Honeywell KLN 90B GPS Abbreviated Operation Manual page 32

AFIS - aerodrome flight information service
CL B -Class B airspace (VFR frequency)
CL C -Class C airspace (VFR frequency)
TRSA -Terminal Radar Service Area (VFR frequency)
CTA - control area (VFR frequency used outside USA)
TMA - terminal area (VFR frequency used outside USA)
APR - approach control
DEP - departure control
CTR - center (when center is used for approach/departure control)
ARVL - arrival
RDO - radio
RDR - radar only frequency
DIR - director (approach control/radar)
AWOS - automatic weather observing station
ASOS - automated surface observation system
AAS - aeronautical advisory service
PCL - pilot controlled lighting
In addition to the standard VHF frequencies, HF frequencies are shown at
airports that utilize "high frequency" communications that fall in the 2000
kHz to 30,000 kHz frequency band. These are typically used in remote
areas of the world. One way to tell HF frequencies is that they do not con-
tain a decimal point. A display of 6547 would indicate a frequency of
6,547 kHz.
Airports which have numerous communication frequencies will have mul-
tiple Airport 4 pages indicated by APT+4.
Part-time operation, such as for a control tower, is indicated with an * to
the left of a frequency.
The frequencies associated with a CL B, CL C, TRSA, CTA, or TMA are
VFR frequencies. Airports which have one of these categories of frequen-
cies also have APR and DEP which are IFR frequencies.
Where required, APR, DEP, CL B, CL C, TRSA, CTA, and TMA frequen-
cies are sectorized. That is, a frequency may be used only within a cer-
tain range of radials from a designated reference location. The format for
displaying the sectorization is to show the frequency first, followed by the
identifier of the associated reference point, followed next by the associ-
ated altitude restrictions.
NOTE: When an altitude restriction is shown on the Airport 4 page, the
abbreviation BEL means at and below the specified altitude. Likewise,
the abbreviation ABV means at and above the specified altitude. Thus,
ABV 4000FT means at and above 4000 feet and BEL 3999FT means at
and below 3999 feet.
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