Purpose of this Document

This document is intended to provide design guidance for the development and installation of a new generation of Cockpit Voice Recorders (CVRs) which may utilize solid state memory and employ analog to digital conversions and related voice encoding techniques. The document supersedes the earlier ARINC Characteristic 557 and covers the overall Cockpit Voice Recorder system requirement but does take into consideration the detailed audio distributing system in the aircraft. The Cockpit Voice Recorder will be utilized to record aural communication between crew members and record the sounds of the acoustical environment of the cockpit. Attachment 1 shows a general system block diagram and the interfaces to the Cockpit Voice Recorder. The document provides specific guidance for the installation and for information to ensure customer controlled interchangeability of the equipment in a standard aircraft installation. Further, it assists in the functional verification and retrieval of the recorded information.