Lighting the way to safety: airport lighting systems20 February 2013
Nothing is more important to the aviation industry than safety, no matter what commercial concerns may arise. Jim Banks analyses FAA guidelines covering lighting control and monitoring systems that set the standard for using technology to manage airport lighting systems.
The importance of airport lighting to the safe management of air traffic cannot be overstated, and the mechanisms through which lighting is controlled and monitored are a key focus for investment among technology developers. The need to make the management of lighting systems quicker, simpler and more reliable means that IT systems are constantly evolving.
One of the latest trends is for airports to install computerised touchscreen controls for airport lighting systems, and regulatory bodies have had to ensure that they issue updated guidance to address these systems.
An airport lighting control and monitoring system (ALCMS) simplifies the control and monitoring of lighted visual aids and enhances airport safety. Furthermore, as the basic function of an ALCMS remains the same, whether it is for a general aviation airport that supports only a few operations a day or a large commercial airport that caters to hundreds, the guidelines have to be sufficiently broad to be relevant to all airport operators.
According to the Federal Aviation Administration (FAA), safety is the first and foremost driver behind the implementation of an ALCMS in North America. The system provides programmable intelligence for the control and monitoring of airfield runway and taxiway lighting circuits to meet the requirements of FAA Advisory Circular (AC) 150/5345-56B.
The FAA AC 150/5345-56B 'Airport Lighting Control and Monitoring System L-890XY' standard issued in September 2011 specifies the minimum requirements for an ALCMS and states that only equipment qualified in accordance with that specification would be listed as adhering to AC 150/5345-53, 'Airport Lighting Equipment Certification Programme' (ALECP).
At the start of 1990, a new programme was put in place, which named a commercial testing laboratory - under the oversight of an industry technical advisory committee - as the programme certification body. Five years later, the FAA took steps to recognise that a number of other commercial laboratories might be interested in acting as certification bodies, and in 1995 established ALECP. This programme stated that any commercial laboratory meeting certain criteria could participate as a certification body, and provided a framework for FAA oversight and acceptance of these bodies.
Under the ALECP, the FAA now has a list of accepted certification bodies that evaluate and certify airport lighting equipment and licenced suppliers to mark qualifying products. The FAA maintains a list of certified equipment as part of the AC addendum to assist airport sponsors in determining that equipment meets the applicable FAA specifications and is eligible for funding under the federal grant assistance programme for airports.
Runway centreline and touchdown zone lighting systems are designed to facilitate landings, roll-outs and take-offs. The touchdown zone lights are primarily a landing aid, while the centreline lights are used for both landing and take-off operations. Runway edge lighting defines the lateral and longitudinal limits of the usable landing area of the runway. 'Low visibility' taxiway lighting systems such as taxiway centreline lights, runway guard lights, stop bars and clearance bars are designed to facilitate taxiing safely
in these conditions. These taxiway lighting systems protect high-speed, low-visibility operations on the runway, enhance safe ground movement of aircraft and other vehicles on the airport surface, and standardise marking and lighting.
The ALCMS can automatically control and monitor stop bars or runway guard lights as part of a surface movement guidance and control system (SMGCS. In addition, the system can control and monitor land-and-hold-short systems and can be customised to interface with constant current regulators, generators, approach lighting or other devices requiring remote control and/or monitoring.
The ALCMS also provides the appropriate settings for runway and taxiway lighting intensity in the support of aircraft take-off and landing operations.
Ready for the future
The changes in the lighting certification programme over the years reflect the changes in the resources of the FAA as well as the potential for other capable bodies to play a part in the certification process. They also ensure that changes in technological capability can be successfully factored into the approval cycle.
Under the current guidance, airports that have previously installed an airport lighting control and monitoring system will not be required to replace their existing system; however, future installations of replacement ALCMS projects funded with Airport Improvement Programme (AIP) grant funding or Passenger Facility Charge (PFC) funds will be required in order to meet the technical standards of the Advisory Circular.
The FAA has recognised the fact that many airports have a desire to install computerised touchscreen controls for airport lighting systems. The original specification for lighting control panels in AC 150/5345-3, 'Specification for L-821, Panels for Control of Airport Lighting' did not include specifications for these kinds of controls; however, under the FAA's modification of standards provisions, computerised touchscreen control panels have been installed at some airports and have proven to meet the functional requirements for lighting control panels as specified in AC 150/5345-3 and other related ACs.
The FAA says that it is not aware of any current challenges regarding legislation governing the use of the ALCMS. Such systems are eligible under the Airport Improvement Program (AIP) and may be supported with AIP grants or PFC revenue. There are currently six FAA-certified ALCMS manufacturers that support several levels of desired capability. These desired capabilities are based on customer requirements and are typically composed of a combination of monitoring levels and fail-safe design requirements.
The existing guidance is also structured to cope with technological advances, such as touchscreen controls, and as additional requirements emerge they can be added relatively simply to an open architecture framework for the ALCMS (see Figure 1, below).
The FAA AC for the ALCMS specifies several designs that give airports the flexibility to expand their system architecture as the airports' requirements change and as the FAA requires new capabilities. The open architecture of the ALCMS allows the system to be integrated with any of the latest advanced airport systems technologies.