Radio altimeter requirements due to 5G transmissions - (CD 2513AS)

Overview

We are working with the aviation industry and the Australian Communications and Media Authority (ACMA) to ensure flight safety during the expansion of the 5G network in Australia.

This includes steps to reduce potential interference from 5G to radio altimeters (radalts).

We are seeking feedback on amendments to four Manuals of Standards (MOS) that will ensure radalts operate reliably in the presence of radio frequency transmissions from 5G.

The amendments formalise requirements communicated to impacted aircraft operators over the past 12 months.

To enact these critical safety requirements, we have drafted changes to the MOS for:

• Part 91
• Part 121
• Part 133
• Part 135 of the Civil Aviation Safety Regulations 1998 (CASR).

Aircraft operators affected

The requirements apply to aircraft (aeroplanes and rotorcraft) that use the following instrument approach procedures which are reliant on radalts:

• Low-visibility approaches
• Required navigation performance – authorisation required (RNP-AR) operations.

From 1 April 2026 aircraft operators who use the above approaches must ensure their radio altimeters meet the tolerance to radio frequency interference described in the following United States Federal Aviation Administration (FAA) airworthiness directives:

• FAA Airworthiness Directive AD 2023-10-02 for aeroplanes
• FAA Airworthiness Directive AD 2023-11-07 for rotorcraft

The amendments will also apply to:

• foreign air transport Air Operator’s Certificate (AOC) holders
• AOC holders with Australia New Zealand Aviation (ANZA) privileges.

Background - impact of 5G on radalt frequency bands

Radalts are critical for safe landings in low-visibility conditions. Studies show that 5G transmissions can interfere with radalt performance, and can cause:

• intermittent operation
• false data and indications
• system failure.

We have developed more information about the impact of 5G on radalts in our Airworthiness Bulletin AWB 34-020 Issue 9.

The ACMA currently has measures in place to reduce the risk, but these will end on 31 March 2026. As a result, we are making these amendments to ensure radalts continue to operate reliably in the presence of 5G transmissions.

Details of the conditions imposed by ACMA can be found in the Radiocommunications Assignment and Licensing Instruction (RALI MS47).

Further information

You can find more information about 5G and aviation safety at the following:

• Get fitted to protect against 5G by 31 March 2026 - provides instructions and steps for aircraft operators to take
• Airworthiness Bulletin AWB 34-020 - provides further information including a request for pilots to report any suspected cases of radalts being affected by radio frequency interference
• FAA airworthiness directives available at the FAA Dynamic Regulatory System.

Why your views matter

Your feedback will help us make sure 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 2513AS, which provides background on the proposed amendments
• Consultation draft - Parts 91, 121, 133 and 135 Manuals of Standards Amendment Instrument 2025
• Consultation draft - CASA 34/25 — Foreign Registered Aircraft in Australian Territory (Radio Altimeters) Direction 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 on an ongoing basis. It will be important for pilots to report any incidents of radalts anomalies, especially those suspected to be caused by radio frequency interference.