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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”

Haha, not much choice on takeoff... For landing, it has to be "power for speed" ("pitch for speed" is the only choice in gliders ), then, one day I had to "unlearn" as some airline guy wanted to see "pitch for glide" (like his coupled auto-pilote) and "power for speed" (like his auto-throttle) I the preference between Gear-Flap-Flap or Flap-Gear-Flap seems to depend on airframe specs as well as operator training background. Personally, I am all for "Gear first" in M20J, however, I used "Flaps first" twice when some examiner (who checks students on multi engine or Arrow) wanted to see Flaps, Gear, Flaps as part of "skill-test or check-ride pass standard" Are there any single engine retracts with draggy 40deg flap and under-powered engine? most ASEL with 40deg flaps seems to be fixed gear... "STOL + Complex/RG" don't mix very well (unless it's DC3: stol retract with 40deg flaps)

Yes few aircraft have “extra transient drag” from gear retraction, so have more emphasis on flaps-gear-flaps sequence

I am sure there are variations, like the choice of power for speed? or pitch for speed? * "Point and power" when it's blasting * "Pitch for speed" when it's sluggish Some pilots do both without thinking For flaps & gear, in Mooney, I teach people to go slowly on power, sensible pitch, gear, flap: it works well this way. In school, we get students in Arrow to raise drag flap, then gear, then clean flaps: Flaps retract to 25º, positive rate, Gear Up What I find interesting, the Arrow gear is way more draggy than Mooney gear... Anyway, the recommendation from FAA in absence of POH info is still flaps-gear-flaps sequence: https://www.faa.gov/sites/faa.gov/files/regulations_policies/handbooks_manuals/aviation/airplane_handbook/10_afh_ch9.pdf

With one caveat, The standard for teaching and testing tend to be immediate 100% power then flaps-gear-flaps, this seems to be tailored for some types with draggy flaps and underpowered engines. I think one needs to show this on check-rides, if the examiner want to see it that way Other examiners only care about getting back in one piece without safety compromised: Ok, as long as one has good reason to deviate from POH or understands any implications on performance. Outside such check-rides, I see nothing “wrong” or “illegal” in say M20J with: 50% power gear up, re-trim, 100% power, then flaps. It’s mostly for convenience…

One can “legally” opt to land and takeoff without flaps, if they wanted. So I fail to see why order (or deviation) from POH matters? As far as I know there is nothing legally binding in Mooney POH (or any other CS23/FAR23 aircraft) regarding the use of flaps, they are always treated “as required by pilot”. For part91, only limitations in TCDS and Section2. matters… If someone go and write “operator book”, the FAA won’t approve it unless it complies with all sections of POH (or they have a waiver from FAA or aircraft manufacturer), this stuff is very relevant for say part121 airline or part141 school: if they will have flaps failure on approach, they call it “abnormal landing” and do the paperwork after, if they have flaps failure before takeoff, they look at CDL/MEL and decide if it’s “abnormal takeoff” covered by their “operator book” or call engineers. If pilot is not flying by the book, someone will throw the book at him

VPRacing/LyondellBasell are a relatively new and small player in Avgas, they are mainly into "formula", however, they went for PAFI/ASTM, which is the "slow & together" As for their 100E, they passed most of serious testing in TSIO550K, and now they are working through ASTM While 100LL may go away the big players like Shell, Total...who drive ASTM will be around for a while (they have SAF, JetA, Mogas)

I have done some of these, it's not practical (many places have tons of rules on noise). Sometimes it's what one needs to do in places where options ahead are limited with built up areas ahead, the majority of these places down here already require 45deg turn right after departure from runway axis as "normal noise departure"... Flying tight pattern with steep angle (less power) is also helpful, although, this skill is not longer in fashion as pilots are taught from day 1 to fly "wide B52 bomber patterns" on "PAPI/VASI using 3deg glide" with "stable approach". Anyway, tight departure and tight pattern helps when flying VFR: one day as one will need it, as we say, it's good to invest in own luck rather than waiting for surprise ! Then there is IFR flying: prescribed SID or ILS paths or low vectoring, especially IMC, not much choices than keeping straight wing level, on sensible speed, and hope for the best...

I remember reading the UK TEL company Innospec wanted to get out of TEL market by 2030 I am sure someone else can fill the void, the question how much they will charge? https://avweb.com/air-shows-events/at-some-point-producing-the-lead-in-leaded-avgas-can-become-too-expensive-to-be-worth-it/ TEL price contribution to 100LL is in order of 0.1€/L (it was 0.04€/L 5 years ago), even if they double the price, it is still under 5c per USG of 100LL

Sunday was a great day to visit Microlights MULM expo (LSA machines) in France, I am very impressed by the new shinny "250 ULM/LSA": they can fly at FL250 or 250ft agl doing 250kts speeds, unfortunately at 250k€ they are still beyond my budget, I can get an Ovation or Encore for that price Return flight was done IFR over Paris, we wanted to overfly Disney, our flat and see Melun airshow from 7000ft but ATC want us at 5000ft before being vectored away: two Pitts were using all the airspace in their RAT at the way to 5500ft !! Kid waiting for the "mini-train" Route over Disney in East of Paris, Disney, On ILS for Toussus (LFPN)

Thanks, I watched that part (starts at 40:00), as expected UND were abusing their engines…even with 100LL they would have the exact same problem (they did not even run 50% vs 50% of fleet on 100L vs UL94) Definitely not aromatics as Lycoming suggested, I did run the same Archer with same engine on UL91 (Avgas available in Europe, basically 100LL without TEL and no aromatics) and many times using SP98 auto-fuel (full of aromatics, sort of EN228/AKI93 with even lower MON 87 octane rating), however, I flew richer than 100ROP and I swear, I never ever let CHT slip above 380F, that Archer still fly using Mogas with no issues ! Swift claimed no one else had valve recession problems using UL94 in the last 10 years, except UND (they have engines replaced regularly on warranty anyway even with 100LL )

By the time you reach that place, you have no other choice than buying, otherwise you are not going back

Did UND share any public data on their story? I recall GAMI repeoduced detonation and valve recession with UL94 while 100LL performed well (likely true in extreme scenario), then Lycoming blamed aromatics in 100R (likely wrong), Swift blamed "operator technique" (likely true as UND were very aggressive with engines) http://avweb.com/aviation-news/swift-recommends-limiting-peak-or-lean-of-peak-operations-with-94ul-for-now/ I went with the latter: UND students don't know how to manage engines (I recall reading the SOP is to red-box at 20ROP or peakEGT when using 70%-80% power while CHT north of 450F) For engines, with all these initial "roll-out of new fuel" one has to be careful with selection bias on the operator aide, like all sort of feedbacks sometimes the issue is NOT the product but "A SPECIFIC" user, we will see more and more of operators getting into engine management education as more alternative fuels gets introduced. For airframe, things are different, the user has no choice if the fuel is bad for paint, pipes, sealants. In terms of costs, I need to decide between engine overhaul (60k$ job)? or tank reseal with new paint (25k$+25k$ job)? in the meantime, I am fine with keeping CHT < 380F, I already do this when using 100LL, happy to pay +2GPH or -10kts to achieve it

I think home airfields, one can have few places to "put it" or "cut the loss", also, one would have sampled all low level pattern and all runways under different winds. However, the two absolute height limits will apply everywhere: one height to "turn back" and one height to "level wing" before crash... Not long time ago, a Mooney M20F tried return from under 300ft agl, https://asn.flightsafety.org/wikibase/520704 With partial power, the decision of making "land ahead" or "turn back" is even more complex but one has to adjust the "two decision altitudes"

I agree there is that gamblea element and it gives a flase sense of security. Aside from myriades of variables like wind, length and layout, most of these "impossible turn videos" talk about ONE SINGLE variable: the critical altitude from which you you bank 45deg (or 60deg) and pull to turn near stall or like there is no tomorrow... What is missing is SECOND variable which is the altitude by which you tend to level wings on 1G with speed near Vref? I assume second altitude is about 300ft-400ft agl in Mooney? and reasonable altitude loss for 270 deg turn is 600ft? while reasonable altitude loss for 360 deg turn is 800ft, so there you go 1100ft-1200ft agl for 360 return and 900ft agl for 180 return (even if one can fly tighter turns in 20s, they ars still showing -1000fpm for these), these are the usual "patten altitudes" where one can make it back from engine failures, anything bellow is "highly optimised": as someone said, in emergency, you either raise to the occasion or descend to the lowest level of competance Without some sort of "stop loss" for altitude, the whole manœuvre is pure gamble (or it's "all-in") When one fly forced landing from an altitude higher than pattern, they tend to have some key position ("called low key") to reasses if they need to stretch or tighten their base leg (or put flaps), when one fly forced landing straight, they tend to have an aiming point in the field ahead, when one flies "impossible turn", it's more like do it or die hard trying...

Of course, the quickest way to lose altitude is dynamique stall (spins also consume lot of altitude per turn) However, to fly a turn with minimum altitude loss you need 45deg bank and few kts above 45 deg stall speed, the typical "best turn speed" is something like 1.2×VS + 10kts (same for min sink speeds at 45 deg), doing 45deg turn at best glide Vbg with unloaded wings (1G) to result in huge altitude loss in turn. All of this stuff is theoritical, the only case where one is interested in this is gliding ("stalling inside tight thermal to climb" ). If one is interested in more theoritical stuff, a wingover flown at 0G is the quickest was to fly 180 with minimal loss of altitude I have done 180 chandelles with power and 180 wingovers without power: in Mooney, with +/-200ft, you are on opposite heading quicker than 45deg loaded turn (in glider -150ft, I am on opposite heading after wingover), unless stuff after an EFATO as no one is brave enough to do it... All this theoritical aerobatics stuff go into the bin at low altitudes as the human factors kicks in when one loses visual reference of the horizon (the scary ground fills the whole view outside), I was flying with a Polish national champion who did aerobatics by the numbers, he finished with loop at 500ft and wingover at 300ft straight to land on final with zero energy left On my side, I tend to keep wings level once under 400ft agl and the speed near Vbg or Vref. I may do +/-20deg bank angle to pick left and right within +/-30deg (sort of rate1 turn as some IFR pilots call it)

I am sure most of us don't exceed CHT > 420F on takeoff? in M20J, you need to climb at VX with cowl flap closed to 2000ft with OAT at 100F, assuming one is full rich (they need to be at least 250F - 350F Rich of Peak to keep out of "red-box"). Most of us already accept lower climb gradients as we tend to "baby sit" engines under 390F on climb by using more speed or more fuel to keep out of red-box, same when we lean LOP under 65% power, it's not optimal but that's how one keep their engines running for a long time. I don't feel that I compromise any safety for keeping CHT < 400F even while using 100LL: I can still fly where I want with no apparent limitations, well I use full rich for takeoff (unless high density), I climb at Vy to cool my engine and I tend to LOP under 65% power. I would do the same with 100R, Of course there are pilots who can melt an IO360 by aggressive leaning toward peak EGT at 100%-75% power, having 100LL or 100R, won't change anything for such pilot...

The problem with UND was not "full power (rich climb)", it was their "leaning technique (cruise)". In UND, they were running Archers at 70%-80% power on peak EGT with CTH > 450F as "normal business", I get that Lycoming engines are certified by FAA to cope with continuous max power and max CHT = 500F on 100LL, however, only a monkey flies like that (most of us tend to babysit the engine). I have operate the Archer that UND flew, albeit on less hours (450h over 5 years), I flew it using SP98 (87 Octane) on Mogas STC, takeoff were never a problem and I never let CHT > 390F in climbs or cruise: * Patterson STC, prohibited peak EGT operation on Mogas EN228. * Lycoming advise against peak EGT operations at 75% on Avgas 100LL. Basically, they were "red-boxing" even with 100LL, it's not advisable and it's false fuel economy. Most schools tend to have various SOP to keep CHT under 400F, use 55%-65% power? keep full rich? I think on gently engine management, I am sure one can make sacrifices but for airframe, fuel tanks, paint...there is not much one can do... If 100R is fine for airframe, I am fine using it even with bunch of placards on leaning or CHT

Did they find some Roman's empire remains? (a British joke or excuse everytime someone digs and leave it that way)