When they take off and land it will be the complex network of runway lights that assists with their navigation to guide the pilots for as safe as possible take-offs and landings, as and when the sun goes down or visibilities change. This is by design. It is not just an aesthetic feature, it is one precise visual system with everything from color to placement to how it all appears having meaning to those working around airport equipment, so the relevant specifications should be at their fingertips. This guide is an overview of airport runway lights.
The Language of Light: Colour Coding and Placement
Specification for runway lights begins with color. Runway edge lights are most white with color changes only at the last 600meters or 2000feet to signal to pilot that he or is nearing the end of runway. These specific colored lights on instrument runways can be amber/yellow so that a pilot will more obviously discern it. However, on occasion under very challenging circumstances pilots will want WHITE throughout due to the visibility conditions.
Should they need WHITE, they will understand that they will have to attain flight to an above the runway height position while flying as high to their limits, in an effort to clear or risk an impact with the runway in cases of pilot misjudgment or overshoot, since WHITE lighting makes the runway not clear for at an later stage the pilot is attempting to come in on descent, while RED lights indicates end to the Runway for all intents and purposes of the airplane pilot as compared to the GREEN lights indicating it has started a run or has been in a run.
Airport operators will advise that when runway has entered a pilots view, that then only green lights and red lights are of concern – when on or around and on the approach to take off that will begin at green lights and at some point along the runway end the lights will be at red; as to distinguish the ends. There will be white lights running down the center of the runway as it is the main path of travel. If a runway ends will be lined with lights which goes around the edge of it, as it can be with the WHITE lights going round but changing at 900 meters from solid white to red and white alternating, until three hundred meters distance to the end lights, of which that will be solid red, as a warning to pilots on their approaches. Hence colors are the global signal.
Approach Lighting Systems: Extending Guidance
On approach to an airport, at night or with less than perfect conditions, runway lighting on the approach to and at the runway is very important depending upon the design of the runway and what level of complexity it is that is required. For example, in a less stringent need the approach lighting on the runway itself might simply be Short Approach lighting System (SALS) which will consist of lights all down one of sides of the approach strip, on occasions with a cross bar at the end. On the other hand, a full approach lighting on an instrument rated runway in category 11 or 111 low-visibility conditions can be far more extensive and extend hundreds of meters past the designated runway.
The brightness and directions for lights are a significant detail that would appear on lighting and is often used for runway identification lights, landing lights and others which may not all be fitted as the standard runway edge lights is the only necessary one to give reference in poor visibilities. Specifications are given as to where the lighting will be set into the pavement or in frangible stands in order to avoid damage to the lighting system and/or airframe in case of overrun. However, it is light directions and intensities that are specified by the CAA/FAA to achieve the best guidance. Some are 2032mm out from the edge, 3.05 meters from the rim of runway lighting set, and consists of two flashing green lights at a frequency dictated by the CAACI/FAA in addition.
Power Control and Intensity Management
The ability to switch and to regulate lights enables different lighting configurations to be established for all of the lighting conditions required in the lighting regulations; The system for the controlling and maintenance of runway lights is called Airport lighting control system (ALCS) or the management of Airport lighting system (ALCMS) which have regulated control of Airport lights driven by these systems.
A switch controls light intensities varying from full down through medium to low, while a smart light knows that you are trying to get out when you activate the system in question and has the facility to automatically control lights to the optimum level required for the airport's conditions using solid-state electronic switching with precise control voltage and current regulate the lights or using smart lights technology. Runway lights' control involves specific discrete lighting levels available to controllers, e.g. Runway edge lights range from light (no need to use a high intensity and blinding condition) all the way up to and includes 100% on the dial. To control voltage and current is with the use of constant current regulators (CCRs), earlier versions using thyristors, but new generation versions use switched mode power supplies for a much tighter current and voltage regulation.
Operational and Environmental Specifications
Other very important specification features are that the lighting should be operationally sound and environmentally compliant. The lighting units must withstand extreme temperatures between -40 and +60C, be weatherproof (to high I.P. Rating), withstand any jet blast directed at them and also impact from an overrun.
The specifications regarding candela outputs and the relevant light intensity levels for operational, approach lights and, in the case of runway lights with edge lighting at 3 light 3 degree dispersion and50 percent intensities 3.5dispersion light spread are given to guide the pilot effectively. For the reasons, it is usually best to ensure lights manufactured are made of high-strength glass, with appropriate guards fitted to protect the lamps from damage in the case of any type of over-run incident. Tests to ensure these lights meet the criteria should have been carried out. The majority of LED Airport Lighting can have bulb replacement if needed, while older Tungsten Halogen lighting requires full unit replacement though some are supplied with replaceable lamps.