Honeywell ED-56A User Manual

SSCVR

SOLID-STATE COCKPIT VOICE RECORDER

PRODUCT DESCRIPTION

SSCVR

Solid-State Cockpit Voice Recorder

ED-56a Voice Recording System

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SOLID-STATE COCKPIT VOICE RECORDER Description

SOLID-STATE CVR PRODUCT DESCRIPTION

The Solid-State Cockpit Voice Recorder (SSCVR) combines the extremely high reliability of integrated
circuit memory technology with the most advanced protective enclosure in the industry. This equipment
fully satisfies the most recent FAA and EUROCAE Minimum Operational Performance Requirements
(MOPR) for Cockpit Voice Recorders used on commercial air transport and general aviation aircraft, whilst
allowing direct retro-fit into existing ARINC-557 installations. These specifications are:

•••• EUROCAE Documents ED-56, and ED-56a, October 1993

•••• FAA Technical Standard Order TSO C-123

•••• ARINC-557 and ARINC-757, Cockpit Voice Recorder (CVR), August 1993 (draft 2)

•••• JAR requirement for 2 Hour audio recording per ED-56a

In addition, the SSCVR currently includes provisions in anticipation of the following future legislation:

•••• Legislation making the recording of data linked air traffic control messages mandatory

via a dedicated ARINC-429 Input

The SSCVR utilizes a modular crash survivable memory unit (CSMU) for protection of the solid state voice
recording memory. The CSMU retains the most recent 30 minutes or 2 hours of audio, digital, and timing
information. Both Honeywell’s 30 minute and 2 Hour SSCVR models are approved to TSO C-123.

"State of the art" high density FLASH memory devices are combined with the use of mature industry
standard audio digitization and encoding integrated circuits (ICs).

•••• Provides a consistently high level of recording quality over the entire audio range.

•••• Avoids the risk and complexity of immature proprietary compression algorithms.

Figure 1 shows the SSCVR and its major features, while Figure 2 provides a simplified diagram showing its
major aircraft interfaces.

ED-56a Crash Survivable
Memory Unit (CSMU)
(30 min. or 2 hr. model)

Under Water
Locator Beacon

(ULB)

115Vac/28Vdc
Power Supply

ED-56a
Microphone Monitor

ARINC-757
Aircraft Interface

Controller Board
ED-56a Audio Processor

Figure 1: Solid-State CVR System, Major Features

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SOLID-STATE COCKPIT VOICE RECORDER Description

Microphone

Monitor

Mic. #1 Mic. #2

Rotor
Tachometer

Capt. Clock

14:30:15

Mic. #3

Narrow Band Audio

Rot. Freq.

Flight Data
Acquisition Unit

Test/Erase/Status
Composite Audio

Area Mic. (WB audio)

GMT

FSK Timing

SSCVR

Recorder

BITE

ATC

OMSCMU

Other Subsystem Provisions

Figure 2: Solid-State CVR, Major Aircraft Interfaces

The SSCVR is the most modern available, incorporating the latest interface characteristics defined in
ARINC 757. Audio interface provisions include one (1) wide band and three (3) narrow band channels
meeting the improved signal to noise and bandwidth characteristics specified in ED-56a. In addition to the
audio inputs, the SSCVR also records timing information from either of two sources, GMT from the
captains clock or FSK from the flight data acquisition unit. A dedicated tachometer input is provided for
recording of rotor speed in helicopter applications.

Both the 30 minute and 2 hour SSCVR currently include two ARINC-429 interfaces; one is reserved for
future recording of air traffic control digital message communications, and the second is provided for new
generation aircraft equipped with Onboard Maintenance Systems.

The SSCVR has been designed to achieve a high degree of reliability, as well as facilitating simplified
maintenance and minimal component sparing over competing models.

•••• High Mean Time Between Failure -

in excess of 10,000 hours predicted (per MIL-HDBK-217F) and
in excess of 20,000 hours field operation anticipated.

•••• No Scheduled or Periodic Maintenance is required.

•••• Consists of only (3) three Shop Replaceable Units.

•••• Dual voltage power supply provides fleet wide commonalty.

Extensive micro-processor based built-in-test greatly simplifies test and trouble shooting, thereby
minimizing technician training and support equipment costs.

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SOLID-STATE COCKPIT VOICE RECORDER Description

1.0 SSCVR DESIGN OVERVIEW

The SSCVR is a single Line Replaceable Unit (LRU) in a standard ARINC-404A style avionics form
factor. The SSCVR chassis includes three (3) Shop Replaceable Units (SRU's) and an optional underwater
locating device. SRUs include:

a) Interface and Control Board (ICB)
b) 115Vac/28Vdc Dual Voltage Power Supply (PS)
c) Crash Survivable Memory Unit (CSMU)
d) Under Water Locator Beacon (ULB)

The breakdown of major components and SRU accesses are summarized in Figure 3.

Handle or

Underwater Locator

Beacon (ULB)

CSMU Mounting Shelf

Interface & Control

Circuit Board (ICB)

ICB Access Cover

ULB Mounting

(4 Places)

Crash Survivable
Memory Unit (CSMU)

PS Access Cover

Power Supply (PS)

ARINC-404A

Chassis

ARINC-404A
Connector

Figure 3: SSCVR Exploded View Showing Major SRUs

All three SRUs are readily accessible without requiring major disassembly. The CSMU may be removed
from its mounting shelf by simply removi ng four bolts and releasing its mati ng connector. The plug-in
power supply may be accessed by removing the top (power supply) access panel. Access to the plug-in
interface controller board is accomplished by removing the bottom cover panel from the SSCVR chassis.

An optional under water locator beacon (ULB) approved to TSO C-121 is mounted on the front of the unit
and also serves as a handle. Four (4) mounting bolts firmly attach the ULB directly to the front of the
CSMU to avoid separation in the event of an incident. The mounting of the ULB also facilitates easy access
for replacement of its battery. If the SSCVR is purchased without the ULB, a hollow metal tube is mounted
in its place.

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