Which of the following best describes the PT6B-37A engine type?

• A. Turbojet
• B. Piston
• C. Turboshaft
• D. Hybrid

Answer: (C)

The PT6B-37A engine is a turboshaft engine, which is designed specifically for use in helicopters and other rotorcraft. Turboshaft engines are characterized by their ability to convert the thermal energy from combustion gas into mechanical energy, which is then used to drive a shaft that powers the rotor system. This makes them particularly suitable for applications requiring high power-to-weight ratios and efficient performance at varying power levels.

In a turboshaft configuration, the engine focuses on delivering power to a rotor rather than generating thrust directly, as seen in turbojet engines. This structure allows for smooth operation and efficient use of fuel, which is vital in aviation, especially in helicopters like those powered by the PT6B-37A.

The other choices—turbojet, piston, and hybrid—do not accurately describe the functional characteristics or applications of the PT6B-37A engine, which is solely designed as a turboshaft engine to meet the specific needs of its operational environment.