[bergesenha]

My best guess is fuel efficiency at small size scales and is probably the same reason that make them economical in large buses, but not small cars. The usual intuition is explained using the Reynolds number, a dimensionless quantity that can help to predict the possibility of maintaining laminar flow or wether the flow breaks down into turbulence in the generator, drastically reducing efficiency in the compression-combustion-expansion cycle. As a side note, when I did a type rating on the Eurocopter AS350, I learned that the gas turbine could also run on normal automobile gasoline instead of Jet-A 1 for a limited amount of time in emergencies with drastically reduced limits on altitude, torque etc...

[Zak]

It's my understanding that most gas turbine engines can be convinced to run on a wide range of flammable liquids, with some impact to performance and longevity. That the AS350 is actually designed to do so is interesting.