> How does this give you
redundancy? If either pump fails, you end up without access to that tank's
gas.
True, but that's not an
immediate emergency, just a reason to land soon. Redundancy of fuel supply
to the engine was what I was after. Anything happens to one supply - fuel
contamination, leak in lines, blocked filer, failed pump etc. and you have a
spare system.
John
Its not an emergency unless you have already used most (or all) of
the fuel in that tank. You may think that you never plan to run a
particular tank empty. So how much are you ALWAYS going to leave in each
tank? Probably 1/2 hour at a minimum. That would be about 4
gal. Which means you now have 8 gal of unusable fuel. Or, to
look at it another way, that is 1/2 hr. of effective range you would
otherwise have if you were to run the 2nd tank empty.
You also have to always remember to stop using that tank when there have
about 4 gal left. I find it very easy to get distracted and forget to
switch exactly when I intended. It will also be difficult to know when
you have only 4 gal left, you will be conservative and usually leave more fuel
than that. This will further reduce your effective range and mean that
you are carrying around 4 extra gallons of fuel (24#) EVERYWHERE you fly for
the life of the plane....
I like to use up the fuel in my 2nd tank early while still en route, then
I maximize the fuel in the tank I use while in the approach and landing
phase.