Hi Nigel..
Well.. it's 6 of one.. half a dozen of another mate. Real World fuel loading would put equal amounts of fuel in each tank and any extra would be put into the inner tanks. FlyNET loads the inners first and moves outward if the fuel requirement is more. If it IS more.. engines 1 and 4 will not cut and you can continue on your way with the minimum of fuss ;-) You will NOT.. to the best of my knowledge.. have an engine out situation by running the outers dry in flight as the fuel demand is continuous so the inners will takeover automatically. I've never had this happen anyway
What the model doesn't like is having fuel in the outers then suddenly no fuel in the outers which is what happens when FlyNET loads fuel so if you start with engines running, to pre-empt the 'engine out'.. open the inter-engine cocks (on the pedestal) then close the outer boost pumps (lower right panel) FIRST. Of course.. if you start from cold.. this hardly matters though the inter-engine cocks and boost pumps will still have to be operated to enable fuel to get to the outer engines ;-)
It all sounds kinda complicated but it isn't really and once you've done it a couple of times.. you know what to expect and it stops embarrassing situations where you're 'live' on FlyNET and stuck on the end of the runway with only 2 engines running and can't start the outers

I can't remember off the top of my head if crossfeed is required on the Viscount but my guess is that it's not. Crossfeed is only used if you get a fuel imbalance (which you will NOT get unless FlyNET induces an engine failure) and should this unlikely event happen.. you can either sit tight and put up with it or manage the fuel by opening X-FEED and turning off the boost pumps from the 'light' side until the fuel remaining is equal. Neither the Viscount or Vanguard are able to transfer fuel so crossfeed is the only way out of a fuel imbalance situation.
Re the boost pumps..
All these do is pump fuel from a tank to an engine. In a 'normal' situation.. (make that real world).. tank 1 will feed engine 1.. tank 2 will feed engine 2 e t c. If you have no fuel in tank 1 or 4 (which is a likely startup scenario in FlyNET unless you are travelling a distance requiring more fuel than can be carried in tanks 2 and 3).. you open the inter-engine cocks and close the outer boost pumps to allow engines 1 and 4 to draw fuel from the inner tanks. You turn the outer boost pumps off to stop them pumping air. No fuel.. no boost pumps ;-)
Good ere innit!
Should you decide at some point to take the Vanguard on.. exactly the same applies ;-)
ATB
DaveB :tab: