The world’s best-selling helicopter is currently the Robinson R44. Now Robinson are selling the turbine-powered R66. If the success of the R44 is any measure, one might expect the R66 to do similarly well.
Reciprocating aircraft engines are designed to use leaded fuel, and there are efforts to ‘get the lead out’. New fuel formulas must be compatible with existing engines. There are a few Diesel engines flying, but they are relatively few. And there are jets. Jet-A is what turbines run on, and it’s very close to Diesel fuel. The bad news is that turbines burn more fuel (23 gph in the R66 vs. 15 gph in the R44). The good news is that it’s cheaper than avgas. The bad news is that the supply of petroleum is finite. The good news is that Diesel fuel can be made from plants and animals. ISTM that what may become the world’s best-selling jet-powered helicopter might be a good consumer of biodiesel. It would demonstrate the viability of the fuel and contribute to the ‘greening’ of aviation.
How hard would it be to certify a turbine engine, specifically the Rolls-Royce RR300, to run on biodiesel fuel? I’m asking about actually running the engines reliably, and not just the official certification. What are the technical/chemical issues?