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.
Chuck Jensen