What do propellers do?

• A. Absorb fuel to reduce weight
• B. Absorb power from the engine and convert the energy into aircraft forward motion
• C. Store energy for later use
• D. Increase airspeed by generating lift

Answer: (B)

Propellers transform engine power into forward thrust by spinning blades that push air backward. As the blades accelerate a mass of air rearward, a reaction force pushes the airplane forward. The propeller is taking energy from the engine (shaft power) and delivering it to the air as kinetic energy, with the result being thrust that drives the aircraft ahead. They don’t store energy, they don’t absorb fuel to shed weight, and their job isn’t to generate lift—that’s the role of wings or rotor blades, while thrust from the prop pushes the airplane forward.