"Greg Reid" wrote in message
om...
I've installed a 12-gallon fuel cell aux tank in the tailcone of my
4-place conventional low-wing plane -- intended for go-fast trimming
when flying solo more than for its extra fuel capacity. As you know,
a typical 4-place is terribly nose-heavy with only front-seat
passengers and no baggage. The tank would be emptied if flying with a
full load of passengers and baggage.

Greg,
Thats a bunch of weight and complexity to add for trim fiddling. I can
see the benefits but think that a fixed/removable ballast bar bolted to
somewhere
around the rudder post weighs less, is less complex, gets you 90% of what
you are looking
to achieve and has no failure modes that would be critical to flight. Make
a bar for solo,
one for 2 up. Some certificated gliders and helicopters do it this way.
But I'm afraid it
might be too simple..........

Scott