Snanceki..
How does fuel get from the CWT to the engines?
a. Via the wing tanks (i.e.pumped from CWT into the wing tanks then out again using the wing tank pumps) OR
b. direct from the CWT to a rail / manifold etc common with the output from the wing tanks, with the higher boost pressure from the CWT pump giving it priority to supply the engines?
Anybody got a pic?
How many boost pumps (not water scavenge) are there in the CWT. 1 or 2 (1 LH and 1 RH)?
JFI is this a 777 specific or standard approach to engine fuel supply management?
The engine fuel feed line is split into two. Left and Right. These are connected by Crossfeed valves, two in parallel, normally closed.
There are two CWT Boost pumps. They feed into this line,one each side of the crossfeed valves. These pumps have a higher supply pressure than the wing tank boost pumps and so are the preferred supplier of engine fuel when they are running.
This system of fuel supply is normal in twin engined jet aircraft. The B737 B757 and B767 are basically identical. The A320 in nearly the same.