ACARS
Aircraft Communication Addressing and Reporting System (ACARS) is a system which provides a digital data link for the transmission of messages between flying aircraft and ground stations. ACARS has been in use since 1978 and originally operated on the VHF transmission frequencies (Skybrary, 2016). The system conveys messages from three primary sources based on the information that each source provides, which are messages from the ATC, Aeronautical Operational Control (AOC) and Airline Administrative Control (AAC) respectively. ACARS ATC messages typically consist of information about Pre-Departure, Automatic Terminal Information Service (ATIS) and en-route clearances. AOC and AAC messages can convey information between the aircraft and it’s operating base, and the content varies due to different organization needs. Examples of contents are weather information; aircraft technical performance data; aircraft position, diversion and ETA; fuel quantity; and aircraft faults. ACARS is also capable of free text messaging. The advantage of the ACARS system is that it works in addition to the normal protocol of voice communications. This provides redundancy in terms of communications to the aircraft. In addition, ACARS can monitor aircraft parameters and send the information back to home base automatically before the aircraft lands. This provides a form of on-board diagnostics, allowing for airlines to better monitor the health of their aircraft and hence, ACARS is useful to aviation safety programs.
Proactive and Predictive SMS
Both FOQA and ACARS have the capability integrate into a proactive and predictive SMS program. FOQA is a form of flight data monitoring that records flight data, allowing for the subsequent trend analysis and implementation of safety measures to mitigate future accidents. Previously unknown risks can be uncovered using FOQA, and hence this system is proactive and predictive. Organizations will be able to use this data to determine which areas of concern need to be addressed first, and allocate their limited resources accordingly.
ACARS is a system whereby a digital data link is formed for the transmission of text messages between the aircraft and the organization on the ground. This system can be proactive and predictive as it allows for the automatic transmission of critical aircraft parameters to the ground control centers, aiding the airlines with monitoring the health of their aircraft. Airlines can better plan for unscheduled maintenance when a fault is detected, instead of waiting for the fault to manifest into a bigger problem leading to an incident.