Advisory Circular AC 90-42F (Traffic Advisory Practices at Non-Towered Airports)

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The full text of the FAA bulletin.

Digital version of this AIM section was provided courtesy of Summit Aviation, publisher of the Computerized Aviation Reference Library CDROM which may be purchased on-line here on AVweb.

DOT LogoAdvisory Circular AC 90-42F

Traffic Advisory Practices at Airports Without Operating Control Towers

U.S. Department of Transportation
Federal Aviation Administration

5/21/90
Initiated by: ATP-230

1. PURPOSE.

This advisory circular (AC) contains good operating practices and procedures for use when approaching or departing airports without an operating control tower and airports that have control towers operating part time. This AC has been updated to include changes in radio frequencies and phraseology.

2. CANCELLATION.

Advisory Circular 90-42E, dated November 23, 1988, is canceled.

3. REFERENCES.

The following ACs also contain information applicable to operations at such uncontrolled airports.

a. AC 90-66, Recommended Standard Traffic Patterns for Aircraft Operations at Airports Without Operating Control Towers.

b. AC 150/5340-27A, Air-to-Ground Radio Control of Airport Lighting Systems.

4. DEFINITIONS.

a. COMMON TRAFFIC ADVISORY FREQUENCY (CTAF) - A designated frequency for the purpose of carrying out airport advisory practices while operating to or from an airport that does not have a control tower or an airport where the control tower Is not operational. The CTAF is normally a UNICOM, MULTICOM, flight service station (FSS) frequency, or a tower frequency. CTAF will be identified in appropriate aeronautical publications.

b. UNICOM - A nongovernment air/ground radio communication station which may provide airport information at public use airports.

c. MULTICOM - A mobile service, not open to public correspondence use, used for essential communications in the conduct of activities performed by or directed from private aircraft.

d. MOVEMENT AREA - The runways, taxiways, and other areas of an airport/heliport which are utilized for taxiing/hover taxiing, air taxiing, takeoff and landing of aircraft, exclusive of loading ramps, and parking areas.

5. DISCUSSION.

a. In the interest of promoting safety, the Federal Aviation Administration, through its Airman's Information Manual, Airport Facility Directory, Advisory Circular, and other publications provides frequency information, good operating practices, and procedures for pilots to use when operating to and from an airport without an operating control tower.

b. There is no substitute for awareness while in the vicinity of an airport. It is essential that pilots remain alert and look for other traffic and exchange traffic information when approaching or departing an airport without the services of an operating control tower. This is of particular importance since other aircraft may not have communication capability or, in some cases, pilots may not communicate their presence or intentions when operating into or out of such airports. To achieve the greatest degree of safety, it is essential that all radio equipped aircraft transmit/receive on a common frequency identified for the purpose of airport advisories.

c. The key to communicating at an airport without an operating control tower is selection of the correct common frequency. The CTAF for each airport without an operating control tower is published in appropriate aeronautical information publications. The CTAF for a particular airport can also be obtained by contacting any FSS. Use of the appropriate CTAF, combined with visual alertness and application of the following recommended good operating practices, will enhance safety of flight into and out of all such airports.

d. There are two ways for pilots to communicate their intentions and obtain airport/traffic information when operating at an airport that does not have an operating tower: by communicating with an FSS that is providing airport advisories on a CTAF or by making a self-announced broadcast on the CTAF.

6. RECOMMENDED TRAFFIC ADVISORY PRACTICES.

All inbound traffic should continuously monitor and communicate, as appropriate, on the designated CTAF from a point 10 miles from the airport until clear of the movement area. Departing aircraft should continuously monitor/communicate on the appropriate frequency from startup, during taxi, and until 10 miles from the airport unless the Federal Aviation Regulations or local procedures require otherwise.

7. AIRPORT ADVISORY SERVICE (AAS) PROVIDED BY AN FSS.

a. An FSS physically located on an airport may provide airport advisory service (AAS) at an airport that does not have a control tower or where a tower is operated on a part-time basis and the tower is not in operation. The CTAFs for FSSs which provide this service are published in appropriate aeronautical publications.

b. An FSS AAS provides pilots with wind direction and velocity, favored or designated runway, altimeter setting, known traffic, Notices to Airmen, airport taxi routes, airport traffic pattern, and instrument approach procedures information. Pilots may receive some or all of these elements depending on the current traffic situation. Some airport managers have specified that under certain wind or other conditions, designated runways are used. Therefore, pilots should advise the FSS of the runway they intend to use. It is important to note that not all aircraft in the vicinity of an airport may be in communication with the FSS.

c. In communicating with an FSS on CTAF, establish two-way communications before transmitting outbound/inbound intentions or information. Inbound aircraft should initiate contact approximately 10 miles from the airport. Inbounds should report altitude, aircraft type, and location relative to the airport; should indicate whether landing or overflight; and should request airport advisory. Departing aircraft should, as soon as practicable after departure, contact the FSS and state the aircraft type, full identification number, type of flight planned; i.e., visual flight rules (VFR) or instrument flight rules (IFR), the planned destination or direction of flight, and the requested services desired. Pilots should report before taxiing, before entering the movement area, and before taxiing onto the runway for departure. If communication with a UNICOM is necessary, pilots should do so before entering the movement area or on a separate transceiver. It is essential that aircraft continuously monitor the CTAF within the specified area.

d. Examples of AAS phraseology:

(1) Inbound:

VERO BEACH RADIO, CENTURION SIX NINER DELTA DELTA ONE ZERO MILES SOUTH, TWO THOUSAND, LANDING VERO BEACH. REQUEST AIRPORT ADVISORY.

(2) Outbound:

VERO BEACH RADIO, CENTURION SIX NINER DELTA DELTA, READY TO TAXI, VFR, DEPARTING TO THE SOUTHWEST. REQUEST AIRPORT ADVISORY.

8. INFORMATION PROVIDED BY AERONAUTICAL ADVISORY STATIONS (UNICOM).

UNICOM stations may provide pilots, upon request, with weather information, wind direction, the recommended runway, or other necessary information. If the UNICOM frequency is designated as the CTAF, it will be identified in appropriate aeronautical publications. If wind and weather information are not available, it may be obtainable from nearby airports via Automatic Terminal Information Service or Automated Weather Observing System frequency.

9. SELF-ANNOUNCE POSITION AND/OR INTENTIONS.

a. General. "Self-announce" is a procedure whereby pilots broadcast their position, intended flight activity or ground operation on the designated CTAF. This procedure is used primarily at airports which do not have a control tower or an FSS on the airport. The self-announce procedure should also be used when a pilot is unable to communicate with the local FSS on the designated CTAF.

b. If an airport has a control tower which is either temporarily closed or operated on a part-time basis and there is no operating FSS on the airport, pilots should use the published CTAF to self-announce position and/or intentions.

c. Where there is no tower, FSS, or UNICOM station on the airport, use MULTICOM frequency 122.9 for self-announce procedures. Such airports will be identified in appropriate aeronautical information publications.

d. Practice Approaches. Pilots conducting practice instrument approaches should be particularly alert for other aircraft that may be departing in the opposite direction. When conducting any practice approach, regardless of its direction relative to other airport operations, pilots should make announcements on the CTAF as follows:

(1) when departing the final approach fix, inbound;

(2) when established on the final approach segment or immediately upon being released by ATC;

(3) upon completion or termination of the approach; and

(4) upon executing the missed approach procedure.

NOTE: Departing aircraft should always be alert for arrival aircraft that are opposite direction.

10. UNICOM COMMUNICATION PROCEDURES.

a. In communicating with a UNICOM station, the following practices will help reduce frequency congestion, facilitate a better understanding of pilot intentions, help identify the location of aircraft in the traffic pattern, and enhance safety of flight:

(1) Select the correct CTAF frequency.

(2) State the identification of the UNICOM station you are calling in each transmission.

(3) Speak slowly and distinctly.

(4) Notify the UNICOM station approximately 10 miles from the airport, reporting altitude, aircraft type, aircraft identification, location relative to the airport, and whether landing or overflight. Request wind information and runway in use.

(5) Report on downwind, base, and final approach.

(6) Report leaving the runway.

b. Examples of UNICOM Phraseologies:

(1) Inbound:

FREDERICK UNICOM CESSNA EIGHT ZERO ONE TANGO FOXTROT 10 MILES SOUTHEAST DESCENDING THROUGH (ALTITUDE) LANDING FREDERICK, REQUEST WIND AND RUNWAY INFORMATION FREDERICK.

FREDERICK TRAFFIC CESSNA EIGHT ZERO ONE TANGO FOXTROT ENTERING DOWNWIND/BASE/FINAL (AS APPROPRIATE) FOR RUNWAY ONE NINE (FULL STOP/TOUCH-AND-GO) FREDERICK.

FREDERICK TRAFFIC CESSNA EIGHT ZERO ONE TANGO FOXTROT CLEAR OF RUNWAY ONE NINE FREDERICK.

(2) Outbound:

FREDERICK UNICOM CESSNA EIGHT ZERO ONE TANGO FOXTROT (LOCATION ON AIRPORT) TAXIING TO RUNWAY ONE NINE, REQUEST WIND AND TRAFFIC INFORMATION FREDERICK.

FREDERICK TRAFFIC CESSNA EIGHT ZERO ONE TANGO FOXTROT DEPARTING RUNWAY ONE NINE. "REMAINING IN THE PATTERN" or "DEPARTING THE PATTERN TO THE (DIRECTION) (AS APPROPRIATE)" FREDERICK.

11. EXAMPLES OF SELF-ANNOUNCE PHRASEOLOGIES.

It should be noted that aircraft operating to or from another nearby airport may be making self-announce broadcasts on the same UNICOM or MULTICOM frequency. To help identify one airport from another, the airport name should be spoken at the beginning and end of each self-announce transmission.

(1) Inbound:

STRAWN TRAFFIC, APACHE TWO TWO FIVE ZULU, (POSITION), (ALTITUDE), (DESCENDING) OR ENTERING DOWNWIND/BASE/FINAL (AS APPROPRIATE) RUNWAY ONE SEVEN FULL STOP, TOUCH-AND-GO, STRAWN.

STRAWN TRAFFIC APACHE TWO TWO FIVE ZULU CLEAR OF RUNWAY ONE SEVEN STRAWN.

(2) Outbound:

STRAWN TRAFFIC, QUEENAIRE SEVEN ONE FIVE FIVE BRAVO (LOCATION ON AIRPORT) TAXIING TO RUNWAY TWO SIX STRAWN.

STRAWN TRAFFIC, QUEENAIRE SEVEN ONE FIVE FIVE BRAVO DEPARTING RUNWAY TWO SIX. DEPARTING THE PATTERN TO THE (DIRECTION), CLIMBING TO (ALTITUDE) STRAWN.

(3) Practice Instrument Approach:

STRAWN TRAFFIC, CESSNA TWO ONE FOUR THREE QUEBEC (NAME - FINAL APPROACH FIX) INBOUND DESCENDING THROUGH (ALTITUDE) PRACTICE (TYPE) APPROACH RUNWAY THREE FIVE STRAWN.

STRAWN TRAFFIC, CESSNA TWO ONE FOUR THREE QUEBEC PRACTICE (TYPE) APPROACH COMPLETED OR TERMINATED RUNWAY THREE FIVE STRAWN.

12. SUMMARY OF RECOMMENDED COMMUNICATIONS PROCEDURES.

a. Facility at Airport: UNICOM (no Tower or FSS)
Frequency Use: Communicate with UNICOM station on published CTAF frequency (122.7, 122.8, 122.725, 122.975, or 123.0). If unable to contact UNICOM station, use self-announce procedures on CTAF.

b. Facility at Airport: No Tower FSS, or UNICOM
Frequency Use: Self-announce on MULTICOM freq. 122.9
Communication/Broadcast Procedures: See Below.

c. Facility at Airport: No Tower in Operation, FSS Open
Frequency Use: Communicate with FSS on CTAF
Communication/Broadcast Procedures: See Below.

d. Facility at Airport: FSS Closed (No Tower)
Frequency Use: Self-announced on CTAF
Communication/Broadcast Procedures: See Below.

e. Facility at Airport: Tower or FSS not in Operation
Frequency Use: Self-announced on CTAF
Communication/Broadcast Procedures: See Below.

Communication/Broadcast Procedures:

Outbound: Before taxiing and before taxiing on the runway for departure.

Inbound: 10 miles out, and entering downwind, base, and final, and leaving the runway.

Practice Instrument Approach: Departing final approach fix (name) inbound, and approach completed/terminated.

13. IFR AIRCRAFT.

When operating in accordance with an IFR clearance, if air traffic control (ATC) approves a change to the advisory frequency, change to and monitor the CTAF as soon as possible and follow the recommended traffic advisory procedures.

14. GROUND VEHICLE OPERATION.

Drivers of airport ground vehicles equipped with radios should monitor the CTAF frequency when operating on the airport movement area and remain clear of runways/taxiways being used by aircraft. Radio transmissions from ground vehicles should be confined to safety related matters.

15. RADIO CONTROL OF AIRPORT LIGHTING SYSTEMS.

Whenever possible, the CTAF will be used to control airport lighting systems at airports without operating control towers. This eliminates the need for pilots to change frequencies to turn the lights on and allows a continuous listening watch on a single frequency. The CTAF is published on the instrument approach chart and in other appropriate aeronautical information publications. For further details concerning radio controlled lights, see AC 150/15340-27.

16. DESIGNATED UNICOM/MULTICOM FREQUENCIES.

The following listing depicts appropriate UNICOM and MULTICOM frequency used as designated by the Federal Communications Commission (FCC).

Frequency Use
覧覧 覧覧覧覧覧覧覧覧覧-
122.700 --- Airports without an operating control tower
122.725 --- Airports without an operating control tower
122.750 --- Air-to-air communications & private airports
(not open to the public)
122.800 --- Airports without an operating control tower
122.900 --- (MULTICOM FREQUENCY) Activities of a temporary,
seasonal, or emergency nature.
122.925 --- (MULTICOM FREQUENCY) Forestry management and
fire suppression, fish and game management and
protection, and environmental monitoring and protection.
122.950 --- Airports with control tower or FSS on airport
122.975 --- Airports without an operating control tower
123.000 --- Airports without an operating control tower
123.050 --- Airports without an operating control tower
123.075 --- Airports without an operating control tower

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 interference" 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.*

NOTE 2: Wind direction and runway information may not be available on UNICOM frequency 122.950.

17. 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.

18. MISCELLANEOUS.

Operations at airports without operating control towers require the highest degree of vigilance on the part of pilots to see and avoid aircraft while operating to or from such airports. Pilots should stay alert at all times, anticipate the unexpected, use the published CTAF frequency, and follow recommended airport advisory practices.

Harold W. Becker
Acting Director, Air Traffic
Rules and Procedures Service