This VHF digital transmission system, used by many civilian and business aircraft, can be likened to "email for airplanes", as the registration of each aircraft represents a unique address in the network. The system was developed by aeronautical radio giant ARINC (Aeronautical Radio, Inc.) and all traffic is routed via ARINC computers.

With ACARS, such routine items as departure reports, arrival reports, passenger loads, fuel data, engine performance data, and much more, can be requested by the ground control and retrieved from the aircraft at specified intervals. Reciprocally, instructions to the crew can be relayed automatically and printed out on a cockpit printer.

WiNRADiO users can get obtain access to ACARS information very easily. All that is needed is a WiNRADiO receiver (such as WR-G305e) and the WiNRADiO Advanced Digital Suite software. The software is very easy to use and allows its user to watch pilot's instructions exactly as they are printed on the cockpit printer, in addition to other interesting information being transmitter to and from the aircraft.

Here are some examples of ACARS messages:

3/4/2007 18:46:24
ACARS Mode: 2
Aircraft registration: .VH-OJE - Australia
Acknowledge: No
Message label: C1 - Uplink to cockpit printer No. 1
Block id: C
Message no: AKL
Flight id: QF101
Message: 40745OS/VDU REF OS3735/04MAR98
AGM
AN VH-OJE/GL AKL
AIRPORT UPLINK MESSAGE
QF101 GOOD EVENING GATE 1 TONIGHT
OUTBOUND LOAD 15P 45J 330Y
POTABLE WATER 1400KGS OR 7/8
ALL TRANSITS TO DISEMBARK PLSE

The following example is a position report generated by an United Airlines Boeing 777 en route from London Heathrow to San Francisco.

25/02/2007 15:22:16
ACARS Mode: E
Aircraft registration: .N797UA - United States
Acknowledge: No
Message label: H1 - Message to/from terminal
Block id: 4
Message no: F11A - Digital Flight Data Acquisition Recorder
Flight id: UA0931 - United Airlines
Message: #M1BPOSN55260W003356,TLA04,152222,310,
STN,154759,6110N,M9,28370,16216367