scope:

This change minimizes nuisance error messages being sent to the aircraft when the flight crew initiates a request to the receiving ATSU prior to the connection being enabled. The current system provides indication of when the connection has been established but not when the CPDLC connection has been enabled. The change minimizes nuisance error messages to the flight crew by providing them indication of the CPDLC June 2014 RTCA List of Available Documents Page 49 of 142 connection being enabled when the R-ATSU sends a CPDLC message to the aircraft containing the facility designation, facility name, and facility function. Correct errors: This change corrects an error in the safety requirement SR 11 for ACL, DCL, and DSC. The corresponding latency requirement ETRESPONDER is associated with the time needed to "send" the message, not "receive the message".