flydog...
you are correct about the SOP/GOM and logging SIC hours in a single pilot airplane... However...
I believe what makes it all legal is the fact that SIC'c (at least at Airnet) are "assigned crewmembers" specific to certain flights therefore making them "required crewmembers". I believe, I could be wrong about this next part, that it also has to do with operating 135 with pax and the use of auto pilots. I know there is a reg that requires 2 pilots flying pax in IFR conditions if an auto pilot is not installed or working. Now as we all know Airnet is a freight company, but we do have the capability of carrying jumpseaters, who are then pax, on our aircraft which brings that whole reg into play. Now how often do we put a jumpseater on a plane with a PIC and an assigned SIC, well not too often, but i have done it. We just put the third seat on the rails in the back of the old baron, place all cargo in a separate area from the pax, and then you have a plane that meets the far's.
All in all, it has to do with the fact that our ops manual gives us the right to have an SIC on board a single pilot aircraft and the fact that the SIC's choose a run to stay on and then are assigned as a "required crewmember", all the while letting him log SIC for the time he operates the radios and does the co-pilot duties. Now don't forget that we switch legs, so the time the SIC is flying he logs as PIC and the capt does the radios and the co-pilot duties.
Overall though, i believe you could operate your 172 with 2 required pilots if you wanted to. Just remember, as someone above pointed out, we have a very good "friendship"...if you want to use that horrible term... with the FAA, and our company is continuously talking with them to approve things and make sure everything is legal that we do, and if you were patient enough with the FAA you could make it work with your 172. By the way, how much would you pay? Make me a GOOD offer and let's go from there.
If all the above is completely off base and makes no sense, just understand i have been dealing with my 16 month old all day and i can barely see the screen i am so beat!!!!!