Obstacle Limitation Surface Designation
Wellington Airport has had an Airspace Obstacle Limitation Surface (OLS) Designation in the Wellington City Council Operative District Plan since 1999. This has been rolled over into the Council’s Proposed District Plan.
Link: Wellington City Proposed District Plan
What is an OLS?
Civil Aviation rules require airports to provide Obstacle Limitation Surfaces around an airport.
OLS are defined three dimensional surfaces that radiate outwards from an airports runway and exist in the airspace above and adjacent to the airport as shown in Figure 1 below. They are necessary to enable aircraft to maintain a satisfactory level of safety while manoeuvring at low altitude in the vicinity of the airport and to protect against collision.
These surfaces should be free of obstacles and subject to controls to prevent objects such as buildings, structures and even trees from penetrating them. The OLS designation is the tool to impose height limits on objects around an airport.
Figure 1: A three-dimensional depiction of thge obstacle limitation surfaces surrounding an airport.
Figure 2 below shows a 2-dimensional version of the Wellington Airport OLS. As can be seen, the OLS extends some distance beyond the Airports actual location.
Given the hilly terrain of Wellington, much of the terrain already penetrates the OLS. These areas are shown with a blue outline in Figure 2.
Figure 2: Wellington International Airport Obstacle Limitation Surfaces
What type of objects are the Airport concerned about?
Permanent and temporary objects (or activities) can result in the OLS being penetrated and therefore have the potential to adversely impact on the safety of flight operations within the vicinity of the airport.
This includes structures and buildings, and the equipment used to construct them – such as cranes, house wraps/scaffolding. Trees can also be problematic.
My property is within the Airports OLS Airport Designation – What does this mean?
As can be seen in Figure 2 above, most properties within the Wellington District have the WIAL OLS designation in the airspace over them. What matters however is whether a proposed object/building/structure will penetrate the OLS, and if it does penetrate, the extent of that penetration and whether it will affect aircraft safety. The designation restrictions do not apply to objects/buildings/structures that are located within the airspace beneath a relevant Obstacle Limitation Surface.
It is important to understand that notwithstanding any permitted height allowances in the Wellington City District Plan rules, if an object/building/structure penetrates the OLS you should notify Wellington Airport.
How do I find out of my proposal penetrates the OLS?
To find out whether your proposed building/structure or other object will penetrate the OLS, you can quickly check on Wellington City Councils interactive District Planning Map which will tell you which OLS surface is relevant and how many metres above ground level you can build before you actually penetrate the Airport’s OLS.
My proposal will penetrate the Airports OLS – What do I do?
Once you have found out which OLS Surface your property is within (and you know that your proposal will penetrate the OLS), you should notify or get written consent from the Airport.
Please fill out this Notification and/or Request for WIAL Consent OLS Penetration Form here and send it, along with the required information/plans to planning@wellingtonairport.co.nz.
Once you have sent this information to the Airport, we will then make an assessment of your proposal as to whether it will affect aircraft safety. This will be assessed on a case-by-case basis. Whether written consent is given for your project will be dependent on factors such as whether there is higher terrain in the vicinity that effectively shields the proposal from causing any adverse effects on aircraft safety. In some cases, you might be required to provide an Aeronautical Study, and/or apply to the Civil Aviation Authority for approval under Part 77 of the Civil Aviation Rules.
The table below outlines what height you require the Airports written consent for:
| OLS Surface | When to notify Wellington Airport is required | When to request written consent from Wellington Airport |
|---|---|---|
Properties on Bridge Street, Cairns Street, Jean Batten Drive and Coutts Street in Rongotai with specific height restrictions - depicted in Figure 1 of WIAL 1 Designation: Proposed District Plan - Wellington City Proposed District Plan (Runway Strip, Transitional Side Slope and Approach Surface) |
Any increase in height requires written consent from WIAL. |
Any increase in height to these properties in Bridge Street, Cairns Street, Jean Batten Street and Coutts Street in Rongotai. |
Transitional Side Slope Inner Horizontal Conical Take-off and Approach Surfaces Visual Segment Surface |
A building/structure or other object that penetrates the OLS and is 8 metres or less in height above ground level. |
A building/structure or other object that penetrates the OLS and is more than 8 metres above ground level. |
Outer Horizontal Surface |
A building/structure or other object that penetrates the OLS and is 30 metres or less in height above ground level. |
A building/structure or other object that penetrates the OLS and is more than 30 metres above ground level |
After considering your proposal and all relevant information, the Airport will determine whetherit is prepared to provide written consent for the proposal. It is important to note that if the Airport does not provide its written consent, the proposal cannot go ahead as to do so would breach section 176 of the RMA.
For further information or queries please email planning@wellingtonairport.co.nz