Against the Wind - National Air Traffic Controllers Association

occasions. In a yearlong effort, the safety committee
at Dallas-Fort Worth Tower and TRACON documented
numerous problems with the ARTS software,
which displayed aircraft information on radarscopes.
A contract provision entitled union members to join
other industry representatives in NTSB accident investigations.
NATCA had also established review
committees to help oversee training and performance
standards.
But its role in the research and development
of new technology remained
slim to nonexistent.
A classic example involved a
computer onboard airliners known
as the Traffic Alert/Collision Avoidance
System. TCAS monitors traffic
and instructs pilots to climb or descend
if it senses a potential collision.
Before TCAS was deployed in
the late 1980s and early ’90s, however,
controllers had very little input
in its design and operation, even though
the computer inserted a third element in the
critical equation of communications between pilots
and controllers.
With the advent of TCAS, cockpit crews sometimes
received conflicting instructions from controllers
and the computer. Early versions of the software
generated targets for nonexistent planes on radar-
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Feb.
scopes. Other problems resulted in frequent false
alerts. Some of these led to dangerous near misses
when pilots deviated from their assigned altitude by
as much as 1,000 feet. During a 4½-month period in
1991, deviations occurred in 70 percent of the 590
incidents that were reported. 2
“It is like a puppy walking over a game of chess,
destroying the board’s composition,” Executive Vice
President Joseph Bellino
said. “Every controller
is executing a plan.
When one plane
deviates from its
assigned space,
it affects all the
aircraft under the
controller’s plan,
making the controller
scramble
to develop another
plan in seconds.” 3
NATCA was unable to
halt deployment of the new equipment until the
bugs were fixed. But extensive field documentation
by safety representatives helped TCAS manufacturers
fine-tune the software and problems gradually
diminished.
The experience was not lost on the FAA. As
frustrations mounted over poor communication, a
Transportation Secretary Federico F. Peña leaves office after serving
since January 21, 1993. Rodney E. Slater takes over. Slater, who previously
directed the Federal Highway Administration, also served as assistant
Chapter 6: Spreading its Wings
177
Traffic alert: NATCA Safety and Technology
Director Will Faville Jr., left, and Ray
Gibbons from Chicago TRACON testified
at an international symposium in 1992
(and before Congress a year earlier) about
TCAS deployment problems. Gibbons, the
union’s national TCAS representative for
terminals, and Greg Meyer, his counterpart
for centers, led the effort to gather
compelling statistics showing that early
versions of the collision avoidance system
adversely affected safety. / NATCA archives
attorney general of Arkansas and as a member of then-Gov. Bill Clinton’s
staff.