User's Manual

UniLink UL-800/801 FANS
SCN 30.X
Operator’s Manual
4 23-20-06.02
December 2011
Applications
FANS 1/A + is principally composed of three applications:
• Controller-Pilot Datalink Communications (CPDLC) –
CPDLC allows datalink messages to substitute for traditional
voice communications for routine communications between a
crew and an air traffic controller. CPDLC messages can be
used to request and grant clearances, to inform the ground of
the aircraft’s position and situation, and to provide instructions
to the crew.
• Air Traffic Services Facilities Notification (AFN) – This
application requires no crew action. AFN allows the aircraft
and an Air Traffic Services (ATS) provider on the ground to
exchange addresses, as well as information about which
FANS applications they support.
•
• Automatic Dependent Surveillance-Contract (ADS-C) –
This application requires no crew action. ADS-C allows ATS
providers to query the aircraft to provide position reports and
other situational data at regular intervals or in response to
events specified by the ATS provider, such as a change in
altitude or lateral deviation.