14-3-3
Abnormal Conditions
JO 7110.65BB, Change 3, effective July 9, 2026 · Official text on faa.gov
- If any portion of the automated transfer fails, the controller should attempt to initiate the transfer manually. If unable to complete the data link transfer, the controller should advise the pilot to log on to the next facility and send an End Service (EOS) message.
- If CPDLC fails, voice communications must be utilized until CPDLC connections can be reestablished.
- If the CPDLC connection is lost on a specific aircraft, the controller should send a connection request message (CR1) or advise the pilot via backup communications to log on again.
- If CPDLC service is to be canceled, the controller must advise the pilot as early as possible to facilitate a smooth transition to voice communications. Workload permitting, the controller should also advise the pilot of the reason for the termination of data link.
- When there is uncertainty that a clearance was delivered to an aircraft via CPDLC, the controller must continue to protect the airspace associated with the clearance until an appropriate operational response is received from the flight crew. If an expected operational response to a clearance is not received, the controller will initiate appropriate action to ensure that the clearance was received by the flight crew. On initial voice contact with aircraft preface the message with the following:
TBL 14-3-1 Response 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), ERROR.
NOTE– 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), ERROR
NOTE– 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), ERROR.
NOTE– 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, ERROR.
FANS 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. Yes
Valid 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 14-3-2 Route Uplink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use UM74 (position) W/U Instruction to proceed directly to the specified position. UM75 position
NOTE– This message element is equivalent to SUPU-5 plus RTEU-2 in Doc 4444.
W/U Instruction to proceed directly to the specified position. UM76 AT (time) PROCEED DIRECT TO (position) W/U Instruction to proceed, at the specified time, directly to the specified position. UM77 AT (position) PROCEED DIRECT TO (position) W/U Instruction to proceed, at the specified position, directly to the next specified position. UM78 AT (altitude) PROCEED DIRECT TO (position) W/U Instruction to proceed upon reaching the specified altitude, directly to the specified position. UM79 CLEARED TO (position) VIA (route clearance) W/U Instruction to proceed to the specified position via the specified route. UM80 (route clearance) W/U Instruction to proceed via the specified route. UM83 AT (position) CLEARED (route clearance) W/U Instruction to proceed from the specified position via the specified route. UM85 route clearance R Notification that a clearance to fly on the specified route may be issued. UM86 AT (position) EXPECT (route clearance) R Notification that a clearance to fly on the specified route from the specified position may be issued. UM87 position R Notification that a clearance to fly directly to the specified position may be issued. UM88 AT (position) EXPECT DIRECT TO (position) R Notification that a clearance to fly directly from the first specified position to the next specified position may be issued. UM89 AT (time) EXPECT DIRECT TO (position) R Notification that a clearance to fly directly to the specified position commencing at the specified time may be issued. UM90 AT (altitude) EXPECT DIRECT TO (position) R Notification that a clearance to fly directly to the specified position commencing when the specified altitude is reached may be issued. UM93 time R Notification that an onwards clearance may be issued at the specified time. UM99 procedure name
NOTE– Used when a published procedure is designated.
R Notification that a clearance may be issued for the aircraft to fly the specified procedure or clearance name. UM137 CONFIRM ASSIGNED ROUTE
NOTE– NE response attribute.
NE Request to confirm the assigned route. UM147 REQUEST POSITION REPORT NE Request to make a position report. TBL 14-3-3 Route Downlink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use DM22 REQUEST DIRECT TO (position) Y Request for a direct clearance to the specified position. DM23 procedure name Y Request for the specified procedure or clearance name. DM24 route clearance Y Request for the specified route. DM25 REQUEST CLEARANCE Y Request for the specified clearance. DM26 REQUEST WEATHER DEVIATION TO (position) VIA (route clearance) Y Request for a weather deviation to the specified position via the specified route. DM40 route clearance N Confirmation that the assigned route is the specified route. DM48 position report N Position report. DM51 WHEN CAN WE EXPECT BACK ON ROUTE Y Request for the time or position that can be expected to rejoin the cleared route. DM70 degrees Y Request for the specified heading. DM71 degrees Y Request for the specified ground track. TBL 14-3-4 Lateral Uplink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use UM64 OFFSET (distance offset) (direction) OF ROUTE W/U Instruction to fly a parallel track to the cleared route at a displacement of the specified distance in the specified direction. UM65 AT (position) OFFSET (distance offset) (direction) OF ROUTE W/U Instruction to fly a parallel track to the cleared route at a displacement of the specified distance in the specified direction and commencing at the specified position. UM66 AT (time) OFFSET (distance offset) (direction) OF ROUTE W/U Instruction to fly a parallel track to the cleared route at a displacement of the specified distance in the specified direction and commencing at the specified time. UM67 PROCEED BACK ON ROUTE W/U Instruction to rejoin the cleared route. UM68 position W/U Instruction to rejoin the cleared route before passing the specified position. UM69 time W/U Instruction to rejoin the cleared route before the specified time. UM70 position W/U Notification that a clearance may be issued to enable the aircraft to rejoin the cleared route before passing the specified position. UM71 time W/U Notification that a clearance may be issued to enable the aircraft to rejoin the cleared route before the specified time. UM72 RESUME OWN NAVIGATION W/U Instruction to resume own navigation following a period of tracking or heading clearances. May be used in conjunction with an instruction on how or where to rejoin the cleared route. UM82 CLEARED TO DEVIATE UP TO (distance offset) (direction) OF ROUTE W/U Instruction allowing deviation up to the specified distance(s) from the cleared route in the specified direction(s). UM98 IMMEDIATELY TURN (direction) HEADING (degrees)
NOTE– This message element is equivalent to EMGU-2 plus LATU-11 in Doc 4444.
W/U Instruction to turn left or right as specified on to the specified heading. UM127 REPORT BACK ON ROUTE
NOTE– R response attribute.
W/U Instruction to report when the aircraft is back on the cleared route. UM130 position
NOTE– R response attribute.
W/U Instruction to report upon passing the specified position. UM132 CONFIRM POSITION NE Instruction to report the present position. UM138 CONFIRM TIME OVER REPORTED WAYPOINT NE Instruction to confirm the previously reported time over the last reported waypoint. UM139 CONFIRM REPORTED WAYPOINT NE Instruction to confirm the identity of the previously reported waypoint. UM140 CONFIRM NEXT WAYPOINT NE Instruction to confirm the identity of the next waypoint. UM141 CONFIRM NEXT WAYPOINT ETA NE Instruction to confirm the previously reported estimated time at the next waypoint. UM142 CONFIRM ENSUING WAYPOINT NE Instruction to confirm the identity of the next plus one waypoint. UM145 CONFIRM HEADING NE Instruction to report the present heading. UM146 REPORT GROUND TRACK NE Instruction to report the present ground track. UM152 WHEN CAN YOU ACCEPT (specified distance) (direction) OFFSET NE Instruction to report the earliest time when the specified offset track can be accepted. TBL 14-3-5 Lateral Downlink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use DM15 REQUEST OFFSET (specified distance) (direction) OF ROUTE Y Request for a parallel track from the cleared route at a displacement of the specified distance in the specified direction. DM16 AT (position) REQUEST OFFSET (specified distance) (direction) OF ROUTE Y Request that a parallel track, offset from the cleared track by the specified distance in the specified direction, be approved from the specified position. DM17 AT (time) REQUEST OFFSET (specified distance) (direction) OF ROUTE Y Request that a parallel track, offset from the cleared track by the specified distance in the specified direction, be approved from the specified time. DM27 REQUEST WEATHER DEVIATION UP TO (specified distance) (direction) OF ROUTE Y Request for a weather deviation up to the specified distance(s) off track in the specified direction(s). DM31 position N Report indicating passing the specified position. DM33 position N Notification of the present position. DM35 degrees N Notification of the present heading in degrees. DM36 degrees N Notification of the present ground track in degrees. DM41 BACK ON ROUTE N Report indicating that the cleared route has been rejoined. DM42 position N The next waypoint is the specified position. DM43 time N The ETA at the next waypoint is as specified. DM44 position N The next plus one waypoint is the specified position. DM45 position N Clarification of previously reported waypoint passage. DM46 time N Clarification of time over previously reported waypoint. DM59 DIVERTING TO (position) VIA (route clearance)
NOTE 1. – H alert attribute.
NOTE 2. – N response attribute.
N Report indicating diverting to the specified position via the specified route, which may be sent without any previous coordination done with ATC. DM60 OFFSETTING (distance offset)(direction) OF ROUTE
NOTE 1. – H alert attribute.
NOTE 2. – N response attribute.
N Report indicating that the aircraft is offsetting to a parallel track at the specified distance in the specified direction off from the cleared route. DM80 DEVIATING (deviation offset)(direction) OF ROUTE
NOTE 1. – H alert attribute.
NOTE 2. – N response attribute.
N Report indicating deviating specified distance or degrees in the specified direction from the cleared route. DM67 WE CAN ACCEPT (direction) (distance offset) AT (time) N We can accept a parallel track offset the specified distance in the specified direction at the specified time. DM67 WE CANNOT ACCEPT (direction) (distance offset) N We cannot accept a parallel track offset the specified distance in the specified direction. DM67 altitude N We cannot accept the specified altitude. TBL 14-3-6 Altitude Uplink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use UM6 (altitude) R Notification that an altitude change instruction should be expected. UM7 (time) R Notification that an instruction may be expected for the aircraft to commence climb at the specified time. UM8 position R Notification that an instruction may be expected for the aircraft to commence climb at the specified position. UM9 time R Notification that an instruction may be expected for the aircraft to commence descent at the specified time. UM10 position R Notification that an instruction may be expected for the aircraft to commence descent at the specified position. UM11 (time) R Notification that an instruction should be expected for the aircraft to commence cruise climb at the specified time. UM12 position R Notification that an instruction should be expected for the aircraft to commence cruise climb at the specified position. UM13 AT (time) EXPECT CLIMB TO (altitude) R Notification that an instruction should be expected for the aircraft to commence climb at the specified time to the specified altitude. UM14 AT (position) EXPECT CLIMB TO (altitude) R Notification that an instruction should be expected for the aircraft to commence climb at the specified position to the specified altitude. UM15 AT (time) EXPECT DESCENT TO (altitude) R Notification that an instruction should be expected for the aircraft to commence descent at the specified time to the specified altitude. UM16 AT (position) EXPECT DESCENT TO (altitude) R Notification that an instruction should be expected for the aircraft to commence descent at the specified position to the specified altitude. UM17 AT (time) EXPECT CRUISE CLIMB TO (altitude) R Notification that an instruction should be expected for the aircraft to commence cruise climb at the specified time to the specified altitude. UM18 AT (position) EXPECT CRUISE CLIMB TO (altitude) R Notification that an instruction should be expected for the aircraft to commence cruise climb at the specified position to the specified altitude. UM19 (altitude) W/U Instruction to maintain the specified altitude. UM20 (altitude) W/U Instruction that a climb to the specified altitude is to commence and once reached is to be maintained. UM21 AT (time) CLIMB TO AND MAINTAIN (altitude) W/U Instruction that at the specified time a climb to the specified altitude is to commence and once reached is to be maintained.
NOTE– This message element would be preceded with uM19 MAINTAIN (altitude) to prevent the premature execution of the instruction.
UM22 AT (position) CLIMB TO AND MAINTAIN (altitude) W/U Instruction that at the specified position a climb to the specified altitude is to commence and once reached is to be maintained.
NOTE– This message element would be preceded with uM19 MAINTAIN (altitude) to prevent the premature execution of the instruction.
UM23 (altitude) W/U Instruction that a descent to the specified altitude is to commence and once reached is to be maintained. UM24 AT (time) DESCEND TO AND MAINTAIN (altitude) W/U Instruction that at the specified time a descent to the specified altitude is to commence and once reached is to be maintained. UM25 AT (position) DESCEND TO AND MAINTAIN (altitude) W/U Instruction that at the specified position a descent to the specified altitude is to commence and once reached is to be maintained. UM26 CLIMB TO REACH (altitude) BY (time) W/U Instruction that a climb is to be completed such that the specified altitude is reached before the specified time. UM27 CLIMB TO REACH (altitude) BY (position) W/U Instruction that a climb is to be completed such that the specified altitude is reached before passing the specified position. UM28 DESCEND TO REACH (altitude) BY (time) W/U Instruction that a descent is to be completed such that the specified altitude is reached before the specified time. UM29 DESCEND TO REACH (altitude) BY (position) W/U Instruction that a descent is to be completed such that the specified altitude is reached before passing the specified position. UM30 MAINTAIN BLOCK (altitude) TO (altitude) W/U Instruction to maintain the specified vertical range. UM31 CLIMB TO AND MAINTAIN BLOCK W/U Instruction that a climb to the specified vertical range is to commence and once reached is to be maintained. UM32 DESCEND TO AND MAINTAIN BLOCK (altitude) TO (altitude) W/U Instruction that a descent to the specified vertical range is to commence and once reached is to be maintained. UM33 altitude Instruction that authorizes a pilot to conduct flight at any altitude from the minimum altitude up to and including the altitude specified in the clearance. Further, it is approval for the pilot to proceed to and make an approach at the destination airport. UM34 altitude W/U A cruise climb is to commence and continue until the specified altitude is reached. UM35 altitude W/U A cruise climb can commence once above the specified altitude. UM36 altitude W/U Instruction that a climb to the specified altitude or vertical range is to commence and once reached is to be maintained. UM37 (altitude) W/U Instruction that a descent to the specified altitude or vertical range is to commence and once reached is to be maintained. UM38 altitude W/U Instruction that a climb to the specified altitude or vertical range is to commence and once reached is to be maintained. UM39 altitude W/U Instruction that a descent to the specified altitude or vertical range is to commence and once reached is to be maintained. UM40 altitude W/U Urgent instruction to immediately stop a climb once the specified altitude is reached. UM41 altitude W/U Urgent instruction to immediately stop a descent once the specified altitude is reached. UM128 altitude
NOTE– R response attribute.
W/U Instruction to report upon leaving the specified altitude. UM129 altitude
NOTE– R response attribute.
W/U Instruction to report upon maintaining the specified altitude. UM133 CONFIRM ALTITUDE NE Instruction to report the present altitude. UM135 CONFIRM ASSIGNED ALTITUDE
NOTE– NE response attribute.
NE Request to confirm the assigned altitude. UM148 altitude
NOTE– NE response attribute.
NE Request for the earliest time or position when the specified altitude can be accepted. UM149 CAN YOU ACCEPT (altitude) AT (position) A/N Request to indicate whether or not the specified altitude can be accepted at the specified position. UM150 CAN YOU ACCEPT (altitude) AT (time) A/N Request to indicate whether or not the specified altitude can be accepted at the specified time. UM171 vertical rate W/U Instruction to climb at the specified rate or greater. UM172 vertical rate W/U Instruction to climb at the specified rate or less. UM173 vertical rate W/U Instruction to descend at the specified rate or greater. UM174 vertical rate W/U Instruction to descend at the specified rate or less. UM175 altitude R Instruction to report when the aircraft has reached the specified altitude.
NOTE– To be interpreted as “Report reaching an assigned altitude.”
UM177 AT PILOTS DISCRETION N Used in conjunction with a clearance or instruction to indicate that the pilot may execute when prepared to do so. UM180 REACHING BLOCK (altitude) TO (altitude)
NOTE– R response attribute.
W/U Instruction to report upon reaching the specified vertical range. TBL 14-3-7 Altitude Downlink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use DM6 (altitude) Y Request to fly at the specified altitude. DM7 REQUEST BLOCK (altitude) TO (altitude) Y Request to fly at the specified vertical range. DM8 altitude Y Request to cruise climb to the specified altitude.
NOTE– Due to different interpretations between the various ATS units, this element should be avoided.
DM9 (altitude) Y Request for a climb to the specified altitude or vertical range. DM10 (altitude) Y Request for a descent to the specified altitude or vertical range. DM11 AT (position) REQUEST CLIMB TO (altitude) Y Request for a climb/descent to the specified altitude to commence at the specified position. DM12 AT (position) REQUEST DESCENT TO (altitude) Y Request for a climb/descent to the specified altitude to commence at the specified position. DM13 AT TIME (time) REQUEST CLIMB TO (altitude) Y Request for a climb/descent to the specified altitude to commence at the specified time. DM14 AT TIME (time) REQUEST DESCENT TO (altitude) Y Request for a climb/descent to the specified altitude to commence at the specified time. DM28 altitude N Notification of leaving the specified altitude. DM29 altitude N Report indicating climbing to the specified altitude. DM30 altitude
NOTE– N alert attribute.
N Notification of descending to the specified altitude. DM32 altitude N Notification of the present altitude. DM37 altitude N Report indicating that the specified altitude is being maintained. DM38 (altitude) N Confirmation that the assigned altitude is the specified altitude or vertical range. DM52 WHEN CAN WE EXPECT LOWER ALTITUDE Y Request for the earliest time or position that a descent can be expected. DM53 WHEN CAN WE EXPECT HIGHER ALTITUDE Y Request for the earliest time or position that a climb can be expected. DM54 altitude Y Request for the earliest time at which a clearance to cruise climb to the specified altitude can be expected. DM61 (altitude)
NOTE– Urgent alert attribute.
N Report indicating descending to the specified altitude. DM67 ‘WE CAN ACCEPT (altitude) AT TIME (time)’ N We can accept the specified altitude at the specified time. DM67 ‘WE CANNOT ACCEPT (altitude)’ N Indication that the specified altitude cannot be accepted. DM67 ‘WHEN CAN WE EXPECT CLIMB TO (altitude)’ N Request for the earliest time at which a clearance to climb to the specified altitude can be expected. DM67 ‘WHEN CAN WE EXPECT DESCENT TO (altitude)’ N Request for the earliest time at which a clearance to descend to the specified altitude can be expected. DM72 altitude N Notification that the aircraft has reached the specified altitude. DM75 AT PILOTS DISCRETION N Used in conjunction with another message to indicate that the pilot wishes to execute the request when the pilot is prepared to do so. DM76 REACHING BLOCK (altitude) TO (altitude) N Report indicating reaching the specified vertical range. DM77 ASSIGNED BLOCK (altitude) TO (altitude)
NOTE– Used for a vertical range.
N Confirmation that the assigned vertical range is the specified vertical range. TBL 14-3-8 Crossing Constraint Uplink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use UM42 EXPECT TO CROSS (position) AT (altitude) R Notification that a altitude change instruction should be expected which will require the specified position to be crossed at the specified altitude. UM43 EXPECT TO CROSS (position) AT OR ABOVE (altitude) R Notification that a altitude change instruction should be expected which will require the specified position to be crossed at or above the specified altitude. UM44 EXPECT TO CROSS (position) AT OR BELOW (altitude) R Notification that a altitude change instruction should be expected which will require the specified position to be crossed at or below the specified altitude. UM45 EXPECT TO CROSS (position) AT AND MAINTAIN (altitude) R Notification that a altitude change instruction should be expected which will require the specified position to be crossed at the specified altitude which is to be maintained subsequently. UM46 CROSS (position) AT (altitude) W/U Instruction that the specified position is to be crossed at the specified altitude. UM47 CROSS (position) AT OR ABOVE (altitude) W/U Instruction that the specified position is to be crossed at or above the specified altitude. UM48 CROSS (position) AT OR BELOW (altitude) W/U Instruction that the specified position is to be crossed at or below the specified altitude. UM49 CROSS (position) AT AND MAINTAIN (altitude) W/U Instruction that the specified position is to be crossed at the specified altitude. UM50 CROSS (position) BETWEEN (altitude) AND (altitude) W/U Instruction that the specified position is to be crossed within the specified vertical range. UM51 CROSS (position) AT (time) W/U Instruction that the specified position is to be crossed at the specified time. UM52 CROSS (position) AT OR BEFORE (time) W/U Instruction that the specified position is to be crossed before the specified time. UM53 CROSS (position) AT OR AFTER (time) W/U Instruction that the specified position is to be crossed after the specified time. UM54 CROSS (position) BETWEEN (time) AND (time) W/U Instruction that the specified position is to be crossed between the specified times. UM55 CROSS (position) AT (speed) W/U Instruction that the specified position is to be crossed at the specified speed. UM56 CROSS (position) AT OR LESS THAN (speed) W/U Instruction that the specified position is to be crossed at or less than the specified speed. UM57 CROSS (position) AT OR GREATER THAN (speed) W/U Instruction that the specified position is to be crossed at or greater than the specified speed. UM58 CROSS (position) AT (time) AT (altitude) W/U Instruction that the specified position is to be crossed at the specified time and at the specified altitude. UM59 CROSS (position) AT OR BEFORE (time) AT (altitude) W/U Instruction that the specified position is to be crossed before the specified time and at the specified altitude. UM60 CROSS (position) AT OR AFTER (time) AT (altitude) W/U Instruction that the specified position is to be crossed after the specified time and at the specified altitude. 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.
W/U Instruction that the specified position is to be crossed at the altitude specified, and at the specified speed. UM62 AT (time) CROSS (position) AT AND MAINTAIN (altitude) W/U Instruction that the specified position is to be crossed at the specified time and at the specified altitude. UM63 AT (time) CROSS (position) AT AND MAINTAIN (altitude) AT (speed) W/U Instruction that the specified position is to be crossed at the specified time at the specified altitude, and at the specified speed. TBL 14-3-9 Speed Uplink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use UM100 AT (time) EXPECT (speed) R Notification that a speed instruction may be issued to take effect at the specified time. UM101 AT (position) EXPECT (speed) R Notification that a speed instruction may be issued to take effect at the specified position. UM102 AT (altitude) EXPECT (speed) R Notification that a speed instruction may be issued to take effect at the specified altitude. UM103 AT (time) EXPECT (speed) TO (speed) R Notification that a speed range instruction may be issued to be effective at the specified time. UM104 AT (position) EXPECT (speed) TO (speed) R Notification that a speed range instruction may be issued to be effective at the specified position. UM105 AT (altitude) EXPECT (speed) TO (speed) R Notification that a speed range instruction may be issued to be effective at the specified altitude. UM106 speed W/U Instruction to maintain the specified speed. UM107 MAINTAIN PRESENT SPEED W/U Instruction to maintain the present speed. UM108 speed W/U Instruction to maintain the specified speed or greater. UM109 speed W/U Instruction to maintain the specified speed or less. UM110 MAINTAIN (speed) TO (speed) W/U Instruction to maintain the specified speed range. UM111 speed W/U Instruction that the present speed is to be increased to the specified speed and maintained until further advised. UM112 speed W/U Instruction that the present speed is to be increased to the specified speed or greater, and maintained at or above the specified speed until further advised. UM113 speed W/U Instruction that the present speed is to be reduced to the specified speed and maintained until further advised. UM114 speed W/U Instruction that the present speed is to be reduced to the specified speed or less, and maintained at or below the specified speed until further advised. UM115 speed W/U The specified speed is not to be exceeded. UM116 RESUME NORMAL SPEED W/U Instruction to resume a normal speed. The aircraft no longer needs to comply with a previously issued speed restriction. UM134 CONFIRM SPEED
NOTE– NE response attribute.
NE Request to report the speed defined by the speed type(s). UM136 CONFIRM ASSIGNED SPEED
NOTE– NE response attribute.
NE Request to confirm the assigned speed. UM151 speed
NOTE– NE response attribute.
NE Request for the earliest time or position when the specified speed can be accepted. TBL 14-3-10 Speed Downlink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use DM18 speed Y Request for the specified speed. DM19 REQUEST (speed) TO (speed) Y Request to fly within the specified speed range. DM34 speed N Report indicating the speed defined by the specified speed types is the specified speed. DM39 speed N Confirmation that the assigned speed is the specified speed. DM49 speed Y Request for the earliest time or position that the specified speed can be expected. DM50 WHEN CAN WE EXPECT (speed) TO (speed) Y Request for the earliest time at which a clearance to a speed within the specified range can be expected. DM67 ‘WE CAN ACCEPT (speed) AT TIME (time)’ N Indication that the specified speed can be accepted at the specified time. DM67 ‘WE CANNOT ACCEPT (speed)’ N Indication that the specified speed cannot be accepted. TBL 14-3-11 Air Traffic Advisory Uplink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use UM123 beacon code W/U Instruction to select the specified SSR code. UM124 STOP SQUAWK W/U Instruction to disable SSR transponder responses. UM125 SQUAWK ALTITUDE W/U Instruction to include altitude information in the SSR transponder responses. UM126 STOP ALTITUDE SQUAWK W/U Instruction to stop including altitude information in the SSR transponder responses. UM144 CONFIRM SQUAWK
NOTE– NE response attribute.
NE Request to confirm the selected SSR code. UM153 (altimeter)
NOTE– The facility designation and the time of measurement cannot be provided.
R Advisory providing the specified altimeter setting for the specified facility. UM154 RADAR SERVICES TERMINATED R Advisory that the ATS surveillance service is terminated. UM155 position
NOTE– The provision of the position is required.
R Advisory that ATS surveillance service has been established. A position may be specified position. UM156 RADAR CONTACT LOST R Advisory that ATS surveillance contact has been lost. UM158 ATIS code
NOTE– The airport is not provided.
R code UM163 ICAO facility designation NE Notification to the pilot of an ATSU identifier. UM168 DISREGARD N/E The indicated communication should be ignored.
The previously sent uplink CPDLC message shall be ignored. DISREGARD should not refer to a clearance or instruction. If DISREGARD is used, another element shall be added to clarify which message is to be disregarded.
UM179 SQUAWK IDENT W/U Instruction that the ‘ident’ function on the SSR transponder is to be actuated. UM182 CONFIRM ATIS CODE NE Instruction to report the identification code of the last ATIS received. TBL 14-3-12 Air Traffic Advisory Downlink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use DM47 code N Report indicating that the aircraft is squawking the specified SSR code. DM79 ATIS code N The code of the latest ATIS received is as specified. TBL 14-3-13 Voice Communications Uplink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use UM117 CONTACT (ICAO unit name)(frequency) W/U Instruction to establish voice contact with the specified ATS unit on the specified frequency. UM118 AT (position) CONTACT (ICAO unit name) (frequency) W/U Instruction at the specified position to establish voice contact with the specified ATS unit on the specified frequency. UM119 AT (time) CONTACT (ICAO unit name) (frequency) W/U Instruction at the specified time to establish voice contact with the specified ATS unit on the specified frequency. UM120 MONITOR (ICAO unit name)(frequency) W/U Instruction to monitor the specified ATS unit on the specified frequency. The flight crew is not required to establish voice contact on the frequency. UM121 AT (position) MONITOR (ICAO unit name) (frequency) W/U Instruction at the specified position to monitor the specified ATS unit on the specified frequency. The flight crew is not required to establish voice contact on the frequency. UM122 AT (time) MONITOR (ICAO unit name) (frequency) W/U Instruction at the specified time to monitor the specified ATS unit on the specified frequency. The flight crew is not required to establish voice contact on the frequency. UM157 frequency
NOTE– R response attribute.
R Instruction to check the microphone due to detection of a continuous transmission on the specified frequency. TBL 14-3-14 Voice Communications Downlink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use DM20 REQUEST VOICE CONTACT
NOTE– Used when a frequency is not required.
Y Request for voice contact on the specified frequency. DM21 frequency
NOTE– Used when a frequency is required.
Y Request for voice contact on the specified frequency. TBL 14-3-15 Emergency/Urgency Uplink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use UM131 REPORT REMAINING FUEL AND SOULS ON BOARD
NOTE– NE response attribute.
Y Request to provide the fuel remaining (time) and the number of persons on board. UM38
UM39
Used in combination with LVLU-6 and LVLU-9, which is implemented in FANS 1/A as:
altitude
altitude
N Instruction to immediately comply with the associated instruction to avoid imminent situation. TBL 14-3-16 Emergency/Urgency Downlink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use DM55 PAN PAN PAN
NOTE– N response attribute.
N Indication of an urgent situation. DM56 MAYDAY MAYDAY MAYDAY
NOTE– N response attribute.
N Indication of an emergency situation. DM57 (remaining fuel) OF FUEL REMAINING AND (remaining souls) SOULS ON BOARD
NOTE– N response attribute.
N Report indicating fuel remaining (time) and number of persons on board. DM58 CANCEL EMERGENCY
NOTE– N response attribute.
N Indication that the emergency situation is canceled. TBL 14-3-17 Standard Response Uplink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use UM0 UNABLE N Indication that the message cannot be complied with. UM1 STANDBY N Indication that the message will be responded to shortly. UM2 REQUEST DEFERRED NE Indication that a long‐term delay in response can be expected. UM3 ROGER N Indication that the message is received. UM4 AFFIRM NE Indication that ATC is responding positively to the message. UM5 NEGATIVE NE Indication that ATC is responding negatively to the message. UM143 CONFIRM REQUEST N Request to confirm the referenced request since the initial request was not understood. The request should be clarified and resubmitted. TBL 14-3-18 Standard Response Downlink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use DM0 WILCO N Indication that the instruction is understood and will be complied with. DM1 UNABLE N Indication that the instruction cannot be complied with. DM2 STANDBY N Indication that the message will be responded to shortly. DM3 ROGER
NOTE– ROGER is the only correct response to an uplink free text message.
N Indication that the message is received. DM4 AFFIRM N Indication of a positive response to a message. DM5 NEGATIVE N Indication of a negative response to a message. TBL 14-3-19 Supplemental Uplink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use UM164 WHEN READY NE Indication that the associated instruction is to be executed when the flight crew is ready. UM165 THEN NE Used to link two messages, indicating the proper order of execution of clearances/ instructions. UM166 DUE TO TRAFFIC N Indication that the associated message is issued due to the specified reason. UM167 DUE TO AIRSPACE RESTRICTION N Indication that the associated message is issued due to the specified reason. UM176 MAINTAIN OWN SEPARATION AND VMC W/U Notification that the pilot is responsible for maintaining separation from other traffic and is also responsible for maintaining Visual Meteorological Conditions. TBL 14-3-20 Supplemental Downlink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use DM65 DUE TO WEATHER N Indication that the associated message is issued due to specified reason. DM66 DUE TO AIRCRAFT PERFORMANCE N Indication that the associated message is issued due to specified reason. TBL 14-3-21 Free Text Uplink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use UM169 (free text) R A message or part of a message that does not conform to any standard message element in the PANSATM (Doc 4444). UM169 (free text) R See Note UM169 (free text) R See Note UM169 (free text) R See Note UM169 (free text) R See Note UM169 (free text) R See Note UM169 (free text) R See Note TBL 14-3-22 Free Text Downlink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use DM67 free text
NOTE– Medium (M) alert attribute.
N 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.
Y TBL 14-3-23 System Management Uplink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use UM159 (error information) N System‐generated notification of an error. UM160 (ICAO facility designation)
NOTE– The facility designation is required.
N System‐generated notification of the next data authority or the cancellation thereof. UM161 END SERVICE NE Notification to the avionics that the data link connection with the current data authority is being terminated. UM162 SERVICE UNAVAILABLE NE Notification that the ground system does not support this message. TBL 14-3-24 System Management Downlink Message Elements FANS 1/A Message Identifier Message Content Response Message element intended use DM62 (error information) N System‐generated notification of an error. DM63 NOT CURRENT DATA AUTHORITY N System‐generated rejection of any CPDLC message sent from a ground facility that is not the current data authority. DM64 (ICAO facility designation)
NOTE– Use by FANS 1/A aircraft in B1 environments.
N 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. TBL 14-3-25 Additional Uplink Messages FANS 1/A Message Identifier Message Content Response Message element intended use UM176 MAINTAIN OWN SEPARATION AND VMC W/U Notification that the pilot is responsible for maintaining separation from other traffic and is also responsible for maintaining Visual Meteorological Conditions. TBL 14-3-26 Additional Downlink Messages FANS 1/A Message Identifier Message Content Response Message element intended use DM74 REQUEST TO MAINTAIN OWN SEPARATION AND VMC N States a desire by the pilot to provide his/her own separation and remain in VMC. DM78 AT (time) (distance) (to/from) (position) N At the specified time, the aircraft's position was as specified.