ATSAP Resolves Automated Routing Glitch at Dulles
Thursday, May 03, 2012

Thanks to controllers filing ATSAP reports, an automation snag that added to their workload and potentially threatened safety in the Washington, D.C. area has been resolved.

A flight restricted zone (FRZ), instituted after the terrorist attacks of Sept. 11, 2001, banned foreign carriers and general aviation aircraft from a frequently used eastbound Washington Dulles International Airport departure route. But until recently, Host, the en route computer system that processes flight plans, treated plans complying with the security zone restrictions as incorrect and moved the flights to a route through the FRZ.

The glitch created extra work for controllers on the clearance delivery position at Washington Dulles Tower (IAD), who had to manually reroute as many as 100 flights a day away from the FRZ. It also affected Washington Center (ZDC) and Potomac TRACON (PCT), which assisted IAD controllers when they were inundated with rerouting work.

Foreign carriers “would file a route to take them out around the FRZ and the computer would stick them back on a route to fly through the FRZ,” said Todd Warr, an IAD staff specialist.

General aviation pilots who knew of the FRZ would file flight plans to take them around it, and the same thing would happen to them. But quite a few didn’t know of the restrictions and the Host system allowed them to file plans to fly through the secure airspace.

Controllers filed ATSAP reports about the situation because they felt the extra work could lead to a safety issue. NATCA and management representatives formed a group with input from all three facilities and held several meetings to come up with a solution.

“ATSAP resulted in the first big effort to solve [the issue],” Warr said. The solution has eliminated at least 95 percent of the manual reroutes, he said.

“I can't overemphasize how big this issue was for all three facilities,” said Scott Starkey, the NATCA facility representative at IAD. “Pilots were getting in trouble for filing routes that they should know they are not allowed to fly. Other pilots were being deviated. Many were chased out of the FRZ and [ended up] on the news. Prior to ATSAP, controllers at Dulles were being decertified and retrained for not manually fixing this bad routing that bad automation was causing.”

Controllers would often have to make the most out of the manual reroutes during the busy evening departure rush when international carriers leave Dulles, Warr said. During the summer, FRZ reroutes were often made at the same time controllers were slammed with rerouting planes around thunderstorms.

“For years this problem could not be solved,” said Jim Slate, air traffic manager at IAD. “Then the issue was raised through ATSAP, and now the routing and automation issues caused by the added security measures have largely been mitigated. It was great how well the three facilities worked out a solution.”

The breakthrough idea came from Dulles, said Phil Kain, the Program Operations field manager at ZDC.

By processing aircraft by categories, the Host computer system would know which planes should fly around the FRZ.

“If we put all general aviation aircraft in a category, we could create a set of preferential routes that apply only to general aviation aircraft,” he said.

Host can put aircraft in just a limited number of categories, but because of a recent Host cleanup effort to prepare for En Route Automation Modernization, or ERAM, at ZDC, a category was available.

“Host (now) applies routes that take general aviation flights around the FRZ, but allow air carriers to fly through it,” Kain said.

Host also now automatically reroutes general aviation flight plans now that mistakenly intrude on the FRZ.

There was not another category available for the international carriers, but a change was made to the way Host processes routes and the automation system now permits those flights to bypass the FRZ.

The solution has eliminated at least 95 percent of the manual reroutes, Warr said.

“I used to receive discrepancy forms every day,” Warr said. Controllers would file them “due to their frustration that the problem hadn't been corrected. And now I don't receive any. Folks are extremely happy with the end result.”

The positive effects of the resolution have extended beyond the issue with the FRZ, according to Starkey.

“Fixing this issue with ATSAP at Dulles has had a bigger impact then you may think,” he said. “Everyone at Dulles now sees that this ATSAP program works. ATSAP has become an easy sell for me both as the Fac Rep and as the Dulles NATCA ATSAP instructor. The controllers, front line managers and staff all now see the benefits of ATSAP.”