December 2004 - Materials Science Institute - University of Oregon

Tower control
DID YOU KNOW...
➤ OCEANS AWAY: Three air route centers—in New York City, Oakland,
Calif., and Anchorage, Alaska—monitor traffi c over the Atlantic and
Pacifi c oceans. Radar does not cover the vast airspace, so pilots
must radio in at predetermined points along strict fl ight paths,
allowing controllers to calculate separation between planes, which
must be at least 100 miles. The Oakland center will soon test GPS
tracking to see if it could safely reduce that buffer.
➤ HELP WANTED: The nation’s 26,000 controllers work a 40-hour
week, although overtime is not uncommon. In its job descriptions,
the U.S. Bureau of Labor Statistics says, “During busy times,
controllers must work rapidly and effi ciently. Total concentration
AIR ROUTE CONTROL CENTER guides a plane from Tracon as it climbs
to high altitude, where it then cruises along prescribed jetways over
established navigation beacons. Controllers hand off planes as they
cross into the next air route sector, which may extend up to 300 miles
across. The destination Tracon takes over when approach begins.
Airport A
Airport C
SMALL GENERAL AVIATION
craft fl y by sight and are
responsible for staying out
of controlled airspace.
is required. The mental stress of being responsible for the safety of
several aircraft and their passengers can be exhausting for some
persons.” Because many of today’s controllers will retire within
a decade, “substantial” replacements will be needed, the bureau
notes. Median annual earnings are about $92,000.
➤ NO CONTROL: Tens of thousands of small, private “general
aviation” craft that fl y from little airports are not tracked by air
traffi c control, chiefl y because they do not have the needed radar
or radio equipment. Pilots fl y under “visual fl ight rules”—they fi le a
fl ight plan with a local fl ight service station, navigate by altimeter
and visual cues, and stay out of controlled airspace.
Terminal radar
approach control
(Tracon)
Terminal
control
Air route
control center
TERMINAL RADAR APPROACH CONTROL,
called Tracon, directs departure, ascent,
descent and approach paths at airports in
its sector. All maneuvers take place within
layers from the ground up to as much as
17,000 feet, extending as far as 50 miles.
A metropolitan Tracon space resembles
an upside-down wedding cake, but each
Tracon nationwide is unique; dimensions
noted here are typical.
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