Portable airfield lighting systems may be used by the military for airstrips in austere locations. Similar specialist lighting is found at heliports, on oil platforms, onboard ships and on aircraft carriers.
Airfield lighting is essential to aviation safety and serves three main purposes. Firstly, it helps pilots find an airfield in bad weather or at night when visibility can be severely hampered. Secondly, airfield lighting helps pilots land their aircraft safely. Thirdly, lighting helps pilots move around an airfield safely when on the ground. Airfields have dedicated lighting for their runways, taxiways and aprons. Tall structures and potential obstructions on and around the airfield may also be marked with red warning lights.
Evolution and Design
Dedicated airfield lighting is almost as old as human-powered flight. By the 1920s rotating lights were being used to help pilots find an airfield at night. Some airfields continue to use these which are not unlike lighthouses found in coastal areas. These rotating beacons are comprized of two lights positioned back-to-back. One is green and the other white. They illuminate a bright light visible for several nautical miles beyond the airfield, rotating at a steady speed. This white-green configuration ensures the pilot will not confuse them with other lights nearby.
Lighting helps pilots make safe landings at night and in bad weather. Special lighting systems tell a pilot if they are approaching a runway at a safe angle from the correct direction. If a pilot approaches the runway at too high an altitude, they will only see one color of light, usually white. If they are approaching too low, they will only see red lights. If their angle is correct, they see a mix of red and white lights. Visual Approach Slope Indicators (VASIs) and Precision Approach Path Indicators (PAPIs) perform this role.
Safety and Approach Lighting
Approach lighting helps guide an aircraft to a runway. These extend some distance beyond the runway and are often outside the airfield perimeter. They indicate the direction of the runway’s centreline to the pilot as a runway’s direction can be hard to discern in darkness or bad weather. Additional runway lights indicate the runway centreline, threshold and the touchdown zone where the pilot should land. Lighting elsewhere on the airfield indicates taxiways. Their edges are usually in blue with the taxiway centreline depicted by green lights. Safety lighting in red and green shows the pilot when it is safe to enter the runway. Elsewhere on the airfield, signage indicating taxiway and runway designations is illuminated.
Technology and Regulation
Today’s airfields use Light Emitting Diode (LED) systems. LED lights are long-lasting, energy efficient and low maintenance. International standards for airfield lighting are governed by the International Civil Aviation Organization (ICAO). ICAO standards are adopted by national aviation authorities and militaries. This ensures a global harmonization of airfield lighting. Aviation’s international nature makes this essential. Pilots must be familiar with airfield lighting wherever they are. This is greatly assisted by commonality. Most airfields have installed fixed lighting systems. However, some may use portable systems. These may only be needed in bad weather conditions, or when flights are occurring outside normal hours of operation.