G'Day Indian,
On some aircraft I have flown, the 'taught' procedure was to T/O on "Both", then, when at a safe altitude, change to either the left or right tank for 'fuel management' and 'trim' purposes.
In early Bonanzas, beware the fuel return system from the fuel distributor valve - it was returned to the LEFT tank only....so if you selected the right tank for engine use, the 'excess' was returned to the left, until it was FULL again, and then it 'conveniently' drained out over the side via the underwing vent - just where it would not be noticed.....
So, obviously the 'trick' there was to use the left tank for a 'good hour or so', then use the right tank for an hour, and 'lo and behold' the LEFT was almost full again!!
But of course, as we had all 'been endorsed on type' in dem dere days, we knew this - it was 'drummed' into us - and, it was in the book!
They've fixed that little anomoly now, so you don't have to worry about it anymore....
Cheers
