ATSAP Clears Clutter from Boise Scopes
Friday, March 29, 2013

(Editor’s Note: This is the latest in a series of stories written by FAA Communications with NATCA involvement to highlight issues successfully addressed through ATSAP.)

When a controller at Boise Tower (BOI) was faced with cluttered radar screens for new navigational procedures, they reported the issue through the Air Traffic Safety Action Program (ATSAP), triggering a quick fix to the related video maps.

“[The response] was light speed compared with what we previously had been accustomed to,” BOI Manager Gordon Stewart said.

The new maps made it possible for his team to start using area navigation approaches for two runways within days after the ATSAP Western Service Area Event Review Committee shared a report — with the submitter’s permission — that included a request for less confusing maps.

The concern surfaced after the publication of new RNAV Z approach routes for Runways 28R and 28L at Boise Airport. Southwest Airlines was a big advocate of the new flight paths because of the expected fuel savings, and Alaska Airlines planned to use them, too.

But Stewart said controllers at BOI recognized a problem immediately. The number of waypoints on the digital maps increased as planes neared the airport, and each waypoint was represented on the radar screen by an icon about the size of a pencil eraser.

“Every time [a plane gets] close to one of those, it’s another piece of information you have to display on a radar screen, which is limited,” he said. The icons “were as big as the airplane target, so it was really easy to lose your airplanes in all this background clutter.”

Multiple layers of maps on the screen further complicated the situation. Front Line Manager Jeremy Yahn said BOI typically overlays two of its 10 digital maps to direct air traffic but adds a third and sometimes a fourth when running the RNAV Z approach. As a result, 22 waypoints were displayed within 10 miles of the airport, Yahn said.

“There’s too much information displayed on the radar map, and it makes it difficult to see the information that is necessary for normal operations,” NATCA Facility Representative Mark Griffin said.

Stewart compared the situation to controllers trying to pick a speck of pepper from a surface full of sand.

“We absolutely felt it was unsafe to use,” he said.

His team wrote Notices to Airmen that put the approach routes out of service until maps with fewer satellite-based directions could be created.

About six months later, BOI was surprised to see the same RNAV Z routes published again. That’s when a controller filed an ATSAP report to highlight the uncertainty of the new routes, and the fact that they made it difficult for controllers to track and manage incoming aircraft.

Appealing for a fix through ATSAP worked. The ATSAP event review committee responded quickly, and Yahn drafted new maps in the RNAV-oriented Terminal Area Route Generation Evaluation and Traffic Simulation software over a two-day period.

“I drew it up in TARGETS as to what we wanted [the maps] to look like” and sent the specifications to the Aeronautical Navigation Products office to be finalized, Yahn said. The whole process usually takes six to eight weeks but was expedited thanks to ATSAP.

BOI had new maps in less than 10 days, Stewart said, and they achieved the dual goal of “retaining a valuable aid to aircraft while still ensuring that controllers had the necessary tools to sequence aircraft.”

The new maps depicted only seven key waypoints, Yahn said. Those markers included the base turn of approaching aircraft, which helps controllers ensure proper separation among planes.

“That’s the key turn for us,” Stewart said. “You know at that point [the pilot is] committed.”

Technicians plugged the maps into the equipment, and the navigation is working well now. Yahn said Southwest and Alaska Airlines are averaging a combined three to four RNAV approaches per day.

“We were stunned at how fast the work was done,” Griffin said, adding that he sees the response “not only as a success story for ATSAP but as a success story for collaboration in the agency.”