Fuel Systems Quiz

Fuel Systems

• If the swash plate of a positive displacement swash plate pump is perpendicular to the axis of the pump, the flow will be zero.
• A spring moves the swash plate away from the minimum stroke position.
• The burner fuel flow is at maximum at I.S.A. sea level.
• Servo pressure, which is used to control fuel pump swash plate angle, is obtained from pump delivery pressure through variable restrictions.
• If the B.P.C half ball valve in the servo line sticks open, it will cause an increase of fuel flow, therefore an increase in RPM.
• An A.C.U is fitted to a gas turbine engine to limit the rate of increase in fuel flow during sudden acceleration.
• If fuel pump servo pressure is reduced, pump output will decrease.
• The B.P.C is fitted in a gas turbine engine fuel system to vary pressure pump output in relation to the pressure variation at the intake.
• A kinetic valve is a device used to control H.P pump output, achieved by movement of a knife blade.
• Specific fuel consumption at altitude will increase.
• During any stabilised running condition, the spill or half ball valve is lightly seated.
• The purpose of the attenuator fitted between the H.P fuel pump and the B.P.C in a fuel system is to damp out pulsations in the fuel delivery to the B.P.C.
• The hydromechanical governor is fitted to a gas turbine engine fuel pump to enable the engine to operate over a wide range of fuel SGs.
• A barometric Pressure Controller controls fuel flow to suit atmospheric pressure changes.
• Kinetic valves are used because they are more sensitive.
• When considering a centrifugal type engine speed governor, an increase in fuel S.G. will cause a reduction in maximum RPM.
• On a FADEC engine, A channel uses a separate winding of the control alternator to B channel.
• Normal fuel/air ratio for successful combustion is 15:1.
• The purpose of the L.P. pump is to prevent cavitation of the H.P. Fuel pump.
• The fuel pump plungers are lubricated by the Fuel.
• Which forces control the maximum RPM governor in a non-hydromechanical swashplate type of pump? Rotor centrifugal pressure opposed to tension spring loading.
• The holes in the body of the duple burner provide air to the shroud around the burner head to minimise carbon formation on the burner face.
• A fuel heater prevents LP filter icing.
• On a FADEC engine, the E.E.C. has electronic control of the hydro-mechanical fuel control unit in all modes.
• During normal running conditions, combustion is self-supporting.
• On a FADEC engine, the channel reset selects standby which becomes active on the next start.
• With a decrease in fuel SG, what is the result when the engine is fitted with an uncompensated fuel governor? Maximum RPM increase.
• The maximum RPM of a turbine engine is limited by reduction of the fuel pump stroke by a spill valve sensitive to centrifugally generated fuel pressure.
• To what condition does the fuel flow respond during aircraft acceleration? Mass airflow rate through the engine.
• During acceleration, the fuel flow is increased at a controlled rate in order to prevent surge and the risk of flame-out.
• The B.P.C controls the F.C.U by pressure sensing.