Making runways safer

The Federal Aviation Administration has scaled back a software program it

is developing to warn air traffic controllers about potential collisions

on airport runways so that the agency can deploy the system to airports

faster.

The Airport Movement Area Safety System (AMASS) was originally intended

to prevent runway incursions — when an aircraft, vehicle or person on the

ground moves into the path of another aircraft. The FAA also planned for

the system to provide alerts if aircraft moved too close to other aircraft

taking off, intending to take off, landing or intending to land.

However, AMASS sounded alarms anytime an aircraft turned toward a runway,

regardless of whether a controller had instructed the pilot to stop before

entering the runway. AMASS is an audio and visual enhancement of the Airport

Surface Detection Equipment Model 3 (ASDE-3) radars being installed at 34

airports.

"It was a "cry wolf' machine; the alarms were always going off,"

said Bill Blackmer, director of safety and technology for the National Air

Traffic Controllers Association. "We hate false alerts. We rely upon information

and we expect it to be accurate all the time."

As a result, air traffic controllers would have to guess whether an

alarm signaled a potential collision or was a false alarm.

The FAA has designed AMASS to monitor only runways, rather than the

entire air operations area, which includes taxiways, areas around gates

or anywhere that vehicles and aircraft go, said Michael Huffman, the FAA's

AMASS project lead.

During tests in the late 1990s, the alarm on a prototype AMASS system

in San Francisco frequently went off, and "it was a nuisance to the controllers,"

Huffman said.

AMASS is particularly important for airports as air traffic increases.

Last year, there were 322 runway incursions in the United States, according

to the FAA, up 71 percent from 1993.

Runway safety is high on the FAA's list of priorities. The agency established

a new program office in August 1999 to tackle runway safety issues, and

this March it announced a series of regional runway safety meetings to bring

together airlines, airports, general aviation organizations, pilots and

air traffic controllers. In June, the FAA sponsored a national summit on

runway safety to review new technologies and human factors studies. It also

launched a one-year program to encourage pilots who have been involved in

runway incursions to discuss the incidents with FAA safety inspectors without

fear of punishment.

The National Transportation Safety Board has also been pushing for improving

runway safety since 1990. But NTSB Chairman Jim Hall has repeatedly expressed

concern about the FAA's delays in fielding AMASS, which the agency first

said would be operational in 1994. The FAA has continued to revise those

schedules since then, but Huffman said the system, designed by Northrop

Grumman Corp.'s Norden Systems and Dimensions International Inc., is back

on track.

The commissioning of AMASS was scheduled for the end of this year, but

the FAA delayed that until 2002 to correct software and hardware deficiencies,

Huffman said. During operational tests last year, the FAA discovered that

AMASS information appeared on top of the ASDE-3 displays, obstructing other

important data. The team had to change the displays and the voice alert,

which required changes to the spacing of words and order of words to make

it more similar to the way controllers speak, Huffman said.

In June, the FAA finished validating the changes and plans to begin

testing the system Sept. 1 at San Francisco International Airport. The same

process will begin Oct. 1 in Detroit.

A decision whether to commission AMASS at all 34 airports is slated

for January 2001, Huffman said.

NTSB is still concerned that, despite the improvements, AMASS may not

give controllers enough time to avoid collisions, and the agency believes

that further testing should be done.

Blackmer hailed the incremental approach to AMASS development as a way

to get useful tools into controllers' hands quickly and let them help the

FAA discover the limits of the system. "The other option is to wait and

have nothing until we figure out the taxiway problem," he said.

Blackmer noted that AMASS is only part of the solution. Controllers

need to "look out the window" for potential conflicts, and the FAA and air

industry need to look at other promising technologies for tracking aircraft

and vehicles at airports. Automatic Dependent Surveillance Broadcast, which

broadcasts position and time data collected by a Global Positioning System

receiver, would work well for surface tracking, but it will take a long

time to equip the fleets of aircraft and other vehicles, he said.

Outside the FAA, the American Association of Airport Executives is designing

an interactive training program on avoiding incursions for vehicle drivers

in the air operations areas. It has already sold 10 units to the Seattle

airport, said Will James, staff vice president of accreditation and training

for AAAE. The system includes a Web-based database that allows airport managers

to keep track of the employees who have completed driver training.