What is the function of the accessory gearbox in a gas turbine engine?

• A. To drive engine accessories such as the fuel pump, lubrication pump, starter, electrical generator, and hydraulic pumps
• B. To regulate turbine inlet temperature
• C. To monitor blade tip clearance
• D. To manage exhaust gas recirculation

Answer: (A)

The accessory gearbox provides the mechanical power to run the engine’s external devices by taking drive from the engine’s core and delivering it to a set of accessories at the correct speed and pressure. It is driven off the high-speed spool through a drive shaft and gear train, which reduces the fast turbine/compressor speeds to a usable rate for components such as the fuel pump, lubrication pump, starter, electrical generator, and hydraulic pumps. This arrangement keeps fuel delivery, oil circulation, engine starting, electrical power, and hydraulic actuation functioning as the engine spins at different speeds throughout start and operation.

It isn’t responsible for regulating turbine inlet temperature, monitoring blade tip clearance, or managing exhaust gas recirculation, which are handled by other systems in the engine.