The obstacle clearance surfaces around CAA and EASA licensed aerodromes are defined within CAP 168 ‘Licensing of Aerodromes’ or within the relevant EASA certification specifications, which are based on those in ICAO Annex 14. Guidance for the obstacle clearance requirements at unlicensed airports and airfields is given in CAP 793 ‘Safe Operating Practices at Unlicensed Aerodromes’. In such cases, the safeguarding requirements are less stringent although some unlicensed aerodromes adopt the criteria in CAP 168 or its EASA equivalent. In addition to the constraints on building development, the safeguarding policy agreed with local planning authority can require mandatory consultation on other proposed activities near the airfield including the siting of cranes, shooting, kite flying etc. Any planning application which might lead to increased bird activity near the airport should also be referred to the licence holder, including those involving rubbish tips, lakes and landscaping.
The typical format for an airport safeguarding map is shown in the example below:
Belfast City Airport – Safeguarding Map
In addition to the safeguarding criteria, those UK airports with more than 1,500 air transport movements (ATMs) per month should establish Public Safety Zones (PSZs) at all runway ends. This Public Safety Zones should be prepared by the airport operator based on the statistical risk of an individual living or working within the area dying as a result of an aircraft accident. Under current Department for Transport (DfT) legislation, PSZs for 1 in 100,000 and 1 in 10,000 annual risk contours should be prepared every seven years and lodged with the local planning authority. Except in certain specific cases, there should be a presumption of no new or replacement residential development within the 1 in 100,000 annual risk contour although certain types of commercial development such as warehousing, with relatively few employees on site are deemed to be acceptable, The 1 in 10,000 annual risk contour should be free of all residential and commercial property and, if this is not the case, the airport operator is expected to make a compulsory purchase order to acquire and demolish these properties. There are some exceptions to this requirement, including land used for long-stay car parking, buildings housing machinery etc without any associated permanent employees and golf course (but not clubhouses). The precise definition of a PSZ requires detailed modelling based on the expected movement levels and accident data for the types of aircraft flown. A typical example, showing the 1 in 10,000 contour (in blue) and the 1 in 100,000 contour (in red) is shown below:
Farnborough Airport – Public Safety Zones