Design and operation of the airspace associated with Avalon, and the lack of implementation of safety recommendations following a 2020 CASA airspace review

A controller has expressed a safety concern regarding the design and operation of the airspace associated with Avalon, and the lack of implementation of safety recommendations following a 2020 CASA airspace review.

The reporter states that Avalon airspace consists of a tower control zone of Class D airspace from the surface to 2,500 ft, with Class C airspace beginning at 4,500 ft above this. Between these two bands of airspace, an area of Class E airspace is included from 2,500 ft to 4,500 ft.

Due to the differing requirements of these airspaces, aircraft operating under VFR may operate within class E airspace without being under positive control of ATC, while aircraft operating under IFR are subject to control by ATC in this same airspace. As such, controllers are unable to take effective responsibility for the separation of IFR aircraft departing or arriving at Avalon while transiting class E airspace, when VFR aircraft are present.

The reporter advises that on a number of occasions, due to VFR aircraft operating in class E airspace in close proximity to Avalon, they have been unable to issue satisfactory departure instructions to departing high capacity IFR aircraft, often requiring these high capacity aircraft to accept visual departures and reducing the level of safety that an aircraft operating within controlled airspace is normally afforded. In addition to this, on a number of occasions inbound high capacity RPT aircraft have been required to hold or accept avoidance manoeuvres issued by controllers due to VFR aircraft not being required to comply with ATC instructions within class E airspace, increasing controller and pilot workload during a critical phase of flight.

The ATSB notes that CASA conducted a review of the Avalon airspace in February 2020, published as document D19/48884. This review identified a number of safety concerns relating to the design of the Avalon airspace in its present configuration, including that “changes to airspace classification around Avalon during tower hours would enhance aviation safety”.

As a result of this review, CASA made a number of recommendations to improve the safety and efficiency of Avalon airspace, one of which was that “Airservices Australia should review the airspace design at Avalon and submit an Airspace Change Proposal (ACP) within 12 months to remove the Class E airspace and replace it with Class D or Class C airspace as appropriate, to optimise and enhance the level of air traffic services provided at Avalon”.

The reporter states that despite the recommendations, to date no Airspace Change Proposal has been produced by Airservices Australia, and notes that the recommended timeframe for this to be conducted has now passed. The reporter is concerned that the current design of the Avalon airspace presents an unacceptable level of safety.

Named Party’s response

In response to the review of Airspace at Avalon by the Office of Airspace Regulation (OAR), Airservices wrote to the Civil Aviation Safety Authority (CASA) in April 2021. In that correspondence, Airservices highlighted that in accordance with the Australia Airspace Policy Statement (AAPS, 2018) and as the OAR is the design authority for Australian administered airspace, the responsibility to submit an Airspace Change Proposal (ACP) following an airspace review must sit with CASA. It was agreed that CASA would take carriage on any changes to the airspace but that Airservices, as the Air Navigation Service Provider (ANSP) for Australia, would work closely with CASA on any proposals to amend the airspace.