The engine-driven fuel boost pump mounted on the accessory module of the engine is driven by which section of the engine?

• A. N2 section
• B. NG section
• C. N1 section
• D. Piston section

Answer: (B)

The engine-driven fuel boost pump on the accessory module is powered by the engine’s gas generator section via the accessory drive gearbox. This gear train is connected to the Ng spool, the rotational speed of the gas generator, so as the engine spools up to start and continues to run, the pump receives the mechanical drive needed to supply fuel under pressure. The other spools—N1, N2—and the piston section refer to different parts of the engine’s rotating assemblies and do not drive the accessory gearbox in this configuration. Connecting the boost pump to the Ng spool ensures a reliable fuel supply from start through normal operation.