Question

Which of the following is not a thrust-producing powerplant?

(a) turbojet

(b) turbofan

(c) rocket

(d) piston engine

I got this question during an internship interview.

My query is from Thrust Producing Power Plant topic in division Aircraft Force Systems and the Equations of Motion of Aircraft Performance

Answer 1

Correct choice is (d) piston engine

To elaborate: The two forms of powerplant used in aircraft propulsion are thrust-producing and power producing. A thrust-producing powerplant is the one whose propulsive force is obtained by increasing momentum of the airflow through the engine. Examples of thrust-producing powerplant are turbojet, turbofan and rocket.