7754 Vol 2 Flyleaf - ICAO Public Maps

V.II-A1
Attachment A
BASIC ELEMENTS FOR THE DETERMINATION OF THE
NEED FOR ATS AIR-GROUND COMMUNICATION CHANNELS
AND THEIR ECONOMIC USE
(Paragraph 30, Part IV — CNS of the EUR Basic ANP refers)
DETERMINATION OF THE NEED FOR
ATS AIR-GROUND COM CHANNELS
Description of terms used
1. When the following terms are used in describing
the basic elements involved in the determination of the need
for ATS air-ground communication channels, they shall
have the following meaning:
ATS radio control position. That part of an ATS unit
performing a specific ATS function requiring the direct and
unrestricted access to a VHF air-ground communication
channel.
Note.— At present, this is met by the assignment of a
discrete channel per ATS radio control position.
Sector. A defined portion of the airspace within which
air traffic services are provided by one or more ATS radio
control positions.
Note.— Normally a sector is part of a control area
and/or an FIR/UIR. It could also be a defined area around
major aerodromes wherein specific approach functions are
performed.
Factors to be taken into account
2. When studying the need for the establishment of
individual ATS radio control positions, the following
factors are used:
a) the amount of air traffic;
b) the configuration of the airspace;
c) the method of control used;
d) effects on the total communications load resulting from
the systematic reduction of air-ground communications
and/or the use of “silent control”;
e) special national requirements; and
f) the average capability of the control personnel.
Terms and definitions
3. When assessing the amount of traffic in accordance
with the factor listed in 2 a) above, the following terms and
definitions are used:
a) Traffic load. The number of movements of air traffic
handled by an ATS unit or part thereof during a given
period of time.
b) Weekly traffic load. The traffic load handled during the
7-day period from 1 to 7 July inclusive or other 7-day
period more appropriate to a specific Contracting State,
when a common period is not necessary by the nature of
the task.
c) Peak hourly traffic load. The traffic load handled
during that clock hour in the period from 1 to 7 July, or
any other 7-day period more appropriate to a specific
Contracting State when a common period is not
necessary by the nature of the task, during which the
highest number of movements occurs.
d) Maximum instantaneous traffic load. The traffic load at
the busiest instant within the peak hour as defined in c)
above.