8/15/19 AIM  En Route Procedures 5 − 3 − 12 DM63 NOT CUR- RENT DATA AU- THORITY DM63 NOT CURRENT  DATA AUTHOR- ITY N SYSD − 3 System − generated rejection of any CPDLC message sent from a ground facility that is not the current data au- thority. SYSD − 3 DM64  (ICAO facility designation) Note  −  Use by FANS 1/A aircraft in B1 envi- ronments. DM107 NOT AUTHORIZED NEXT DATA AUTHORITY Note  −  CDA and NDA cannot be provided. N SYSD − 5 System − generated notification that the ground system is not designated as the next data au- thority (NDA), indi- cating the identity of the current data authority (CDA). Identity of the NDA, if any, is also reported. SYSD − 5