- Navigation Authorisations - Amendments to Civil Aviation Order (CAO) 20.91
ICAOs highest priority is to rapidly implement PBN in order to maximise the associated safety, economic and environmental benefits which have been made possible by advances in navigation technology and the development of internationally agreed standards. This international initiative aims to safely maximise the utilisation of available airspace through initiatives such as reductions in oceanic and en-route separation standards and track miles flown during approach to land procedures in terminal airspace.
Project AS 08/19 was initiated to develop CAO 20.91 - Navigation Authorisations. To ensure that the project team was inclusive and that all relevant issues were identified and duly considered, nominations for team members were sought using the Standards Consultative Committee process. A project team consisting of CASA, Airservices Australia (AA), ICAO, International Air Transport Association (IATA) and Industry representatives was then established to discuss the scope of the issues.
NPRM 1002AS identifying seven key change proposals was published on 29 July 2011, and proposed the making of CAO 20.91 covering Navigation Authorisations. The submission period closed on 23 September 2011.
An Addendum to NPRM 1002AS was published on 23 April 2012 including Appendix 3 - Requirements for use of RNP 2 and an associated Advisory Circular (AC) 91U-II-C-2 (0) Navigation Authorisations - RNP 2. The submission period closed on 7 May 2012. A shorter period for public consultation was provided as the RNP 2 navigation authorisation was in the same format as the other RNAV and RNP navigation authorisations and the CASA/AA/Industry Project Team reviewed the RNP 2 proposals prior to wider public consultation.
Navigation authorisations in the form of Subpart 91U of the Civil Aviation Safety Regulations 1998 (CASR 1998) approvals for RNP 10 and RNP 4 were considered to be outside the scope of the project. During the rationalisation phase all RNAV and RNP navigation authorisations will be included in Subpart 91U of CASR 1998. The NPRM referred to RNAV 10 navigation authorisations contained in Subpart 91U of CASR 1998 but they should be more correctly referred to as RNP 10 navigation authorisations. The PBN Manual states that due to the extensive approvals in existence, aircraft approvals will continue to use the term RNP 10 while the PBN application will be known as RNAV 10.
Transitional arrangements, safety cases, rules and procedures etc. are yet to be fully developed, however, based upon known aircraft equipage characteristics, it is reasonable to conclude that in the harmonisation phase Australian operators will transition from Australian unique to ICAO PBN navigation specifications as follows:
- GPS RNAV to an RNP 2 navigation authorisation;
- GPS Oceanic to an RNP 4 navigation authorisation; and
- Australian RNAV approval to an RNAV 5 navigation authorisation.
Australian operators will also be able to transition from European and United States RNAV (US-RNAV) authorisations to ICAO PBN navigation specifications as follows:
- European Basic RNAV (B-RNAV) or equivalent to an RNAV 5 navigation authorisation;
- European Precision RNAV (P-RNAV) to an RNAV 1 and RNAV 2 navigation authorisation; and
- US-RNAV Type A or Type B to an RNAV 1 and RNAV 2 navigation authorisation.
Contact: Ron Doggett, PBN Specialist
- NFRM 1002AS - Navigation Authorisations - Amendments to Civil Aviation Order (CAO) 20.91
- Annex A - Summary of Responses to NPRM 1002AS - Navigation Authorisations - Proposed CAO 20.91 Navigation Authorisations - Incorporating ICAO PBN Navigation Specifications
- Annex B - Civil Aviation Order 20.91 (Instructions and directions for performance-based navigation) 2012
- Annex C - Final Advisory Circulars - Part 91U