时间:2011-04-18 00:47来源:蓝天飞行翻译 作者:航空 点击:次
4.1.11. Designated UNICOM/MULTICOM Frequencies Frequency use a. The following listing depicts UNICOM and MULTICOM frequency uses as designated by the Federal Communications Commission (FCC). (See TBL 4.1.2.)TBL 4.1.2 Unicom/Multicom Frequency Usage Use Frequency Airports without an operating control tower. 122.700 122.725 122.800 122.975 123.000 123.050 123.075 (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 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. b. The following listing depicts other frequency uses as designated by the Federal Communications Commission (FCC). (See TBL 4.1.3.)Services Available to Pilots 4.1.6 TBL 4.1.3 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 4.1.12. Use of UNICOM for ATC Purposes UNICOM service may be used for ATC purposes, only under the following circumstances: a. Revision to proposed departure time. b.Takeoff, arrival, or flight plan cancellation time. c.ATC clearance, provided arrangements are made between the ATC facility and the UNICOM licensee to handle such messages. 4.1.13. Automatic Terminal Information Service (ATIS)a. 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 A/FD indicates airports for which ATIS is provided. b.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 AIM 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. EXAMPLE. Dulles International information Sierra. 1300 zulu weather. Measured ceiling three thousand overcast. Visibility three, smoke. Temperature six eight. Wind three five zero at eight. Altimeter two niner niner two. ILS runway one right approach in use. Landing runway one right and left. Departure runway three zero. Armel VORTAC out of service. Advise you have Sierra. c.Pilots should listen to ATIS broadcasts whenever ATIS is in operation. d.Pilots should notify controllers on initial contact that they have received the ATIS broadcast by repeating the alphabetical code word appended to the broadcast. EXAMPLE. “Information Sierra received.” e. When a pilot acknowledges receipt of the ATIS broadcast, controllers may omit those items con-tained in the broadcast if they are current. Rapidly changing conditions will be issued by ATC and the ATIS will contain words as follows: EXAMPLE. “Latest ceiling/visibility/altimeter/wind/(other condi-tions) will be issued by approach control/tower.” NOTE. The absence of a sky condition or ceiling and/or visibility on ATIS indicates a sky condition or ceiling of 5,000 feet or above and visibility of 5 miles or more. A remark may be made on the broadcast, “the weather is better than 5000 and 5,” or the existing weather may be broadcast. f. Controllers will issue pertinent information to pilots who do not acknowledge receipt of a broadcast Services Available to Pilots 4.1.7 or who acknowledge receipt of a broadcast which is not current. g.To serve frequency limited aircraft, FSSs are equipped to transmit on the omnirange frequency at most en route VORs used as ATIS voice outlets. Such communication interrupts the ATIS broadcast. Pilots of aircraft equipped to receive on other FSS frequencies are encouraged to do so in order that these override transmissions may be kept to an absolute minimum. |