TBL 5-3-13 Standard Response Downlink Message Elements (RSPD) CPDLC Message Sets FANS 1/A ATN B1 Operational Definition in PANS-ATM (Doc 4444) Response Message Element Identifier Message Element Intended Use Format for Message Element Display DM0 WILCO DM0 WILCO RSPD-1 Indication that the instruction is understood and will be complied with. WILCO DM1 UNABLE DM1 UNABLE RSPD-2 Indication that the message cannot be complied with. UNABLE DM2 STANDBY DM2 STANDBY 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 RSPD-4 Indication that the message is received. ROGER TBL 5-3-14 Supplemental Uplink Message Elements (SUPU) CPDLC Message Sets FANS 1/A UM166 DUE TO TRAFFIC UM167 DUE TO AIRSPACE RESTRICTION Operational Definition in PANS-ATM (Doc 4444) ATN B1 Response Message Element Identifier SUPU-2 Message Element Intended Use Indication that the associated message is issued due to the specified reason. Format for Message Element Display DUE TO (specified reason uplink) TBL 5-3-15 Supplemental Downlink Message Elements (SUPD) CPDLC Message Sets FANS 1/A DM65 DUE TO WEATHER DM66 DUE TO AIRCRAFT PERFORMANCE En Route Procedures Operational Definition in PANS-ATM (Doc 4444) ATN B1 Response Message Element Identifier DM65 DUE TO WEATHER DM66 DUE TO AIRCRAFT PERFORMANCE SUPD-1 Message Element Intended Use Indication that the associated message is issued due to the specified reason. Format for Message Element Display DUE TO (specified reason downlink) 5-3-9