there is no SIC checkride. and you dont actually need an SIC type rating to act as SIC.... but you can get one if you want.
As far as I know.. for him to be able to act as a crewmember during 135 legs, he has to have a 135 checkride. Check out 135.293. If no checkride is required what would stop me from having a random commercial-multi rated pax jump up front, take my place, and have a try at a landing or two.
The OP didn't say it was part 135, I guess I was assuming it is part 91.
When I was acting as SIC for a 135 company we needed to complete a 135.293 check (same as the PIC check). We did not need to do the 135.297 check, but the company made us complete the 61.57 check to stay current.
Thankyou!
8900 3-1279 said:[FONT="]G. [/FONT] SIC Qualification in Aircraft Not Requiring an SIC. The basic qualification module for an SIC in any operation (VFR or IFR) for which no SIC is required by regulation is either an instrument proficiency or VFR competency check in any aircraft of the same category and class and the written or oral test required by § 135.293(a)(2) for the type of aircraft involved.