• FAA recommends airlines preserve cockpit-voice recordings after safety incidents.
• Guidance is voluntary, not mandatory, despite NTSB urging action.
• Pilots can preserve audio by pulling circuit breakers.
• NTSB has long flagged issue of missing CVR audio in investigations.

The FAA's guidance may indicate a growing concern about data preservation in safety investigations. The voluntary nature of the recommendations suggests the agency could be balancing regulatory oversight with industry flexibility, which may impact the effectiveness of the guidance. The issue of missing CVR audio could have significant implications for safety investigations and may lead to further regulatory action.