Or you can just do what's already done: drive a propeller off the turbine. Which is what's done in turboprop engines, the most efficient airplane propulsion sys

Or you can just do what's already done: drive a propeller off the turbine. Which is what's done in turboprop engines, the most efficient airplane propulsion system available. Nothing is more efficient under power; turbines are only inefficient at low power settings (descents, taxiing, etc.)