ATSAP Clears Path Through Trees for S.C. Airport Radar
Thursday, August 23, 2012

Editor's Note: The following is an article collaboratively produced by NATCA and Air Traffic Organization (ATO) Communications.

When the trees at the Greenville-Spartanburg International Airport, in Greer, S.C., get too tall, they block the Airport Surveillance Radar’s (ASR) signal, causing problems for controllers at Greer TRACON. The targets on their scopes disappear, jump or lose their data blocks.

The tree interference prompted controllers to file Air Traffic Safety Action Program (ATSAP) reports. As a result of the reports, the Event Review Committee (ERC) representing the Eastern Service Area issued a Corrective Action Request. After local discussions, the airport this spring cut the trees that were causing the problem, giving controllers better radar coverage of the airspace.

NATCA Representative James Royer said ATSAP was a key component in resolving the issue.

“The ATSAP process took our problem and raised awareness to other departments in the FAA, which were able to come to a consensus on what needed to be done,” he said. “The ERC and ATSAP were a tremendous help.”

The issue dates to the late 1990s, according to Royer and Air Traffic Manager Lamar Foster.

The FAA convinced the airport to remove the trees twice before — in 1997 and 2006 — but the airport was reluctant to carry out the cutting. The airport has won awards for beautification efforts and it runs a working tree farm. And it’s not just a couple trees that cause the problem. To provide a clear path for the ASR, the airport had to raze dozens of acres.

The problem begins gradually, according to Royer, as new trees start to grow.

“The first thing you start losing are the primary targets — the radar beacon returns — at the lower altitudes,” he said. “And as the trees get higher, the loss starts to increase. Instead of not seeing airplanes at 2,500 or 3,000 feet, now you can’t see them at 4,000 feet.”

That forces controllers to work traffic in the affected parts of Greer’s airspace using nonradar procedures, which means extra flying time and fuel costs for pilots and extra work for controllers who could otherwise be scanning for potential conflicts.

It adds another challenge for controllers at a facility that is already busy due to its location between Atlanta Hartsfield-Jackson International Airport and Charlotte Douglass International Airport, Foster said.

“We handle a lot of overflights, and a lot of reroutes around Charlotte’s airspace,” he said.

And the tree interference doesn’t just impact Greer. The facility shares airspace boundaries with Charlotte TRACON, Augusta TRACON and Columbia TRACON. Instead of performing automated handoffs between the TRACONs, Royer noted that added steps become necessary to counteract the issue.

“When we have this problem, we have to call them ahead of time and coordinate those planes in a nonradar setting,” Royer said.

As a long-term solution, the FAA is planning to put the ASR on a taller tower.

The 2013 budget request will include funding to raise the ASR tower, according to John Fowler, a lead planner for Mission Support Services Planning and Requirements group.

If the ASR program is fully funded, Greenville-Spartanburg’s radar should finally soar above the treetops for quite awhile.

Related information

To view new ATSAP refresher training, go to: and click on "ATSAP–What to Expect" under Resources. For Mac users, Firefox may work best for the provided link.

The course number for the eLMS class is: FAA68000314

When you watch the video on the eLMS platform, it will show that you have taken it in your learning history.