Ibra

Week-end trip from Rouen (LFOP) to Saumur (LFOD), the hardest bit was climb to 2000ft as it was windy (storm Amy), however, we know the worst was behind and we were flying toward nicer weather. On return the windsock has given up indicating !

Short flights to Chantilly racecourse and Reims-en-Champagne (LFQA) for visit of Vranken Pommery champagne caves

Such days are a pain: you go “vmc-on-top” to find the sun, then you find another layer above ! You have more guarantees when paying for “UV session”

That is very true, people and government seem alarmed these days with pollution, however, there is literally nothing new under the sun ! I recall reading the most polluted day in history of Paris was in 1900, the solution was switching to ICE cars (politician are exactly the same: making laws on the fly, showing they are doing something, taxes and bans here and there…). https://earth.org/data_visualization/air-pollution-in-paris/ Around the year 1900, Parisians knew they had a serious pollution problem. No, not smog and particulate matter, they said, but the dung from over 80,000 horses carrying people and loads around the city everyday. Officials decided to test moving horse-drawn vehicles to the verge of the Champs-Elysees causeway, while motorized vehicles would be given the center. The contrast between the manure-laden and rubber-smoothed aisles left people convinced (translated from a French article in the “Figaro”): “It is easy to see that, from a hygienic standpoint, automobiles whose exhaust is rapidly absorbed by the air, are preferable to equestrian carriages.” https://www.lefigaro.fr/histoire/archives/2016/07/01/26010-20160701ARTFIG00300-en-1900-le-pic-de-pollution-a-paris-est-du-aux-moteurs-a-crottin.php#:~:text=En 1900%2C on compte près,%2C de «parfums pernicieux».

We still need to see those Rotax that match 200hp-310hp bands, say IO360 or TSIO550, Rotax made lot of competition and innovation 80hp-160hp band, however, they still short in 200hp-310hp band, they tried V6Cyl AeroEngine but no luck https://www.kitplanes.com/crystal-balling-what-will-rotax-do-next/ The problem now for GA is that they have a lot of money to make in multi-rotors or drones markets, so they will become another dinosaur in 80hp-180hp band. The Rotax market is the same as UL94 market (or UL91 or Mogas in Europe) with 80hp-160hp engines, these already have unleaded fuel solution even with Lyco or Conti, when it comes to detonation? There is a big added value from Rotax in 80hp-160hp band: being able to crunch 80-87 MON Mogas Autofuel with 10% ethanol and full of aromatics without vapour lock. However, they have not made any major discoveries to replace "100MON engines". They also have own detonation problems when running turbos on SP95, SP98, UL91, UL94, 100LL with octane rating from 80MOM to 100MON, their last service letters made lot of advisories on MP/RPM operating envelopes and choice of fuels... UL91 in Turbo Bristell, https://www.bristell.com/wp-content/uploads/2024/02/ADxC-73-SB-042_A-Fuel-Grade-UL91-avoidance.pdf MAP limits for SP95 and SP98 auto-fuels, https://share.google/zArSzOfzxGHFd7Ovt I am sure they have smart people to innovate but getting into the "real 100 octane market" is not a walk in the park: my understanding, they are going for twin engines market with 2×160hp rather than 310hp single engine market while consolidating their position in 80hp-160hp, especially with drone applications (zero incentive to try anything else).

Follow the brick

Yes it's a refined design already I am sure it can be refined more (not a lot) with EIS or FADEC and some operators may take it, however, only they can get lot of maintenance credit in exchange...

Like many things in aviation, in new application? MAYBE, in "retrofitting"? lilely NO At overhaul, this may get some traction but there is not much interest neither? I recall, Lycoming makes 2000 engines and overhauls 2000 engines every year, even if all these gets fitted, it will take 100 years to recycle the whole fleet It's hard to compare with automotive industry, due to economies of scale: the car engine builders spends more when building factory that produces car engines than what Lycoming makes in engine revenues for 5 decades ! As @N201MKTurbo said it's a stale design for 90 years already, the new EIS or FADEC may get some traction if FAA throws a "big bone" to some operators when it comes to maintenance, overhauls, TBOs...

Of course, Swift is responsible for submitting tests for ASTM to get their rubber stamps and approvals. Strictly speaking Swift does not even "test" their own fuels. For detonation, they send their 100R to Lycoming, Lycoming run detonation testing on their facilities, they issue some paper to Swift, then Swift sends that paper to FAA or ASTM, then FAA or ASTM will do a rubber stamp.... Anytime one talks about ASTM or FAA testing, they refer to the process to get approval (this does not imply that FAA or ASTM runs independent testing on their side, they may do in some cases where the FAA conducts their own "independent testing", however, in most cases, the FAA or ASTM will rely on participant to submit testing work, then they "independently review and approve")

They did leave it for 3.5 years now in aircraft tanks, this seems to tick all of the boxes, they think composition could remain the same for 5 years inside aircraft tanks, however, they need more data and time to support such claim... For aircraft, they have to show that anyway if it's an industry standard or stc'ed fuel, I think the requirement is something like 2 years when ASTM and 6 months when STC for "stability and oxidation" testing in aircraft. ASTM also test for "stability and testing" in trucks, containers and pumps, I think this is where 5 years matters more? if I am not flying aircraft for 6 months, I would have other worries than draining fuel. Not sure if this is guaranteed when fuels are mixed? most of the proposals seems to aim for ability to mix with 100LL and remain stable (however, they shy away from ability to mix with other 100UL fuels). I would be interested in shelf life of VPRacing 100E fuel as it may have unstable composition and may have high risk of oxidation and unstability (car fuels specs and variants are guaranteed for 3 months or 6 months, they won't last for say 2 years or 5 years unless one adds lot of additives and stabilisers)

No idea but they already have unleaded car racing fuels with high octane that rely on "oxygenation", for a long time now... For aviation certification, if they stick with this route they will have tough time passing PAFI tests or ASTM tests regarding fuel stability and oxidation (how long it stays in tank) as well as pressure and vapour lock limits (pump, pipes) It would be interesting to know what "they have for us", maybe their fuel will need some additives depending on the intended usage (turbos, temperature, high altitude)? flying or storage? "Winter Avgas vs Summer Avgas with mandatory calendar change"

Me too, I think the current STC candidates (100R or G100UL) are not "drop-in": they either need extra work on airframe (joints, pipes, sealant, paint...) or more work on engine (variable timing, de-rated cruise, extra rop...). By design, one can argue that "STC route" will overfit on specific engines and specific airframes, the ones that were tested until things "looked ok" to FAA, however, they may cause lot of problems elsewhere when such fuel goes into the wild with all variability in fleet, airframes and engine, as well as how they are operated. VPRacing is going with 100E, this is the real "drop-in" if it ever gets PAFI performance pass while staying within ASTM control parameters, however, they have much slower progress and they may never come out of it one day. Even when one looks at 100LL, it has it's own problems (or noise): it can also cause leaks on airframes, we see more broken cylinders or valves on some engines, operators have more problems than others. Even if FAA or PAFI says a new 100UL fuel is equivalent to 100LL, it will be really hard to show equivalence in "real world" as the various operators tends to be impacted differently, someone used to flying with 100LL at CHT redline with 499F CHT may feel 100R is not good, while someone who keep CHT under 380F will find it to be ok. Similarly, someone with 45 years original sealant vs someone with new tank reseal job, may have different feelings about G100UL

Indeed, that’s 20h of heavy streaming per month Unless one flies 300h per year, they won’t reach that…

We already did.. In one had, the 100R is already "blessed" by Lycoming in IO36, they had no objection to FAA STC for 100R in C172S In the other hand, G100UL in IO360 is not approved by Lycoming, they have "strong" objection to FAA STC for G100UL in C172S Maybe the difference between Lycoming approval for 100R vs objection for G100UL has to do with Swift involvement in ASTM? As for 550s, yes Swift seems way behind the curve compared to GAMI, they have challenges with these, they may get something from FAA subject to operational limitation or ignition changes. For "550s", an ASTM drop-in fuel could be very hard to achieve one has to work on formulations within some tight controlled parameters. This may take 18 months or even more: Let's be honest some engines break cylinders and valves every 800h on 100LL, I doubt they will make it past TBO on 100R...

It was removed for a while now: all “in motion” plans (roaming, priority…), the only restriction on speed is 550mph… Now, I think they wanted to split airlines from anything bellow. Previously, it was splitting turboprops from anything bellow (240kts). Initially, it was splitting cars or walking from anything else (10mph, 100mph limit) and before that they had none. The only restrictions now for “in motion” plans are data (50Gb) and geographical (international waters, countries…) Of course, it’s hard to know “what is next”