Go to top of page

CASR Part 21 - Certification and airworthiness requirements for aircraft and parts

Part 21 of CASR deals with the certification and airworthiness requirements for aircraft and aircraft parts. It includes rules relating to Type Certificates, Type Acceptance Certificates, Supplemental Type Certificates, Production Certificates, Certificates of Airworthiness and export airworthiness approvals. It also covers the approval of aircraft engines, propellers, and certain materials and parts. It calls up the airworthiness certification standards mentioned in Parts 22-35:

  • 22 - Sailplanes
  • 23 - Small Aeroplanes
  • 25 - Transport Category Aeroplanes
  • 26 - Primary/Intermediate category aeroplanes
  • 27 - Rotorcraft
  • 29 - Rotorcraft (Transport Category)
  • 31 - Manned free balloons
  • 32 - Engines for Very Light Aeroplanes
  • 33 - Aircraft Engines
  • 35 - Aircraft propellers.

Subpart 21.H: covers the certification of a new category of aircraft called Light Sport Aircraft (LSA). The LSA category will generally include aircraft used for aviation sport and recreational activities, such as ultra- light airplanes, gliders, balloons, powered parachutes, weight-shift control aircraft and gyroplanes. The proposed legislative requirements, which are simply an amendment of the existing Subpart 21.H and several consequential amendments to the Civil Aviation Orders, continue the approach taken in Part 21 whereby Australia's aircraft airworthiness requirements are generally harmonised with those of the USA Federal Aviation Regulations (FARs). The amendment to Subpart 21.H will incorporate the existing airworthiness acceptance criteria for aircraft potentially eligible for the LSA category contained in the current Civil Aviation Order (CAO) Part 95 exemption series, and in Part 21 and Parts or Part 200  - Exemptions.

Subpart 21.J: the new Subpart 21.J commenced on 1 March 2014. Subpart 21.J prescribes the rules for certification and operations of approved design organisations (ADOs), who may carry out certain design and technical data approval functions regulated by Part 21, without further reference to CASA or an authorised person. Any individual or body corporate may apply for a certificate of approval as an approved design organisation. The applicant is not required to hold a type certificate or production approval.

The new Subpart 21.J expands on the existing regulation 30 of CAR for design organisations to provide for a more systematic and comprehensive system for design approval by organisations. Consequently, coordination and management of many certification projects, currently mostly conducted by CASA, will be devolved to suitably rated ADOs. The scope of the design activities that CASA may authorise will depend on the ADO's demonstrated capabilities and the systems that the ADO has in place to carry out the activities

Who Part 21 affects

Part 21 affects anyone in the Australian aviation community involved in the design, manufacture and airworthiness certification of aircraft, aeronautical products and parts.

Subparts 21.J and 21.M post-implementation review (PIR)

On 1 March 2014, Subpart 21.J replaced the then current Instrument of Appointment with organisational approvals. The new rules set out the requirements for approval as an approved design organisation, as well as the associated privileges and obligations.

Standards Development project CS 13/12 was initiated to review the implementation of Subpart 21.J  and to conduct a post-implementation review of Subpart 21.M.

Find out more about Subpart 21.J.


Current regulation

Part 21 can be found in volume 1 of the CASR. Recent amendments to this Part may be listed in the Unincorporated Amendments.

Refer to the ComLaw search guidance or contact the ComLaw Help Desk for assistance with finding and navigating the CASR.

Advisory documents

AC 21-1(1)Aircraft Airworthiness Certification Categories and Designations ExplainedDecember 2000
AC 21-2(1)Standard Certificates of AirworthinessNovember 2010
AC 21-3(1)Special Certificates of Airworthiness - OverviewNovember 2010
AC 21-4(2)Amateur-Built Experimental Aircraft - CertificationSeptember 2000
AC 21-5(0)Limited Category Aircraft - CertificationNovember 1998
AC 21-6(0)Restricted Category Aircraft - CertificationOctober 1998
AC 21-7(0)Primary Category Aircraft - CertificationJune 2000
AC 21-08 v1.0Approval of modification and repair designs under Subpart 21.MFebruary 2015
AC 21-09(2)Special Flight PermitsMarch 2009
AC 21-10(2.1)Experimental CertificatesJanuary 2016
AC 21-11(1)Amateur-Built (ABAA) Aircraft - CertificationSeptember 2000
AC 21-12 v1.0Classification of design changesMarch 2015
AC 21-13(0)Australian-Designed Aircraft - Type CertificationSeptember 1999
AC 21-14 v4.0Production CertificatesJune 2014
AC 21-15 v3.0Supplemental Type Certificates - CertificationMarch 2015
AC 21-16(0)Approval of Materials, Parts, Processes and AppliancesSeptember 1999
AC 21-17(0)Export Airworthiness ApprovalsApril 1999
AC 21-18 v1.0Design and maintenance of containers: transportation of live aquatic animals using compressed oxygen or compressed airMay 2015
AC 21-19 v1.0Aircraft modification - flight test considerationsMay 2015
AC 21-20(0)Production Under Type Certificate OnlySeptember 1999
AC 21-21 v1.0Aircraft production - flight test considerationsMay 2015
AC 21-22(0)Approval of Imported Engines, Propellers, Materials, Parts and AppliancesSeptember 1999
AC 21-24 v1.0Flight recorder and underwater locating device maintenanceMay 2015
AC 21-25(3)Limited Category Aircraft - Permit IndexJuly 2012
AC 21-27(0)Manufacturing Approval - OverviewSeptember 1999
AC 21-28 v1.0Permissible unserviceabilities - unrepaired defects (r. 21.007)January 2015
AC 21-29(0)Commercial Assistance During Construction of Amateur-Built Experimental Aircraft and Amateur-Built (ABAA) AircraftJune 2000
AC 21-30(2)Type Acceptance Certificates for Imported AircraftMarch 2009
AC 21-31(0)Type Certificates for Imported AircraftDecember 1998
AC 21-33(0)Delivery of Aircraft to AustraliaSeptember 1999
AC 21-35(1.1)Calibration - Inspection and test equipmentAugust 2015
AC 21-36 v2.2Global Navigation Satellite System (GNSS) Equipment: Airworthiness GuidelinesNovember 2014
AC 21-37(0)Airworthiness Approval of Navigation or Flight Management Systems Integrating Multiple Navigation SensorsFebruary 2005
AC 21-38(0)Aircraft Electrical Load Analysis and Power Source CapacityMarch 2005
AC 21-40(0)Measurement of Airspeed in Light Aircraft - Certification RequirementsApril 2005
AC 21-41(0)Light Sport Aircraft Certificate of AirworthinessSeptember 2005
AC 21-42 v2.0Light sport aircraft manufacturers' requirementsMay 2014
AC 21-43(0)Experimental Certificates for Unmanned AircraftJune 2006
AC 21-45 v2.2Airworthiness Approval of Airborne Automatic Dependent Surveillance Broadcast EquipmentJune 2015
AC 21-46 v3.0Airworthiness Approval of Avionics EquipmentOctober 2014
AC 21-47(0)Flight Test SafetyApril 2012
AC 21-50 v1.0Approval of software and electronic hardware partsMay 2014
AC 21-99(1)Aircraft Wiring and BondingSeptember 2013
AC 21-601(0)Australian Technical Standard Order AuthorisationJuly 2005
AC 21.J-01 v1.0Approved design organisationsJune 2014

Part 21 history

Part 21 of the CASRs was made on 15 July 1998, with certain subparts taking effect on 1 October 1998 and the remainder on 1 December 1998.

The Part 21 history includes project and consultation activities conducted in relation to Part 21, including Subparts 21.H and 21.J.

Contact details

Email: Certification and Airworthiness Standards
SCC: Certification and Manufacturing Standards Sub-committee