Is the Robinson R66 helicopter safer than the R44?

Some pilots refuse to fly piston-engined helicopters, preferring turbine-powered machines. Their argument is that turbine engines are much less likely to fail in flight than piston engines.

Does this mean that the Robinson R66 with its Rolls-Royce turbine engine is a safer helicopter than the Robinson R44 with its Lycoming piston engine?

Not according to Robinson.

Robinson has for years taken the contrarian view, suggesting that pilots are actually safer in piston-powered helicopters. While the large turbine engines used in passenger planes are incredibly reliable, the small turbine engines used in helicopters are not.
According to Robinson, accident statistics favor piston helicopters.

Turbine engines have a reputation for being extremely reliable, but physically small turbines, such as those used in low-power helicopter engines, are subject to high thermal loads and are not as reliable as the turbines in, for example, Airbus aircraft. Piston engines are notorious for their failure rates, but that's a theory that comes from the days when engines were run at 100 percent power. The R44 demonstrates the greatest reliability that can be obtained from a piston engine. The Robinson R66 and similar light turbine helicopters demonstrate the least reliability that can be obtained from a turbine engine, especially when you consider the need for a very advanced gearbox (the turbine spins at up to 50,000 rpm; the helicopter rotor spins at about 400 rpm).

Robinson has always sidestepped the subject, saying nothing about the lower reliability of the R66 or the higher reliability of the R44.

The decision to use a turbine engine really had nothing to do with reliability. The data showed that the Lycoming 0-540 in the R44 was extremely reliable.

If Robinson believed that small turbine engines were less reliable than piston engines, why did Robinson introduce a turbine helicopter in the first place?

According to Robinson, the market needed a helicopter with better high-altitude performance and a better power-to-weight ratio. Many customers wanted a helicopter that could use jet fuel, as avgas was becoming increasingly difficult to obtain in some parts of the world. Only a turbine-powered helicopter could meet these requirements.

In short, spending a lot more money on the R66 would not provide an additional margin of safety.

In fact, if you believe what Robinson has been saying about small turbine engines for the past twenty years, the R66 should prove less reliable, and therefore less safe, than Robinson's cheaper piston version.