Airspace Protection at Leased Federal Airports


Obstructions in the vicinity of an airport have the potential to create air safety hazards and to seriously limit the scope of aviation operations into and out of the airport. The effects of individual obstacles may be relatively minor, but together a number of obstacles may seriously limit runway utilisation, cause airspace congestion and reduce the effective handling capacity of the airport.

While the most critical areas of concern are the immediate approach and take-off areas, it is equally true that objects up to and beyond 20 kilometres from the airport and apparently unrelated to the runway alignment can cause problems for pilots approaching or departing an airport.

What is the law?

Part 12 of the Airports Act 1996 and the Airports (Protection of Airspace) Regulations 1996 establish a framework for the protection of airspace at and around airports.

The Airports Act 1996 defines certain activities resulting in an intrusion into an airport's protected airspace to be a “controlled activity”, and requires that controlled activities cannot be carried out without approval.

The Regulations provide for the Department or the airport operator to approve applications to carry out controlled activities, and to impose conditions on an approval.

Carrying out a controlled activity without approval is an offence under Section 183 of the Airports Act 1996, and is punishable by a fine of up to 250 penalty units. It is an offence under Section 185 of the Act to contravene any conditions imposed on an approval. Under Section 186 of the Act it is an offence not to give information to the airport operator that is relevant to a proposed controlled activity.

What is Protected Airspace?

International standards have been adopted which define two sets of invisible surfaces above the ground around an airport. The airspace above these surfaces forms the airport's protected airspace. These two surfaces are the:

  • Obstacle Limitation Surface (OLS); and
  • Procedures for Air Navigational Services—Aircraft Operations (PANS-OPS) surface

The OLS is generally the lowest surface and is designed to provide protection for aircraft flying into or out of the airport when the pilot is flying by sight. The PANS-OPS surface is generally above the OLS and is designed to safeguard an aircraft from collision with obstacles when the aircraft's flight may be guided solely by instruments, in conditions of poor visibility.

What is a Controlled Activity?

Controlled activities require approval before they can be carried out and include the following:

  • constructing permanent structures, such as buildings, intruding into the protected airspace
  • temporary structures such as cranes intruding into the protected airspace
  • activities causing non-structural intrusions into the protected airspace such as air turbulence from stacks or vents, smoke, dust, steam or other gases or particulate matter.

The Regulations differentiate between short-term (less than 3 months) and long-term controlled activities. The Regulations provide for the airport operator to approve short-term controlled activities, excluding PANS-OPS  intrusions, and for the Department to approve long-term controlled activities, or short-term controlled activities referred to it by the airport operator, including short-term intrusions of the PANS-OPS surface. However, long term intrusions of the PANS-OPS surface are prohibited.

How do you know you need an approval?

The activity you intend carrying out will generally require an approval by State or local government authorities. Larger projects may require an Environment Impact Statement while most projects will require the issue of a building permit by the local council.

Local councils in the vicinity of an airport's protected airspace are required to review all building and development applications they receive for any intrusions of protected airspace.

These local councils refer proposals to the airport operator if an intrusion is likely to occur. The proponent will then need to apply through the airport operator for approval.

Airport operators are required to make charts of the OLS and PANS-OPS surfaces available to the public. In most cases these charts are also incorporated into the local council's planning information databases. To avoid any doubt, applicants (e.g. developers, builders and crane operators) should check with the airport operator (or their local council) at the earliest possible stage.

How do you apply?

Applications to carry out a controlled activity are to be made to the airport operator in writing. The information required in the application must include:

  1. a description of the proposed controlled activity (building construction, crane operation etc.)
  2. its precise location (street directory grid references are suitable)
  3. if the controlled activity consists of the erection of a building or structure:
    • the proposed maximum height of the structure above the Australian Height Datum (including any antennae or towers), and
    • the proposed maximum height of any temporary structure or equipment (e.g. cranes) intended to be used in the erection of the structure
  4. the purpose of the controlled activity.

Assessment of Applications

The airport operator will conduct the initial assessment of the application in terms of:

  • whether the activity results in an intrusion into the OLS or PANS-OPS surface
  • the extent of the intrusion
  • the precise location of the development or activity.

The airport operator is required to invite the following organisations to assess or comment on an application:

  • the Civil Aviation Safety Authority (CASA)
  • Airservices Australia
  • the local council authority responsible for building approvals
  • the Department of Defence in the case of joint-user airports.

For short term controlled activities, comments are only required from CASA and Airservices.

Approval Process

The approval process varies depending on the type of controlled activity:

  • short-term controlled activities which penetrate the OLS can be approved/refused by the airport operator after consultation with CASA and Airservices, or referred by the airport to the Department for a decision. However, if the short term controlled activity penetrates the PANS-OPS airport operators are required to consult with CASA and Airservices and then refer applications to the Department for a decision. This referral is to include advice about whether the short-term penetration of the PANS-OPS has the support of the airport operator;

  • long-term controlled activities penetrating the OLS are referred by the airport to the Department for a decision after consultation with CASA, Airservices and the relevant building authority;

  • long-term controlled activities penetrating the PANS-OPS airspace are not permitted, and the airport operator can notify the refusal of such controlled activities.

The Regulations require any decision by the airport operator to be made in the interests of the safety, efficiency or regularity of existing or future air transport operations into or out of the airport.

An approval may be subject to specific conditions. These conditions may concern how the controlled activity is carried out (e.g. hours of operation of a crane), or may require the building or structure to be marked or lit in a certain way. These conditions must also be in the interests of the safety, efficiency or regularity of existing or future air transport operations.

The Regulations set the following timeframes for the approval of controlled activities:

  • a decision on short term controlled activities is required to be made within 21 days of the airport operator receiving the application, unless the application is referred to the Department for a decision

  • a decision on long term controlled activities is required to be made by the Department within 28 days of the Department's receipt of the application.

  • If the airport operator, CASA, Airservices or the Department requires further information in respect of individual applications, the decision is to be made within 21 days (for short-term intrusions) or 28 days (for long-term intrusions) of the extra information being provided by the applicant.