DFDR
(Digital Flight Data Recording System)
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DFDR (Digital Flight Data Recorder)
DFDR Presentation
DFDR Architecture
DFDR operation
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DFDR Presentation
 Record various critical flight
parameters in a solid state
memory to fulfill the mandatory
requirements of crash recording.
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DFDR Architecture
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DFDR Architecture
1. Flight Data Interface Unit (FDIU):
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It is the heart of the DFDRS.
The FDIU acquires, formats and supplies the
SSFDR with the mandatory parameters from
various aircraft systems.
The Centralized Fault Display Interface Unit
(CFDIU) is connected to the FDIU for system
test and failure data purposes.
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DFDR Architecture
2. Solid State Flight Data Recorder (SSFDR):
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Stores in a solid state memory located in a
crash and fire protected housing, the data of
the last 25 hours collected by the FDIU.
It is located in the unpressurized area of the
rear fuselage.
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DFDR Architecture
3. LINEAR ACCELEROMETER:
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located close to the aircraft Center of Gravity.
The Linear Accelerometer measures the
acceleration of the aircraft in all three axes (X,
Y, Z).
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DFDR Architecture
4. The System Data Acquisition
Concentrators (SDACs):
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digitalize the analog signal of the Linear
Accelerometer and then send it to the FDIU.
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DFDR Architecture
5. DFDR EVENT PUSHBUTTON
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record an event mark in the SSFDR memory.
It is located on the cockpit center pedestal.
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DFDR Architecture
6. GND CTL PUSHBUTTON
− The (GND CTL) pushbutton enables the
SSFDR to be supplied, via the power
interlock circuit, when the aircraft is on the
ground for preflight check before engine
start or for test and maintenance purposes.
− It is located on the Recorder (RDCR) panel
of the overhead panel.
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DFDR Architecture
7. Quick Access Recorder (QAR)
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Records the same parameters and is supplied in
the same conditions as the SSFDR.
The recording is made on a magnetic tape or
an optical disk. In case of an optical disk
storage media, the QAR is called Optical QAR
(OQAR).
The QAR is dedicated to ground performance,
maintenance or condition monitoring tasks.
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DFDR Operational Conditions
1. In flight (Auto).
2. On ground (Auto).
A - Work after the 1st engine run.
B - Still working for 5 min after 2nd engine shut
down.
3. On GND (Manual) from GND CTL
pushbutton.
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