Before diving into the performance section of the RFM check out the rest of it first. If it does not offer you the opportunity to cruise on one engine then at least check it out with the regulators before going down that road. In the UK, and probably in the rest of EASA-land you would have to demonstrate in your Ops Manual that the risks involved are in no way increased - which is a bit tricky!!!
I know of only one twin helicopter certified for single engine flight and that is the independently developed 'Gemini' version of the Longranger which, if my memory serves me right was eventually taken over by Bell. I assume this unique approval was due to the fact that it was originally certified as a 'single' and the second engine was an addition.
G
