Some
random experiences in Fuel (mis)management.
Gotcha
#1. Left Madison, Wisc, minetes ahead of a rapid moving cold front
in a C-180 ambhibian. Full tanks, checked cover on old style fuel
tank - appeared on (the wing is 12+ feet in the air) so didn't crawel
the ladder! On way to Midway airport, swithched tanks over what is
now Tri-State expressway. Tank # 2 empty because cap loose under
the old style cover. Landed without incident on the Tri-state
(prior to concrete being laid.)
Gotcha
#2. In a T-6. Three hours Fuel in two tanks, switching tanks
every 1/2 hour. Made fuel selector swith twice without problem, on
third switch attempt the selector handle broke off. Now unable to
fly on fuller tank, so diverted to alternate airport and landed.
No passenger in back seat as there is a second selector there.
Henceforth carried a vicegrip as do about 1/3 of the knowledgeable T-6
pilots.
Gotcha
#3. In a twin comanche with tip tanks. Heated hangar in N.
Wisc. Drained during preflight a small amount of fuel from the
twins peculiar low point central drain. Left for Florida, with
full mains, full aux and full tips. My proceedure is to taxi out on
the mains, switch to aux for run up then back to mains for take
off. Uneventfull cruise at 8500'. Full aux and tips showing
on the gauges. At cruise I swith to left Aux tank, engine quites, back
to main everything ok. Same with rt engine. Analysis frozen
water in both aux tanks. After landing and over night in heated
hanger drain over a gallon of water from sump. A/c always
hangared!
Gotcha#4. I
was checking out a CFI in a tailwheel Aeronca Champ, 85hp it had a fuel
system not unlike a Lnc-2. Header tank, 2 wing tanks that gravity feed
to the header. The CFI "student" checks the fuel. " half
full header, half full wing aux tanks". We were only going to do
touch and goes in Sedona, AZ. After 2-3 landings we turned on
the aux which drains into the mains so as to continue circuits and
the 4th landing was "dead stick".
Moral of
the story(s), is that; when possible I fly on the top half of the tanks
and enjoy the luxury of capacitance gauges, fuel flow/totalizers and
hopefully no more GOTCHA'S.
Bob
Mitchell
L320
Subject: [LML] Re: Fuel
Planning
I rely
heavily on the fuel totalizer in the Velocity. On refueling, it is
invariably accurate to within a gallon on a 30-70 gallon burn, but
there is one scenario where reliance on the totalizer can leave you
in the lurch, and a bad one at that. If a leak develops upstream
of the fuel totalizer sensor, or you leave a fuel cap off, you can be
draining or vacuuming a large fraction of your fuel overboard, but the
fuel totalizer does not recognize this loss, nor will you, if you rely
only on the totalizer.
Accordingly,
we need a means of sensing, or directing reading of, the fuel left in
the tank(s) to know that we haven't had an unexpected loss and that we
can rely on the fuel totalizer.