Originally Posted by tanker

In the case of PlaneSense the OpSpecs requires the SIC at all times, even under Part 91. Prior to the change in the regs it didn't matter what the OpSecs said because the FAA under Part 91 considered the SIC as a passenger not a required crewmember. Now with the change in the Regs as long as the OpsSpecs require a SIC for 91K and 135 then the SIC is also required for 91 and the FAA considers the SIC a required crewmember at all times. Therefore all flight time is loggable.