//Surely these are standard items that come with this type of
conveyance.//
The rules:
Flight Data Recorders.
Required for:
• Multiengine turbine-powered airplanes or rotorcraft seating 10+ passengers
• Multiengine turbine-powered airplanes or rotorcraft seating 6+ passengers and requiring two pilots
[plus some others which do not concern us]
Cockpit Voice Recorders.
Required for:
• multiengined turbine-powered rotorcraft seating 20+ passengers
• multiengined turbine-powered planes and rotorcraft seating 6+ passengers and requiring two pilots
[plus some others which do not concern us]
The aircraft was a Sikorsky S-76-B. It has two engines but requires only a single pilot. There are various configurations of seating but I believe the one involved had eight passenger seats. So, neither were required.