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READING PASSAGE 3
AIR TRAFFIC CONTROL IN THE USA
A
An accident that occurred in the skies over the Grand Canyon in 1956 resulted in the establishment
of the Federal Aviation Administration (FAA) to regulate and oversee the operation of aircraft in the
skies over the United States, which were becoming quite congested. The resulting structure of air
traffic control has greatly increased the safety of flight in the United States, and similar air traffic
control procedures are also in place over much of the rest of the world.
B
Rudimentary air traffic control (ATC) existed well before the Grand Canyon disaster. As early as the
1920s, the earliest air traffic controllers manually guided aircraft in the vicinity of the airports, using
lights and flags, while beacons and flashing lights were placed along cross-country routes
to establish the earliest airways. However, this purely visual system was useless in bad weather,
and, by the 1930s, radio communication was coming into use for ATC. The first region to have
something
approximating today’s ATC was New York City, with other major metropolitan
areas following soon after.
C
In the 1940s, ATC centres could and did take advantage of the newly developed radar and improved
radio communication brought about by the Second World War, but the system remained
rudimentary. It was only after the creation of the FAA that full-
scale regulation of America’s airspace
took place, and this was fortuitous, for the advent of the jet engine suddenly resulted in a large
number of very fast planes,
reducing pilots’ margin of error and practically demanding some set of
rules to keep everyone well separated and operating safely in the air.
D
Many people think that ATC consists of a row of controllers sitting in front of their radar screens at
the nation’s airports, telling arriving and departing traffic what to do. This is a very incomplete part of
the picture. The FAA realised that the airspace over the United States would at any time have many
different kinds of planes, flying for many different purposes, in a variety of weather conditions, and
the same kind of structure was needed to accommodate all of them.
E
To meet this challenge, the following elements were put into effect. First, ATC extends over virtually
the entire United States. In general, from 365m above the ground and higher, the entire country is
blanketed by controlled airspace. In certain areas, mainly near airports, controlled airspace extends
down to 215m above the ground, and, in the immediate vicinity of an airport, all the way down to the
surface. Controlled airspace is that airspace in which FAA regulations apply. Elsewhere, in
uncontrolled airspace, pilots are bound by fewer regulations. In this way, the recreational pilot who
simply wishes to go flying for a while without all the restrictions imposed by the FAA has only to stay
in uncontrolled airspace, below 365m, while the pilot who does want the protection afforded by ATC
can easily enter the controlled airspace.
F
The FAA then recognised two types of operating environments. In good meteorological conditions,
flying would be permitted under Visual Flight Rules (VFR), which suggests a strong
reliance
on visual cues to maintain an acceptable level of safety. Poor visibility necessitated a set of
Instrumental Flight Rules (IFR), under which the pilot relied on altitude and navigational information
provided by the
plane’s instrument panel to fly safely. On a clear day, a pilot in controlled
airspace can choose a VFR or IFR flight plan, and the FAA regulations were devised in a way which
accommodates both VFR and IFR operations in the same airspace. However, a pilot can only
choose to fly IFR if they possess an instrument rating which is above and beyond the ba
sic pilot’s
license that must also be held.
G
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Controlled airspace is divided
into several different types, designated by letters of the alphabet.
Uncontrolled airspace is designated Class F, while controlled airspace below 5,490m above sea
level and not in the vicinity of an airport is Class E. All airspace above 5,490m is designated Class A.
The reason for the division of Class E and Class A airspace stems from the type of planes operating
in them. Generally, Class E airspace is where one finds general aviation aircraft (few of which can
climb above 5,490m anyway), and commercial turboprop aircraft. Above 5,490m is the realm of the
heavy jets, since jet engines operate more efficiently at higher altitudes. The difference between
Class E and A airspace is that in Class A, all operations are IFR, and
pilots must be instrument-
rated, that is, skilled and licensed in aircraft instrumentation. This is because ATC control of the
entire space is essential. Three other types of airspace, Classes D, C and B, govern the vicinity of
airports. These correspond roughly to small municipal, medium-
sized metropolitan and major metropolitan airports respectively, and encompass an increasingly
rigorous set of regulations. For example, all a VFR pilot has to do to enter Class C airspace
is establish two-way radio contact with ATC. No explicit permission from ATC to enter is needed,
although the pilot must continue to obey all regulations governing VFR flight. To enter Class B
airspace, such as on approach to a major metropolitan airport, an explicit ATC clearance
is required.
The private pilot who cruises without permission into this airspace risks losing their license.
