4/20/23 

AIM 

TBL 5

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3

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13 

Standard Response Downlink Message Elements (RSPD) 

CPDLC Message Sets 

Operational Definition in PANS

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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 5

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3

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14 

Supplemental 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 

N 

SUPU

−

2 

Indication that the 

associated message 

is issued due to the 

specified reason. 

DUE TO 

(specified reason 

uplink)

UM167 DUE TO 

AIRSPACE 

RESTRICTION 

TBL 5

−

3

−

15 

Supplemental 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 

DM65 DUE TO 

WEATHER 

DM65 DUE TO 

WEATHER 

N 

SUPD

−

1 

Indication that the 

associated message 

is issued due to the 

specified reason. 

DUE TO 

(specified reason 

downlink)

DM66 DUE TO 

AIRCRAFT 

PERFORMANCE 

DM66 DUE TO 

AIRCRAFT 

PERFORMANCE 

En Route Procedures 

5

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3

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9