Some objects and structures pose risks to aircraft safety. They may be permanent or temporary, including:
- obstacles in airspace
- objects and structures that are hard to see
- bright or distracting artificial lights or sunlight glare
- sources of air turbulence, such as fast gas plumes
- smoke, dust, particles or steam that reduce visibility.
Developers, owners and operators should report potential hazards. This will help pilots avoid them and plan safe flights.
Read our guidance on obstacles and aviation hazards, which includes instructions on how to report them, and who to report them to.
Assess aviation safety risks
You should understand whether a structure's height or location affects protected airspace and Obstacle Limitation Surfaces (OLS) early in the planning process. We recommend you commission an aviation safety study and risk assessment. Planning authorities consider the study when assessing the development application.
They may seek our advice about risk mitigation strategies, such as:
- adding the object or structure to obstacle databases and aviation charts
- marking or lighting the structure
- issuing a notification to airmen (NOTAM).
Lighting requirements
We assess marking and lighting needs case by case and will tell you what is required when we assess your application.
We consider:
- the structure’s height
- location, including how close it is to aerodromes and protected airspace
- the operational risk.
You can find information on obstacle lighting requirements in section 5.2 of the guidance on objects and structures that affect aviation safety.
For temporary structures such as cranes you may need:
- temporary marking or lighting
- a NOTAM while the hazard is there.
Report potential hazards
You may need to report hazards, depending on the structure’s height and location. Reporting includes:
- the nature of the development or activity
- its height and location
- the hazard it may present
- the timing of the development or operation.
Tall structures
Obstacle databases and aviation charts need complete, accurate information about tall structures like wind farms across Australia. This includes structures that could be dangerous for low-flying aircraft, such as in agriculture, firefighting and search-and-rescue operations.
It is good practice to report to Airservices Australia if a potential hazard is:
If a potential hazard is 100m or higher above ground level, you must notify CASA's section responsible for airspace protection so we can assess the impact on aviation operations.
To report a hazard or tall structure:
- Open the Multipart AC 139.E-01 and 175.E-02.
- Go to Section 3.1.3, page 19 and read Reporting of objects, structures and hazardous plume sources.
Near aerodromes
Objects and structures of any height can be risks for low-flying aircraft during take-off and landing.
Certified aerodromes
Within 15 km of a certified aerodrome, it is good practice to ask the aerodrome operator if the object or structure is in protected airspace. To report potential hazards inside an aerodrome's protected airspace:
- Contact the aerodrome operator. If CASA needs to provide input, the aerodrome operator will liaise with us.
- Submit a Development Application Submission form to Airservices Australia.
Report to Airservices Australia if a potential hazard is:
- 30 m above ground level or higher and within 30 km of a certified aerodrome
- 45 m above ground level or higher elsewhere.
Military aerodromes
Within 15 km of a military aerodrome, advise the air base command post or safety officer about structures taller than the defence aviation area height restriction.
Within 30 km of a military aerodrome, report structures 30 m or higher to Airservices Australia.
Leased federal airports
To report a potential hazard in the airspace of a leased federal airport, notify:
- the airport
- local government.
The airport will advise whether you need approval from the Department of Infrastructure, Transport, Regional Development, Communications, Sport and the Arts.
Uncertified aerodromes
We do not oversee uncertified aerodromes. Where there is an airspace hazard, operators should consider closing or limiting the runway. We may issue NOTAMs in exceptional circumstances.