In flight, ACARS ( ; acronym for handling plane communication and reporting system ) is a digital data system for short message transmission between plane and earth station via radio or satellite airband. The protocol was designed by ARINC and deployed in 1978, using the Telex format. More ACARS radio stations were added later by SITA.
Video ACARS
Sejarah ACARS
Prior to the introduction of in-flight datalink, all communications between aircraft and ground personnel were performed by flight crews using voice communications, using VHF or HF sound radio. In many cases, the information conveyed by voice involves the radio operator and a special digital message sent to the airline's teletype system or the successor system.
Furthermore, the hourly rate for the salary of the crew and the cabin depends on whether the aircraft is flying in the air or not, and if on land whether it is at the gate or not. The flight crew reported this time by voice to geographically dispersed radio operators. Airlines wishes to eliminate their self-reported time to prevent inaccuracies, whether intentional or intentional. Doing so also reduces the need for human radio operators to receive reports.
In an effort to reduce the workload of the crew and improve data integrity, the engineering department at ARINC introduced the ACARS system in July 1978, as an automated clock time system. The Teledyne control generates avionics and launch customers is Piedmont Airlines. The original expansion of the abbreviation is "Arinc Communications Addressing and Reporting System". Then, changed to "Aircraft Communications, Address and Reporting System". The original avionics standard is ARINC 597, which defines the ACARS Management Unit consisting of discrete inputs for doors, parking brakes and weight on wheel sensors to automatically determine flight phases and generate and transmit as telex messages. It also contains MSK modems, which are used to transmit reports through existing VHF voice radios. The global standard for ACARS is prepared by the Electronic Airlines Engineering Committee (AEEC). The first day of operation ACARS saw about 4,000 transactions, but did not experience widespread use by major airlines until the 1980s.
The initial ACARS system was extended for many years to support aircraft with digital bus data interfaces, flight management systems, and printers.
Maps ACARS
System description and function
ACARS as a term refers to a complete air and ground system, which consists of equipment on board, onshore equipment, and service providers.
The on-board ACARS equipment consists of an end system with a router, which routes messages through air-ground subnets.
The ground equipment consists of a radio transceiver network managed by a central site computer called AFEPS (Arinc Front End Processor System), which handles and routes messages. Generally, terrestrial ACARS units are government agencies such as the Federal Aviation Administration, airline operations headquarters, or, for small flights or general aviation, third party subscription services. Usually government agencies are responsible for leeway, while aviation operations handle gate duties, maintenance, and passenger needs.
Soil processing system
Provision of land systems is the responsibility of either participating ANSP or aircraft operators. Aircraft carriers often contract out functions to DSP or to separate service providers. Messages from the aircraft, especially those generated automatically, can be pre-configured according to the message type so that the message is automatically delivered to the right receiver as messages from the mainland can be configured to reach the correct plane.
The ACARS equipment in the aircraft is tied to it on land by the datalink service provider. Since the ACARS network is modeled after a point-to-point telex network, all messages come to the central processing location to be diverted. ARINC and SITA are the two main service providers, with smaller operations than others in some areas. Some areas have many service providers.
message type ACARS
ACARS messages can consist of three broad types:
- Air traffic control messages are used to request or allow leeway.
- Flight operation control
- Administrative control of airlines
Control messages are used to communicate between the aircraft and its base, with messages standardized in accordance with ARINC Standard 633, or user-defined in accordance with ARINC 618 Standard. The content may be an OOOI event, flight plan, weather information, equipment health, flight status connected, etc.
Event OOOI
The main function of ACARS is to automatically detect and report the start of each major flight phase, called the OOOI event in the industry ( o ut gate, o from the ground, o n ground, and i nto gates). This OOOI event is detected using input from a plane sensor mounted on the door, parking brake, and struts. At the start of each flight phase, an ACARS message is sent to the ground describing the flight phase, timing of occurrence, and other relevant information such as the amount of fuel in the aircraft or the origin of the flight and destination. These messages are used to track the status of aircraft and crew.
The aviation management system interface
The ACARS interface with the flight management system (FMS), acts as a communication system for flight plans and weather information to be sent from the ground to FMS. This allows the airline to update the FMS while in flight, and allows the flight crew to evaluate new weather conditions or alternative flight plans.
Health and equipment maintenance data
ACARS is used to transmit information from aircraft to ground stations on the conditions of various aircraft systems and sensors in real-time. Maintenance errors and abnormal events are also transmitted to the earth station along with detailed messages, used by airlines to monitor equipment health, and to plan for better repair and maintenance of the activities.
Ping Message
Automatic ping messages are used to test the connection of aircraft with communication stations. In the case that the aircraft's ACARS unit has been stationary longer than the prescribed time interval, the earth station can ping the aircraft (directly or via satellite). The ping response shows a healthy ACARS communication.
Messages sent manually
ACARS interacts with an interactive display unit in the cockpit, which can be used by aircrews to send and receive messages and technical reports to or from earth stations, such as weather or leeway or connected flight status requests. Response from the ground station is received on the plane through ACARS as well. Each airline adjusts the ACARS with this role to meet its needs.
Communication details
ACARS messages can be sent using a choice of communication methods, such as VHF or HF, either directly to ground or via satellite, using modif-minimum shift modulation (MSK).
ACARS can send messages via VHF if the VHF ground station network is in the current plane area. VHF communication is the typical line-of-sight propagation and reach of up to 200 nautical miles at high altitudes. If VHF does not exist, HF network or satellite communications can be used if available. Satellite coverage may be limited to high latitudes (trans-polar flights).
The role of ACARS in air crash and incident
After the fall of Air France Flight 447 in 2009, there was discussion about making ACARS an "online black box" to reduce the effects of flight recorder loss. However no changes were made to the ACARS system.
In March 2014, ACARS messages and Doppler satellite data communications analysis of ACARS played a very significant role in the quest to track Malaysia Airlines Flight 370 to the forecast site. While the main ACARS system on the MH370 board has been shut down, a second AARA system called Classic Aero is active during the plane, and continues to make connections to the Inmarsat satellite every hour.
ACARS on Airbus A320 from EgyptAir Flight 804 reported "irregularities" to ground staff on three separate occasions, resulting in three emergency landing, within 24 hours before the plane crash to the Mediterranean Sea on May 19, 2016, which killed all 66 people in it. The specific nature of the irregularities is not explained, but in each instance the aircraft is given permission to continue its flight.
Use of ACARS out of flight
In 2002, the ACARS was added to the NOAA Observation System Architecture. Thus commercial aircraft can act as weather data providers for weather agencies to use in their approximate models, sending meteorological observations such as wind and temperatures over ACARS networks. NOAA provides real-time weather maps.
See also
- Acronyms and abbreviations in avionics
- Aeronautical Telecommunication Network (ATN)
- Future Air Navigation System (FANS)
- SELCAL
References
External links
- ARINC, inventor of ACARS
- acarsd, free ACARS decoder software for Linux/Windows
- ARINC Standard Document List, list and describe ARINC standard
Source of the article : Wikipedia
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