Although not a mainstream sim, FlightGear is a terrific tool and a great sim -- not just for those that can't afford one of the more "commercial" sims but mostly because the flight model is pretty good.
Our friends over at FGUK are always developing new stuff for FlightGear and they have came out with this new release that brings a whole new level of realism to helicopters in this sim.
Where to get the FGUK Gazelle for FlightGear
You can get the Gazelle for FlightGear here.
