Plain English Meaning
It is a way for pilots to receive things like weather reports and clearances as printed text messages in the cockpit, instead of listening to them on the radio.
Full Definition
A datalink service that delivers flight information — such as terminal weather (ATIS), pre-departure clearances, and other advisory messages — to the cockpit as text via the ACARS network, rather than over voice radio.
Context Anchor
Seen in RNAV departure and cockpit information-system discussions, especially where an aircraft can receive updated flight information electronically before or during flight.
Derivation
D-FIS = Data Link Flight Information Services. ACARS dates from the late 1970s as a digital messaging system between aircraft and ground stations. Putting them together: flight information delivered through the ACARS text-message pipe.
Why Pilots Care
Gives pilots immediate access to essential updates without voice radio calls, reducing workload and improving awareness.
Intuition Check
Do not treat D-FIS ACARS as a navigation system. It is a messaging path for flight information, not the equipment that guides the aircraft along an RNAV route.
Example Sentence 1
Before pushback, the first officer pulled the latest ATIS through D-FIS ACARS and printed it to the cockpit printer.
Example Sentence 2
D-FIS ACARS delivered the latest NOTAMs directly to the flight deck display.