Public Safety Zones

Overview

Public Safety Zones are based on the risk to an individual from an aircraft accident over a year. They comprise an outer boundary which is the 1 in 100,000 risk contour and an inner, higher risk zone, based on the 1 in 10,000 risk contour.

Previously NATS have been responsible (under contract to the Department for Transport) for modelling the risk contours that predict the size and shape of PSZs. This is done using the Department’s Third-Party Risk modelling methodology and is based on data supplied from airports on traffic forecasts for the next 15 years. To determine which airports should have PSZs, the Department considers CAA Statistics on Air Traffic Movements as well as drawing on background knowledge of the types of activities at individual airports.

There are currently 32 airports with PSZs in the UK who will be affected by this proposed change. PSZ reviews have historically been carried out on a 7-year cycle, although there are no particular policy reasons for this.

NATS have given notice to stop providing the risk modelling service and this, combined with the change in aviation safety over the last number of years, has led us to review the PSZ Policy.

Therefore, the proposal, based on the knowledge that PSZ areas have not significantly changed in the last decade, is to standardise the zone profile and withdraw the review period. The proposed standardised shape, to replace the risk-based model profile, will capture 90-95% of accidents shown to be located outside the aerodrome boundary.

This proposal will reduce the burden, both financially and resource, on aerodromes to review the zones at least every 7 years. Globally, there is an initiative to reduce the protection areas around aerodromes to take account of the flight performance of new aircraft types. This performance increases substantially with the introduction of each new aircraft type. The consequence of this is a decrease in the amount of accidents outside the aerodrome boundary. It is widely known that despite growing air traffic, the number of accidents is decreasing.

Proposal

Public Safety Zones have been established at all the airports with above 18,000 air traffic movement a year.

They comprise an outer boundary which is the 1 in 100,000 risk contour and an inner, higher risk zone, based on the 1 in 10,000 risk contour. The length of the 1:100,000 risk contour for an aerodrome with less than 45,000 ATMs per year has been set at 1,000m from the landing threshold. For an aerodrome with greater than 45,000 ATMs, the PSZ follows the same lateral plan but extends to 1,500m.

The width of the 1 in 100,000 risk contour at the landing threshold is equal to the relevant runway strip.

Regardless of ATMs, the length of the 1:10,000 risk contour has been set at 500m from the landing threshold.

The width of the 1:10,000 risk contour at the landing threshold is equal the cleared and graded area.

In all cases the Public Safety Zones are based on the landing threshold for each end of the runway and taper away from the runway.

The standardised shape that replaces the risk-based model profile and has been defined using the latest data on accidents shown to be located outside the aerodrome boundary.

The diagram of the two PSZ zones is included.

Why your views matter

While the change will only affect a small number of aerodromes, we felt we needed to ensure that all related stakeholders needed to be included in a consultation so that they have the opportunity to express any concerns.

Those stakeholder may include Local Planning Authorities and Land owners affected by the change to the shape of the new zones.

Your views are invited

We welcome views on any of the issues raised in this proposal. The consultation period will close on 23 December 2020.

Please e-mail responses to FSTechnicalSupportTeam@caa.co.uk