EricJ

With forced induction a good controller can do that. On an NA engine if the intake is well designed, or at least not a limitation, then the torque curve can also be very flat. Basically, on an NA engine with a decent intake the torque curve can be flat until the intake (or something else, e.g., valves) becomes the limitation. Once the intake can no longer flow sufficiently to support the demand at increasing rpm, torque starts dropping off. There've been a lot of trick intakes in the automotive world that change geometry based on rpm to better optimize flow across a wider rpm range and flatten the torque curve. https://en.wikipedia.org/wiki/Variable-length_intake_manifold Many of our horizontally-opposed GA airplane engines have relatively large displacement but turn very slowly (in comparison to auto engines), and wind up with a pretty flat torque curve without any fancy tricks in the intake.

They have a few different mechanical configurations, but they're all floats. I don't know if anybody has a capacitive sender for certified GA yet. https://ciescorp.net/products/magneto-resistive-fuel-liquid-level/

I do.

That's true for just traffic related stuff, but if one wants some long-term parking Scottsdale (SDL) is similarly bad. But, yeah, IWA is bad to even just stop to pick somebody up or have lunch or something. And the restaurant there is really good!

Storage includes the material compatibility in the trucks and vendor tanks, and all of the related equipment including pumps, gaskets, hoses, valves, etc. Basically everything that could be exposed to the fuel for long periods. Vendors and distributors don't want to pay to replace or update equipment, nor do they want additional maintenance issues or surprises down the road. Because the aromatic components are different in G100UL there are significant and real concerns. George has said this publically and said it at the event I attended at Buckeye. A few item tests aren't conclusive and "test it in the field" isn't what most of the community or regulators are looking for, and especially not the distributors and vendors. I suspect this may be one of the bigger barriers, but we really don't know. The AOPA Baron had a tank patch fail in the bladders on the side holding G100UL, but it isn't known whether or not this was related to age or the G100UL. In any case, it's not true that there have been "no issues".

For props there's no "core" exchange of anything, though, correct?

"Some degree of accuracy" isn't the same as highly accurate or, more specifically, "calibrated". Part 1 doesn't have a definition for "calibrated" other than for airspeed. A "rough" indication may meet the requirement at levels other than zero usable. Regardless, the wording of the regs can be interpreted that the indication at zero usable fuel is held to a higher standard than at other levels, so the Pilot's Handbook and the usual tribal wisdom are not incorrect from that point of view.

I think it's a reasonable interpretation of that reg. If it is only required to be "calibrated" to a specific quantity at the empty condition (which is what the reg says), then that's the only place where a calibrated accuracy is required. The indication of "usable quantity" is not required to be calibrated. The indicator is required to be "calibrated in the appropriate units", which just means the scale is consistent with the units indicated (and many don't even have units). So the Pilot's Handbook isn't necessarily wrong even for Part 23. Part 23 didn't apply to Mooney certification, or many GA airplanes, which were done under CAR3. CAR3 says: § 3.672 Fuel quantity indicator. Means shall be provided to indicate to the flight personnel the quantity of fuel in each tank during flight. Tanks, the outlets and air spaces of which are interconnected, may be considered as one tank and need not be provided with separate indicators. Exposed sight gauges shall be so installed and guarded as to preclude the possibility of breakage or damage. Fuel quantity indicators shall be calibrated to read zero during level flight when the quantity of fuel remaining in the tank is equal to the unusable fuel supply as defined by § 3.437. For CAR3 there really isn't any requirement for what the gauge says other than at zero usable fuel in level flight. 3.437 is just about how to determine what "unusable fuel" is. So it really isn't a myth for GA airplanes, especially for those certificated under CAR3. Part 23 gets better, for sure, but still seems to only require a "calibrated" reading at zero fuel.

If Chandler (CHD) is further from where you need to be, then try Falcon Field (FFZ). It's also very GA intensive and friendly. The local CAF museum is there. If you need maintenance there, a friend of mine has a popular shop there, but there are a lot of options. There's an instrument shop there as well. It's busy, but all of the fields around here are.

That's a good document for further illuminating the issues.

Clogged injector on #5? Sometimes they clear themselves, so it'd be hard to say for certain.

Storage and material compatibility has been mentioned a number of times, and George has said that it may be an issue.

Nope. George has done some work, and has a product that obviousy "works" (at least in a fundamental, first-order sense), but we are highly unlikely to be seeing all of the data he has, and, having been in very similar plays from multiple angles myself, he likely doesn't know everything, either. Even when you have a highly skilled team with state-of-the-art equipment and do all the testing you can possibly think of, when you start to bring it in front of standards bodies, regulators, potential partners, customers, other competitors, etc., you can suddenly find out stuff you didn't think of. I've been there many times from multiple sides. George is not a fuel industry insider. He is not a petroleum or chemical engineer. He makes himself out to be a victim of the FAA. He's just not what a lot of people make him out to be. That takes nothing away from what he has accomplished, which is impressive considering the credentials he doesn't have. When you hear from or talk to other players in this particular pageant, you hear about different factors that matter that you don't hear about from George. He's promoting a product, he's essentially a salesman of that product, and he's selected a particular strategy to promote it and he's executing that fairly successfully so far. There's a lot more to the story, though, and we see through a glass darkly because most of what happens is not in front of us, it's in front of the decision makers in the FAA, ASTM, distributors, etc., etc. We don't matter much at this point, so we don't hear much from the other sides and don't know details of the issues that are the actual barriers right now. If G100UL was really everything all the decision makers think it needs to be it would likely have been in distribution by now. I don't think it's snake oil, but I don't think it's been anything close to proven to be a complete solution. That includes factors beyond whether it'll run in a motor or not, it also includes production and distribution and insurability factors. And it's pretty normal in a forum like this to say this and just be accused of being a negative Nancy, or accusing George of something bad, but when you've been through similar processes enough times to know the drill it's just the way things work. Sometimes players invovled really are snake oil salesman or selling a pig in a poke, and I don't think that's what's happening here at all.

D'oh...I read that as 430.

Too bad he wasn't an Avidyne dealer! Could have just slid in an Avidyne replacement and been on your way.

Storage matters, and keeping it in the barrel at reasonable temperatures apparently can make the difference from a few months to a year. Sunoco says there fuel will last a year if properly stored: "Sunoco E85-R does not contain metallic additives and will not harm oxygen sensors. It should be stored in dark, tightly sealed containers where the temperature is stable. Handled under such conditions, shelf life is in excess of 1 year." https://www.sunocoracefuels.com/fuels/fuel/e85-r Another issue with random suppliers (as alluded on the Sunoco page), is that the blends aren't consistent. My racing friends that use it that have tunes and setups for a particular blend, test the fuel every time it is drawn from the barrel, both to see what they got (initially) and how well it has aged. If it gets too far out of the spec for their tune they'll make adjustments to the fuel. I think the only reason we still have E15 (or so) at the pumps is left over from when the corn grower's lobby was still powerful and got the requirements changed. Until somebody changes it back we're stuck with it.

If the women don't find ya handsome, they should at least find ya handy.

I'm a hick so I just put aluminum tape around there.

They're in the middle of the Avare to Avarex transition, and it turned into enough of a cluster that I switched to iFly. FltPlanGo is still free, albeit a bit clunkier, but it is now owned by Garmin so I suspect may be more likely to support the 345r. Avare is an excellent EFB, but the chart updates have gotten unreliable, support is much less than good, and it's being deprecated in favor of Avarex, which is a mess imho. I'm keeping my fingers crossed that Avarex eventually turns into something nicer than Avare was, but it has a ways to go, imho.

And it spoils over time, i.e., it has a very limited shelf life. Many of my racing friends around here have been running ethanol blends (usually E85) for many years, buy it by the barrel, and have to very carefully plan when to buy the barrel and manage their consumption so that they use it fast enough that it doesn't go bad. For those wondering why ethanol is desirable for making more power when the energy content is lower, if you pump more of it in (with larger injectors) and tune appropriately, you can make significantly more power with it, even with an NA motor. It runs cooler, too, so there's some win-win. Since you need to flow more of it to make the power, your tank doesn't get you as far, but if what you want is output power it's a good way to do it. The gasoline/ethanol blends wind up with higher octane numbers than running either by themselves, so it's a popular way to make more power on a track when the rules allow. The downsides are significant enough to keep it out of general use, though, especially the material compatibility issues, which also seems to be one of the significant concerns with G100UL.

An RTL-SDR USB tuner, like could be used with a Raspberry Pi, can digitize the entire VOR spectrum at one time, so that you can simultaneously digitally tune as many VORs as you can find in range. Whether or not you can do that in software in a GPS depends on a lot of things, including whether the tuner has enough bandwidth or not and whether there's enough processing power available to do the job. If the tuner is narrow band and can only tune one VOR at time, then it'd be a bit slower and clunkier, but could potentially still work reasonably depending on other things. I suspect only the most modern GPSs may have wideband digital tuners, and I don't know which do or don't. Because of some work I've done with the Avidynes I think they *might*, but I'm not sure. What I do know is that it's not an issue with an RTL-SDR and an RPi, so for a few hundred bucks (at the most) you could have the capability connected to your tablet via WiFi.

In the southwest some of the places you fly to may not have other people, let alone bike rental.

I've been saying it for years. Several years ago somebody in the UK had achieved basic functionality with an RPi and could show location on a map just from VOR inputs, but I never tried using that particular app and it doesn't look like it got a lot of use. I initially lost interest in doing it because that guy had done it, but it doesn't look like that solution went anywhere. Adding DME would improve accuracy, but also add a lot of cost and complexity and would require FCC certification since it transmits.

There was a fair amount of pushback from here regarding the midair a few years ago. I don't think they've been back much since then.

It might drain every time you shut down, too, I don't know.