Originally Posted by JohnBurke

An Operations Specifications isn't necessary to require a SIC under Part 135, in a single pilot turobjet multi-engineoperated under IFR, carrying passengers. The SIC is required under the regulation.

An operator requires authorization to do single pilot IFR with an autopilot in lieu of a SIC...

Passenger carrying operations under IFR, under 14 CFR 135:

https://www.ecfr.gov/current/title-14/section-135.101



Note that it doesn't matter if it's a single pilot airplane. The SIC is still required equipment. An exception is required (via OpSpec) if the operator desires to operate single pilot with passengers.

Operations Specifications authorization required for single-pilot IFR under 135, with autopilot in lieu of the SIC:

https://www.ecfr.gov/current/title-14/section-135.105



Having said that, Cutter has a high turnover, and is frequently advertising for pilots. Why might that be?