What type of pump is the low pressure engine driven pump in the PC-12?

The correct choice identifies the low pressure engine driven pump in the PC-12 as an accessory gearbox pump. This type of pump is directly connected to the aircraft's engine through the accessory gearbox, which allows it to operate efficiently by using the engine's power to provide the necessary hydraulic pressure for various systems. Accessory gearbox pumps are designed to deliver hydraulic fluid to critical components, such as flight control surfaces and landing gear systems, ensuring proper functionality and safety during flight operations.

In contrast, hydraulic pumps typically refer to systems that generate hydraulic pressure but may not specifically denote the engine-driven aspect within an accessory gearbox. Thermal expansion pumps operate on a different principle, involving temperature changes to move fluids, which is not applicable in this context. Vacuum pumps are utilized to create a vacuum for various instruments and systems but are distinct from hydraulic functions.