Applicants who require approval for equipment to be installed in EASA aircraft should make an application for a European Technical Standard Order Authorisation (ETSOA), which must comply with Part 21, Subpart O and the relevant ETSO Standard(s) (CS-ETSO).

Applicants that require approval of equipment to be installed in non-EASA aircraft should apply for a UK CAA national approval (British Civil Airworthiness Requirements (BCAR) Approval). Equipment that meets an ETSO may also be installed in non-EASA aircraft and does not need additional national approval.

EUROPEAN TECHNICAL STANDARD ORDER (ETSO) AUTHORISATIONS (EUROPEAN APPROVAL)

All ETSO Authorisations are prefixed with one of the following:

• EASA.21O. (ETSO Authorisation)
  This is an Authorisation (approval) issued for an EU manufactured piece of equipment.

• EASA.IM.21O. (ETSO Authorisation for Import)
  This is an Authorisation (approval) issued to a manufacturer from a non-EU Member State.

In addition, before EASA can issue an ETSO Authorisation for Import (under Part 21, Subpart O), EASA must have an 'Arrangement' with the exporting Authority.

General information and a complete listing of ETSO Authorisations (issued) can be found on the EASA website.

JOINT TECHNICAL STANDARD ORDER (JTSO) AUTHORISATIONS (EUROPEAN APPROVAL)

JTSO Authorisations that were issues by the UK CAA are prefixed with one of the following:

• CAA.O. (JTSO Authorisation)
  This is an Authorisation (approval) issued for a UK manufactured piece of equipment, which complies with JAR-21, Subpart O and the relevant JTSO Standard (JAR-TSO).

• CAA.N-O. (JTSO Authorisation for Import)
  This is an Authorisation (approval) issued to a manufacturer from a non-JAA Member State, which complies with JAR-21, Sub-subpart N-O and the relevant JTSO Standard.

In addition, before a JAA Authority could issue a JTSO Authorisation for Import (under JAR-21 Sub-subpart N-O), the JAA must have had an 'Arrangement' with the exporting Authority (as required by JAR 21N5). The UK CAA had such an Arrangement with the following non-JAA exporting Authority:

• Federal Aviation Administration (FAA) in the United States of America.

General information and a complete listing of JTSO Authorisations (issued) can be found on the JAA Website.

There are currently five other National Aviation Authorities (NAAs) within the JAA which are able to issue JTSO Authorisations. Country and approval number prefixes are as follows:-

• Austria - ' ACG '
• France - ‘ F. ‘
• Germany - ‘ LBA. ‘
• Italy - ‘ ENAC. ‘
• Sweden - ' LFV '

Aircraft equipment approved in the United Kingdom or originally approved in the United Kingdiwn and now supported by EASA under Grandfather Rights, falls into the following categories indicated by the approval numbers prefixed by the following letters;

BRITISH CIVIL AIRWORTHINESS REQUIREMENTS (UK NATIONAL APPROVAL)

Radio Equipment

CAP 208 - Aircraft Radio Equipment

Volumes 1 and 2 of CAP 208 - 'Aircraft Radio Equipment', are now considered to be obsolescent in that these volumes no longer represent current minimum performance requirements or complete and definitive records of aircraft radio equipment approved by CAA. Volume 1 of CAP 208, listed certain ICAO standards (for example, ICAO annex 10 requires VHF communication transceivers to have a frequency stability operation of plus or minus 0.003%), which have been superseded by later requirements.

Airframe Parts and Equipment