3.
Data retrieval or transmission
Data Acquisition
In this substep, the data acquisition unit collects flight parameters from the aircraft systems and sensors. Then, the data acquisition unit converts the data into digital format for output to the flight data recorder (FDR) and also to second recorder. It is this second recorder, which provides the data for the aircraft condition monitoring.
Data Recording & Storage
Once the flight data are converted they are sent to a device where it is recorded and stored onboard the aircraft. The most utilized devices are the "quick access recorders" (QAR) using either a removable magneto-optical disks or PCMCIA card to record data. Another option for recording and storage is a wireless QAR that is a fully automated system and transmits data automatically via mobile telephone networks.
Data Retrieval or Transmission
In this sub-stage the flight data is transferred from the recording device onboard the aircraft to an analysis workstation. Depending on the recording device used, this happens in one of two ways:
.
Manual retrieval and return of physical media to and from the aircraft in order to transfer the data to an analysis facility. Retrieval is usually done between 1 to 5 days depending of the data recording media.
.
Automatic, wireless transmission from a wireless recorder to the analysis facility after the aircraft is at the gate (transmission happens automatically from anywhere in the world when the required infrastructure is in place).
Analysis
The Analysis step of Flight Data Monitoring can be split into two substeps:
1.
Events identification
2.
Information Reporting
Events identification
The primary goal of the Analysis step is to identify any events or deviations from predefined limits ("excedences") that may have occurred during flight. These limits are determined by the combination of the aircraft limitations and the operator's flight operations procedures. Since there can be over 150 such events that must be checked for every flight, computer analysis software is used to scan for events where trigger values may have been exceeded. A the end of this substep qualified Flight Operation Analysts and System Engineer eliminate flight or events which are irrelevant (recorder or sensor problems, etc.) in order to not to populate the database with illogical events. Events that have been identified are stored for further analysis, in accordance with operator policy.
Information Reporting
In this substep the analysis software generates reports that yield statistical information, trend analysis, and risk assessment on a routine, periodic basis. If a third party has done the analysis and prepared reports these are sent electronically to the operator to assist them in interpreting flight data. Turning data into information is where the real value resides.
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本文链接地址：getting to grips with FOM Flight Operations Monitoring handb(30)
