What i did to save my flight was crossfeed and turn on center fuel pump and then start my engines is this the proper procedure?Next time am I supposed to kick in the center tank cross feed before reaching no fuel in the left and right tank?As sophisticated as the FMC is why did I get no warning about this not even insufficent fuel?P.s. I love the FMC just curious though!

Hello Joe!First of all: engine-out due to fuel is not a failure but an engine flame-out ;-)Nothing failed in that perfectly working engine... :-)It seems, that you don't use your center tank first.You should. Maybe even must (aircraft limits).Center tank needs to be emptied first, always. This is due to the stress from wing to fuselage.Switching those two centertank fuel pumps on, will override the fuel coming out of the wingtanks. When the center tank is empty, the fuel from the wingtank automatically starts feeding to the engines.With the centertank empty, the centertank pumps will have low pressure on the low end and thus the lights come on on the overhead panel. That's where you switch them of.Using wingtanks only will presume you have no fuel in the center tank. That's why there is no warning or caution light for that.regardsTeeloo

thank you.so when preparing aircraft all fuel pumps need to be on, b4 departure then ener tank will burn 1st?as far as cross feed valve shuld be closed? straight position until center tank empty?

Yes if you do have center tank fuel (depends on how long your flight is) you need to have all pumps on.No need to use the crossfeed valve in normal flight.It is only used in unusual situations.regardsTeeloo

Crossfeed valves are also used inflight during ETOPS - pilots are required to perform a 'crossfeed valve check' during these operations.Good thing to implement in your flights if you are serious about the NG.