TBL 5-3-6 Crossing Constraint Message Elements (CSTU) CPDLC Message Sets Operational Definition in PANS-ATM (Doc 4444) FANS 1/A ATN B1 Response Message Element Identifier 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 Doc 4444. 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) 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 level or within the vertical range, as specified, and at the specified speed. CROSS (position) AT (level) AT (speed) Message Element Intended Use Format for Message Element Display TBL 5-3-7 Air Traffic Advisory Uplink Message Elements CPDLC Message Sets FANS 1/A UM154 RADAR SERVICES TERMINATED 5-3-6 Operational Definition in PANS-ATM (Doc 4444) ATN B1 Response Message Element Identifier ADVU-2 Message Element Intended Use Advisory that the ATS surveillance service is terminated. Format for Message Element Display SURVEILLANCE SERVICE TERMINATED En Route Procedures