GEN 3.3 Air Traffic Services

1.. Responsible Authority

The authority responsible for the overall administration of air traffic services provided for civil aviation in the U.S. and its territories, possessions and international airspace under its jurisdiction is the Chief Operating Officer of the Air Traffic Organization, acting under the authority of the Federal Aviation Administration (FAA).

2.. Area of Responsibility

Air traffic services as indicated in the following paragraphs are provided for the entire territory of the conterminous U.S., Alaska, Hawaii, Puerto Rico and the U.S. Virgin Islands, as well as the international airspace in oceanic areas under the jurisdiction of the U.S. which lies within the ICAO Caribbean (CAR), North Atlantic (NAT), North American (NAM), and Pacific (PAC) regions.

3.. Air Traffic Services

With the exception of terminal control services at certain civil aerodromes and military aerodromes, air traffic service in the U.S. is provided by the Air Traffic Organization, FAA, Department of Transportation (DOT), U.S. Government.
Air Traffic control is exercised within the area of responsibility of the U.S.:
1. On all airways.
2. In Class B, C, D, and E Airspace; and
3. Within the Class A airspace whose vertical extent is from 18,000 feet to and including FL 600 throughout most of the conterminous U.S. and, in Alaska, from 18,000 feet to and including FL 600 but not including the airspace less than 1,500 feet above the surface of the earth and the Alaskan Peninsula west of longitude 1605 00I West. (A complete description of Class A airspace is contained in the Code of Federal Regulations (CFR), Title 14, Part 71.)
Air traffic control and alerting services are provided by various air traffic control (ATC) units and are described in ENR 1.1.
Radar service is an integral part of the air traffic system. A description of radar services and procedures is provided in ENR 1.1.
The description of airspace designated for air traffic services is found in ENR 1.4.
Procedural data and descriptions are found in ENR 1.5.
Numerous restricted and prohibited areas are established within U.S. territory. These areas, none of which interfere with normal air traffic, are explained in ENR 1.5. Activation of areas subject to intermittent activity is notified in advance by a Notice to Airmen (NOTAM), giving reference to the area by its identification.
In general, the air traffic rules and procedures in force and the organization of the air traffic services are in conformity with ICAO Standards, Recommended Practices and Procedures. Differences between the national and international rules and procedures are given in GEN 1.7. The regional supplementary procedures and altimeter setting procedures are reproduced in full with an indication wherein there is a difference.
Coordination between the operator and air traffic services is effected in accordance with 2.11 of Annex II, and 2.1.1.4 and 2.1.2.5 of Part VIII of the PANS-ATM (Doc 4444).
Minimum flight altitudes on the ATS routes as listed in ENR 1.4 have been determined so as to ensure at least 1,000 feet vertical clearance above the highest obstacle within 4 nautical miles (NM) on each side of the centerline of the route. However, where the regular divergence (4.5 degrees) of the navigational aid signal in combination with the distance between the navigational aids could result in the aircraft being more than 4 NM on either side of the centerline, the 4 NM protection limit is increased by the extent to which the divergence is more than 4 NM from the centerline.
Pilot Visits to Air Traffic Facilities. Pilots are encouraged to participate in local pilot/air traffic control outreach activities. However, due to security and workload concerns, requests for air traffic facility visits may not always be approved. Therefore, visit requests should be submitted through the air traffic facility as early as possible. Pilots should contact the facility and advise them of the number of persons in the group, the time and date of the proposed visit, and the primary interest of the group. The air traffic facility will provide further instructions if a request can be approved.
Operation Rain Check. Operation Rain Check is a program designed and managed by local air traffic control facility management. Its purpose is to familiarize pilots and aspiring pilots with the ATC system, its functions, responsibilities and benefits.

4.. En Route Procedures

Air Route Traffic Control Center (ARTCC)
An ARTCC is a facility established to provide air traffic control service to aircraft operating on instrument flight rule (IFR) flight plans within CONTROLLED AIRSPACE and principally during the en route phase of flight. When equipment capabilities and controller workload permit, certain advisory/assistance services may be provided to visual flight rule (VFR) aircraft.

ARTCC Communications

Direct Communications, Controllers and Pilots

ARTCCs are capable of direct communications with IFR air traffic on certain frequencies. Maximum communications coverage is possible through the use of Remote Center Air/Ground (RCAG) sites comprised of very high frequency (VHF) and ultra high frequency (UHF) transmitters and receivers. These sites are located throughout the U.S. Although they may be several hundred miles away from the ARTCC, they are remoted to the various centers by land lines or microwave links. As IFR operations are expedited through the use of direct communications, pilots are requested to use these frequencies strictly for communications pertinent to the control of IFR aircraft. Flight plan filing, en route weather, weather forecasts, and similar data should be requested through Flight Service Stations, company radio, or appropriate military facilities capable of performing these services.
An ARTCC is divided into sectors. Each sector is handled by one or a team of controllers and has its own sector discrete frequency. As a flight progresses from one sector to another, the pilot is requested to change to the appropriate sector discrete frequency.

Controller Pilot Data Link Communications (CPDLC) is a system that supplements air/ground voice communications. The CPDLC's principal operating criteria are:

Voice remains the primary and controlling air/ground communications means.
Participating aircraft will need to have the appropriate CPDLC avionics equipment in order to receive uplink or transmit downlink messages.

En Route CPDLC offers many services including the following: Altimeter Setting (AS); Transfer of Communications (TOC); Initial Contact (IC); route assignments including airborne reroutes (ABRR); altitude assignments; speed assignments; crossing constraints; holding; and advisory and emergency messages.

Altimeter settings will be uplinked automatically when appropriate after a Monitor TOC. Altimeter settings will also be uplinked automatically when an aircraft receives an uplinked altitude assignment below FL 180. A controller may also manually send an altimeter setting message.
NOTE-

When conducting instrument approach procedures, pilots are responsible to obtain and use the appropriate altimeter setting in accordance with 14 CFR Section 97.20. CPDLC issued altimeter settings are excluded for this purpose.
Initial contact is a safety validation transaction that compares a pilot's initiated altitude downlink message with an aircraft's stored altitude in the ATC automation system. When an IC mismatch or Confirm Assigned Altitude (CAA) downlink time-out indicator is displayed in the Full Data Block (FDB) and Aircraft List (ACL), the controller who has track control of the aircraft must use voice communication to verify the assigned altitude of the aircraft, and acknowledge the IC mismatch/time-out indicator.
Transfer of communications automatically establishes data link contact with a succeeding sector.
Menu text transmissions are scripted nontrajectory altering uplink messages.

The CPDLC Message Elements available for use in domestic enroute operations are contained in TBL TBL GEN 3.3-1 through TBL GEN 3.3−22, Message Elements, below.

TBL GEN 3.3-1Response Attribute of CPDLC Message Element
Response Attribute	Description
For Uplink Message
W/U	*Response required.Valid responses. WILCO, UNABLE, STANDBY, NOT CURRENT DATA AUTHORITY, NOT AUTHORIZED NEXT DATA AUTHORITY, LOGICAL ACKNOWLEDGEMENT (only if required), ERRORNote – WILCO, UNABLE, NOT CURRENT DATA AUTHORITY, NOT AUTHORIZED NEXT DATA AUTHORITY and ERROR will close the uplink message.* FANS 1/A.– WILCO, UNABLE, STANDBY, ERROR, NOT CURRENT DATA AUTHORITY.**
A/N	*Response required.Valid responses. AFFIRM, NEGATIVE, STANDBY, NOT CURRENT DATA AUTHORITY, NOT AUTHORIZED NEXT DATA AUTHORITY, LOGICAL ACKNOWLEDGEMENT (only if required), ERRORNote – AFFIRM, NEGATIVE, NOT CURRENT DATA AUTHORITY, NOT AUTHORIZED NEXT DATA AUTHORITY and ERROR will close the uplink message.* FANS 1/A.– AFFIRM, NEGATIVE, STANDBY, ERROR, NOT CURRENT DATA AUTHORITY.**
R	*Response required.Valid responses. ROGER, UNABLE, STANDBY, NOT CURRENT DATA AUTHORITY, NOT AUTHORIZED NEXT DATA AUTHORITY, LOGICAL ACKNOWLEDGEMENT (only if required), ERRORNote – ROGER, NOT CURRENT DATA AUTHORITY, NOT AUTHORIZED NEXT DATA AUTHORITY and ERROR will close the uplink message.*** FANS 1/A.– ROGER, STANDBY, ERROR, NOT CURRENT DATA AUTHORITY. FANS 1/A aircraft do not have the capability to send UNABLE in response to an uplink message containing message elements with an “R” response attribute. For these aircraft, the flight crew may use alternative means to UNABLE the message. These alternative means will need to be taken into consideration to ensure proper technical and operational closure of the communication transaction.
Y	Response required.Valid responses: Any CPDLC downlink message, LOGICAL ACKNOWLEDGEMENT (only if required).
N	No response required unless logical acknowledgement is required.Valid Responses (only if LOGICAL ACKNOWLEDGEMENT is required). LOGICAL ACKNOWLEDGEMENT, NOT CURRENT DATA AUTHORITY, NOT AUTHORIZED NEXT DATA AUTHORITY, ERRORFANS 1/A.– “N” is defined as “no response is required,” but not used. Under some circumstances, an ERROR message will also close an uplink message.
NE	[Not defined in Doc 4444] FANS 1/A.– The WILCO, UNABLE, AFFIRM, NEGATIVE, ROGER, and STANDBY responses are not enabled (NE) for flight crew selection. An uplink message with a response attribute NE is considered to be closed even though a response may be required operationally. Under some circumstances, a downlink error message may be linked to an uplink message with a NE attribute.
For Downlink Message
Y	Response required. YesValid responses. Any CPDLC uplink message, LOGICAL ACKNOWLEDGEMENT (only if required).
N	Response required. No, unless logical acknowledgement required.Valid responses (only if LOGICAL ACKNOWLEDGEMENT is required). LOGICAL ACKNOWLEDGEMENT, SERVICE UNAVAILABLE, FLIGHT PLAN NOT HELD, ERROR FANS 1/A.– Aircraft do not have the capability to receive technical responses to downlink message elements with an “N” response attribute (other than LACK or ERROR for ATN B1 aircraft). In some cases, the response attribute is different between FANS 1/A aircraft and Doc 4444. As an example, most emergency messages have an “N” response attribute for FANS 1/A whereas Doc 4444 defines a “Y” response attribute for them. As a consequence, for FANS 1/A aircraft, ATC will need to use alternative means to acknowledge to the flight crew that an emergency message has been received.

TBL GEN 3.3-2Route Uplink Message Elements (RTEU)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
UM74 PROCEED DIRECT TO (position)	UM74 PROCEED DIRECT TO (position)	W/U	RTEU-2	Instruction to proceed directly to the specified position.	PROCEED DIRECT TO (position)
UM75 WHEN ABLE PROCEED DIRECT TO (position) Note – This message element is equivalent to SUPU-5 plus RTEU-2 in Doc 4444.	N/A	W/U	RTEU-2	Instruction to proceed directly to the specified position.	PROCEED DIRECT TO (position)
UM77 AT (position) PROCEED DIRECT TO (position)	N/A	W/U	RTEU-4	Instruction to proceed, at the specified at position, directly to the next specified position.	AT (position) PROCEED DIRECT TO (position)
UM78 AT (altitude) PROCEED DIRECT TO (position)	N/A	W/U	RTEU-5	Instruction to proceed, upon reaching the specified level, directly to the specified position.	AT (level) PROCEED DIRECT TO (position)
UM79 CLEARED TO (position) via (route clearance)	UM79 CLEARED TO (position) via (route clearance)	W/U	RTEU-6	Instruction to proceed to the specified position via the specified route.	CLEARED TO (position) VIA (departure data[O]) (en-route data)
UM80 CLEARED (route clearance)	UM80 CLEARED (route clearance)	W/U	RTEU-7	Instruction to proceed via the specified route.	CLEARED (departure data[O]) (en-route data) (arrival approach data)
UM83 AT (position) CLEARED (route clearance)	N/A	W/U	RTEU-9	Instruction to proceed from the specified position via the specified route.	AT (position) CLEARED (en-route data) (arrival approach data)
UM91 HOLD AT (position) MAINTAIN (altitude) INBOUND TRACK (degrees) (direction) TURN LEG TIME (leg type)	N/A	W/U	RTEU-11	Instruction to enter a holding pattern at the specified position in accordance with the specified instructions. Note – RTEU-13 EXPECT FURTHER CLEARANCE AT TIME (time) is appended to this message when an extended hold is anticipated.	AT (position) HOLD INBOUND TRACK (degrees)(direction) TURNS (leg type) LEGS
UM92 HOLD AT (position) AS PUBLISHED MAINTAIN (altitude)	UM92 HOLD AT (position) AS PUBLISHED MAINTAIN (level)	W/U	RTEU-12	Instruction to enter a holding pattern at the specified position in accordance with the published holding instructions. Note – RTEU-13 EXPECT FURTHER CLEARANCE AT TIME (time) is appended to this message when an extended hold is anticipated.	AT (position) HOLD AS PUBLISHED
UM93 EXPECT FURTHER CLEARANCE AT (time)	N/A	R	RTEU-13	Notification that an onwards clearance may be issued at the specified time	EXPECT FURTHER CLEARANCE AT (time)
UM137 CONFIRM ASSIGNED ROUTE Note – NE response attribute.	N/A	Y	RTEU-15	Request to confirm the assigned route.	CONFIRM ASSIGNED ROUTE

TBL GEN 3.3-3Route Downlink Message Elements (RTED)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
DM22 REQUEST DIRECT TO (position)	DM22 REQUEST DIRECT TO (position)	Y	RTED-1	Request for a direct clearance to the specified position.	REQUEST DIRECT TO (position)
DM23 REQUEST (procedure name)	N/A	Y	RTED-2	Request for the specified procedure or clearance name.	REQUEST (named instruction
DM24 REQUEST (route clearance)	N/A	Y	RTED-3	Request for the specified route.	REQUEST CLEARANCE (departure data[O]) (en-route data)(arrival approach data[O])
DM40 ASSIGNED ROUTE (route clearance)	N/A	N	RTED-9	Confirmation that the assigned route is the specified route.	ASSIGNED ROUTE (departure data[O]) (en-route data) (arrival approach data[O])

TBL GEN 3.3-4Lateral Uplink Message Elements (LATU)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
UM82 CLEARED TO DEVIATE UP TO (distance offset) (direction) OF ROUTE	UM82 CLEARED TO DEVIATE UP TO (specified distance) (direction) OF ROUTE	W/U	LATU-10	Instruction allowing deviation up to the specified distance(s) from the cleared route in the specified direction(s).	CLEARED TO DEVIATE UP TO (lateral deviation) OF ROUTE
UM127 REPORT BACK ON ROUTE Note – R response attribute.	N/A	W/U	LATU-18	Instruction to report when the aircraft is back on the cleared route.	REPORT BACK ON ROUTE

TBL GEN 3.3-5Lateral Downlink Message Elements (LATD)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
DM27 REQUEST WEATHER DEVIATION UP TO (specifieddistance) (direction) OF ROUTE	N/A	Y	LATD-2	Request for a weather deviation up to the specified distance off track in the specified direction.	REQUEST WEATHER DEVIATION UP TO (specified distance) (direction) OF ROUTE
DM41 BACK ON ROUTE	N/A	Y	LATD-4	The aircraft has regained the cleared route.	BACK ON ROUTE
DM59 DIVERTING TO (position) VIA (route clearance) Note 1. - H alert attribute Note 2. - N response attribute	N/A	Y	LATD-5	Report indicating diverting to the specified position via the specified route, which may be sent without any previous coordination done with ATC.	DIVERTING TO (position) VIA (en-route data)(arrival approach data[O])
DM60 OFFSETTING (distance offset) (direction) OF ROUTE Note 1. - H alert attribute Note 2. - N response attribute	N/A	Y	LATD-6	Report indicating that the aircraft is offsetting to a parallel track at the specified distance in the specified direction off from the cleared route.	OFFSETTING (specified distance) (direction) OF ROUTE
DM80 DEVIATING (deviation offset)(direction) OF ROUTE Note 1. - H alert attribute Note 2. - N response attribute	N/A	Y	LATD-7	Report indicating deviating specified distance or degrees in the specified direction from the cleared route.	DEVIATING (specifiedDeviation)(direction) OF ROUTE

TBL GEN 3.3-6Level Uplink Message Elements (LVLU)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
UM19 MAINTAIN (altitude) Note - Used for a single level	UM19 MAINTAIN (level)	W/U	LVLU-5	Instruction to maintain the specified level or vertical range.	MAINTAIN (level)
UM20 CLIMB TO AND MAINTAIN (altitude) Note - Used for a single level	UM20 CLIMB TO (level)	W/U	LVLU-6	Instruction that a climb to the specified level or vertical range is to commence and once reached is to be maintained.	CLIMB TO (level)
UM23 DESCEND TO AND MAINTAIN (altitude) Note - Used for a single level	UM23 DESCEND TO (level)	W/U	LVLU-9	Instruction that a descent to the specified level or vertical range is to commence and once reached is to be maintained.	DESCEND TO (level)
UM30 MAINTAIN BLOCK (altitude) TO (altitude) Note – Used for a vertical range.	UM19 MAINTAIN (level)	W/U	LVLU-5	Instruction to maintain the specified level or vertical range.	MAINTAIN (level)
UM31 CLIMB TO AND MAINTAIN BLOCK (altitude) TO (altitude) Note – Used for a vertical range	UM20 CLIMB TO (level)	W/U	LVLU-6	Instruction that a climb to the specified level or vertical range is to commence and once reached is to be maintained.	CLIMB TO (level)
UM32 DESCEND TO AND MAINTAIN BLOCK (altitude) TO (altitude) Note – Used for a vertical range.	UM23 DESCEND TO (level)	W/U	LVLU-9	Instruction that a descent to the specified level or vertical range is to commence and once reached is to be maintained.	DECEND (level)
UM36 EXPEDITE CLIMB TO (altitude) Note - This message element is equivalent to SUPU-3 plus LVLU-6 in Doc 4444.	N/A	W/U	LVLU-6	Instruction that a climb to the specified level or vertical range is to commence and once reached is to be maintained.	CLIMB TO (level)

UM37 EXPEDITE DESCEND TO (altitude)	N/A	W/U	LVLU-9	Instruction that a descent to the specified level or vertical range is to commence and once reached is to be maintained.	DESCEND TO (level)
UM38 IMMEDIATELY CLIMB TO (altitude) Note - This message element is equivalent to EMGU-2 plus LVLU-6 in Doc 4444.	N/A	W/U	LVLU-6	Instruction that a climb to the specified level or vertical range is to commence and once reached is to be maintained.	CLIMB TO (level)
UM39 IMMEDIATELY DESCEND TO (altitude) Note - This message element is equivalent to EMGU-2 plus LVLU-9 in Doc 4444.	N/A	W/U	LVLU-9	Instruction that a descent to the specified level or vertical range is to commence and once reached is to be maintained.	DESCEND TO (level)
UM135 CONFIRM ASSIGNED ALTITUDE Note - NE response attribute	N/A	Y	LVLU-27	Request to confirm the assigned level.	CONFIRM ASSIGNED LEVEL
UM177 AT PILOTS DISCRETION	N/A	NE	See Note	Request to confirm the assigned level.

TBL GEN 3.3-7Level Downlink Message Elements (LVLD)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
DM6 REQUEST (altitude) Note - Used for a single level	DM6 REQUEST (level)	Y	LVLD-1	Request to fly at the specified level or vertical range.	REQUEST (level)
DM7 REQUEST BLOCK (altitude) TO (altitude) Note – Used for a vertical range.	DM6 REQUEST (level)	Y	LVLD-1	Request to fly at the specified level or vertical range.	REQUEST (level)
DM8 REQUEST CRUISE CLIMB TO (altitude)	N/A	Y	N/A	Request to cruise climb to the specified level. Due to different interpretations between the various ATS units, this element should be avoided.	N/A
DM9 REQUEST CLIMB TO (altitude)	DM9 REQUEST CLIMB TO (level)	Y	LVLD-2	Request for a climb to the specified level or vertical range.	REQUEST CLIMB TO (level)
DM10 REQUEST DESCENT TO (altitude)	DM10 REQUEST DESCENT TO (level)	Y	LVLD-3	Request for a descent to the specified level or vertical range.	REQUEST DESCENT TO (level)
DM38 ASSIGNED LEVEL (altitude) Note - Used for a single level	DM38 ASSIGNED LEVEL (level)	N	LVLD-11	Confirmation that the assigned level or vertical range is the specified level or vertical range.	ASSIGNED LEVEL (level)
DM61 DESCENDING TO (altitude) Note - urgent alert attribute	N/A	N	LVLD-14	Report indicating descending to the specified level.	DESCENDING TO (level single)
DM77 ASSIGNED BLOCK (altitude) TO (altitude) Note – Used for a vertical range.	DM38 ASSIGNED LEVEL (level)	N	LVLD-11	Confirmation that the assigned level or vertical range is the specified level or vertical range.	ASSIGNED LEVEL (level)

TBL GEN 3.3-8Crossing Constraint Message Elements (CSTU)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
UM46 CROSS (position) AT (altitude) Note – Used for a single level.	UM46 CROSS (position) AT (level)	W/U	CSTU-1	Instruction that the specified position is to be crossed at the specified level or within the specified vertical range.	CROSS (position) AT (level)
UM49 CROSS (position) AT AND MAINTAIN (altitude) Note 1. - A vertical range cannot be provided. Note 2. - This message element is equivalent to CSTU-1 plus LVLU-5 in Doc4444.	N/A	W/U	CSTU-1	Instruction that the specified position is to be crossed at the specified level or within the specified vertical range.	CROSS (position) AT (level)
UM50 CROSS (position) BETWEEN (altitude) AND (altitude) Note – Used for a vertical range.	UM46 CROSS (position) AT (level)	W/U	CSTU-1	Instruction that the specified position is to be crossed at the specified level or within the specified vertical range.	CROSS (position) AT (level)
UM51 CROSS (position) AT (time)	UM51 CROSS (position) AT (time)	W/U	CSTU-4	Instruction that the specified position is to be crossed at the specified time.	CROSS (position) AT TIME (level)
UM52 CROSS (position) AT OR BEFORE (time)	UM52 CROSS (position) AT OR BEFORE (time)	W/U	CSTU-5	Instruction that the specified position is to be crossed at the specified time.	CROSS (position) BEFORE TIME (time)
UM53 CROSS (position) AT OR AFTER (time)	UM53 CROSS (position) AT OR AFTER (time)	W/U	CSTU-6	Instruction that the specified position is to be crossed at the specified time.	CROSS (position) AFTER TIME (time)
UM54 CROSS (position) BETWEEN (time) AND (time)	UM54 CROSS (position) BETWEEN (time) AND (time)	W/U	CSTU-7	Instruction that the specified position is to be crossed at the specified time.	CROSS (position) BETWEEN TIME (time) AND TIME (time)
UM55 CROSS (position) AT (speed)	UM55 CROSS (position) AT (speed)	W/U	CSTU-8	Instruction that the specified position is to be crossed at the specified time.	CROSS (position) AT (speed)
UM56 CROSS (position) AT OR LESS THAN (speed)	UM56 CROSS (position) AT OR LESS THAN (speed)	W/U	CSTU-9	Instruction that the specified position is to be crossed at or less than the specified speed.	CROSS (position) AT (speed) OR LESS
UM57 CROSS (position) AT OR GREATER THAN (speed)	N/A	W/U	CSTU-9	Instruction that the specified position is to be crossed at or less than the specified speed.	CROSS (position) AT (speed) OR LESS
UM50 CROSS (position) BETWEEN (altitude) AND (altitude) Note - Used for a vertical range.	UM46 CROSS (position) AT (level).	W/U	CSTU-1	Instruction that the specified position is to be crossed at the specified level	CROSS (position) AT (level)
UM61 CROSS (position) AT AND MAINTAIN (altitude) AT (speed) Note 1. - A vertical range cannot be provided. Note 2. - This message element is equivalent to CSTU-14 plus LVLU-5 in Doc 4444.	UM61 CROSS (position) AT AND MAINTAIN (level) AT (speed)	W/U	CSTU-14	Instruction that the specified position is to be crossed at the specified time.	CROSS (position) AT (level) AT (speed)

TBL GEN 3.3-9Speed Uplink Message Elements (SPDU)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
UM106 MAINTAIN (speed)	UM106 MAINTAIN (speed)	W/U	SPDU-4	Instruction to maintain the specified speed.	MAINTAIN (speed)
UM107 MAINTAIN PRESENT SPEED	UM107 MAINTAIN PRESENT SPEED	W/U	SPDU-5	Instruction to maintain the specified speed.	MAINTAIN PRESENT SPEED
UM108 MAINTAIN (speed) OR GREATER	UM108 MAINTAIN (speed) OR GREATER	W/U	SPDU-6	Instruction to maintain the specified speed or greater.	MAINTAIN (speed) OR GREATER
UM109 MAINTAIN (speed) OR LESS	UM109 MAINTAIN (speed) OR LESS	W/U	SPDU-7	Instruction to maintain the specified speed or less.	MAINTAIN (speed) OR LESS
UM116 RESUME NORMAL SPEED	UM116 RESUME NORMAL SPEED	W/U	SPDU-13	Instruction to resume a normal speed. The aircraft no longer needs to comply with a previously issued speed restriction.	RESUME NORMAL SPEED
UM134 CONFIRM SPEED Note – NE response attribute.	N/A	Y	SPDU-15	Request to report the speed defined by the speed type(s).	REPORT (speed types) SPEED

TBL GEN 3.3-10Speed Downlink Message Elements (SPDD)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
DM34 PRESENT SPEED (speed)	N/A	N	SPDD-3	Report indicating the speed defined by the specified speed types is the specified speed.	(speed types) SPEED (speed)

TBL GEN 3.3-11Air Traffic Advisory Uplink Message Elements (ADVU)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
UM154 RADAR SERVICES TERMINATED	N/A	R	ADVU-2	Advisory that the ATS surveillance service is terminated.	SURVEILLANCE SERVICE TERMINATED

TBL GEN 3.3-12Voice Communications Uplink Message Elements (COMU)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
UM117 CONTACT (ICAO unit name) (frequency)	UM117 CONTACT (unit name) (frequency)	W/U	COMU-1	Instruction to establish voice contact with the specified ATS unit on the specified frequency.	CONTACT (unit name) (frequency)
UM120 MONITOR (ICAO unit name) (frequency)	UM120 MONITOR (unit name) (frequency)	W/U	COMU-5	Instruction to monitor the specified ATS unit on the specified frequency. The flight crew is not required to establish voice contact on the frequency.	MONITOR (unit name) (frequency)

TBL GEN 3.3-13Voice Communications Downlink Message Elements (COMD)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
DM20 REQUEST VOICE CONTACT Note - Used when a frequency is not required.	N/A	Y	COMD-1	Request for voice contact on the specified frequency.	REQUEST VOICE CONTACT (frequency)

TBL GEN 3.3-14Emergency/Urgency Downlink Message Elements (EMGD)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
DM55 PAN PAN PAN Note - N response attribute	N/A	Y	EMGD-1	Indication of an urgent situation.	PAN PAN PAN
DM56 MAYDAY MAYDAY MAYDAY Note - N response attribute	N/A	Y	EMGD-2	Indication of an emergency situation.	MAYDAY MAYDAY MAYDAY
DM57 (remaining fuel) OF FUEL REMAINING AND (remaining souls) SOULS ON BOARD Note - N response attribute	N/A	Y	EMGD-3	Report indicating fuel remaining (time) and number of persons on board.	(remaining fuel) ENDURANCE AND (persons on board) PERSONS ON BOARD
DM58 CANCEL EMERGENCY Note - N response attribute	N/A	Y	EMGD-4	Indication that the emergency situation is canceled.	CANCEL EMERGENCY

TBL GEN 3.3-15Standard Response Uplink Message Elements (RSPU)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
UM0 UNABLE	UM0 UNABLE	N	RSPU-1	Indication that the message cannot be complied with.	UNABLE
UM1 STANDBY	UM1 STANDBY	N	RSPU-2	Indication that the message will be responded to shortly.	STANDBY
UM2 REQUEST DEFERRED	N/A	N	RSPU-3	Indication that a long-term delay in response can be expected.	REQUEST DEFERRED
UM3 ROGER	UM3 ROGER	N	RSPU-4	Indication that the message is received.	ROGER

TBL GEN 3.3-16Standard Response Downlink Message Elements (RSPD)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
DM0 WILCO	DM0 WILCO	N	RSPD-1	Indication that the instruction is understood and will be complied with.	WILCO
DM1 UNABLE	DM1 UNABLE	N	RSPD-2	Indication that the message cannot be complied with.	UNABLE
DM2 STANDBY	DM2 STANDBY	N	RSPD-3	Indication that the message will be responded to shortly.	STANDBY
DM3 ROGER Note - ROGER is the only correct response to an uplink free text message.	DM3 ROGER	N	RSPD-4	Indication that the message is received.	ROGER

TBL GEN 3.3-17Supplemental Uplink Message Elements (SUPU)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
UM166 DUE TO TRAFFIC	N/A	NE	SUPS-2	Indication that the associated message is issued due to the specified reason.	DUE TO (specified reason uplink)
UM167 DUE TO AIRSPACE RESTRICTION	N/A	NE	SUPU-2	Indication that the associated message is issued due to the specified reason.	DUE TO (specified reason uplink)

TBL GEN 3.3-18Supplemental Downlink Message Elements (SUPD)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
UM165 DUE TO AIRSPACE RESTRICTION	DM65 DUE TO WEATHER	N	SUPU-1	Indication that the associated message is issued due to the specified reason.	DUE TO (specified reason uplink)
UM166 DUE TO AIRSPACE RESTRICTION	DM66 DUE TO WEATHER	N	SUPU-1	Indication that the associated message is issued due to the specified reason.	DUE TO (specified reason downlink)

TBL GEN 3.3-19Free Text Uplink Message Elements (TXTU)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
UM169 (free text)	UM203 (free text)	R	TXTU-1	A message or part of a message that does not conform to any standard message element in the PANSATM (Doc 4444).	(free text) Note - M alert attribute.
UM169 (free text) CPDLC NOT IN USE UNTIL FURTHER NOTIFICATION	N/A	R	N/A	See Note	N/A
UM169 (free text) “[facility designation]” LOCAL ALTIMETER (for Altimeter Reporting Station)	N/A	R	N/A	See Note	N/A
UM169 (free text) “[facility designation] LOCAL ALTIMETER MORE THAN ONE HOUR” OLD	N/A	R	N/A	See Note	N/A
UM169 (free text) DUE TO WEATHER	N/A	R	N/A	See Note	N/A
UM169 (free text) REST OF ROUTE UNCHANGED	N/A	R	N/A	See Note	N/A
UM169 (free text) TRAFFIC FLOW MANAGEMENT REROUTE	N/A	R	N/A	See Note	N/A
UM169 (free text) DUE TO SPACING	N/A	R	N/A	See Note	N/A
UM169 (free text) ATC HAS YOUR REQUEST	N/A	R	N/A	See Note	N/A
UM169 (free text) ATC ADVISORY	N/A	R	N/A	See Note	N/A

TBL GEN 3.3-20Free Text Downlink Message Elements (TXTD)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
DM68 (free text) Note 1. – Urgency or Medium (M) alert attribute. Note 2. – Selecting any of the emergency message elements will result in this message element being enabled for the flight crew to include in the emergency message at their discretion.	N/A	Y	N/A	N/A	(free text) Note - M alert attribute.

TBL GEN 3.3-21System Management Uplink Message Elements (SYSU)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
UM159 ERROR (error information)	UM159 ERROR (error information)	N	SYSU-1	System-generated notification of an error.	ERROR (error information)
UM160 NEXT DATA AUTHORITY (ICAO facility designation) Note - The facility designation is required.	UM160 NEXT DATA AUTHORITY (facility) Note - Facility parameter can specify a facility designation or no facility.	N	SYSU-2	System-generated notification of the next data authority or the cancellation thereof.	NEXT DATA AUTHORITY (facility designation [O])

TBL GEN 3.3-22System Management Downlink Message Elements (SYSD)
CPDLC Message Sets	Operational Definition in PANS-ATM (Doc 4444)
FANS 1/A	ATN B1	Response	Message Element Identifier	Message Element Intended Use	Format for Message Element Display
DM62 ERROR (error information)	DM62 ERROR (error information)	N	SYSD-1	System-generated notification of an error.	ERROR (error information)
DM63 NOT CURRENT DATA AUTHORITY	DM63 NOT CURRENT DATA AUTHORITY	N	SYSD-3	System-generated rejection of any CPDLC message sent from a ground facility that is not the current data authority.	NOT CURRENT DATA AUTHORITY
DM64 (ICAO facility designation) Note - Use by FANS 1/A aircraft in B1 environments.	N/A	N	N/A	System-generated notification that the ground system is not designated as the next data authority (NDA), indicating the identity of the current data authority (CDA). Identity of the NDA, if any, is also reported.	N/A

ATC Frequency Change Procedures
1. The following phraseology will be used by controllers to effect a frequency change:
  EXAMPLE-
  
  (Aircraft identification) CONTACT (facility name or location name and terminal function) (frequency) AT (time, fix, or altitude).
  NOTE-
  
  Pilots are expected to maintain a listening watch on the transferring controller's frequency until the time, fix, or altitude specified. ATC will omit frequency change restrictions whenever pilot compliance is expected upon receipt.
2. The following phraseology should be utilized by pilots for establishing contact with the designated facility:
  1. When operating in a radar environment:
    1. On initial contact, the pilot should inform the controller of the aircraft's assigned altitude preceded by the words “level,” or “climbing to,” or “descending to,” as appropriate; and the aircraft's present vacating altitude, if applicable.
      EXAMPLE-
      
      (Name) CENTER, (aircraft identification), LEVEL (altitude or flight level).
      
      (Name) CENTER, (aircraft identification), LEAVING (exact altitude or flight level), CLIMBING TO OR DESCENDING TO (altitude or flight level).
      NOTE-
      
      Exact altitude or flight level means to the nearest 100 foot increment. exact altitude or flight level reports on initial contact provide ATC with information required prior to using Mode C altitude information for separation purposes.
  2. When operating in a nonradar environment:
    1. On initial contact, the pilot should inform the controller of the aircraft's present position, altitude and time estimate for the next reporting point.
      EXAMPLE-
      
      (Name) CENTER, (aircraft identification), (POSITION), (altitude), ESTIMATING (reporting point) at (time).
    2. After initial contact, when a position report will be made, the pilot should give the controller a complete position report.
      EXAMPLE-
      
      (Name) CENTER, (aircraft identification), (position), (time), (altitude), (type of flight plan), (ETA and name of next reporting point), (the name of the next succeeding reporting point), AND (remarks).
      REFERENCE-
      
      AIP, Position Reporting, Paragraph 6.
3. At times controllers will ask pilots to verify the fact that they are at a particular altitude. The phraseology used will be: “VERIFY AT (altitude).” In climbing/descending situations, controllers may ask pilots to “VERIFY ASSIGNED ALTITUDE AS (altitude).” Pilots should confirm that they are at the altitude stated by the controller or that the assigned altitude is correct as stated. If this is not the case, they should inform the controller of the actual altitude being maintained or the different assigned altitude.
  NOTE-
  
  Pilots should not take action to change their actual altitude or different assigned altitude to that stated in the controller's verification request unless the controller specifically authorizes a change.
ARTCC Radio Frequency Outage. ARTCC's normally have at least one back-up radio receiver and transmitter system for each frequency which can usually be pressed into service quickly with little or no disruption of ATC service. Occasionally, technical problems may cause a delay but switchover seldom takes more than 60 seconds. When it appears that the outage will not be quickly remedied, the ARTCC will usually request a nearby aircraft, if there is one, to switch to the affected frequency to broadcast communications instructions. It is important, therefore, that the pilot wait at least one minute before deciding that the ARTCC has actually experienced a radio frequency failure. When such an outage does occur, the pilot should, if workload and equipment capability permit, maintain a listening watch on the affected frequency while attempting to comply with the recommended communications procedures which follow.
1. If two-way communications cannot be established with the ARTCC after changing frequencies, a pilot should attempt to recontact the transferring controller for the assignment of an alternative frequency or other instructions.
2. When an ARTCC radio frequency failure occurs after two-way communications have been established, the pilot should attempt to reestablish contact with the center on any other known ARTCC frequency, preferably that of the next responsible sector when practicable, and ask for instructions. However, when the next normal frequency change along the route is known to involve another ATC facility, the pilot should contact that facility, if feasible, for instructions. If communications cannot be reestablished by either method, the pilot is expected to request communications instructions from the FSS appropriate to the route of flight.
  NOTE-
  
  The exchange of information between an aircraft and an ARTCC through an FSS is quicker than relay via company radio because the FSS has direct interphone lines to the responsible ARTCC sector. Accordingly, when circumstances dictate a choice between the two, during an ARTCC frequency outage, relay via FSS radio is recommended.

5.. Radio Communications Failure

Pilots of IFR flights experiencing two-way radio failure are expected to adhere to the procedures prescribed in GEN 3.4, paragraph 12.
REFERENCE-

14 CFR Section 91.185

6.. Position Reporting

The safety and effectiveness of traffic control depends to a large extent on accurate position reporting. In order to provide the proper separation and expedite aircraft movements, ATC must be able to make accurate estimates of the progress of every aircraft operating on an IFR flight plan.
Position Identification
1. When a position report is to be made passing a VOR radio facility, the time reported should be the time at which the first complete reversal of the “to/from” indicator is accomplished.
2. When a position report is made passing a facility by means of an airborne automatic direction finder (ADF), the time reported should be the time at which the indicator makes a complete reversal.
3. When an aural or light-panel indication is used to determine the time passing a reporting point, such as a fan marker, Z marker, cone of silence or intersection of range courses, the time should be noted when the signal is first received and again when it ceases. The mean of these two times should then be taken as the actual time over the fix.
4. If a position is given with respect to distance and direction from a reporting point, the distance and direction should be computed as accurately as possible.
5. Except for terminal transition purposes, position reports or navigation with reference to aids not established for use in the structure in which flight is being conducted will not normally be required by ATC.
Position Reporting Points
1. Federal Aviation Regulations require pilots to maintain a listening watch on the appropriate frequency and, unless operating under the provisions of subparagraph 6.4, to furnish position reports passing certain reporting points. Reporting points are indicated by symbols on en route charts. The designated compulsory reporting point symbol is the solid triangle ; the “on request” reporting point symbol is the open triangle . Reports passing an “on request” reporting point are only necessary when requested by ATC.
Position Reporting Requirements
1. Flights Along Airways or Routes. A position report is required by all flights regardless of altitude, including those operating in accordance with an ATC clearance specifying “VFR-on-top,” over each designated compulsory reporting point along the route being flown.
2. Flight Along a Direct Route. Regardless of the altitude or flight level being flown, including flights operating in accordance with an ATC clearance specifying “VFR-on-top,” pilots must report over each reporting point used in the flight plan to define the route of flight.
3. Flights in a Radar Environment. When informed by ATC that their aircraft are in “RADAR CONTACT,” PILOTS SHOULD DISCONTINUE POSITION REPORTS OVER DESIGNATED REPORTING POINTS. They should resume normal position reporting when ATC advises “RADAR CONTACT LOST” or “RADAR SERVICE TERMINATED.”
  NOTE-
  
  ATC will inform pilots that they are in “radar contact” (a) When their aircraft is initially identified in the ATC system; and (b) When radar identification is reestablished after radar service has been terminated or radar contact has been lost. Subsequent to being advised that the controller has established radar contact, this fact will not be repeated to the pilot when handed off to another controller. At times, the aircraft identity will be confirmed by the receiving controller; however, this should not be construed to mean that radar contact has been lost. The identity of transponder-equipped aircraft will be confirmed by asking the pilot to “ident, squawk standby,” or to change codes. Aircraft without transponders will be advised of their position to confirm identity. In this case, the pilot is expected to advise the controller if in disagreement with the position given. If the pilot cannot confirm the accuracy of the position given because of not being tuned to the NAVAID referenced by the controller, the pilot should ask for another radar position relative to the tuned in NAVAID.
4. Flights in an Oceanic (Nonradar) Environment. Pilots must report over each point used in the flight plan to define the route of flight, even if the point is depicted on aeronautical charts as an “on request" (non‐compulsory) reporting point. For aircraft providing automatic position reporting via an Automatic Dependent Surveillance‐Contract (ADS‐C) logon, pilots should discontinue voice position reports.
Position Report Items
1. Position reports should include the following items:
  1. Identification.
  2. Position.
  3. Time.
  4. Altitude or flight level (Include actual altitude or flight level when operating on a clearance specifying “VFR-on-top.”).
  5. Type of flight plan (not required in IFR position reports made directly to ARTCCs or approach control).
  6. ETA and name of next reporting point.
  7. The name only of the next succeeding reporting point along the route of flight.
  8. Pertinent remarks.

7.. Additional Reports

The following reports should be made to ATC or FSS facilities without a specific request:
1. At all times, report:
  1. When vacating any previously assigned altitude/flight level for a newly assigned altitude/flight level.
  2. When an altitude change will be made if operating on a clearance specifying “VFR-on-top.”
  3. When unable to climb/descend at a rate of at least 500 feet per minute.
  4. When approach has been missed. (Request clearance for specific action; i.e., to alternative airport, another approach, etc.).
  5. Change in the average true airspeed (at cruising altitude) when it varies by 5 percent or 10 knots (whichever is greater) from that filed in the flight plan.
  6. The time and altitude/flight level reaching a holding fix or point to which cleared.
  7. When leaving any assigned holding fix or point.
    NOTE-
    
    The reports in subparagraphs 7.1.1.6 and 7.1.1.7 may be omitted by pilots of aircraft involved in instrument training at military area facilities when radar service is being provided.
  8. Any loss, in controlled airspace, of VOR, TACAN, ADF, low frequency navigation receiver capability, GPS anomalies while using installed IFR-certified GPS/GNSS receivers, complete or partial loss of ILS receiver capability or impairment of air/ground communications capability. Reports should include aircraft identification, equipment affected, degree to which the capability to operate under IFR in the ATC system is impaired, and the nature and extent of assistance desired from ATC.
    NOTE-
    
    When reporting GPS anomalies, include the location and altitude of the anomaly. Be specific when describing the location and include duration of the anomaly if necessary.
  9. Any information relating to the safety of flight.
    NOTE-
    
    Other equipment installed in an aircraft may effectively impair safety and/or the ability to operate under IFR. If such equipment; e.g., airborne weather radar, malfunctions and in the pilot's judgment either safety or IFR capabilities are affected, reports should be made as above.
When not in radar contact, report:
1. When leaving the final approach fix inbound on final approach (nonprecision approach) or when leaving the outer marker or fix used in lieu of the outer marker inbound on final approach (precision approach); or
2. A corrected estimate at anytime it becomes apparent that an estimate as previously submitted is in error in excess of 2 minutes. For flights in the North Atlantic (NAT), a revised estimate is required if the error is 3 minutes or more.
Pilots encountering weather conditions which have not been forecast, or hazardous conditions which have been forecast, are expected to forward a report of such weather to ATC.

8.. Quota Flow Control

Quota Flow Control is designed to balance the ATC system demand with system capacity.
ARTCCs will hold the optimum number of aircraft that their primary and secondary holding fixes will safely accommodate without imposing undue limitations on the control of other traffic operating within the ARTCC's airspace. This is based on the user's requirement to continue operating to a terminal regardless of the arrival rate at that terminal. When staffing, equipment, or severe weather will inhibit the number of aircraft the arrival ARTCC may safely hold, a reduction may be necessary.
When an ARTCC is holding the optimum number of aircraft, the adjacent ARTCCs will be issued quotas concerning aircraft which can be cleared into the impacted ARTCC's airspace. When the adjacent center's demand exceeds the quota, aircraft will be held in the adjacent ARTCC's airspace until they can be permitted to proceed.
The size of the hourly quota will be based initially on the projected arrival rate and thereafter on the actual landing and diversion totals. Once quotas have been imposed, departures in the arrival and adjacent ARTCC's area to the affected airport may be assigned ground delay, if necessary, to limit airborne holding to ATC capacity. However, when a forecast of improved arrival rate appears reliable, in the opinion of the arrival ARTCC, additional above-quota flights may be approved based on the expectation that by the time these additional above-quota flights become an operational factor in the affected area, the system will be able to absorb them without undue difficulty.
Long distance flights, which originate beyond the adjacent ARTCC area, will normally be permitted to proceed to a point just short of the arrival ARTCC boundary where a delay, at least equal to the delays (ground/airborne) being encountered, will be assigned.
ARTCCs imposing ground delays make efforts to advise the users when lengthy delays are a prospect to preclude unnecessary boarding and subsequent unloading prior to actual takeoff due to lengthy unanticipated ground delays. Users should advise the ARTCC through FSS or operation offices when there is any significant change in the proposed departure time so as to permit more efficient flow control planning. Airborne aircraft holding in the adjacent ARTCC airspace generally receive more benefit than ground delayed aircraft when increases unexpectedly develop in the quota number because the reaction time is less. For this reason, whenever operationally feasible, adjacent ARTCCs may offer airborne delay within their areas instead of ground delay.
Flights originating beyond the adjacent ARTCC areas may not have sufficient fuel to absorb the total anticipated delay while airborne. Accordingly, the concerned adjacent ARTCC may permit these flights to land in its area while retaining previously accumulated delay for the purpose of quota priority. When the amount of air traffic backlogging in an adjacent ARTCC area is approaching the saturation point, additional en route traffic will be subject to prior approval.
Generally, movement of arrival aircraft into the impacted airport terminal area will be made on the basis that those flights with the most accumulated delay, either ground, airborne, or a combination of both, normally receive priority over other traffic. This applies only to delays encountered because of the situation at the airport of intended landing.
Pilots/operators are advised to check for flow control advisories which are transmitted to FSSs, to selected airline dispatch offices, and to ARTCCs.

9.. Advisory and Air Traffic Information Services

Approach Control Service for VFR Arriving Aircraft
1. Numerous approach control facilities have established programs for arriving VFR aircraft to contact approach control for landing information. This information includes: wind, runway, and altimeter setting at the airport of intended landing. This information may be omitted if contained in the ATIS broadcast and the pilot states the appropriate ATIS code.
  NOTE-
  
  Pilot use of “have numbers” does not indicate receipt of the ATIS broadcast. In addition, the controller will provide traffic advisories on a workload permitting basis.
2. Such information will be furnished upon initial contact with the concerned approach control facility. The pilot will be requested to change to the tower frequency at a predetermined time or point, to receive further landing information.
3. Where available, use of this procedure will not hinder the operation of VFR flights by requiring excessive spacing between aircraft or devious routing. Radio contact points will be based on time or distance rather than on landmarks.
4. Compliance with this procedure is not mandatory, but pilot participation is encouraged. (See ENR 1.1, paragraph 40, Terminal Radar Services for VFR Aircraft.)
  NOTE-
  
  Approach control services for VFR aircraft are normally dependent on air traffic control radar. These services are not available during periods of a radar outage.
Traffic Advisory Practices at Airports Without Operating Control Towers
1. Airport Operations Without an Operating Control Tower
  1. There is no substitute for alertness while in the vicinity of an airport. It is essential that pilots be alert and look for other traffic and exchange traffic information when approaching or departing an airport without 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:
    1. All radio-equipped aircraft transmit/receive on a common frequency identified for the purpose of airport advisories; and
    2. Pilots use the correct airport name, as identified in appropriate aeronautical publications, to reduce the risk of confusion when communicating their position, intentions, and/or exchanging traffic information.
  2. An airport may have a full or part-time tower or FSS located on the airport, a full or part-time UNICOM station or no aeronautical station at all. There are three ways for pilots to communicate their intention and obtain airport/traffic information when operating at an airport that does not have an operating tower: by communicating with an FSS, a UNICOM operator, or by making a self-announce broadcast.
    NOTE-
    
    FSS airport advisories are available only in Alaska.
  3. Many airports are now providing completely automated weather, radio check capability and airport advisory information on an automated UNICOM system. These systems offer a variety of features, typically selectable by microphone clicks, on the UNICOM frequency. Availability of the automated UNICOM will be published in the Chart Supplement and approach charts.
2. Communicating on a Common Frequency
  1. The key to communicating at an airport without an operating control tower is selection of the correct common frequency. The acronym, CTAF, which stands for common traffic advisory frequency, is synonymous with this program. A CTAF is a frequency designated for the purpose of carrying out airport advisory practices while operating to or from an airport without an operating control tower. The CTAF may be a UNICOM, MULTICOM, FSS, or tower frequency and is identified in appropriate aeronautical publications.
    NOTE-
    
    FSS frequencies are available only in Alaska.
  2. CTAF (Alaska Only). In Alaska, a CTAF may also be designated for the purpose of carrying out advisory practices while operating in designated areas with a high volume of VFR traffic.
  3. The CTAF frequency for a particular airport or area is contained in the Chart Supplement, Alaska Terminal Publication, Instrument Approach Procedure Charts, and Instrument Departure Procedure (DP) Charts. Also, the CTAF frequency can be obtained by contacting any FSS. Use of the appropriate CTAF, combined with a visual alertness and application of the following recommended good operating practices, will enhance safety of flight into and out of all uncontrolled airports.
3. Recommended Traffic Advisory Practices
  1. Pilots of inbound aircraft should monitor and communicate on the designated CTAF from 10 miles to landing. Pilots of departing aircraft should monitor/communicate on the appropriate frequency from start-up, during taxi, and until 10 miles from the airport unless the Code of Federal Regulations (CFR) or local procedures require otherwise.
  2. Pilots of aircraft conducting other than arriving or departing operations at altitudes normally used by arriving and departing aircraft should monitor/communicate on the appropriate frequency while within 10 miles of the airport unless required to do otherwise by the CFR or local procedures. Such operations include parachute jumping/dropping (see ENR 5.1, Paragraph 2.3, Parachute Jump Aircraft Operations), en route, practicing maneuvers, etc.
  3. In Alaska, pilots of aircraft conducting other than arriving or departing operations in designated CTAF areas should monitor/communicate on the appropriate frequency while within the designated area, unless required to do otherwise by CFRs or local procedures. Such operations include parachute jumping/dropping, en route, practicing maneuvers, etc.
4. Airport Advisory/Information Services Provided by a FSS
  1. There are two advisory type services provided at selected airports.
    1. Local Airport Advisory (LAA) is available only in Alaska and provided at airports that have a FSS physically located on the airport, which does not have a control tower or where the tower is operated on a part-time basis. The CTAF for LAA airports is disseminated in the appropriate aeronautical publications.
    2. Remote Airport Information Service (RAIS) is provided in support of special events at nontowered airports by request from the airport authority and must be published as a NOTAM D.
  2. In communicating with a CTAF FSS, check the airport's automated weather and establish two-way communications before transmitting outbound/inbound intentions or information. An inbound aircraft should initiate contact approximately 10 miles from the airport, reporting aircraft identification and type, altitude, location relative to the airport, intentions (landing or over flight), possession of the automated weather, and request airport advisory or airport information service. A departing aircraft should initiate contact before taxiing, reporting aircraft identification and type, VFR or IFR, location on the airport, intentions, direction of take-off, possession of the automated weather, and request airport advisory or information service, as applicable. Also, report intentions before taxiing onto the active runway for departure. If you must change frequencies for other service after initial report to FSS, return to FSS frequency for traffic update.
    1. Inbound
      EXAMPLE-
      
      Vero Beach radio, Centurion Six Niner Delta Delta is ten miles south, two thousand, landing Vero Beach. I have the automated weather, request airport advisory.
    2. Outbound
      EXAMPLE-
      
      Vero Beach radio, Centurion Six Niner Delta Delta, ready to taxi to runway 22, VFR, departing to the southwest. I have the automated weather, request airport advisory.
  3. Airport advisory service includes wind direction and velocity, favored or designated runway, altimeter setting, known airborne and ground traffic, NOTAMs, airport taxi routes, airport traffic pattern information, and instrument approach procedures. These elements are varied so as to best serve the current traffic situation. Some airport managers have specified that under certain wind or other conditions designated runways be used. Pilots should advise the FSS of the runway they intend to use.
  4. Automatic Flight Information Service (AFIS) - Alaska FSSs Only
    1. AFIS is the continuous broadcast of recorded non-control information at airports in Alaska where an FSS provides local airport advisory service. Its purpose is to improve FSS specialist efficiency by reducing frequency congestion on the local airport advisory frequency.
      1. The AFIS broadcast will automate the repetitive transmission of essential but routine information (for example, weather, favored runway, braking action, airport NOTAMs, etc.). The information is continuously broadcast over a discrete VHF radio frequency (usually the ASOS frequency).
      2. Use of AFIS is not mandatory, but pilots who choose to utilize two-way radio communications with the FSS are urged to listen to AFIS, as it relieves frequency congestion on the local airport advisory frequency. AFIS broadcasts are updated upon receipt of any official hourly and special weather, and changes in other pertinent data.
      3. When a pilot acknowledges receipt of the AFIS broadcast, FSS specialists may omit those items contained in the broadcast if they are current. When rapidly changing conditions exist, the latest ceiling, visibility, altimeter, wind or other conditions may be omitted from the AFIS and will be issued by the FSS specialist on the appropriate radio frequency.
        EXAMPLE-
        
        “Kotzebue information ALPHA. One six five five zulu. Wind, two one zero at five; visibility two, fog; ceiling one hundred overcast; temperature minus one two, dew point minus one four; altimeter three one zero five. Altimeter in excess of three one zero zero, high pressure altimeter setting procedures are in effect. Favored runway two six. Weather in Kotzebue surface area is below V-F-R minima - an ATC clearance is required. Contact Kotzebue Radio on 123.6 for traffic advisories and advise intentions. Notice to Airmen, Hotham NDB out of service. Transcribed Weather Broadcast out of service. Advise on initial contact you have ALPHA.”
        NOTE-
        
        The absence of a sky condition or ceiling and/or visibility on Alaska FSS AFIS 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.”
    2. Pilots should listen to Alaska FSSs AFIS broadcasts whenever Alaska FSSs AFIS is in operation.
      NOTE-
      
      Some Alaska FSSs are open part time and/or seasonally.
    3. Pilots should notify controllers on initial contact that they have received the Alaska FSSs AFIS broadcast by repeating the phonetic alphabetic letter appended to the broadcast.
      EXAMPLE-
      
      “Information Alpha received.”
    4. While it is a good operating practice for pilots to make use of the Alaska FSS AFIS broadcast where it is available, some pilots use the phrase “have numbers” in communications with the FSS. Use of this phrase means that the pilot has received wind, runway, and altimeter information ONLY and the Alaska FSS does not have to repeat this information. It does not indicate receipt of the AFIS broadcast and should never be used for this purpose.
      NOTE-
      
      All aircraft in the vicinity of an airport may not be in communication with the FSS.
5. Information Provided by Aeronautical Advisory Stations (UNICOM)
  1. UNICOM is a nongovernment air/ground radio communication station which may provide airport information at public use airports where there is no tower or FSS.
  2. On pilot request, UNICOM stations may provide pilots 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.
  3. Unavailability of Information from FSS or UNICOM. Should LAA by an FSS or Aeronautical Advisory Station UNICOM be unavailable, wind and weather information may be obtainable from nearby controlled airports via Automatic Terminal Information Service (ATIS) or Automated Weather Observing System (AWOS) frequency.
6. Self-Announce Position and/or Intentions
  1. General.Self‐announce is a procedure whereby pilots broadcast their position or intended flight activity or ground operation on the designated CTAF. This procedure is used primarily at airports which do not have an FSS on the airport. The self‐announce procedure should also be used if a pilot is unable to communicate with the FSS on the designated CTAF. Pilots stating, “Traffic in the area, please advise” is not a recognized Self-Announce Position and/or Intention phrase and should not be used under any condition.
  2. If an airport has a tower which is temporarily closed or operated on a part-time basis, and there is no FSS on the airport or the FSS is closed, use the CTAF to self-announce your position or intentions.
  3. 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.
  4. Straight‐in Landings. The FAA discourages VFR straight‐in approaches to landings due to the increased risk of a mid‐air collision. However, if a pilot chooses to execute a straight‐in approach for landing without entering the airport traffic pattern, the pilot should self-announce their position on the designated CTAF approximately 8 to 10 miles from the airport and coordinate their straight-in approach and landing with other airport traffic. Pilots executing a straight-in approach (IFR or VFR) do not have priority over other aircraft in the traffic pattern, and must comply with the provisions of 14 CFR 91.113 (g), Right‐of‐way rules.
  5. Traffic Pattern Operations. All traffic within a 10‐mile radius of a non‐towered airport or a part‐time‐towered airport when the control tower is not operating, should monitor and communicate on the designated CTAF when entering the traffic pattern. Pilots operating in the traffic pattern or on a straight‐in approach must be alert at all times to other aircraft in the pattern, or conducting straight‐in approaches, and communicate their position to avoid a possible traffic conflict. In the airport traffic pattern and while on straight‐in approaches to a runway, effective communication and a pilot's responsibility to see‐and‐avoid are essential mitigations to avoid a possible midair collision. In addition, following established traffic pattern procedures eliminates excessive maneuvering at low altitudes, reducing the risk of loss of aircraft control.
    REFERENCE-
    
    FAA Advisory Circular (AC) 90-66, Non-Towered Airport Flight Operations.
  6. 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. Departing the final approach fix, inbound (nonprecision approach) or departing the outer marker or fix used in lieu of the outer marker, inbound (precision approach).
    2. 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.
  7. Departing aircraft should always be alert for arrival aircraft coming from the opposite direction.
  8. Recommended Self-Announce broadcasts. 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. When referring to a specific runway, pilots should use the runway number and not use the phrase “Active Runway.”
    1. Inbound
      EXAMPLE-
      
      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
      EXAMPLE-
      
      Strawn traffic, Queen Air Seven One Five Five Bravo (location on airport) taxiing to runway two six Strawn.
      
      Strawn traffic, Queen Air Seven One Five Five Bravo departing runway two six. “Departing the pattern to the (direction), climbing to (altitude) Strawn.”
    3. Practice Instrument Approach
      EXAMPLE-
      
      Strawn traffic, Cessna Two One Four Three Quebec (position from airport) inbound descending through (altitude) practice (name of approach) approach runway three five Strawn.
      
      Strawn traffic, Cessna Two One Four Three Quebec practice (type) approach completed or terminated runway three five Strawn.
7. UNICOM Communication Procedures
  1. 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 UNICOM frequency.
    2. State the identification of the UNICOM station you are calling in each transmission.
    3. Speak slowly and distinctly.
    4. Report approximately 10 miles from the airport, reporting altitude, and state your aircraft type, aircraft identification, location relative to the airport, state whether landing or overflight, and request wind information and runway in use.
    5. Report on downwind, base and final approach.
    6. Report leaving the runway.
  2. Recommended 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 NINER FULL STOP/TOUCH-AND-GO FREDERICK.
      
      FREDERICK TRAFFIC CESSNA EIGHT ZERO ONE TANGO FOXTROT CLEAR OF RUNWAY ONE NINER 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.

IFR Approaches/Ground Vehicle Operations

IFR Approaches. When operating in accordance with an IFR clearance and ATC approves a change to the advisory frequency, make an expeditious change to the CTAF and employ the recommended traffic advisory procedures.
Ground Vehicle Operation. 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.

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.

TBL GEN 3.3-23Summary of Recommended Communication Procedures
			COMMUNICATION/BROADCAST PROCEDURES
	Facility at Airport	Frequency Use	Outbound	Inbound	Practice Instrument Approach
1.	UNICOM (No Tower or FSS)	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.	Before taxiing and before taxiing onto the runway for departure.	10 miles out; entering downwind, base, and final; leaving the runway.
2.	No Tower, FSS, or UNICOM	Self‐announce on MULTICOM frequency 122.9.	Before taxiing and before taxiing onto the runway for departure.	10 miles out; entering downwind, base, and final; leaving the runway.	Departing final approach fix (name) or on final approach segment inbound.
3.	No Tower in operation, FSS open (Alaska only)	Communicate with FSS on CTAF frequency.	Before taxiing and before taxiing onto the runway for departure.	10 miles out; entering downwind, base, and final; leaving the runway.	Approach completed/ terminated.
4.	FSS closed (No Tower)	Self‐announce on CTAF.	Before taxiing and before taxiing onto the runway for departure.	10 miles out; entering downwind, base, and final; leaving the runway.
5.	Tower or FSS not in operation	Self‐announce on CTAF.	Before taxiing and before taxiing onto the runway for departure.	10 miles out; entering downwind, base, and final; leaving the runway.
6.	Designated CTAF Area (Alaska Only)	Self‐announce on CTAF designated on chart or Chart Supplement Alaska.	Before taxiing and before taxiing on the runway for departure until leaving designated area.	When entering designated CTAF area.

Designated UNICOM/MULTICOM Frequencies
1. Frequency Use
  1. TBL GEN 3.3-24 depicts UNICOM and MULTICOM frequency uses as designated by the Federal Communications Commission (FCC).
    NOTE-
    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.
    
    Wind direction and runway information may not be available on UNICOM frequency 122.950.
  2. TBL GEN 3.3-25 depicts other frequency uses as designated by the FCC.

Use of UNICOM for ATC purposes

UNICOM service may be used for air traffic control purposes, only under the following circumstances:

Revision to proposed departure time.
Takeoff, arrival, or flight plan cancellation time.

ATC clearance, provided arrangements are made between the ATC facility and the UNICOM licensee to handle such messages.

TBL GEN 3.3-24UNICOM/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

TBL GEN 3.3-25Other Frequency Usage Designated by FCC
Use	Frequency
Air‐to‐air communication (private fixed wing aircraft).	122.750
Helicopter air-to-air communications; Air traffic control operations.	123.025
Aviation instruction, Glider, Hot Air Balloon (not to be used for advisory service).	123.300 123.500
Assignment to flight test land and aircraft stations (not for air-to-air communication except for those aircraft operating in an oceanic FIR).	123.4001 123.4502

1This frequency is available only to itinerant stations that have a requirement to be periodically transferred to various locations.

2Mobile station operations on these frequencies are limited to an area within 320 km (200 mi) of an associated flight test land station.

Automatic Terminal Information Service (ATIS)
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 continuously 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 Chart Supplement indicates airports for which ATIS is provided.
2. ATIS information includes:
  1. Airport/facility name
  2. Phonetic letter code
  3. Time of the latest weather sequence (UTC)
  4. Weather information consisting of:
    1. Wind direction and velocity
    2. Visibility
    3. Obstructions to vision
    4. Present weather consisting of: sky condition, temperature, dew point, altimeter, a density altitude advisory when appropriate, and other pertinent remarks included in the official weather observation
  5. 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 must 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.
    
    Dulles International information Sierra. One four zero zero zulu. Wind three five zero at eight. Visibility one zero. Ceiling four thousand five hundred broken. Temperature three four. Dew point two eight. Altimeter three zero one zero. ILS runway one right approach in use. Departing runway three zero. Advise on initial contact you have information sierra.
3. Pilots should listen to ATIS broadcasts whenever ATIS is in operation.
4. 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.”
5. When the pilot acknowledges receipt of the ATIS broadcast, controllers may omit those items contained on 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 conditions) will be issued by approach control/tower.”
  NOTE-
  
  The absence of a sky condition/ceiling and/or visibility on ATIS indicates a sky condition/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 5,000 and 5,” or the existing weather may be broadcast.
6. Controllers will issue pertinent information to pilots who do not acknowledge receipt of a broadcast or who acknowledge receipt of a broadcast which is not current.
7. 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.
8. While it is a good operating practice for pilots to make use of the ATIS broadcast where it is available, some pilots use the phrase “Have Numbers” in communications with the control tower. Use of this phrase means that the pilot has received wind, runway and altimeter information ONLY and the tower does not have to repeat this information. It does not indicate receipt of the ATIS broadcast and should never be used for this purpose.
Airport Reservation Operations and Special Traffic Management Programs
1. This section describes procedures for obtaining required airport reservations at airports designated by the FAA and for airports operating under Special Traffic Management Programs.
2. Slot Controlled Airports.
  1. The FAA may adopt rules to require advance reservations for unscheduled operations at certain airports. In addition to the information in the rules adopted by the FAA, a listing of the airports and relevant information will be maintained on the FAA website www.fly.faa.gov/ecvrs.
  2. The FAA has established an Airport Reservation Office (ARO) to receive and process reservations for unscheduled flights at the slot controlled airports. The ARO uses the Enhanced Computer Voice Reservation System (e‐CVRS) to allocate reservations. Reservations will be available beginning 72 hours in advance of the operation at the slot controlled airport. Standby lists are not maintained. Flights with declared emergencies do not require reservations. Refer to the website for the current listing of slot controlled airports, limitations, and reservation procedures.
  3. For more detailed information on operations and reservation procedures at a slot controlled airport, please see 14 CFR Part 93, Subpart K – High Density Traffic Airports.
3. Special Traffic Management Programs (STMP)
  1. Special programs may be established when a location requires special traffic handling to accommodate above normal traffic demand (for example, NFL Super Bowl, EAA AirVenture Oshkosh, SUN 'n FUN Aerospace Expo) or reduced airport capacity (for example, significant airport runway closures for airport construction). The special programs may remain in effect until the problem has been resolved or until local traffic management procedures can handle the volume and a need for special handling no longer exists.
  2. If an STMP is used to accommodate a special event, a domestic notice will be issued relaying the website address: www.fly.faa.gov/estmp. Domestic notice information includes: what airports are included in the STMP, the dates and times reservations are required, the time limits for reservation requests, the point of contact for reservations, and any other instructions.
4. Making Reservations. Detailed information and User Instruction Guides for using the Web interface to the reservation systems are available on the websites for the slot controlled airports (e‐CVRS), www.fly.faa.gov/ecvrs; and STMPs (e‐STMP), www.fly.faa.gov/estmp.
  NOTE-
  
  Users may contact the ARO at (540) 422-4246 if they have a problem with their reservation.
5. Prior Permission Required (PPR)
  1. A PPR may be required at locations where air traffic demand does not require an STMP, but operations may be impacted by on-airport activity or by a nearby event.
  2. Events that may require a PPR include, but are not limited to:
    1. Construction on or near an active runway requiring time to remove personnel and equipment.
    2. Limited ramp space for parking aircraft.
    3. Snow removal at airports without an operating control tower.
    4. General aviation operations into military airports.
  3. Pilots are responsible for coordinating operations related to the PPR. Controllers may be aware of the PPR, but they do not enforce or otherwise oversee compliance. Operations contrary to a PPR could result in a safety hazard to persons or property on the ground.
  4. PPRs are disseminated via NOTAM or published in the airport remarks section of the Chart Supplement and typically includes a phone number or frequency to coordinate operations. An identification number may be issued that is to be included in the Remarks section of the flight plan. Major airports with PPRs are listed on the FAA's National Airspace System Status website (https://nasstatus.faa.gov).
Operations at Uncontrolled Airports with Automated Surface Observing System (ASOS)/Automated Weather Observation System (AWOS)
1. Many airports throughout the National Airspace System are equipped with either ASOS or AWOS. At most airports with an operating control tower or human observer, the weather will be available to you in a METAR hourly or special observation format on the Automatic Terminal Information Service (ATIS) or directly transmitted from the controller/observer.
2. At uncontrolled airports that are equipped with ASOS/AWOS with ground-to-air broadcast capability, the one-minute updated airport weather should be available to you within approximately 25 NM of the airport below 10,000 feet. The frequency for the weather broadcast will be published on sectional charts and in the Chart Supplement. Some part-time towered airports may also broadcast the automated weather on their ATIS frequency during the hours that the tower is closed.
3. Controllers issue SVFR or IFR clearances based on pilot request, known traffic and reported weather; i.e., METAR/SPECI observations, when they are available. Pilots have access to more current weather at uncontrolled ASOS/AWOS airports than do the controllers who may be located several miles away. Controllers will rely on the pilot to determine the current airport weather from the ASOS/AWOS. All aircraft arriving or departing an ASOS/AWOS equipped uncontrolled airport should monitor the airport weather frequency to ascertain the status of the airspace. Pilots in Class E airspace must be alert for changing weather conditions which may affect the status of the airspace from IFR/VFR. If ATC service is required for IFR/SVFR approach/departure or requested for VFR service, the pilot should advise the controller that he/she has received the one-minute weather and state his/her intentions.
  EXAMPLE-
  
  “I have the (airport) one-minute weather, request an ILS runway 14 approach.”
  REFERENCE-
  
  Section GEN 3.5, Paragraph 7, Weather Observing Programs.