William, Thanks for the detailed explanation. This group is pure gold for newcomers like me. Thanks to you and all for your kind patience and advice.
Steve On Sep 6, 2010, at 10:30 PM, William R. Bayne wrote: > > > Hi Steve, > > Welcome! > > Kevin never empties his wing tanks so as to begin using the five or six > gallons (depending on serial number) that the transfer pump and overflow > system keep in the fuselage tank. In the sense that the fuel in the fuselage > tank is always there should he need it, he isn't "robbing himself". > > On the other hand, if your worst fuel burn in the last six months was 4.5 > gph, then a mere 2.25 gallons of usable fuel in the fuselage tank would > affords you a full half hour of reliable powered flight remaining as > "reserve" at flight's end. At 100 mph ground speed, that's fifty miles. To > be fifty miles "off" at the end of a three our flight would seem to require > an unusual degree of inattention from the moment of takeoff. That's why a > half hour "reserve" is deemed adequate for VFR operation under normal > conditions. If operating over water or in rapidly changing weather, more > would be prudent. > > My practice has been to: > > 1. calibrate my tanks and gauges at each annual (usually) so as to be aware > if and when a cork is becoming gasoline-soaked (less buoyant) > > 2. divide the number of gallons fueled by tach hours (and decimals thereof) > since the previous. (my fuel burn record) > > 3. For cross-country flight: > a. flight plan assuming 100 mph ground speed to destination or next > fuel stop). > b. pre-select visually confirmable checkpoints approximately an hour > apart > c. pre-select an alternate landing destination an hour "short" > (nearer) > and an hour "long" (further) than my next fuel stop. > d. Compute while en route how much "ahead" or "behind" I am at > each such checkpoint. I thus know well in advance whether > actual > conditions differ enough to warrant changing where I land for > fuel. > > If an Ercoupe with 24 gallons usable fuel is thus found to have an endurance > of 5.33 hours (5.03 hours usable landing with a half hour reserve), the owner > that chooses to land every three hours, come what may, WOULD seem to be > "robbing themselves" thusly: > > 1. Their reasonable operational range is reduced by approximately 40% > > 2. A tail wind reduces time en route and fuel consumed to a fuel stop, > but > seldom makes possible flying to a further fuel stop (on a > 3-hour leg). > > 3. Performance is reduced at all times and in all weather by carrying > 54 lbs. > of fuel (nine gallons) everywhere that is absolutely without > purpose > from each and every takeoff to each and every landing. > > If my bladder limited me to three hour legs, I would prefer to depart "nine > gallons light" and enjoy additional performance. I would prefer to carry a > GPS, a teddy bear or rabbit's foot in place fuel obviously not needed. Most > of us like the comfort of minimum condensation and so keep our tanks full at > all times. Offloading fuel already in the plane entails considerable > inconvenience and unnecessary risk. I suppose it would be possible to > disable one wing tank, but that's likely not "legal". > > In fact, prewar Ercoupes left the factory with only a single nine gallon wing > tank. Pilots of the early 'forties had less original instruction time, had > less horsepower, and flew over a much less settled country, mostly without > radio communication, and certainly without transponders, ELTs or cell phones. > They knew how to extend range by flying at less power when such was > necessary or otherwise to their advantage. I absolutely refuse to believe > today's pilots are any less capable that take the time to learn and use the > Ercoupe's many advantages and capabilities. > > Nonetheless, the "right" choice is the one each of us make...for ourselves. > One size does NOT fit all. > > Oh, and the reason you fill the fuselage tank first (if you have flown the > wings dry) is so the quart or so (guesstimate) of fuselage tank fuel between > the overflow inlet and the top of the neck can drain down via the gravity > overflow line(s) before both wing tank(s) are too full to accept it. > > Regards, > > WRB > > -- > > > On Sep 6, 2010, at 20:59, Pizzo Stephen wrote: > >> >> >> Kevin, >> Well, but the literature says to fill the main first then the wing tanks. >> Why do you prefer your method instead? And aren't you "robbing' yourself of >> those extra five gallons that would have gone into the main tank? >> >> Steve (the new guy) >> >> On Sep 6, 2010, at 5:52 PM, Kevin wrote: >> >>> I never put fuel in the header tank. I burn the mains and leave the header >>> as reserve so it never need adding to. >>> >>> Kevin1 >>> > > > Pizzo Stephen [email protected] Who is more to be pitied, a writer bound and gagged by policemen or one living in perfect freedom who has nothing more to say? Kurt Vonnegut
