An ATP can conduct training under an approved training program for an aircraft operating under a crew requirement. There might be now, but when I looked into this a few months back, there was NO approved training program for a C510 SIC outside of Part 135 operators approved OPSPEC. As far as part 91 goes, you can get a C510 SIC endorsement but your hours really don't count for anything. Under 135 they count
Correct. This is also how I understand this. I'll get my SIC endorsement but my hours still will not count for anything. But, the experience is still worth something for interview purposes, just not on paper.
I am still teaching as a CFI on my days off. That keeps me current.
Here is how I decided to handle my C510 experience:
My C510 time goes into my "experience" logbook. This logbook I just purchased to show flights where I can not officially log the time since we fly under Part 91, even though I am an acting crew member. I log the flight date, tail number, total turbojet time, total flight time, approaches (only when I do them), IFR time (only if I was the pilot flying), and landings (only when I do them). This is certainly a good resume builder and good to talk about in an interview, but I do not count this time on any application or in my total time in any way.
Then of course my CFI time or any time where I can log PIC or SIC, that goes into my professional logbook.
Now once we purchase the Beechjet XT or the Citation IV, I'll go to Simcom or Flight Safety to get my SIC and then I will finally be able to log the time in my professional logbook as SIC. I look forward to that day.