DISTRIBUTION - DESCRIPTION AND OPERATION

** ON A/C NOT FOR ALL

1. General
The fuel distribution components supplies the fuel for engine operation.

Fuel Distribution - Components

** ON A/C NOT FOR ALL

2. Component Description

A. Main Fuel Pump (MFP)
The two main functions of the MFP are:

To give fuel pressure and flow
To protect the fuel system from over-pressurization with bypass valve.

The MFP is installed on the Accessory Gear Box (AGB).

B. Main Fuel Filter (MFF)
The main function of the MFF is to remove contaminants from the fuel.
The MFF is installed on the fan frame.

C. Servo Fuel Heater (SFH)
The main function of SFH is to heat the fuel entering the servo valves of the Split Control Unit (SCU)/Servo Valve Assembly (SVA) and of the Fuel Metering Unit (FMU) by using oil as a heating medium.
The SFH is installed on the fan frame at 10 o'clock position.

D. Fuel Supply Hose
The fuel system hoses consists of the main fuel supply line and the Fuel Return to Tank (FRTT) line and the necessary mounting hardware.

E. Fuel Nozzle
The main functions of the fuel nozzle are:

To distribute and atomize fuel into the combustion chamber
To inject fuel into the main air premixer flow through main manifold
To spray fuel into the pilot air swirler flow through pilot primary manifold.

There are 19 nozzles installed to the combustor case, with the atomizing spray tip located inside the combustor.

F. Fuel Return Valve (FRV)
The functions of the FRV is:

To allow more cold fuel to be delivered to the IDG oil cooler in case of hot oil temperature
To regulate the level of fuel flow being returned to the fuel tank.

The FRV is installed on the fan frame at 10 o'clock position.

[Rev.10 from 2021] 2026.04.01 03:03:47 UTC