Making runways safer
- By Paula Shaki Trimble
- Aug 07, 2000
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
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
"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,"
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
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.