Appendix F Operational Definition in PANS-ATM (Doc 4444) CPDLC Message Sets Message Element Identifier Message Element Intended Use Format for Message Element Display Resp. FANS 1/A ATN B1 SPCU-5 ATS acknowledgement for the pilot use of the in-trail procedure when the ITP aircraft is behind one reference aircraft and ahead of one reference aircraft. This message element is always concatenated with a vertical clearance.
ITP BEHIND (aircraft identification) AND AHEAD OF (aircraft identification) N UM169 ‘ITP BEHIND (aircraft identification)
AND AHEAD OF (aircraft identification)’ Note: R response attribute.
N/A F-41
Appendix F Table F-18. Spacing Downlink Messages (SPCD) Operational Definition in PANS-ATM (Doc 4444) CPDLC Message Sets Message Element Identifier Message Element Intended Use Format for Message Element Display Resp. FANS 1/A ATN B1 SPCD-1 Advisory indicating that the pilot has the ITP equipment, and provides the specified distance to the reference aircraft, including aircraft identification. This message element is always concatenated with a vertical request.
ITP (specified distance) BEHIND (aircraft identification) N DM67 ‘ITP (distance) BEHIND (aircraft identification)’ N/A SPCD-2 Advisory indicating that the pilot has the ITP equipment, and provides the specified distance from the reference aircraft, including aircraft identification.
This message element is always concatenated with a vertical request.
ITP (specified distance) AHEAD OF (aircraft identification) N DM67 ‘ITP (distance) AHEAD OF (aircraft identification)’ N/A SPCD-3 Advisory indicating that the pilot has the ITP equipment, and provides the specified distance to both reference aircraft, including aircraft identification. This message element is always concatenated with a vertical request.
ITP (specified distance) BEHIND (aircraft identification) AND (specified distance) BEHIND (aircraft identification) N DM67 ‘ITP (distance) BEHIND (aircraft identification) AND (distance) BEHIND (aircraft identification')’ Note: Used with a vertical request, indicating an ITP request when there are two reference aircraft, both behind.
N/A F-42
Appendix F Operational Definition in PANS-ATM (Doc 4444) CPDLC Message Sets Message Element Identifier Message Element Intended Use Format for Message Element Display Resp. FANS 1/A ATN B1 SPCD-4 Advisory indicating that the pilot has the ITP equipment, and provides the specified distance from both reference aircraft, including aircraft identification.
This message element is always concatenated with a vertical request.
ITP (specified distance) AHEAD OF (aircraft identification) AND (specified distance) AHEAD OF (aircraft identification) N DM67 ‘ITP (distance) AHEAD OF (aircraft identification) AND (distance) AHEAD OF (aircraft identification)’ Note: Used with a vertical request, indicating an ITP request when there are two reference aircraft, both ahead.
N/A SPCD-5 Advisory indicating that the pilot has the ITP equipment, and provides the specified distance to one reference aircraft and the specified distance from another reference aircraft, including aircraft identification. This message element is always concatenated with a vertical request.
ITP (specified distance) BEHIND (aircraft identification) AND (specified distance) AHEAD OF (aircraft identification) N DM67 ‘ITP (distance) BEHIND (aircraft identification) AND (distance) AHEAD OF (aircraft identification)’ Note: Used with a vertical request, indicating an ITP request when there are two reference aircraft, one behind and the other ahead.
N/A F-43
Appendix F Table F-19. Emergency/Urgency Uplink Messages (EMGU) Operational Definition in PANS-ATM (Doc 4444) CPDLC Message Sets Message Element Identifier Message Element Intended Use Format for Message Element Display Resp. FANS 1/A ATN B1 EMGU-1 Request to provide the fuel remaining (time) and the number of persons on board.
REPORT ENDURANCE
AND PERSONS ON BOARD Y UM131 REPORT
REMAINING FUEL
AND SOULS ON BOARD Note: NE response attribute.
N/A EMGU-2 Instruction to immediately comply with the associated instruction to avoid imminent situation.
IMMEDIATELY N Used in combination with LVLU-6 and LVLU-9, which is implemented in FANS 1/A as:
UM38
IMMEDIATELY CLIMB TO (altitude) UM39
IMMEDIATELY
DESCEND TO (altitude) N/A EMGU-3 Request to confirm an ADS- C indicated emergency.
CONFIRM ADS-C
EMERGENCY A/N UM169 ‘CONFIRM ADS-C EMERGENCY’ Note: R response attribute.
N/A F-44
Appendix F Table F-20. Emergency/Urgency Downlink Messages (EMGD) Operational Definition in PANS-ATM (Doc 4444) CPDLC Message Sets Message Element Identifier Message Element Intended Use Format for Message Element Display Resp. FANS 1/A ATN B1 EMGD-1 Indication of an urgent situation. PAN PAN PAN Y DM55 PAN PAN PAN Note: N response attribute.
N/A EMGD-2 Indication of an emergency situation.
MAYDAY MAYDAY MAYDAY Y DM56 MAYDAY
MAYDAY MAYDAY Note: N response attribute.
N/A EMGD-3 Report indicating fuel remaining (time) and number of persons on board.
(remaining fuel) ENDURANCE AND (persons on board) PERSONS ON BOARD Y DM57 (remaining fuel)
OF FUEL REMAINING AND (remaining souls)
SOULS ON BOARD Note: N response attribute.
N/A EMGD-4 Indication that the emergency situation is cancelled.
CANCEL EMERGENCY Y DM58 CANCEL
EMERGENCY Note: N response attribute.
N/A F-45
Appendix F Table F-21. Standard Response Uplink Messages (RSPU) Operational Definition in PANS-ATM (Doc 4444) CPDLC Message Sets Message Element Identifier Message Element Intended Use Format for Message Element Display Resp. FANS 1/A ATN B1 RSPU-1 Indication that the message cannot be complied with.
UNABLE N UM0 UNABLE UM0 UNABLE RSPU-2 Indication that the message will be responded to shortly.
STANDBY N UM1 STANDBY UM1 STANDBY RSPU-3 Indication that a long term delay in response can be expected.
REQUEST DEFERRED N UM2 REQUEST
DEFERRED N/A RSPU-4 Indication that the message is received.
ROGER N UM3 ROGER UM169 ‘ROGER MAYDAY’ Note 1: R response attribute.
Note 2: Used to acknowledge emergency downlink reports.
UM169 ‘ROGER PAN’ Note 1: R response attribute.
Note 2: Used to acknowledge urgency downlink reports.
UM3 ROGER RSPU-5 Indication that ATC is responding positively to the message.
AFFIRM N UM4 AFFIRM UM4 AFFIRM RSPU-6 Indication that ATC is responding negatively to the message.
NEGATIVE N UM5 NEGATIVE UM5 NEGATIVE F-46
Appendix F Operational Definition in PANS-ATM (Doc 4444) CPDLC Message Sets Message Element Identifier Message Element Intended Use Format for Message Element Display Resp. FANS 1/A ATN B1 RSPU-7 Indication that the request has been forwarded to the next control unit.
REQUEST FORWARDED N UM169 ‘REQUEST FORWARDED’ Note: R response attribute.
UM211 REQUEST
FORWARDED RSPU-8 Request to confirm the referenced request since the initial request was not understood. The request should be clarified and resubmitted.
CONFIRM REQUEST N UM143 CONFIRM
REQUEST N/A Table F-22. Standard Response Downlink Messages (RSPD) Operational Definition in PANS-ATM (Doc 4444) CPDLC Message Sets Message Element Identifier Message Element Intended Use Format for Message Element Display Resp. FANS 1/A ATN B1 RSPD-1 Indication that the instruction is understood and will be complied with.
WILCO N DM0 WILCO DM0 WILCO RSPD-2 Indication that the instruction cannot be complied with.
UNABLE N DM1 UNABLE DM1 UNABLE RSPD-3 Indication that the message will be responded to shortly.
STANDBY N DM2 STANDBY DM2 STANDBY RSPD-4 Indication that the message is received.
ROGER N DM3 ROGER Note: ROGER is the only correct response to an uplink free text message.
DM3 ROGER RSPD-5 Indication of a positive response to a message.
AFFIRM N DM4 AFFIRM DM4 AFFIRM RSPD-6 Indication of a negative response to a message.
NEGATIVE N DM5 NEGATIVE DM5 NEGATIVE F-47
Appendix F Table F-23. Supplemental Uplink Messages (SUPU) Operational Definition in PANS-ATM (Doc 4444) CPDLC Message Sets Message Element Identifier Message Element Intended Use Format for Message Element Display Resp. FANS 1/A ATN B1 SUPU-1 Indication that the associated instruction is to be executed when the pilot is ready.
WHEN READY N UM164 WHEN READY N/A SUPU-2 Indication that the associated message is issued due to the specified reason.
DUE TO (specified reason uplink) N UM166 DUE TO
TRAFFIC UM167 DUE TO
AIRSPACE
RESTRICTION N/A SUPU-3 Instruction to execute the associated instruction at the aircraft’s best performance rate.
EXPEDITE N Used in combination with LVLU-6, which is implemented in FANS 1/A as:
UM36 EXPEDITE CLIMB TO (altitude).
N/A SUPU-4 Indication that the associated instruction is either a revision to a previously issued instruction or is different from the requested clearance.
REVISED (revision reason[O]) N UM170 ‘REVISED (revision reason[O])’ Note: R response attribute.
N/A SUPU-5 Indication that the associated instruction is to be executed at the earliest point when the pilot is able.
WHEN ABLE N N/A Note: This message element is part of UM75.
N/A F-48
Appendix F Table F-24. Supplemental Downlink Messages (SUPD) Operational Definition in PANS-ATM (Doc 4444) CPDLC Message Sets Message Element Identifier Message Element Intended Use Format for Message Element Display Resp. FANS 1/A ATN B1 SUPD-1 Indication that the associated message is issued due to specified reason.
DUE TO (specified reason downlink) N DM65 DUE TO
WEATHER DM65 DUE TO
WEATHER SUPD-1 Indication that the associated message is issued due to specified reason.
DUE TO (specified reason downlink) N DM66 DUE TO
AIRCRAFT
PERFORMANCE DM66 DUE TO
AIRCRAFT
PERFORMANCE Table F-25. Free Text Uplink Messages (TXTU) Operational Definition in PANS-ATM (Doc 4444) CPDLC Message Sets Message Element Identifier Message Element Intended Use Format for Message Element Display Resp. FANS 1/A ATN B1 TXTU-1 (free text) Note: M alert attribute.
R UM169 (free text) UM203 (free text) TXTU-2 (free text) Note: M alert attribute.
N UM169 (free text) Note: R response attribute.
UM183 (free text) TXTU-3 (free text) Note: N alert attribute.
N UM169 (free text) Note: R response attribute.
N/A TXTU-4 (free text) Note: M alert attribute.
W/U UM169 (free text) Note: R response attribute.
UM196 (free text) TXTU-5 (free text) Note: M alert attribute.
A/N UM169 (free text) Note: R response attribute.
UM205 (free text) F-49
Appendix F Table F-26. Free Text Downlink Messages (TXTD) Operational Definition in PANS-ATM (Doc 4444) CPDLC Message Sets Message Element Identifier Message Element Intended Use Format for Message Element Display Resp. FANS 1/A ATN B1 TXTD-1 (free text) Note: M alert attribute.
Y DM68 (free text) Note 1: Urgency or Distress Alr (M).
Note 2: Selecting any of the emergency message elements will result in this message element being enabled for the pilot to include in the emergency message at their discretion.
N/A TXTD-2 (free text) Note: M alert attribute.
N DM67 (free text) DM98 (free text) F-50
Appendix F Table F-27. System Management Uplink Messages (SYSU) Operational Definition in PANS-ATM (Doc 4444) CPDLC Message Sets Message Element Identifier Message Element Intended Use Format for Message Element Display Resp. FANS 1/A ATN B1 SYSU-1 System-generated notification of an error.
ERROR (error information) N UM159 ERROR (error information) UM159 ERROR (error information) SYSU-2 System-generated notification of the next data authority or the cancellation thereof.
NEXT DATA AUTHORITY (facility designation[O]) N 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.
SYSU-3 System-generated notification that received message is not supported.
MESSAGE NOT
SUPPORTED BY THIS ATC UNIT N UM169 ‘MESSAGE
NOT SUPPORTED
BY THIS ATC UNIT’ Note: R response attribute.
UM162 MESSAGE NOT
SUPPORTED BY THIS
ATS UNIT SYSU-4 System-generated notification that the received is acceptable for display.
LOGICAL
ACKNOWLEDGEMENT N N/A UM227 LOGICAL
ACKNOWLEDGEMENT SYSU-5 System-generated message indicating that requests for logical acknowledgements are not permitted.
USE OF LOGICAL
ACKNOWLEDGEMENT
PROHIBITED N N/A UM233 USE OF LOGICAL
ACKNOWLEDGEMENT
PROHIBITED Note: ATN B1 ground systems may not use UM (as par ETSI CS) since the use of LACK is required.
F-51
Appendix F Operational Definition in PANS-ATM (Doc 4444) CPDLC Message Sets Message Element Identifier Message Element Intended Use Format for Message Element Display Resp. FANS 1/A ATN B1 SYSU-6 Advisory providing the maximum one-way uplink message transmission delay.
LATENCY TIME VALUE (latency value) N UM169 ‘SET MAX
UPLINK DELAY VALUE TO (delayed message parameter) SECONDS’ Note 1: R response attribute.
Note 2: On FANS 1/A aircraft, this message requires specific action from the pilot to manually set the latency value.
N/A SYSU-7 Indication that the received message has a latency greater than the requirement.
MESSAGE RECEIVED TOO
LATE, RESEND MESSAGE
OR CONTACT BY VOICE N N/A UM159 ERROR (error information) + UM183 ‘DOWNLINK DELAYED USE – VOICE’ Note: The error information is set to the value (2).
F-52