Light-emitting diode (LED) airport approach lighting offers many benefits, including reduced power consumption and greater nighttime visibility, but it may also cause difficulties for business aircraft flight crews using enhanced flight vision systems, or EFVS.
Offered on many large business jets, EFVS uses infrared technology (IR) to provide an enhanced display of natural terrain and human-made structures through a head-up display or flight instrumentation. The systems aid pilots flying landing approaches in inclement weather or under other reduced visibility conditions.
However, LED lighting is essentially invisible to most EFVS as, unlike traditional incandescent lights, LEDs do not emit IR radiation. An FAA spokesman noted those concerns were carefully considered as the agency deliberated the switchover to LEDs.
“The FAA conducted testing and evaluations of LEDs to determine their compatibility with EFVS,” the spokesman noted. “The process included field evaluations on how different types of LED lighting interact with EFVS and gathering feedback from pilots to assess whether LED lighting systems might cause issues with visibility, glare or system performance.”
Given the advantages of LEDs – which also include greater durability and reduced maintenance, as well as enhanced color flexibility that eliminates the need for color filters – the FAA opted to issue guidance to flight crews operating with EFVS to airports equipped with LED lighting.
“Pilots conducting an EFVS operation who experience a reduction in sensor performance due to LEDs should execute a go-around unless they have adequate enhanced flight visibility and visual references to continue,” the FAA spokesman added. “Multiple FAA offices are collaborating on how best to track the airfields where LEDs are installed.”
That includes a spreadsheet listing airport runways with LED approach lighting, with plans to include these locations in airport chart supplements. NBAA Director, Flight Operations and Regulations Laura Everington urged flight crews to consider EFVS limitations when flight planning to airports with LED lighting.
“As the FAA and EFVS manufacturers work to mitigate the negative effects of LED lighting on such systems, business aviation pilots must be adequately prepared to handle conditions that may severely limit use of EFVS at critical times,” she added.
Among the solutions in development are multispectral EFVS cameras able to discern LED lighting. A small number of airports, including Savannah/Hilton Head International Airport (SAV) and Harry Reid International Airport (LAS), have equipped LED approach lights to certain runways with IR emitters, allowing retained EFVS functionality.
