Engine Starting without Fuel switches on

[Guest robfather]

Hi All,Just a quick question regarding the ability to start the 737 with fuel switches in the off position. Can't find any relevant info so am assuming that the engines are gravity fed if we can start them without the fuel pumps on. Anyone have any idea's?ThanksRob

[Guest threedeltamax]

Which fuel "switch" are you talking about? The Fuel boost pump Switches? It is entirely possible to start the engines without the fuel boost switches on, as there is a low-pressure pump driven by the engine that will produce flow. It is not possible to start the engines with the fuel cut-off levers closed - as the name suggests, it cuts off all fuel, which would prevent engine starting.

[Guest robfather]

Hi,Yea, was talking about the fuel pump switches, not the valve cutoff. Thanks for the info.Rob

[Qavion 19]

...but (for info) the suction/gravity feed system can't suck fuel out of the Center Tank.Cheers.Q>