Tom Allett attended the recent Mobile Airfield Light Monitoring System (MALMS) user group seminar, hosted by Tailor Made Systems (TMS) in Manchester, UK.
The latest in a series of MALMS User Group Seminars was held at the Manchester United football stadium, Old Trafford, on November 13. It focused on photometric evaluation technology; the general testing and maintenance of airfield lighting and a little history that highlighted how some of today’s cutting-edge products were developed.
Paul Fraser-Bennison, UK CAA Policy Specialist for Aerodrome Standards, explained that the introduction of photometric testing had shown how dramatically the performance of an airport’s runway lighting can deteriorate if it is not properly checked and maintained.
He recalled that photometric testing had shown the airfield lighting standards at UK airports are currently “pretty high”, though when photometric testing was first introduced, the brilliance of one British airport’s runway lights had fallen to just 20% of the expected standard. There is no room for industry complacency though. Recent photometric tests overseas revealed that the lights on one runway at a world-ranking airport were producing just 8% of their intended value.
While the safety implications of sub-standard lighting were obvious, there were also operational benefits for having high-performance lighting.
For example, if runway lights were working at full potential during periods of poor visibility, their output may help airports to introduce inevitably-costly, low-visibility procedures at a later stage or maybe not at all.
Mr Fraser-Bennison said that to test the premise the CAA has conducted detailed studies of lights at several airports and, armed with the information, is looking at the possibility of introducing instrument runway visual range (IRVR) ‘credits’ to airports that can demonstrate high levels of serviceability by regularly testing lighting performance with photometric equipment. He said the authority felt that airports that had invested in the most accurate form of testing: “should get some safety and operational benefits in return.”
He explained that IRVR measuring equipment uses assumed values for the brightness of each light, as a component in calculating the current visibility, therefore regularly ascertaining the performance of each light could lead to a ‘credit’ – a higher assumed value – being used in the equipment’s calculation. Using industry statistics he suggested that this could enable an airport to reduce time spent incurring low-visibility procedures by several minutes per day, thereby enabling extra arrivals or departures and reduce the expense and disruption caused by potential flight diversions to another airport.
Mr Fraser-Bennison concluded with a look at LED lighting. He reassured anyone having concerns about LEDs either causing glare by being too bright or not being suitable in unforeseen ways, and underlined how the technology brings: “exciting opportunities, longer and better whole life costs and greenhouse gas reductions.”
He also added that, although very reliable, its performance in low-visibility conditions was “no better but no worse”, than halogen alternatives. In closing he added that while LEDs were an emerging technology in 2005, UK restrictions on its use for runway applications were lifted on August 17, 2012. Its acceptance for approach lighting is the next big step.
The meeting was honoured to have engineer Tony Smith present. Mr Smith, along with David Johnson, was largely responsible for developing the Precision Approach Path Indicator, commonly referred to as PAPI, at the Royal Aircraft Establishment (RAE) at Bedford/Thurleigh airfield in the 1970s. PAPIs are still at the forefront of visual landing aids and Mr Smith played a film showing how RAE aircraft were used to fly countless approaches at Bedford in low-visibility conditions so that the visual landing aid could be perfected. It was the first time I had seen the film since it formed part of my airline ground-ops training almost 30 years ago! Despite the passage of time the movie still highlighted the problems faced by pilots in poor visibility very well and provided a powerful reminder of the importance of high-quality airfield lighting.
Today’s PAPI-testing regulations determine that they require a daily visual inspection and twice-yearly flight checks. Flight tests are known to be less accurate than visual inspections and an example of TMS’ stand-alone photometric PAPI tester which conducts vertical and horizontal alignment checks was on display at the event.
Things have moved on since the traditional Spot and Block methods of measuring airfield lighting performance were introduced. I am sure that most readers will be familiar with at least some of TMS’ long-established range of MALMS photometric testing products. Having been developed from a UK CAA development programme, the towable MALMS Mobile stands out because traditional photometric testing usually takes up so much time that threshold, runway end, stop bar and low-level approach lights are rarely – in some cases never – photometrically tested. Obviously, this might allow their performance to fall below international standards and make them potentially unsafe.
Wayne Rolfe, TMS’ Sales and Marketing Manager explained that examples of the MALMS trailer, which can be towed behind any vehicle, are already in service at 61 airports. So for the purposes of this article I will concentrate on the most recent additions to the MALMS range – the Transverse, Cleaner and Engineer Airfield products.
MALMS Transverse is an add-on to the MALMS Mobile product. Designed to vertically measure threshold, runway end, stop bar and low level approach lighting, it has 12 sensors and is towed parallel to, but approximately 15ft (4.5m) from, the lights being measured. TMS says it can measure most types of inset and elevated lighting, including approach lighting located to 5ft (1.5m) above the ground. Mr Rolfe explained that MALMS Transverse provides a much faster way of obtaining an accurate measurement time for thresholds, runway ends, stop bars and low-level approach lighting. No extra staff are needed, just the single driver of the vehicle towing the MALMS unit and no specialist training is required as software used can be retrofitted to existing windows-based systems.
Highlighting the fact that good maintenance is just as important to performance as good equipment, TMS has produced the MALMS Cleaner which, as the name suggests, does away with the need for manual or potentially-damaging high-pressure water cleaning at ground level. It is used in conjunction with the basic MALMS test-rig and only cleans the lights that fail the MALMS inspection. GPS takes the engineer directly to the lights than need cleaning, thereby reducing the number of times he or she must access the runway. Even elevated lights can be handled thanks to a manual lance that is provided. Acknowledging today’s environmental standards, MALMS Cleaner uses food-grade bicarbonate of soda as the decontamination agent.
A relatively new inspection and maintenance solution is MALMS Engineer. It removes the need for paper reports by using the MALMS Mobile data-logger to record faults and work required. Scheduled maintenance programmes can be uploaded into the user’s computer, allowing them to use their own airport maps as the basis for individual projects. Lights that are tagged by the MALMS Engineer system can be located even more precisely than GPS can achieve, enabling an engineer to go straight to the problem light every time. It can also be used to log faults on other types of assets; signs, generators, etc, as required. This can be done on the move, there is no need to stop. It also reproduces historic data meaning that all previous work can be traced.
The event concluded with product presentations from established airfield lighting companies – in order – Hella; Erni/Lucebit; Safegate and atg airports. Details of the next MALMS User Group Seminar have yet to be announced.