Building developments near airports often face objections, primarily due to concerns about flight safety. These objections carry significant weight with planning authorities. This guide provides a straightforward overview of common airport concerns and how to address them effectively.
Why Airports Object to Building Developments
Airports prioritize safety above all else. Proposed buildings near airports can introduce various risks that may lead to objections. Understanding these concerns is the first step in navigating the objection process.
Height Restrictions: Obstacle Limitation Surfaces
One of the primary concerns is the height of new structures. Buildings that are too tall can pose a collision hazard to aircraft. To manage this risk, airports implement physical safeguarding assessments. These assessments compare a proposed structure against a series of imaginary surfaces, known as Obstacle Limitation Surfaces (OLS), extending from the airport’s runways. These surfaces are designed to ensure safe flight operations. The methodology is based on guidance from the International Civil Aviation Organization (ICAO) and is widely adopted internationally, including in publications like the UK Civil Aviation Publication ‘CAP 168’.
Figure 1: Example of a physical safeguarding assessment, illustrating a hypothetical obstruction below the Outer Horizontal Surface at Gatwick Airport.
Proximity Concerns: Distance and Location
The closer a building is to an airport, the higher the likelihood of objection. While distance is a key factor, the location of the building relative to the runway alignment also plays a crucial role. Generally, concerns decrease as distance increases.
Beyond approximately 20 kilometers from an airport, developments are typically clear of Obstacle Limitation Surfaces, significantly reducing collision risk concerns. However, proximity remains a factor even at greater distances due to other potential interferences.
Radar Interference
Airports and Air Navigation Service Providers (ANSPs) rely on radar systems to monitor air traffic across vast areas in all weather conditions. These radar systems emit electromagnetic signals to detect aircraft.
Figure 2: A typical radar installation in the UK, showcasing the equipment used for air traffic monitoring.
Large buildings located near radar installations can cause interference. This interference can occur by blocking radar signals or by reflecting them, leading to inaccurate readings or “clutter” on radar displays. Radar operators are more likely to object to developments within a 20 km radius of a radar site, although this is not a strict limit, and each case is assessed individually.
Navigation Aids Interference
Besides radar, airports utilize various other navigation aids, such as Instrument Landing Systems (ILS) and radio beacons. Buildings within a few kilometers of airports can potentially interfere with these radio-based navigation systems, leading to objections. While a detailed review of all navigation aids is beyond this simple guide, it’s important to be aware of potential interference with these systems in close proximity to airports.
Solutions and Mitigation Strategies
While airport objections can seem daunting, solutions and mitigation strategies often exist. Each case is unique and requires individual assessment, but common solutions include:
- Detailed Impact Assessments: A thorough assessment can quantify the potential effects of a building on airport operations. This may demonstrate that the actual impact is minimal or within acceptable limits.
- Building Design Modifications: Adjusting the height or shape of a building can significantly reduce its potential impact. Lower buildings or designs with less reflective surfaces can be effective mitigation measures.
- Technical Mitigation: For certain radar types, particularly Secondary Surveillance Radar (SSR), technical solutions are available. These can involve programming the radar system to recognize and filter out reflections from known structures, effectively suppressing interference.
What Developers Need To Do: A Step-by-Step Guide
Navigating potential airport objections requires a proactive approach. Developers should take the following steps:
- Early Proximity Checks: Determine if the proposed building site is within 20 km of an airport or radar system.
- Height Comparison: Assess if the proposed development is significantly taller than existing surrounding buildings.
- Stakeholder Consultation: If potential concerns are identified, initiate early consultation with the relevant airport and air traffic control stakeholders.
- Detailed Assessment (If Necessary): If an objection is received, commission a detailed assessment to quantify the potential operational impact.
- Explore Mitigation Options: If the assessment predicts a significant impact, investigate and propose suitable mitigation strategies, including building modifications or technical solutions.
By understanding the reasons behind airport objections and taking a proactive, solution-oriented approach, developers can effectively navigate the planning process and minimize potential conflicts. This Simple Objection Guide is designed to provide a starting point for ensuring building projects and airport operations can coexist safely and efficiently.
