Proposed amendments to Part 139 MOS – new system to reassess aerodrome pavement strength and update AIP ERSA - (CD 2502AS)
Feedback updated 20 May 2025
We asked
The consultation, Proposed amendment to the Part 139 Manual of Standards (MOS) (Aerodromes) was open during the period 25 March to 24 April 2025. It asked industry to assess and comment on proposed amendments to the Part 139 MOS associated with the change of pavement strength reporting requirements with the transition from Aircraft Classification Number (ACN)/Pavement Classification Number (PCN) to Aircraft Classification Rating (ACR)/Pavement Classification Rating (PCR).
The consultation has now closed, and a summary of the feedback is provided below.
About this consultation
Prior to the consultation, a working group was established as a sub-group to the National Runway Safety Group. This working group (PCR Transition Working Group - PCRTWG) was able to discuss and resolve many of the issues identified with the transition including the filing of a short-term difference with ICAO to enable a smoother transition.
The transition from ACN/PCN to ACR/PCR would require certified aerodromes that had current PCN values published, to reassess the pavement strength ratings and report the new PCR values to Airservices AIS for publishing in the AIP ERSA.
The consultation survey asked industry whether they agreed with the proposed variations to the Part 139 MOS applicable to the transition from PCN to PCR, and to advise us of any issues that they may have identified with the proposed changes.
You said
In total, there were 9 respondents. The respondents were representatives from aerodromes (0), aircraft owner/operator (1), aviation consultant/contractor (3), pavement engineer (1), ANSP (1), and other (3).
Of the respondents who made written submissions, 7 consented to having them made public and 2 requested their submissions be confidential.
Summary of feedback
The majority of the comments by the respondents supported the change and understood the need for the changes.
Two of the respondents that provided comment queried some elements of the proposed changes; however, also supported the proposal.
One of the respondents had concerns over the possible cost impact to smaller certified aerodromes. This matter has been discussed and addressed numerous times by the PCR Transition WG, and a number of consultants have advised cost effective methods for assisting the smaller aerodromes.
Overall, the common theme was one of support for the proposed changes and amendment to this area of the Part 139 MOS, with some consequential recommended amendments to the AC 139.C-07 Strength Rating of Pavements (currently under review) and AIC 38/24 to better clarify requirements.
We did
Next steps
Overall, respondents have supported the proposal. As a result, CASA will now undertake to implement changes to the Part 139 MOS that reflect the elements of the feedback and the draft amendment.
The amendment will be published before 12 June 2025 to ensure that the Part 139 MOS provides power to AIP ERSA for the publishing of the PCR values.
Overview
We would like your feedback on a proposal to amend the Part 139 Manual of Standards (MOS), to enable the implementation of a new Pavement Classification Rating (PCR) system. This would replace the existing Pavement Classification Number (PCN) system.
When introduced, the new PCR would require aerodrome operators to reassess pavement strength and report this information in the Aeronautical Information Publication (AIP) En-route Supplement Australia (ERSA).
This change is part of a global program for reporting pavement strength, with standards specified in Annex 14 to the Convention on International Civil Aviation (the Chicago convention) - Aerodromes, Volume 1. The new pavement strength rating system offers a more accurate evaluation of the strength of airport pavements and provides a better understanding of pavement life.
Principal changes that would occur
Under the proposed changes to the Part 139 MOS, the following will be required:
- For aerodromes with pavements intended for aircraft with a maximum certificated take-off weight (MTOW) greater than 5,700 kg, aerodrome operators would be obliged to determine and report a PCR value in AIP ERSA.
- For aerodromes with pavements intended for aircraft with an MTOW equal to or less than 5,700 kg, determining and reporting a PCR value would be optional. The aerodrome operator may also elect to publish a weight or tyre pressure value for the pavement.
- If an aerodrome operator is either obliged by the proposed standards to determine and report PCR values and does not provide the required information for the November 2025 AIRAC cycle, or, not obliged by the proposed standards to determine and report PCR values and chooses not to voluntarily do so, the pavement strengths for the aerodrome would be published as ‘unrated’.
Background and engagement
In mid-2024, we initiated a PCR Transition Working Group via the National Runway Safety Group, to assist with the transition from the current Aircraft Classification Number/Pavement Classification Number (ACN/PCN) system to the proposed new regulations for Aircraft Classification Rating (ACR/PCR).
The working group has helped to inform a transition pathway. This pathway includes the lodging of a 12-month ‘notification of difference’ with the International Civil Aviation Organization (ICAO) to allow for a transition period.
The working group also assisted CASA to draft an Aeronautical Information Circular (AIC) (H38/24) that clearly identifies the procedure for assessing and publishing the PCR arrangements.
Why your views matter
Your feedback will help us make sure the proposed requirements are suitable, the final legislation is clear and it will work as intended.
Please submit your comments using the survey link on this page.
If you are unable to provide feedback via the survey link, please email regulatoryconsultation@casa.gov.au for advice.
Documents for review
All documents related to this consultation are attached in the ‘Related’ section at the bottom of the overview page. They are:
- Summary of proposed change on CD 2052AS, which provides background on the proposed standards
- Consultation Draft - Part 139 Manual of Standards Amendment Regulations No.1/2025
- MS Word copy of online consultation for ease of distribution and feedback within your organisation.
What happens next
At the end of the response period, we will:
- review all comments received
- make responses publicly available on the consultation hub (unless you request your submission remain confidential)
- publish a Summary of Consultation which summarises the feedback received and outlines any intended changes and next steps.
All comments received on the proposed legislation will be considered. Relevant feedback that improves upon the proposed instrument will be incorporated into the final instrument.
Post-implementation review
CASA will monitor and review the new rules during the transition phase and on an ongoing basis.
Audiences
- Aerodrome operator
- Air operators
- Pilots
- Air traffic service provider
- Part 175 of CASR Aeronautical information service providers
- Operations Control/Flight Dispatch
- Certified aerodrome owner/operator
- Unregulated aerodrome owner/operator
- Aerodrome owner/operators
- CASA aerodrome inspector
- Aerodrome industry consultant
- VET and tertiary sector organisations providing aviation theory training
- Aerodrome industry consultant
Interests
- Operational standards
- Aerodrome Reporting Officer Training
- Aerodromes
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