What are the three interconnected fuel pumps within the accessory gear box?

What are the three interconnected fuel pumps within the accessory gear box?

• A. Low Pressure Pump; High Pressure Pump; Motive Flow Pump
• B. Fuel Pump A; Fuel Pump B; Fuel Pump C
• C. Primary Pump; Secondary Pump; Tertiary Pump
• D. Low Pressure Pump; Medium Pressure Pump; Motive Flow Pump

Answer: (A)

Fuel delivery from tanks to the engine in an engine’s accessory gearbox relies on three pumps working together. The low-pressure pump provides the initial, bulk flow of fuel to the system, feeding the high-pressure pump and the motive flow pump. The high-pressure pump takes over to raise fuel to the pressure needed by the engine’s fuel control and nozzles, supplying the primary engine fuel pressure. The motive flow pump uses the pressure differential to create additional flow, aiding priming, circulation, and scavenge during start and steady operation. This trio—low-pressure, high-pressure, and motive flow pumps—keeps fuel moving and properly pressurized across all phases of flight, which is why this combination is the correct one.

Fuel delivery from tanks to the engine in an engine’s accessory gearbox relies on three pumps working together. The low-pressure pump provides the initial, bulk flow of fuel to the system, feeding the high-pressure pump and the motive flow pump. The high-pressure pump takes over to raise fuel to the pressure needed by the engine’s fuel control and nozzles, supplying the primary engine fuel pressure. The motive flow pump uses the pressure differential to create additional flow, aiding priming, circulation, and scavenge during start and steady operation. This trio—low-pressure, high-pressure, and motive flow pumps—keeps fuel moving and properly pressurized across all phases of flight, which is why this combination is the correct one.