by Andy Hughes » Tue Jun 29, 2010 5:17 pm
I've been flying for a while (since '94) and don't see the need to switch tanks that often.
In a Mooney (pre-J), cruise is about 9GPH and climb is 12-15 GPH.
Climb at 1000 fpm for 10 minutes - 10K, 500 fpm for 20 minutes - 10K.
Basically I guestimate how long I have to fly before I use up the first 4 or 5 gallons.
It's going to be 20 minutes if I climb to 10K at 500fpm. OR it's about 15 minutes after reaching 8000 if I climbed at 1000 fpm.
Then I switch every hour, so I'm out of balance by no more than 4 or 5 gallons at any one time (24-30 pounds).
I have never noticed much of a tendency to "lean" to one side.
In a comanche, I climb on the main, then switch to the oposite aux tank (outboard, 15 gals), empty it, then empty the other aux, then
switch to the "other main", then switch every hour. Again, no real tendency to lean.
In arrows, again, 1st half hour on one tank, then switch every hour.
FS does not switch the tanks for you automatically, however if you do not set it to one tank or the other, it will draw from both equally.