The turboprop engine is described as providing about how many horsepower per pound of weight?

• A. 5 horsepower per pound
• B. 0.5 horsepower per pound
• C. 2 1/2 horsepower per pound
• D. 1 horsepower per pound

Answer: (C)

Specific power, horsepower per pound, is a quick way to gauge how much power an engine delivers for its weight. A turboprop uses a gas turbine to drive a propeller, and this arrangement tends to yield a relatively high power-to-weight ratio. In practice, turboprops are described as providing about two and a half horsepower for every pound of engine weight, reflecting the efficient conversion of turbine energy into shaft power for a lightweight package. That’s why the value around 2 1/2 horsepower per pound is the best match for this question. Values like five horsepower per pound would imply unrealistically high power for the same weight, while 0.5 or 1 horsepower per pound would be too low for typical turboprop designs.