The LDR simultaneously records:
−
One channel of audio from the pilots Audio Control Panel (ACP). The latest 120 minutes of recorded audio is
retained. This data is stored in a crash-protected flash memory partition segregated from the flight data.
−
One channel of audio from the Cockpit Area Microphone (CAM). The latest 120 minutes of recorded audio is
retained. This data is stored in a crash-protected flash memory partition segregated from the flight data.
−
One channel for flight data information received from the Modular Avionics Unit (MAU) by ARINC 717. The
latest 25 hours of ARINC data at a rate of 256 words per second is retained. This data is stored in a
crash-protected flash memory partition segregated from the audio data.
The LDR provides an internal method of correlating the voice and flight data to within ±1 second.
2
Description
The LDR system includes:
−
An LDR unit installed aft of the pressure bulkhead between frames 36 and 37 and directly bolted to the
airframe.
−
A CVFDR panel installed on the co-pilots auxiliary panel, has the components listed as follows:
●
A CV ERASE/CVFDR TEST rocker switch, which has two positions as follows:
−
CV ERASE - Used to erase the recorded voice data.
−
CVFDR TEST - Tests if the LDR is powered ON and serviceable.
●
A CVFDR TEST LED: The LED comes on when the CVFDR TEST rocker switch is operated and the
LDR is powered ON and serviceable. The LED goes out when the CVFDR TEST switch is released. If the
LDR is not powered ON or has a fault, the LED will not come on when the CVFDR TEST rocker switch is
operated.
−
A CAM: Installed on the lower sidewall right-hand panel in the flight compartment.
−
A 5A CVFDR POWER Circuit Breaker (CB) mounted on a bracket installed on frame 37 adjacent to the LDR.
The LDR is housed in an 203,20 mm (8 in) deep, 61 mm (2.40 in) wide and 125,22 mm (4.93 in) tall case that is
painted international orange. The Crash Survivable Memory Unit (CSMU) is moulded into the side of the LDR unit
adding an additional 37,59 mm (1.48 in) to the width, which creates a total LDR unit width of 98,55 mm (3.88 in).
The LDR unit contains the Interface Circuits and Processing Module (PM) which monitor and control the data and
voice acquisition signals. The PM, also constantly monitors the LDR for faults and continually updates the “Fault
State” in the CVFDR (LDR) Status page. If a fault is detected, the PM records the fault and switches OFF the signal
to the CVFDR TEST LED, so when the CV ERASE/CVFDR TEST rocker switch is selected to CVFDR TEST, the
LED does not come on, thus indicating to the user that a fault condition has occurred.
The CSMU uses 8 GB of non-volatile flash memory to record data.
The LDR unit is powered by a 28 VDC supply, provided from the Battery External Power Junction Box (BEPJB) and
routed through the CVFDR POWER CB.
The LDR connects to the aircraft through a DB50 interface port.
The LDR System Clock (CMOS) is powered by a BR1225 coin type battery, which has a life expectancy of more
than 10 years.
PC-12/47E AMM Doc No 02300, ISSUE 01 REVISION 26 MSN 545, 1001-1719,
1721-1999
12-B-AM-00-00-00-I
UNCLASSIFIED
Effectivity: All
12-B-31-30-01-00A-040A-A
UNCLASSIFIED
2021-12-04 Page 2
