The Airbus A330’s Digital Flight Data Recording System (DFDRS) is an integrated system designed for recording critical flight parameters. This system is crucial for both regular operation monitoring and investigation in the event of an incident.
At the heart of the DFDRS is the Flight Data Interface Unit (FDIU), a part of the Flight Data Interface Management Unit (FDIMU), which is primarily located in the avionics bay. The FDIU’s role is to collect various aircraft system parameters and process them internally. These parameters are then transmitted to the Digital Flight Data Recorder (DFDR) for recording. The FDIU also sends a time reference signal to the Cockpit Voice Recorder (CVR), ensuring synchronization between the voice and flight data.
The DFDR, positioned in the aft part of the aircraft, is a critical component. It stores data in a solid-state memory, capable of holding the last 25 hours of flight data. This memory is housed in a protected box, and the DFDR is equipped with an Underwater Locator Beacon (ULB) for recovery in the event of a crash at sea.
A Linear Accelerometer (LA) is also part of the system, installed at the aircraft’s center of gravity. It provides the FDIU with three-axis acceleration data, crucial for understanding the aircraft’s movements and orientation during flight.
The system includes an EVENT P/B located on the cockpit center pedestal. This button, when pushed, marks specific events in the DFDR’s memory, making it easier for technicians to locate and analyse specific incidents or periods of interest within the recorded data.
Optionally, an aircraft can be equipped with a Quick Access Recorder (QAR). This recorder, which uses optical disk storage, duplicates the DFDR parameters for easier access and analysis, particularly useful for performance or condition monitoring.
The power supply to both the DFDR and QAR is controlled through an interlock circuit. The DFDR automatically receives power when an engine is started and shuts down five minutes after the last engine stops. For maintenance or preflight checks, power can be supplied to these systems via a control switch on the overhead panel.
Additionally, the Aircraft Condition Monitoring System (ACMS) is a significant part of the architecture, designed to monitor engine, Auxiliary Power Unit (APU), and aircraft performance. It helps in troubleshooting and assists in scheduled maintenance. The system collects and processes data, which can be accessed through the Multi-purpose Control and Display Unit (MCDU), removable memory, or printed directly on the aircraft printer.
The ACMS comprises several components, including the Data Management Unit (DMU) within the FDIMU. The DMU is responsible for collecting, storing, and processing various data from the aircraft systems. This data can be stored internally, on a PCMCIA card, or in a Digital ACMS Recorder (if installed). The system generates various condition reports and supports the Smart ACMS Recorder function for compressed data recording.
The Flight Data Interface Management System (FDIMS) controls the FDIMU, integrating the FDIU and DMU with a PCMCIA interface into a single Line Replaceable Unit (LRU). These components work independently but are housed together for efficiency.