Page 18 - ITU-T Focus Group on Aviation Applications of Cloud Computing for Flight Data Monitoring - Use cases and requirements

ITU-T Focus Group on Aviation Applications of Cloud Computing for Flight Data Monitoring
Use cases and requirements

to any combination of the following: a flight deck printer, a flight deck display, a download unit, to ACARS, and
to an auxiliary recorder.

ACMS functions are under the control of a dedicated microprocessor. Depending on where the second
processor is located, it may be called a central processing unit (CPU) #2 or a data management processor
(DMP). For some aircraft types, this processor exists within a dedicated line replaceable unit or in a single box
that includes also the mandatory FDR functions.

ACMS functions involve uploaded application software to:

• manage acquisition of aircraft parameters;
• allow scripts to work on acquired data;

• derive recording modes and flight modes;
• perform triggering;
• perform reasonability testing;

• derive new parameters;
• generate a data stream that, when received by an auxiliary recorder, generates custom flight data recordings;
• in some cases, route a data stream that is a replica of the DFDR data to an auxiliary recorder;

• generate reports which:
• can be interfaced with a flight deck display system for control and display purposes (examples of such
equipment are interactive display units (IDUs), flight data entry panels (FDEPs), precision distance
measuring equipment (PDME), control display units (CDUs) and more commonly multipurpose
control display units (MCDUs));
• can be interfaced with a data loader (for offload);
• can be interfaced with the same auxiliary recorder that records ACMS-related flight data recordings.

Report and message data
Report generation within ACMS relies on other pre-occurring ACMS activities (parameter acquisition, scripts
and triggering). Outputs from the ACMS reporting function, which always contains the American Standard
Code for Information Interchange (ASCII) text, are in two styles:
• Formatted – The layout of information is arranged for human reading.

• Unformatted – The layout of information is arranged for machine reading and efficient transmission
to the ground.

Examples of ACMS reports include take-off reports, engine stable cruise reports, performance reports and
auxiliary power unit (APU) reports. Other reports may exist for environmental control system, brake temperature,
tail strike, hard landing and more. These reports are typically transmitted via ACARS, but alternatives include
cellular or Wi-Fi on the ground. ACMS reports are transmitted on defined criteria, depending on airline
requirements (for instance after take-off, top of decent or at occurrence of a parameter threshold exceedance).

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