9.4 Designated UNICOM/MULTICOM Fre-quencies
9.4.1 Frequency Use
9.4.1.1 TBL GEN 3.3.2 depicts UNICOM and MULTICOM frequency uses as designated by the Federal Communications Commission (FCC).
NOTE.
1.
In some areas of the country, frequency interference may be encountered from nearby airports using the same UNICOM frequency. Where there is a problem, UNICOM operators are encouraged to develop a “least interfer-ence” frequency assignment plan for airports concerned using the frequencies designated for airports without operating control towers. UNICOM licensees are encouraged to apply for UNICOM 25 KHz spaced channel frequencies. Due to the extremely limited number of frequencies with 50 KHz channel spacing, 25 KHz channel spacing should be implemented. UNICOM licensees may then request FCC to assign frequencies in accordance with the plan, which FCC will review and consider for approval.
2.
Wind direction and runway information may not be available on UNICOM frequency 122.950.
9.4.1.2 TBL GEN 3.3.3 depicts other frequency uses as designated by the FCC.
9.5 Use of UNICOM for ATC purposes
9.5.1 UNICOM service may be used for air traffic control purposes, only under the following circum-stances:
9.5.1.1 Revision to proposed departure time.
9.5.1.2 Takeoff, arrival, or flight plan cancellation time.
9.5.1.3 ATC clearance, provided arrangements are made between the ATC facility and the UNICOM licensee to handle such messages.
TBL GEN 3.3.2
UNICOM/MULTICOM Frequency Usage
Use Frequency
Airports without an 122.700
operating control tower. 122.725
122.800
122.975
123.000
123.050
123.075
(MULTICOM FREQUENCY) Activities of a temporary, seasonal, emergency nature or search and rescue, as well as, airports with no tower, FSS, or UNICOM. 122.900
(MULTICOM FREQUENCY) Forestry management and fire suppression, fish and game management and protection, and environmental monitoring and protection. 122.925
Airports with a control tower or FSS on airport. 122.950
TBL GEN 3.3.3
Other Frequency Usage Designated by FCC
Use Frequency
Air-to-air communication (private fixed wing aircraft). 122.750
Air-to-air communications (general aviation helicopters). 123.025
Aviation instruction, Glider, Hot Air Balloon (not to be used for advisory service). 123.300 123.500
9.6 Automatic Terminal Information Service (ATIS)
9.6.1 ATIS is the continuous broadcast of recorded noncontrol information in selected high activity terminal areas. Its purpose is to improve controller effectiveness and to relieve frequency congestion by automating the repetitive transmission of essential but routine information. The information is continu-ously broadcast over a discrete VHF radio frequency or the voice portion of a local NAVAID. ATIS transmissions on a discrete VHF radio frequency are engineered to be receivable to a maximum of 60 NM from the ATIS site and a maximum altitude of 25,000 feet AGL. At most locations, ATIS signals may be received on the surface of the airport, but local conditions may limit the maximum ATIS reception distance and/or altitude. Pilots are urged to cooperate in the ATIS program as it relieves frequency congestion on approach control, ground control, and local control frequencies. The Airport/Facility Directory indicates airports for which ATIS is provided.
9.6.2 ATIS information includes the time of the latest weather sequence, ceiling, visibility, obstructions to visibility, temperature, dew point (if available), wind direction (magnetic), and velocity, altimeter, other pertinent remarks, instrument approach, and runway in use. The ceiling/sky condition, visibility, and obstructions to vision may be omitted from the ATIS broadcast if the ceiling is above 5,000 feet and the visibility is more than 5 miles. The departure runway will only be given if different from the landing runway except at locations having a separate ATIS for departure. The broadcast may include the appropriate frequency and instructions for VFR arrivals to make initial contact with approach control. Pilots of aircraft arriving or departing the terminal area can receive the continuous ATIS broadcast at times when cockpit duties are least pressing and listen to as many repeats as desired. ATIS broadcast shall be updated upon the receipt of any official hourly and special weather. A new recording will also be made when there is a change in other pertinent data such as runway change, instrument approach in use, etc.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：美国航行情报汇编 AERONAUTICAL INFORMATION PUBLICATION AIP 1(112)
