ATSAP Keeps Future of Runway Lighting Appropriately Bright
Friday, August 16, 2013

(Editor’s Note: This is the latest in a series of ATSAP success stories produced by ATO Communications, with assistance from NATCA)

What do you get when you mix old-fashioned light bulbs with LED lights in airport runway lighting systems? Uneven lighting that complicates landings for pilots and distracting alarms that increase the workload of air traffic controllers.

But those obstacles shouldn’t be a problem going forward thanks to ATSAP.

The Event Review Committee (ERC) for the Central Service Area identified the issue by piecing together concerns that controllers raised through the Air Traffic Safety Action Program (ATSAP). The ERC then ordered steps to address the situation at three airports in its area and recommended a new standard for LED lights in the future.

“This was a big win for us,” said Scott Keller, NATCA’s terminal representative on the ERC. “It brought a lot of different entities together to solve a potential safety problem. This is a proud moment for ATSAP.”

Controllers at Abilene Tower (ABI) first brought the issue to the attention of the Central Service Area ERC. They filed ATSAP reports in September 2011 after discovering problems associated with runway lighting and the system that determines the critical runway visual range (RVR), which is how far pilots need to see down a runway on approach.

The problem arose after the airport began installing LED bulbs in some lighting systems but keeping the traditional incandescent bulbs in others. The RVR system included an alarm that sounded whenever the lighting intensity for any of the three runway-related lighting systems differed from the others.

Because LED bulbs shine brighter than incandescent ones, pilots flying into Abilene Regional often requested that controllers adjust the intensity of the lighting systems so they would shine evenly. 

“The intensity [of the LED lights] was so bright that it appeared that there were no lights on the taxiway farther away,” Keller said.

ERC Chairman Robert Hutson added: “It’s in essence like driving into the sun. ... [Pilots] want that visual aspect to be in tune with the eye.”

But whenever controllers adjusted the lighting to aid pilots, the RVR alarm sounded and distracted them, said Rob Marcotte, the terminal air traffic safety representative on the ERC.

A few months later, controllers at Albuquerque Tower (ABQ) filed ATSAP reports highlighting the same issue. That’s when the ERC decided to explore whether the lighting intensity was a system-wide concern.

Ric Loewen, a controller at Dallas Fort Worth Tower (DFW) and NATCA’s representative on runway safety issues, and Runway Safety Program Manager Paul Erway also helped keep the issue active. 

“Our role was to make sure that we didn’t stop looking” for a solution beyond simply turning off the RVR alarms,” Loewen said.

Within the Central Service Area, the committee found a November 2010 ATSAP report about taxiway lighting from Dayton Tower (DAY). That prompted the ERC to explore the ATSAP database for reports from other regions, and they found two from Florida. The one from Orlando (MCO) in August 2010 preceded all of the other reports, and controllers in Daytona Beach (DAB) submitted an ATSAP report in November 2011.

(Above) Ric Loewen makes a point while discussing ATSAP.

“Since LEDs appear to be the future of airport lighting,” the ERC concluded, “this potential problem may continue to grow as airports install ever more efficient lighting systems.”

With that realization in mind, the ERC had to decide how to address the issue. While the RVR alarms didn’t indicate a system failure, the committee concluded, “routinely suppressing system alarms of any kind may increase operational risk.” The panel focused instead on a fix at the lighting source.

Pilots flying into Raleigh-Durham (RDU) also had complained about the impact of the mixed LED and incandescent lights on their vision, and the FAA’s Office of Airports and the Technical Center had worked with the Raleigh-Durham Airport Authority to gauge the ideal intensity for LEDs.

"Pilots were complaining about the intensity ever since the lights were turned on, asking for us to turn down the intensity," NATCA RDU Facility Representative Dennis Wallace said. "We had to explain that they were on the lowest setting."

Flight tests showed that dimming the LED lights to 70 percent of their full brightness struck the right balance. “They were able to turn down the power output where it’s not so offensive to pilots,” RDU Air Traffic Manager Charles Bramble said.

Erway’s research into the issue ultimately led him to an April study on the RDU testing. Citing that study, the ERC issued a corrective action request that incorporated the new standard. Since then the changes to the dimming curve have either been made in the LED firmware or are underway at the affected facilities, Keller said, and “all new implementation will be at that 70 percent value.”

Although individual airports had been aware of the problem, Hutson said ATSAP revealed how broadly it could have affected the national airspace system in the future. “Not until we really brought this up did it get the attention it needed,” he said.

Loewen agreed that ATSAP made the difference. “It raised the issue to the level in the agency that there was sufficient energy around the problem to get an answer to it,” he said.

To see NATCA’s ATSAP page on the website, which includes a complete archive of ATSAP success stories, please click HERE.