| I don't think the fuel level in a Lancair ES can be accurately determined using a dip stick. The fuel is mainly stored towards the wing root and away from the filler port. It doesn't take much flight time for the fuel to disappear from sight when looking into the filler port but there is still a significant amount remaining. Therefore, the sole source of fuel quantity is the gauge. Which leads me to top off before each flight. I then know exactly how much is onboard. The only true source of fuel information is starting with a known quantity and time. Gauges are a great backup until they go blank as can be the case with the electronic screen displays installed in so many of our airplanes.
Personally I always start topped off. Fly 30 minutes on the left (climb power) 1 hour on the right, 1 hour on the left, then back to 30 minute tank switches to a total of 4 flight hours. Then I am looking to land. By that time I am well over 800 miles, needing a rest, wanting to check my airplane mechanically, check in with business and family etc.
Good? Bad? or indifferent? That is my routine. I am used to it, it is the same every flight, it is proven as I have never run out of fuel, the time works for me, I can routinely verify my fuel flow rates, I usually am where I need to be well within 4 flight hours, the airplane handles the weight just fine, my climb rates are more than acceptable (900 fpm), TAS is more than acceptable at higher weight (210+ knots). Am I being inefficient? Probably. Am I putting additional stress on the airplane? Most Likely. Is it worrisome to me? No. The airplane was designed to be flown with the fuel capacity intended. And it is only at this capacity for a portion of the time as fuel is burned.
Bryan Burr N132BB On Jan 1, 2010, at 8:40 AM, mikeeasley wrote: Bill, I saw a quote the other day on a T-shirt in a store: "Confidence is the feeling you have before you fully understand the situation." I definitely think it applies here. I think we are on the same page. Just looking at the fuel gages is taking additional risk that's not necessary. I would say that about 20% of my flights take place with less than full fuel at takeoff. On most of those partially fueled flights, I have done the "mental math" to confirm what's left in the tanks based on fuel flow and time, and I compare that to the fuel quantity gages. Buy I must admit a few times where my plane has been sitting in the hangar for a while, and I don't remember exactly what the previous flight fuel situation was, and I just look in the tanks, trust the fuel quantity gages and go fly. Your points are well taken. Mike Hi Mike, Do you pre-flight your airplane each time before you fly? Do you have SOME system to confirm that what your fuel gauge says is accurate before take-off (e.g. dip stick, full, or even "educated eyeball")? And, can you reliably tell when fuel transfer is not working? If you answer "Yes" to the above, then I would submit that you are starting each flight with a known quantity of fuel and have a reliable system for determining if there is a problem requiring you to land early. I applaud any such a solution. If any of those answers are "no," then you have an opportunity to improve your process. Perhaps the risk is "low," but why take it if a better way takes only seconds? My biggest concern on these forums is that there are folks who have been doing things for decades in a way which works "most of the time" and they've "never had a problem." By posting "advice" that is either incomplete (leaves out an important confirmation step) or is actually they way they do things and leaves out important confirmation, it is possible to leave younger pilots with ideas that can end them up in needless trouble. There are often many "right" ways to do things. The criteria for determining a "right" way is simple: does it insure that you KNOW the condition of your plan before you fly so that you are making planning decisions based on facts rather than assumptions. I had one fellow reply privately to me that he never performs pre-flights. Rather, he post-flights before putting his plane in his hanger after fueling and is the only person who flies the plane. This is the sort of solution that works "most of the time" and "sounds reasonable." However, life isn't reasonable. Things break. Fuel can leak out on the hanger floor, evaporate, and leave no sign. A slowly leaking tire can cause a deadly accident if not checked before flying, rather than after. Etc. In a recent thread, I avoided being critical of people's personal choices - saying only that choosing to fly faster than Vne is a "risk" and noting that apparently no one in a 320/360 has died from this alone (leaving out the T-storms). I am absolutely fine with people taking risks with their own lives that they know that they are taking - it is THEIR life. I am not so good with people taking risks on behalf of others (passengers, people to whom they give advice) who may be trusting them to exercise superior judgment, and when I think I see such behavior I tend to speak up. So to everyone out here - I would ask that you please consider the impact of your "suggestions" on these forums. If you knowingly take risks, then please either don't recommend that technique or make it clear that you know there is a possibility that your system could "fail" at an inopportune time but that you personally find the risk acceptable. Happy New Years All! Bill Reister mikeeasley wrote: I'll give you the "known quantity" definition. But just because the fuel is in your wing doesn't mean you are 100% sure it's available to burn, right? And a properly functioning, accurately calibrated capacitance probe and digital gage is significantly more accurate than the GA standard fuel gages I had in my 201. A couple things I do to confirm the functionality of my fuel gages is to do the math between the fuel flow reading, fuel tank levels, and how much fuel it takes to fill the tanks when I'm at the pump. Those little mental math exercises give me a reality check on a regular basis. For example: If I switch tanks in an hour, my left tank should be down to 30 gallons by then... If I switch tanks now, I should land with about 22 gallons in each tank... It should take about 35 gallons to fill the left tank and 30 gallons to fill the right tank... I completely lost my JPI EDM 900 a few years back, just went black about an hour into a flight. I landed and got it repaired before flying home. I knew I had a bunch of fuel on board and how long I'd been flying on the current tank because I keep good ol' tank switching notes on my flight plan sheet on my lap board. And I do visually check the fuel quantity in my tanks during my preflight, although I can't really tell very accurately how much I have unless the tanks are pretty full. Maybe a paint stick with some Sharpie marks might be a good thing to have for partially fueled flights. Mike Easley Colorado Springs I received two responses to my post; I am responding to both in this post.
To both Grayhawk and Mike Easley I respectfully submit that you are asking for needless trouble.
If you will refer to my original post, I did not say that "Full" was not the only POSSIBLE "known quantity, but rather that it was the only known quantity for each tank on most Lancairs. That is a FACTUAL statement, your arguments about the reliability of your respective fuel gauges notwithstanding.
Do you visually confirm that the amount of fuel in each tank matches what the gauge says, and if so, how? Capacitance gauges, while very accurate today, do have failure modes. Do you know all of them? Do you know how to recognize them in the cockpit? Is it even POSSIBLE to recognize them all in the cockpit?
Fuel starvation is one of the leading causes of accidents and is THE most preventable accident cause.
The same type of gauges were used in the F-4 Phantoms I flew in my mis-spent youth. One day on a training flight after the external tanks were dry, I started noticing that my fuel quantity seemed to be going down more quickly than Lead's. Too, the gauge was "bouncing around more than normal." After a brief discussion with my back seater we decided we would rather be live sissies than end up walking home or worse, so we told Lead we were heading home. Lead, being a rather arrogant ass, asked us to repeat the diagnosis we had already performed and, in level flight, the gauge seemed to level out just a bit below Lead's reading. Logically, if we both started out with full tanks and there was no leakage, our fuel remaining should be about the same. Lead passed off the fluctuation as a simple gauge problem and said, "let's continue the mission and just keep an eye on it;" however, I told him to take the stick if he wanted to fly my airplane, otherwise we were going home with or without him. He grudgingly "led us back."
On the way home, the gauge started falling at an increased pace, so much so that we had Lead drop back twice and look for fuel leaking. None. On short initial the Fuel Low Level light (which was independent from the gauge system) came on - this system was supposed to be "fool proof" and "absolutely reliable" and was supposed to indicate 2200-2300 pounds of fuel remaining (a good 10-12 minutes at reduced power setting). I pitched, throttled back, dropped gear and flaps, turned base, and landed in minimum time with minimum use of throttle. On touchdown I shut down one engine (standard practice); rolled to the end of the runway, turned off and pulled into my hanger (by happenstance the first hanger) all without touching the throttles again and then wrote up the plane for a faulty fuel gauge system.
In order to inspect the fuel system gauges, it was necessary to remove the remaining fuel from the aircraft. Full internal fuel on the F-4 was about 12,500 lbs, or about 1900 gallons which represents a bit over an hour of flying time (~180 gallons = 6 minutes; 18 gallons = 0.6 minutes). When they defueled the aircraft, they only got 6 gallons, or less than 20 seconds of fuel remaining.
Complacency is the single biggest killer in aircraft accidents. If you trust your newfangled gadgets without verifying, you are an accident statistic waiting to happen - period, and I make no apology for that statement.
Now, having said that there ARE legitimate ways to insure there is a "KNOWN QUANTITY" of fuel. My particular Lancair has a header tank, so I can fill that and know I have enough fuel to ferry the aircraft to another airport for cheaper gas. I can (and have) fill a single wing tank, and accept that it will be wing-heavy on takeoff (I lost a gas cap on a cross country, and flew with two tanks rather than be stuck out for a day or more). For those builders who plan ahead ( or a clever person improvising after instruction), tabs can be installed inside t he wing fill caps ala' Piper, so that if you "fill to the tabs" you have both a balanced and known quantity of fuel. Some people have carefully calibrated dip sticks to determine exactly how much fuel is in a given tank.
All of these are acceptable and reliable practices. However, if you choose to steadfastly maintain that looking at your gauge is a "reliable way to determine your fuel" then all I can say is that when the day comes that I see "fuel starvation" as the cause of your accident, I will tell everyone at your funeral that you were provided with information that could have prevented it and that you knowingly chose to act in a dangerous fashion. Oh, and I'll nominate you for a Darwin Award, too... ;-)
Best regards all, Happy New Year, and fly safe!
Bill Reister
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