008, ED 14G/DO-160G dated December 2010, or ED-14G Change 1/DO-160G Change 1 dated January 2015.

Compliance shall be demonstrated entirely with one of the above versions of the applicable environmental standards.

2.2 Software

If the ETSO article includes the software shall be developed with development assurance. The accepted means of compliance for the development assurance of airborne software is contained in the revision of AMC 20115, entitled 'Airborne Software Development Assurance using EUROCAE ED-12 and RTCA document DO178', that is current at the time of the application, or in any later revision. The use of any other means of compliance shall be subject to a deviation request.

The software level, also known as the 'item development assurance level (IDAL)', should be determined by using the guidance proposed in Section 2.4. The applicant must declare the software level(s) to which the software has been developed and verified.

2.3 Airborne electronic hardware (AEH)

If the ETSO article includes airborne electronic hardware, the airborne electronic hardware shall be developed with development assurance. The accepted means of compliance for the development of airborne electronic hardware is contained in the revision of AMC 20 152 1 , entitled 'Development Assurance for Airborne Electronic Hardware' that is current at the time of the application, or in any later revision. The use of any other means of compliance shall be subject to a deviation request.

The hardware development assurance level (DAL), also known as the 'item development assurance level (IDAL)', should be determined by using the guidance proposed in Section 2.4. The applicant must declare the hardware DAL(s) to which it has been developed and verified.

1 Refer to ED Decision 2020/010/R (https://www.easa.europa.eu/document-library/agency-decisions).

SUBPART A -GENERAL

ED Decision 2020/011/R

2.4 Failure conditions classification and development assurance

During the development of an ETSO article, consideration should be given to failure conditions, and the ETSO article should then be developed in accordance with the possible effects of those failure conditions at the system and aircraft levels (see, for instance, AMC CS xx.1309 or AMC CS 23.2500/2510 for further guidance).

The ETSO article shall be developed according to at least the development assurance level that is appropriate to the failure condition classifications that are expected for the intended installation.

If the effects at the system or aircraft level are not known, due to the non-availability of aircraft or system design data, the applicant should make and declare an assumption for the failure classification. The assumed failure classification should be at least as high as the minimum hazard classification level required in the ETSO.

The classification of failure conditions at the level of the ETSO article may change as a result of particular aircraft installation architectures and characteristics.

EUROCAE/SAE document ED79A/ARP 4754A, 'Guidelines for Development of Civil Aircraft and Systems', dated December 2010, should be used to assign the development assurance levels of the ETSO article, software and AEH. The document should also be used as guidance to ensure that a proper development, validation and verification process is followed for the ETSO article and its functional requirements.

2.5 ETSO article using an ETSO-C153()-authorised IMA platform or module

If the ETSO article implements one (or several) ETSO-C153()-authorised integrated modular avionics (IMA) platforms/modules and the applicant seeks compliance credit from this (these) ETSOA authorisation(s) to demonstrate compliance with one or several functional ETSO standard(s), the applicant shall apply for authorisation to the ETSO-C214 standard, together with the intended functional ETSO standard(s).

Note: A functional ETSO standard is any ETSO standard of CS-ETSO that describes an 'aircraft' function, i.e. typically any ETSO standard, except ETSO-C153() and ETSO-C214.

2.6 Information security protection

An ETSO article may be designed with a security assurance level (SAL) that is appropriate for specified security measures, according to the procedure provided in AMC 20-42.

2.7 Open problem reports (OPRs)

Problem reports that are related to ETSO articles that contain software or airborne electronic hardware shall be identified and managed. The accepted means of compliance for the management of OPRs is contained in the revision of AMC 20-189 1 'Management of Open Problem Reports' that is current at the time of application, or in any later revision. The use of any other means of compliance shall be subject to a deviation request.

1 Refer to ED Decision 2020/010/R (https://www.easa.europa.eu/document-library/agency-decisions).

2.8 Embedded batteries

If an ETSO article embeds a lithium battery whose energy is equal to or greater than 2 Wh, the battery shall be approved in accordance with the applicable battery ETSO. Additionally, when the battery ETSO covers the article embedding the battery, the article shall also be approved in accordance with the applicable battery ETSO.

For rechargeable lithium batteries whose energy is less than 2 Wh, the battery shall comply with the UN Recommendations on the Transport of Dangerous Goods - Model Regulations and shall be certified to UL 1642, UL 2054 or IEC 62133, unless it is shown to meet the requirements of RTCA document DO-311A Energy Category 2.

For non-rechargeable lithium batteries whose energy is less than 2 Wh, the battery shall be certified to UL 1642 and shall comply with the UN Recommendations on the Transport of Dangerous Goods - Model Regulations.

If there is no ETSO that is applicable to a particular battery that an applicant intends to use in an ETSO article, the applicant should contact EASA.

3.ADDITIONAL INFORMATION

- 3.1 In some ETSOs, reference is made to an associated FAA standard. In these cases, the corresponding FAA technical standard order (TSO) can be consulted on http://rgl.faa.gov/Regulatory\_and\_Guidance\_Library/rgTSO.nsf/Frameset?OpenPage.

- 3.2 Standards documents referred to in this CS-ETSO may be purchased or obtained from the following organisations: - -ASD-STAN documents:

AeroSpace and Defence Industries Association of Europe -Standardization

Rue Montoyer 10 - 1000 Brussels

(Email: sales@asd-stan.org, website: www.asd-stan.org)

- -ASTM documents:

American Society for Testing and Materials, ASTM International,

100 Barr Harbor Drive, PO Box C700, West Conshohocken, Pennsylvania 19428-2959, USA

(Website: www.astm.org)

- -ETSI European Telecommunications Standards Institute

650, Route des Lucioles

06560 Valbonne - Sophia Antipolis

FRANCE

Telephone: +33 4 92 94 42 00

(https://www.etsi.org/standards#Pre-defined Collections)

- -EUROCAE documents:

European Organisation for Civil Aviation Equipment

923 rue Paul Lafargue, ''Le Triangle'' building, 93200 Saint -Denis, France

Telephone: +33 1 49 46 19 65

- (Email: eurocae@eurocae.net, website: www.eurocae.net) - -EUROCONTROL Surveillance Document Library:

https://www.eurocontrol.int/articles/surveillance-library

- -FAA standards:

Superintendent of Documents, Government Printing Office 732N Capitol Street NW, Washington DC 20401, USA (Website: www.gpoaccess.gov)

- -FCC Documents:

http://www.fcc.gov

- -Global System, Inc., documents:

- Global Systems, Inc., 2144 Michelson Drive, Irvine, California 92715, USA Telephone: (714) 851-0119 - -International Electrotechnical Commission

https://webstore.iec.ch

- -MIL specifications:

DODSSP, Standardization Documents Order Desk Building 4D, 700 Robbins Avenue, PHILADELPHIA, PA 19111-5094, USA or from the ASSIST Customer Service Desk, telephone (215) 697-6396 (Website: http://quicksearch.dla.mil/)

- -NAS specifications:

Aerospace Industries Association (AIA) 1327 Jones Drive, Ann Arbor, MI 48105, USA (Website: www.techstreet.com)

- -RTCA documents:

Radio Technical Commission for Aeronautics, Inc. 1828 L Street NW, Suite 805, Washington DC 20036, USA (Website: www.rtca.org)

- -SAE documents:

Society of Automotive Engineers, Inc. 400 Commonwealth Drive, WARRENDALE, PA 15096-001, USA (Website: www.sae.org)

- -UN United Nations Economic Commission for Europe transport regulations:

United Nations Bookshop GA-1B-103 New York, NY 10017

USA Tel: +1-212-963-7680 Email: bookshop@un.org (Website: https://www.unece.org/trans/danger/publi/unrec/rev13/13nature\_e.html)

- -UL Underwriters Laboratory standards:

(website: https://standardscatalog.ul.com) [Amdt ETSO/3] [Amdt ETSO/6] [Amdt ETSO/7] [Amdt ETSO/8] [Amdt ETSO/12] [Amdt ETSO/14] [Amdt ETSO/15] [Amdt ETSO/16]

SUBPART B -LIST OF ETSOS

This Subpart contains two Indexes:

1 INDEX 1

- 1.1 Index 1 lists all those ETSOs which are technically similar to FAA-TSOs.

- 1.2 When an article has been approved by the Agency to an ETSO listed in Index 1 the article is to be permanently marked with the appropriate ETSO number. Also, all documentation associated with Certification and Release for installation on an aircraft must record this ETSO number. The 'E' Symbol signifies that the article has been certified to the relevant ETSO by the Agency.

- 1.3 Index 1 lists all those ETSOs whose functional requirements are equivalent to those of the corresponding FAA TSOs that have the same identification numbers.

- 1.4 Reserved

- 1.5 The ETSO numbering system is explained as follows: - -ETSO-C5e means: European TSO-Number and revision letter, and so - -ETSO-C95 with no revision letter means initial issue.

NOTE: Copies of ETSOs are listed in Index 1.

2 INDEX 2

- 2.1 Index 2 lists all those ETSOs which are not technically similar to the FAA-TSOs. Index 2 ETSOs are identified by '2C' prefixes, and numbered as follows: - (a) An ETSO with significant differences in the MOPS in comparison with the corresponding FAA TSO is identified by the same number as the corresponding FAA TSO (related to the same type of equipment) with a number in the range from ETSO-2C1 to ETSO-2C499; or - (b) An ETSO for which there is no corresponding FAA TSO (related to the same type of equipment) is identified by a number in sequence from ETSO-2C500 upwards.

ED Decision 2020/011/R

[Amdt ETSO/1] [Amdt ETSO/2] [Amdt ETSO/3] [Amdt ETSO/4] [Amdt ETSO/5] [Amdt ETSO/6] [Amdt ETSO/7] [Amdt ETSO/8] [Amdt ETSO/9] [Amdt ETSO/10] [Amdt ETSO/11] [Amdt ETSO/12] [Amdt ETSO/13] [Amdt ETSO/14] [Amdt ETSO/16]

INDEX 1 EUROPEAN TECHNICAL STANDARD ORDERS