Just wondering what's the longest distance flown between fuel stops. Please, not really interested in those of you with extended range tanks, I had previously flown from (KBXK) Buckeye AZ to (0TX1) Pecan Plantation, which was 965sm, and landed with a little over 12 gal. My trip last Tuesday topped that, but I landed with only 8 gallons. RV10.
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- Thread starter partner14
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Depends on whether I have a 100 knot tailwind, a 100 knot headwind or something in between.
I will say that I won’t take my -10 down to 8 gallons, except in an emergency. I’ve had too many times where someone blew a tire and fouled the runway just as I approached, tower decided to change active runways, I was given a delay vector while multiple airliners landed, fog rolled in quickly or there was some other reason that I had to alter my plan at the last minute. Eight gallons limits options to address late-emerging issues, especially if there aren’t nearby airports that would likely face the same issue (e.g coastal fog), not to mention the possibility that today just happens to be the day that my fuel computer decided to err, I’m a little unsure how remaining fuel is divided between the two tanks, etc…. On long X-Cs, I’m generally WOT and leaned to 10-10.5 gph at cruise (10K’ +/-). Perhaps I’m overly cautious, but I prefer to land with 15 gallons or more in the tank (an hour with a few minutes at climb power) and won’t intentionally go below 12 in a non-emergent scenario. Just my $0.02…
I will say that I won’t take my -10 down to 8 gallons, except in an emergency. I’ve had too many times where someone blew a tire and fouled the runway just as I approached, tower decided to change active runways, I was given a delay vector while multiple airliners landed, fog rolled in quickly or there was some other reason that I had to alter my plan at the last minute. Eight gallons limits options to address late-emerging issues, especially if there aren’t nearby airports that would likely face the same issue (e.g coastal fog), not to mention the possibility that today just happens to be the day that my fuel computer decided to err, I’m a little unsure how remaining fuel is divided between the two tanks, etc…. On long X-Cs, I’m generally WOT and leaned to 10-10.5 gph at cruise (10K’ +/-). Perhaps I’m overly cautious, but I prefer to land with 15 gallons or more in the tank (an hour with a few minutes at climb power) and won’t intentionally go below 12 in a non-emergent scenario. Just my $0.02…
Tom, I agree with most of what you had to say. In all the situations you covered, I would have stopped also. However, my fuel burn in cruise is between the high 7's to mid 9's. The wx was vfr, and lot's of airports (Texas) within a few gallons of where I stopped. Would I have even thought about doing ths in NM, Nev, Wyoming, Colorado, Montana, or several other states? NO. Remaining fuel is NOT divided between the 2 tanks. How long have you been flying your 10? I have over 1400 hours in the 10 I built. Have you done any test to determine usable fuel? I have. I had at least 50 minutes flying time left before I would fall out of the sky.... which is why I landed for fuel. One thing I always try to do in life is tell the truth. Which is why I posted the 2 pics below. I haven't filled the plane up yet, so my guess is that I had somewhere between 8 and 11 gallons remaining.
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All I have to say is that there in no valid excuse for running out of gas in an airplane. Period.
Understood. Not trying to be critical—everyone has their own minimums—or question your honesty. My point about the example situations I mentioned is that by the time they pop up, it’s too late to stop. The only option is to go somewhere else—which is what everyone else is doing too, so there may be a delay.
I’m impressed that you can cruise in the high 7s—at WOT and 10K-ish feet, I can feel the onset of roughness in the mid 9s and in the mid 8s it’s rougher than I’m willing to tolerate on a continuous basis. If you fly one tank to empty, that certainly helps. I’m surprised that your totalizer could leave you thinking that you “had somewhere between 8 and 11 gallons remaining”. I’ve tracked every gallon of gas I’ve added since buying my -10, and compared each purchase with what I expected based on the totalizer.
Maybe I have a touch of OCD. Regardless, the delta between expected and actual need has never been anywhere near 3 gallons. If it were, I might be even more conservative. To your question about experience, nothing particularly unusual. I’ve been flying for 48 years, in my -10 for the last 7 (ironically, purchased from a great couple who live at Pecan Plantation). I’ve flown West Coast (but not the Pacific NW), SW, western mountains, central and upper Midwest and the East Coast (both north and south). The usual certificated GA stuff, plus a smattering of warbirds (T-34, T-28, L-39). The latter has undersized tanks (by design to inhibit defections from the former USSR) and a high burn rate down low. We used to (sort of) joke that it was time to start looking for gas about the time we rotated. Maybe that contributes to my conservative approach.
Have you ‘balanced’ your fuel injection apertures so that all cylinders hit peak EGT at nearly the same time? On my -10 I routinely cruise at 10 g/hr but can lean more (power dropping of course) until the engine is getting no gas. There’s never a hint of roughness.
Tx. Yes, I have. I've worked with Don at AFP, with a couple rounds of restrictor replacements. From stock 0.028s to two at 0.0245, two at 0.025, one at 0.0255 and if memory serves, one at 0.026. I think his comment was something to the effect of "pretty good, about as good as we're going to get". I know that some see spreads as low as 0.1 gph. My GAMI spreads may be affected a bit by fluctuating FF indications--slow oscillations of +/-0.2gph, which can make it a challenge to know when individual cylinders "really" peak. According to Savvy, they see that a lot with IO-540s, although they don't know why. My FF sensor is in the tunnel, upstream from the engine-driven pump (not ideal, but also not uncommon)--I can't help but wonder if that contributes to the fluctuations. Induction leak tests are negative. I repeat those periodically as a simple way to check for intake gasket degradation in between oil changes or other maintenance where I remove the cowl. In the end, I lose enough speed as I lean below 10 gph that I don't really want to run there. EGTs match up well at that FF, so working it further may be a low ROI activity for me.
I also could not get my 540 as close as i got my 320. I am like bob, i can lean a LOT. How ever, i only lean to about 80* and if i want less burn, i start pulling throttle instead. Efficiency has been higher that way for me and the engine is noticeably smoother. Once above about 10k or so, i can leave it wot. I typically target 10.5 between 8&10k. At 14 or 15k, i can get down below 9.5 and still doing 165.
I don’t think you can realistically lean a 540 back to 7 gph at wot at 10k. The afr you would be getting would be in the unigniteable range imho. I certainly have never tried it, but doesn’t make much sense. If you pull back from wot, then it makes sense.
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