Aircraft Systems: ATSU and DCDU

Air Traffic Service Unit (ATSU)

• ATSU case has minimal software and enables uploading of software through Multipurpose Disk Drive Unit (MDDU) or portable data loader
• Processes and organizes data in screen pages to be displayed on Data Control and Display Unit (DCDU)

Data Control and Display Unit (DCDU)

• Displays information received from ATC ground centre and allows sending of answers and messages to the ground centre
• Dedicated to ATC applications
• Provides display capabilities and control means
• Up to 29 messages can be filed in chronological order, with oldest message being number 1
• If message file reaches capacity, amber message "file full" is displayed in information area

ATSU/DCDU Interface

• Performs following functions: Display Recall, Flight crew response, Initialisation, BITE
• BITE consists of DCDU test, error report, DCDU status report, and LRU identification

Air Traffic and Information Management System Architecture

• ACARS utilizes aircraft VHF radio system to transmit data between aircraft and operators AOC facilities
• Information transmitted from aircraft is used to plan aircraft turnarounds and can be stored in airline computer systems for logistics support

Airline Operational Control (AOC) Applications

• Standard AOC applications are datalink applications used by airline for maintenance, flight operations, and administrative purposes
• Uploaded into ATSU by means of software disks, composed to meet airline requirements
• Two types of AOC applications: Remote AOC application and Hosted AOC application

Automatic Dependant Surveillance Broadcast (ADSB)

• Provides identification, position, altitude, velocity, and other data every half a second using same transponder as TCAS
• Broadcasts information to ground stations

FANS Development

• Three stages of FANS development: Pre-FANS, FANS A, and FANS B
• FANS A includes ATC functions, FANS B includes improved ground network and TCAS

Network Information Systems

• Composed of two systems: Aircraft Information Network System (AINS) for maintenance and operations, and Cabin Information Network System (CINS) for passenger information
• AINS gives access to flight crew applications and maintenance applications
• Sends part number and software number of each component of ATIMS system to CMCs
• Acquires A/C configuration parameters from CMCs
• Acquires Aircraft Registration Number (ARN) and Flight Number data

Central Maintenance Computer (CMC)

• Acquires data from AINS
• Used to plan maintenance and logistics support

Flight Management Guidance Envelope Computer (FMGEC)/ATIMS Interface

• FMGEC interfaces with ATSU to acquire flight-management information
• Exchanges data messages for Airline Operational Control (AOC) remote application
• ATSU acts as a router

Multi-Purpose Control and Display Units (MCDU)

• Used for maintenance and application purposes in addition to DCDUs
• Provides aircrew access to specific Air Traffic Control (ATC) system pages
• Loading can be done through portable data loader or MDDU with data loader selector switch on ATSU position

Printer

• ATSU acquires printer status to determine whether it is operational or not

Landing Gear

• ATSU receives information from Landing Gear Control Interface Unit (LGCIU) to determine whether aircraft is on the ground or in flight

Cabin Terminals

• Consist of Passenger Flight Information System (PFIS) and Cabin Passenger Management System (CPMS)
• Interface supports exchange of ARINC 619 messages hosted in cabin terminals
• Cabin terminals use ATSU as an ACARS router