The powerplant converts what type of power?

• A. Mechanical power to chemical power
• B. Electrical power to mechanical power
• C. Chemical power to mechanical power
• D. Thermal power to electrical power

Answer: (C)

The engine’s job is to take the chemical energy stored in the fuel and convert it into mechanical energy that drives the propeller. When fuel combusts, energy is released as heat and pressure, pushing pistons or turning turbine blades, which then produces shaft or propulsion power. That makes chemical power being transformed into mechanical power the correct description of a powerplant. The other options describe different energy conversions (mechanical to chemical, electrical to mechanical, or thermal to electrical) that aren’t how a typical aircraft powerplant operates.