John D. Yarrow (Website: Build a Throttle) found a copy of the sim.
"One of the better points of being the tech at a second-hand computer store is the chance to stumble upon the occasional "antique". Today someone sold us some old stuff and it included the Sierra 3D helicopter sim, on the original 360K disk. In fact, I had to re-install a 51/4" drive to read it. What a shock! While it doesn't feel very happy running on my 533, it did run (in DOS). This thing was actually designed around a 4-axis controller system! Cyclic, Collective AND pedals! While the flight model wasn't up to FS2000, it probably would have been better on more familiar turf, say a 386.
According the readme file, even if you loaded it up as an Apache, it still flew as a Robinson R22. So I guess that's the basis of the flight model."