Aviation safety investigations & reports

Building approval process for structures in the vicinity of Australian airports

Investigation number:
Status: Completed
Investigation completed
Phase: Final report: Dissemination Read more information on this investigation phase

Final Report

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What happened

In October 2009, the operator of Essendon Airport (now Essendon Fields Airport) received an application from the Hume City Council (HCC) to construct a radio mast on top of the council office building at Broadmeadows, Victoria. The application was made under the Airports (Protection of Airspace) Regulations 1996 (APA Regulations) which was only applicable to leased, federally-owned airports, such as Essendon. The application identified that the building and existing masts had not been approved under the regulations. The regulations required any proposed construction that breached protected airspace around specific airports to be approved by the Secretary of the then Department of Infrastructure and Transport (Department). Protected airspace included airspace above a boundary defined by the Obstacle Limitation Surface (OLS). The Secretary was required to reject the application if the Civil Aviation Safety Authority (CASA) determined that the application would have an ‘unacceptable effect on safety’.

CASA’s initial response to the HCC application stated that the building and existing masts represented a hazard to aircraft and should be marked and lit, while the proposed radio mast represented a further hazard and, as such, would not be supported. The advice was considered inadequate by the Department, who instructed CASA that they required advice that either the application for the mast had an unacceptable effect on safety, or it did not. CASA subsequently determined that the application did not have an unacceptable effect on safety, and in addition, advised the Department of specific lighting and marking requirements to mitigate any risk presented by the mast. The Department approved the HCC application on 28 February 2011 conditional on appropriate marking and lighting being affixed to the radio mast and building. The ATSB has since been advised that the radio mast has been removed due to reasons unrelated to aviation safety.

What the ATSB found

The scope of this investigation was limited to the processes associated with protecting the airspace at leased, federally owned airports, and in particular the application of safety management principles as part of that process. The investigation used the HCC application for examining the APA Regulations processes, and as a result identified an issue specifically associated with that application. However, the investigation did not consider whether or not the aerial on the HCC building was unsafe.

The Airports Act 1996, which was administered by the Department, was the principal airspace safety protection mechanism associated with a leased, federally-owned airport’s OLS. The Australian Government had committed to using a safety management framework in the conduct of aviation safety oversight (that is, a systemic approach to ensuring safety risks to ongoing operations are mitigated or contained). In contrast, the conduct of safety oversight of an airport’s airspace under the Airports Act used a prescriptive approach (that is, the obstacle was either acceptable or unacceptable). This approach met the requirements of the Airports Act, but was not safety management-based. With respect to the assessment of the HCC application under the Airports Act, a safety management approach was not used.

What's been done as a result

The Department, now known as the Department of Infrastructure, Regional Development and Cities, has advised that it will confer with key stakeholders in the APA Regulations process regarding relevant risk management practices. The intent is to implement a more systematic approach to risk management, guided by the Commonwealth Risk Management Policy.

The Department has also identified the need to reform the current airspace protection regime based around the Airports Act. In a paper titled ‘Modernising Airspace Protection’, the Department identifies that current airspace protection regulation under the Civil Aviation Act 1988 and the Airports Act requires improvement, and has initiated public consultation regarding reforms into this particular regulatory system.

Safety message

A safety management system approach is considered ‘best practice’ by the International Civil Aviation Organization and has been adopted by Australia as the core method of aviation safety oversight through the State Aviation Safety Program. The Airports Act processes need to adopt safety management principles to the assessment of construction applications involving breaches of prescribed airspace, but rather, used a prescriptive regulatory approach. Construction proposals can impinge on aviation safety margins, such as those represented by the OLS. A fully informed, safety management-based approach should be used to ensure that safety is not compromised.


Download final report
[Download  PDF: 1.19MB]



Safety analysis


Safety issues and actions

Sources and submissions


Safety Issue

Go to AI-2013-102-SI-01 -

The use of risk management principles when considering an application under the Airports (Protected Airspace) Regulations

The Department of Infrastructure, Regional Development and Cities adopted a prescriptive approach to the Hume City Council building application within the obstacle limitation area of Essendon Airport, which was in accordance with the process prescribed under the Airports (Protection of Airspace) Regulations 1996, but did not require the application of risk management principles to the department’s consideration.

Safety issue details
Issue number: AI-2013-102-SI-01
Who it affects: Airports managing protected airspace associated with their runways
Status: Safety action pending
General details
Date: 11 July 2013   Investigation status: Completed  
  Investigation level: Systemic - click for an explanation of investigation levels  
  Investigation phase: Final report: Dissemination  
State: Other    
Release date: 03 May 2018   Occurrence category: Other  
Report status: Final   Highest injury level: None  
Last update 03 April 2020