The document discusses the Aircraft Communication, Addressing and Reporting System (ACARS). It provides details on: - ACARS is a digital data link system used to transmit messages between aircraft and ground stations via radio or satellite. It was developed by ARINC in 1978 to automate communication and reduce crew workload. - The system consists of equipment onboard aircraft and on the ground, as well as data link service providers like ARINC and SITA that connect aircraft to the ground system. - ACARS transmissions play an important role in investigations of air accidents by providing data to help locate crashed aircraft. It has also been used to collect weather data from commercial flights for agencies like NOAA.

1. Aircraft Communication, Addressing andAircraft Communication, Addressing and
Reporting SystemReporting System

2. IntroductionIntroduction
::
 ACARS is a digital data link system forACARS is a digital data link system for
transmission of short messages between aircrafttransmission of short messages between aircraft
and ground station via air band radio or satellite.and ground station via air band radio or satellite.
 The protocol was designed by ARINC andThe protocol was designed by ARINC and
deployed in 1978 using the telex format. Moredeployed in 1978 using the telex format. More
ACARS radio stations were added subsequentlyACARS radio stations were added subsequently
by SITA.by SITA.

3. ACARS SYSTEMACARS SYSTEM

4. History of ACARSHistory of ACARS
 Prior to the introduction of data link in aviation, all communicationPrior to the introduction of data link in aviation, all communication
between the aircraft and ground personnel was performed by flightbetween the aircraft and ground personnel was performed by flight
crew using voice communication, using either VHF (very highcrew using voice communication, using either VHF (very high
frequency) or HF (high frequency) voice radios.frequency) or HF (high frequency) voice radios.
 In an effort to reduce crew workload and improve data integrity, theIn an effort to reduce crew workload and improve data integrity, the
engineering department at ARINC introduced the ACARS system inengineering department at ARINC introduced the ACARS system in
July 1978, as essentially an automated time clock system.July 1978, as essentially an automated time clock system.
 The original expansion of the abbreviation was Arinc Communications,The original expansion of the abbreviation was Arinc Communications,
Addressing and Reporting System. Later, it was changed to AircraftAddressing and Reporting System. Later, it was changed to Aircraft
Communication, Addressing and Reporting System.Communication, Addressing and Reporting System.
 The original avionics standard was ARINC 597 which defined anThe original avionics standard was ARINC 597 which defined an
ACARS management unit consisting of inputs for the doors, parkingACARS management unit consisting of inputs for the doors, parking
brakes and weight on wheels sensors to automatically determine thebrakes and weight on wheels sensors to automatically determine the
flight phase and sends to ground station as telex messages.flight phase and sends to ground station as telex messages.

6. Standards of ARINCStandards of ARINC

7. System description and FunctionsSystem description and Functions
 ACARS as system refers to the complete air and ground systemACARS as system refers to the complete air and ground system
consisting of equipment on board, ground and a service provider.consisting of equipment on board, ground and a service provider.
 On board ACARS equipment consists of end system with a router,On board ACARS equipment consists of end system with a router,
which roots messages through the air ground sub network.which roots messages through the air ground sub network.
 Ground equipment is made up of network of radio transceiversGround equipment is made up of network of radio transceivers
managed by a central side computer called AFEPS (Arinc Front Endmanaged by a central side computer called AFEPS (Arinc Front End
Processor System), which handles and routes messages.Processor System), which handles and routes messages.
 The ACARS equipment on the aircraft is linked to that on the ground byThe ACARS equipment on the aircraft is linked to that on the ground by
data link service provider.data link service provider.
 ARINC and SITA are two primary service providers, with smallerARINC and SITA are two primary service providers, with smaller
operations from others in some areas. some areas have multiple serviceoperations from others in some areas. some areas have multiple service
providersproviders

8. Transmission of MessagesTransmission of Messages

9. Role of ACARS in Air accidentsRole of ACARS in Air accidents
 In the wake of the crash of Air France Flight 447 in 2009, thereIn the wake of the crash of Air France Flight 447 in 2009, there
was discussion about making ACARS an “online-BLACK BOX”was discussion about making ACARS an “online-BLACK BOX”
to reduce the effects of the lose of a flight recorder. However noto reduce the effects of the lose of a flight recorder. However no
changes were made to the ACARS system.changes were made to the ACARS system.
 In March 2014, ACARS messages and Doppler analysis ofIn March 2014, ACARS messages and Doppler analysis of
ACARS satellite communication data played a very significantACARS satellite communication data played a very significant
role in efforts to trace Malaysia Airline flight MH370 to arole in efforts to trace Malaysia Airline flight MH370 to a
appropriate location. While the primary ACARS system on boardappropriate location. While the primary ACARS system on board
MH370 had been switched off, a second ACARS system calledMH370 had been switched off, a second ACARS system called
Classic Aero was active as-long-as the plane was powered up,Classic Aero was active as-long-as the plane was powered up,
and kept trying to establish a connection to an INMARSATand kept trying to establish a connection to an INMARSAT
satellite every hour.satellite every hour.

10. Working of Pitot tubeWorking of Pitot tube

12. Uses of ACARS outside aviationUses of ACARS outside aviation
 In 2002, ACARS was added to NOAA (NationalIn 2002, ACARS was added to NOAA (National
Oceanic and Atmospheric Administration)Oceanic and Atmospheric Administration)
Observing System Architecture. ThusObserving System Architecture. Thus
commercial aircraft can act as weather datacommercial aircraft can act as weather data
providers for weather agencies to use in theirproviders for weather agencies to use in their
forecast models, sending meteorologicalforecast models, sending meteorological
observation like winds and temperatures overobservation like winds and temperatures over
the ACARS networks. NOAA provides real timethe ACARS networks. NOAA provides real time
weather maps.weather maps.

13. NOAA Lockheed WP-3D HurricaneNOAA Lockheed WP-3D Hurricane
HunterHunter

14. 92 Hurricanes studied by Hurricane92 Hurricanes studied by Hurricane
HunterHunter

17. Presented byPresented by
MECHANICAL ENGINEERINGMECHANICAL ENGINEERING
15NG1A037615NG1A0376
URCETURCET