A question about the normal procedures..

[Bearcat]

On page 122 it states to set the fuel selector valve to the Main Tank L.H. ... Why not the center tank? Just curious.. Yesterday and today were the first chances I had to really sit down and read this thing and start getting into it.. I'll be tearing my PC down soon for the move in 2 weeks but I wanted to get a leg in there.. so far I have just gotten a toe in and I'm lovin it... I'm saying to myself.. I am wowed by the little I have seen I may be in trouble once I move and get settled in and actually have some time to really get into this..

[EvilBivol-1]

The P-51D has a fuel relief valve that feeds unused fuel into the left wing tank. So you generally want to use up some fuel out of that tank first to make room for the unused fuel to return to the tank. If the left wing tank is full, the unused fuel will simply be dumped out and wasted. However, if you are carrying fuel in the fuselage tank, it affects aerodynamics significantly and you want to get rid of that first, so once you've made some room in the left wing tank, you would want to switch to the fuselage tank and use all of that fuel before returning to the wing tanks (or drop tanks if those are carried).

[Bearcat]

Thanks ... I knew the center tank would cause a stability problem if full that was why I asked the question... I didn't know about the relief valve though ....:thumbup:

[MTFDarkEagle]

Keep in mind that the return valve feeds about 10 gallons per hour back into the left wing tank. (the 10 gallons is what I remember.. please correct if wrong).

[Bearcat]

I was always curious as to why having differing amounts of fuel in ech wng wouldn't cause a stability problem.. but I guess it did.. I imagine they were constantly switching back and forth to keep thing balanced and trying to malke sure they got tat fuselage tank under 40G well before hitting the combat zone..

[effte]

Not a stability problem per se, but an imbalance problem. You're correct, you have to switch tanks every now and then.