The Solid State Cockpit Voice Recorder (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.  The SSCVR interface provisions include one wide band and three narrow band audio channels; dedicated rotor tachometer input; FSK and GMT time recording; and two ARINC 429 interfaces for future ATC Data Link and optional On-board Maintenance System (OMS).