REDUCING EN ROUTE CONGESTION
In addition to the congestion experienced at major hubs
and terminal areas, certain parts of the en route structure
have reached capacity. Easing the burden on
high-volume airways and eliminating airborne choke
points are some of the challenges addressed by new
airspace plans.
MATCHING AIRSPACE
DESIGN TO DEMANDS
More new RNAV routes are being created, which are
essentially airways that use RNAV for guidance instead
of VORs. They are straighter than the old VOR airways,
so they save flight time and fuel costs. By creating additional
routes, they reduce traffic on existing airways,
adding en route capacity. As new routes are created near
existing airways, chart clutter will become more of an
issue. Electronic chart presentations are being developed
that will allow pilots to suppress information that is irrelevant
to their flight, while ensuring that all information
necessary for safety is displayed. The high degree of
accuracy and reliability of RNP procedures offers
another means of increasing capacity along popular
RNAV routes. Instead of having all the aircraft that are
using the route fly along the same ground track, RNP
allows several closely spaced parallel tracks to be created
for the same route. In essence, this changes a
one-lane road into a multi-lane highway. [Figure 6-8]
REDUCING VOICE COMMUNICATION
Many runway incursions and airborne clearance mistakes
are due to misunderstood voice communications.
During busy periods, the necessity of exchanging
dozens of detailed instructions and reports leads pilots
and controllers to shorten and abbreviate standard
phraseology, often leading to errors. It stands to reason
that better ways to transfer information could reduce
voice communications, and thus reduce the incidence of
communication errors. One such innovation is similar to
the display screen at fast-food drive-up windows. As the
cashier punches in the order, it is displayed on the monitor
so the customer can verify the order. This kind of
feedback reduces the common problem of hearing what
is expected to be heard, which is particularly problematic
in ATC clearances and read backs. Not only does
reducing voice communications reduce frequency
congestion, it also eliminates certain opportunities for
misunderstanding.
Controller pilot data link communication (CPDLC) augments
voice communications by providing a second
communication channel for use by the pilot and controller,
using data messages that are displayed in the
cockpit. This reduces delays resulting from congestion
on voice channels. The initial version of CPDLC will
display a limited number of air traffic messages, but
future versions will have expanded message capabilities
and permit pilot-initiated requests.
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