Which rotorcraft type uses engine-driven rotors for horizontal flight, with propulsion usually via propellers independent of rotor system?

Which rotorcraft type uses engine-driven rotors for horizontal flight, with propulsion usually via propellers independent of rotor system?

• A. Gyrodyne
• B. Gyroplane
• C. Helicopter
• D. Instrument

Answer: (C)

The key idea here is how lift and forward motion are produced in rotorcraft. In a helicopter, the main rotor is powered by an engine, and that same rotor provides the lift needed to stay aloft. By using the cyclic control to tilt the rotor disc, the rotor also generates a forward thrust component, allowing sustained horizontal flight. This is what differentiates a helicopter from rotorcraft that rely on an unpowered rotor (like an autogyro, where forward propulsion comes from a separate propeller) or from hybrids where the rotor is powered for takeoff/hover but a separate propeller handles cruise. So, the helicopter is the rotorcraft type that uses an engine-driven rotor to enable horizontal flight, with propulsion typically handled by a system separate from the rotor in some designs, while the core characteristic is the powered rotor providing the lift and flight torque.

The key idea here is how lift and forward motion are produced in rotorcraft. In a helicopter, the main rotor is powered by an engine, and that same rotor provides the lift needed to stay aloft. By using the cyclic control to tilt the rotor disc, the rotor also generates a forward thrust component, allowing sustained horizontal flight. This is what differentiates a helicopter from rotorcraft that rely on an unpowered rotor (like an autogyro, where forward propulsion comes from a separate propeller) or from hybrids where the rotor is powered for takeoff/hover but a separate propeller handles cruise.

So, the helicopter is the rotorcraft type that uses an engine-driven rotor to enable horizontal flight, with propulsion typically handled by a system separate from the rotor in some designs, while the core characteristic is the powered rotor providing the lift and flight torque.