Marc Cook, Author at ByDanJohnson.com

GAMI Releases G100UL Into the Wild

By Marc Cook || October 31, 2024 4 Comments (Edit)

This week GAMI, which developed the STC-approved G100UL high-octane avgas replacement, announced that a shipment of the fuel has been delivered to the Reid-Hillview airport in California. A load of 7500 gallons will be sold by the county-owned fueling service via truck. Currently, the only fuel available at KRHV is mogas, Jet A and Swift’s UL94 unleaded. Cost of a gallon of G100UL is expected to be close to what the County of Santa Clara is selling UL94 now, $7.59. Note that fuel prices in this part of California vary greatly, from $5.37/gallon at Tracy to $10.87/gallon at San Jose. G100UL received supplemental type certificate approval for all gas engines in fixed-wing aircraft so certified airplanes will need this STC to legally use the fuel. Experimentals do not require the STC. To encourage aircraft owners to try G100UL, GAMI is offering the STC for free at a rollout event this Saturday, November 2, from 9am to 6pm, and will “provide the services of an I.A. at KRHV during the day on Saturday, November 2nd, to ‘sign-off’ the required Form 337 at no charge.” Also, according to GAMI, “Residents of KRHV who purchase a G100UL STC between now and midnight on November 1st, 2024, will receive a full refund of the purchase of that set of STCs. Moreover, by having G100UL “commercially available,” GAMI believes it will have tripped a requirement established by a consent decree that will force some California FBOs to sell any fuel that has lower lead content than 100LL. As reported by AVweb, the load of G100UL had to come from its origin in Louisiana to California entirely by truck. GAMI previously announced that Vitol Aviation has refined some 1 million gallons of G100UL currently being stored in Louisiana. Finally, a note on comments. Previous coverage of the transition from leaded to unleaded fuel has prompted notably heated debate. Whether or not you believe that lead in aviation fuels constitutes a verifiable health hazard, the truth is that industry and legislative action will push general aviation toward an unleaded future. It is inevitable. Please refrain from making this political.

Where Are We On Unleaded Avgas?

By Marc Cook || October 17, 2024 10 Comments (Edit)

AOPA's Beech Baron ran 200 hours with 100LL fueling one engine and GAMI's G100UL the other (Photo: AOPA)

Industry wide progress on a so-called drop-in replacement for high-octane avgas always seems to go in fits and starts. Lots of noise then a period of silence. Is anyone actually doing something on this, you may ask? The answer is most definitely yes, but the recent news has come more in dribs and drabs than the full-firehose effect we expect around the major airshows. But let’s start here. The other shoe dropped on the sale of leaded avgas in California. There had been a legal agreement (a consent decree) that depended on the availability of an alternative to 100LL but now the transition is being forced by new legislation signed into law this month that “would prohibit an airport operator or aviation retail establishment, as defined, from selling, distributing, or otherwise making available leaded aviation gasoline to consumers on or after January 1, 2031.” Coincidentally, the End Aviation Gasoline Lead Emissions (EAGLE) program has as its goal a replacement in place by the end of 2030. Reportedly, the California effort was originally slated to take effect earlier but was pushed back with the help of aviation special interest groups. According to reports, there are still three candidates in the unleaded-avgas derby, so to speak. General Aviation Modifications, Inc. (GAMI) has had its G100UL fuel in development for decades and received a fleetwise STC in 2022 for virtually all fixed-wing aircraft. GAMI has chosen not to participate in either the current EAGLE or its predecessor PAFI programs that are pushing for an ASTM spec for the replacement fuel. GAMI’s path has got it well and truly cross-threaded with the industry groups. One could argue that GAMI is trying to “go it alone,” but recently Swift Fuels, which, in addition to VP/LyondellBasell, makes up the remaining contestants on the scene, has received an STC for its 100R to be used in Cessna 172R and 172S models. Swift CEO Chris d'Acosta said, “Our 100R unleaded avgas product will be the preferred fuel to eliminate toxic lead from avgas. We are actively working with industry and OEMs on FAA-certifications and ASTM International specifications. Yes, the FAA recently approved a critical part of our engine and airframe (STC) certification program. This follows a similar FAA / ASTM approval pattern we architected for UL94 avgas over 9 years ago.” Getting the Swift 100R into public use would help the company gain real-world experience with the fuel. Similarly, the demonstration program undertaken by AOPA last year has concluded, according to reporting by the association. AOPA had run a Beech Baron for 200 hours with one engine consuming just 100LL and one consuming only GAMI’s G100UL. “The pilots who have flown the AOPA fuel demo Baron have been unanimous that the unleaded fuel used—GAMI G100UL—acts just like avgas in flight. No special techniques are required for engine starts, full-power takeoffs and climbs, cruises, or descents. If the airplane didn’t have decals and placards proclaiming the presence of unleaded fuel in the left engine, pilots would be hard pressed to notice,” the association said. Testing did reveal some peculiarities. Apparently an overly rich mixture will leave a dark, ashy deposit on exhaust pipes and spark plugs. In addition, the fuel will apparently stain paint if not carefully cleaned up. In the AOPA report, GAMI founder and developer of the G100UL fuel, George Braly, said “If the fuel is left on the surface and exposed to the UV from sunlight, then that will cause some brown discoloration.” Finally, there was a very public display of a leaking fuel bladder in the Baron on the side that was using G100UL. According to AOPA, the culprit was more likely old fuel bladders, which were originally made in the 1970s (but later “refurbished”), than a corrosive effect of the fuel. So where does that leave us? GAMI has approval for fixed-wing aircraft now but has yet to make G100UL widely available. Swift will be seeing 100R flying in certain Cessnas. And VP/LyondellBasell is still in the development phase, which is working toward getting an ASTM spec. With California backing down from making leaded avgas illegal until 2031, some of the pressure might seem to have come off, but the clock is still very much ticking. https://www.youtube.com/watch?v=H_FOMu2dFq8

Flying Dynon’s Emergency Glide Feature — Go Down Easy (UPDATED)

By Marc Cook || October 9, 2024 3 Comments (Edit)

I probably shouldn’t admit this, but some features that come with the latest electronic flight instruments have left me a little, um, disinterested. Until I try them, that is. A good example is the concept of “safe glide” or even autoland. Garmin introduced both concepts a few years ago, though the full-autoland idea is more recent and limited to high-end aircraft where the system can control the engine directly. That’s not at my pay grade. The more common version is what Garmin calls Smart Glide and, more recently, Dynon rolled out what it calls Emergency Glide. They work similarly: When commanded, they set up a controlled descent to the nearest viable airport and let the pilot concentrate on other things. To be honest, I was a bit meh about them as safety features. After all, you’re trained to set the airplane up for best-glide speed as soon as you recognize a power failure and all good pilots fly along considering which airports beneath them are reachable. Things like terrain-aware glide rings on MFDs and EFBs take much of the guessing out of that. So I was skeptical until I flew with the Dynon version in my own airplane. To get this new functionality in the Dynon universe, you need to be running at least a Dynon HDX system—it is not offered for the Classic or Touch models—or one of the later AFS systems. You need a two-axis Dynon or AFS autopilot. There are a few other requirements, including an up-to-date database and the airplane’s best-glide speed entered into the setup menu. Moreover, you have to have the autopilot’s “expert” mode enabled; but this is what most do and there’s no cost involved, just a setting.

Let’s Try It

Updating the software took but a few minutes and it didn’t break a thing—early success! In fact, there’s no outward indication you have the extra features. Until, that is, you press and hold the NRST key. Doing so brings up a notification on the primary flight display: HOLD TO ENABLE EMERGENCY GLIDE. Continue holding and the mode engages. The first thing it does is engage the autopilot in pitch and roll regardless of the previous autopilot mode. Then it syncs the indicated airspeed (IAS) bug with the preprogrammed best-glide speed and sets the AP to hold that value. Depending on how much power you still have available and your current speed, the autopilot might well pitch up to capture IAS hold but in my experience it does so gradually. Once captured, the AP will hold this IAS value plus or minus about 3 knots. (This could be an artifact of how my system is configured and/or the airplane’s responses.)

Once activated, Dynon's Emergency Glide system tells the pilot it's active right in the PFD section of the screen. You can't miss it.

So that’s pitch, and it’s the right way to go—quickly getting the airplane to its best-glide speed and holding it there while you troubleshoot. If that’s all the system did, it would be valuable as a way to manage energy and relieve the pilot of some workload. Of course, this was the easy part of the programming. Much harder is calculating where the airplane might end up. Dynon’s approach is reasonably conservative. It needs to see an airport within the predicted glide circle that’s reachable given the existing winds and not blocked by terrain. This last feature depends on a 1000-foot buffer and worked well in my tests. Emergency Glide will not point you at a nearer airport if there’s terrain in the way. Two outcomes are possible once you engage Emergency Glide. Either the system sees a viable airport or it doesn’t. In the second case, you get a NO VALID AIRPORT annunciation and the autopilot defaults to a track lateral mode that syncs with the current heading when Emergency Glide is enabled.

If there are no airports in range, the Emergency Glide system warns the pilot and engages a track-hold feature on the last heading.

Head This Way

For airports within range, the system sets the candidate as a direct-to waypoint, the autopilot to GPS NAV, calculates a desired vertical profile to the target and sets the altitude bug for field elevation. Moreover, if you have a Dynon or AFS com radio, the feature will pre-program the needed frequencies. In my case, with the Dynon HDX talking to a Garmin GTR 200, it loads the target airport’s UNICOM or tower frequency into the standby slot. All of this takes but a few seconds, giving the pilot a chance to begin troubleshooting while the airplane is headed in a good general direction at a speed that prolongs the descent.

When you're close to the airport, Emergency Glide prompts you to take control.

Let’s say you have not discovered a tank run dry or some other fixable reason the engine went quiet. The Emergency Glide feature keeps doing its thing. If you have altitude to spare, about a minute before reaching the airport, the system will annunciate NEARING AIRPORT TAKE CONTROL. It doesn’t kick the autopilot off at this point but is warning you that you’re close—time for the pilot to set up for the landing. If you arrive with altitude to spare and have crossed the midpoint of the airport, Emergency Glide will change to CIRCLING APT mode, which is simply a 20° left turn. Dynon notes that because this is a roll-only mode it’s no longer taking wind into account so you could drift away from the airport.

If you get to the target airport with altitude to spare, Emergency Glide will set up a 20-degree left turn around the runway for you. It does not account for wind, though.

Should the airport originally designated become untenable—perhaps the winds have changed or atmospheric conditions have created more sink—Emergency Glide will return to track-only mode with IAS hold. It’s clearly annunciated on the PFD but it’s worth understanding that it could change modes on you. These are all worthy goals but what the Dynon system can’t do—and the company is explicit that it doesn’t—are advanced functions like lining up for a particular runway or even committing the landing. The pilot remains on the hook for configuration control and the hopefully successful touchdown. But there’s little doubt that Emergency Glide is a valuable tool to give the pilot some breathing room to troubleshoot in the air and have the controlled descent handled by the EFIS. The altitude saved or energy preserved by quick actions of the Emergency Glide feature could make the difference between getting back to a runway or putting it down somewhere a lot less hospitable. https://youtu.be/_FUNZeIwk3Q

FAR Revisions to Fix the “LODA Problem”

By Marc Cook || October 3, 2024 2 Comments (Edit)

The FAA takes this explanation further in today’s ruling published in the Federal Register and to become effective December 2, 2024. “Previously, §§ 91.315, 91.319, and 91.325 generally prohibited flight training, checking, and testing when compensation is provided. In 2020, the FAA issued Warbird Adventures, Inc. an emergency cease and desist order restricting the operation of aircraft that held special airworthiness certificates carrying people for compensation or hire. The operator brought a petition for review of the emergency order before the court. On April 2, 2021, the court dismissed the petition for review of the cease and desist order. Following the court's dismissal, several aviation industry groups sought clarification from the FAA on how the decision affected flight training in experimental aircraft since the prohibitory language of § 91.315 for limited category aircraft is the same as that in § 91.319 for experimental aircraft (notably, the same prohibitory language exists in § 91.325 for primary category aircraft). As a result of this court case, in the NPRM, the FAA proposed to clarify prohibitory language and to explicitly enable flight training, checking, and testing under certain conditions in aircraft holding special airworthiness certificates.” That clarification is here. The new rules include a “self-implementing provision that amended the operating rules to permit certain flight training, testing, and checking in experimental aircraft without a letter of deviation authority (LODA). Likewise, section 814 of the FAA Reauthorization Act of 2024 (Pub. L. 118-63) directed that, under certain conditions, flight training, testing, and checking in limited, experimental, and primary category aircraft do not require a LODA from the FAA. The NPRM proposed to modify §§ 91.315, 91.319, and 91.325 to clarify prohibited operations, as well as direct stakeholders to a newly proposed regulation, § 91.326, that provided instruction on conducting certain operations for compensation or hire.” Incidentally, since the rules are not yet in force, you will not find a copy of FAR 91.325 online. Finally, there is some cleanup work around ELSAs. “Lastly, on October 24, 2018, the FAA published an NPRM titled ‘Removal of the Date Restriction for Flight Training in Experimental Light Sport Aircraft.’ For the reasons provided in the document withdrawing the ‘Removal of the Date Restriction for Flight Training in Experimental Light Sport Aircraft’ NPRM, the FAA withdrew the NPRM and, instead, developed this rule to resolve the discrepancy more broadly for all experimental aircraft.” Meaning ELSAs are to be lumped in with other Experimentals in this category.

The FAA has published a glut of rule changes affecting CFR Part 1, 11, 61 and 91 regulations that affect, among other things, pilot privileges across a wide range of activities. But for owners of Experimental/Amateur-Built aircraft, the best news is the rescinding of the so-called LODA rule. Recall that in 2021, the FAA changed its stance on owners getting flight instruction in their own homebuilts, which resulted in the need for a “letter of deviation authority.” The FAA, to its credit, quickly came up with a system to issue LODAs to owners and flight instructors, but the underlying requirement flew in the face of precedent. The FAA takes this explanation further in today’s ruling published in the Federal Register and to become effective December 2, 2024. “Previously, §§ 91.315, 91.319, and 91.325 generally prohibited flight training, checking, and testing when compensation is provided. In 2020, the FAA issued Warbird Adventures, Inc.

See This — Radiant’s Low-Coast Angle of Attack

By Marc Cook || October 1, 2024 1 Comment (Edit)

Sometimes the simpler the better. At least that's the philosophy James Weibe has always seemed to follow. He's definitely embraced that approach with the new visual angle of attack (AoA) indicator. No electronics. No special pitot tube.

The Radiant AoA is a simple vane-style pointer you mount to the wing nearest you—well, because you want to see it. According to Radiant, "Our new Visual AOA provides direct visual feedback of the aircraft’s Angle Of Attack. Any pitch change or power change is immediately reflected in the indication. It is designed to mount on the leading edge of an experimental aircraft. It is available with a generic mount for the leading edge of aircraft. A top side mount for Sonex (low wing) aircraft is also available." The instrument is easily removable to prevent skewering your next Young Eagles ride. (Mom says thanks.) Weibe includes a demo video for your consideration. "When viewed in flight, the responsiveness to pitch change is immediate, and the vane position precisely shows the changes in airflow and AOA. The best example of this is a 30 second demo clip. In the video, James manipulates the pitch of the aircraft, thus causing the AOA vane to show the effect immediately and precisely." Prices start at $59.95. https://www.youtube.com/watch?v=Fy3llLbcWp0 https://www.youtube.com/watch?v=lB1pJj9RKro

Sometimes the simpler the better. At least that’s the philosophy James Weibe has always seemed to follow. He’s definitely embraced that approach with the new visual angle of attack (AoA) indicator. No electronics. No special pitot tube. The Radiant AoA is a simple vane-style pointer you mount to the wing nearest you—well, because you want to see it. According to Radiant, “Our new Visual AOA provides direct visual feedback of the aircraft’s Angle Of Attack. Any pitch change or power change is immediately reflected in the indication. It is designed to mount on the leading edge of an experimental aircraft. It is available with a generic mount for the leading edge of aircraft. A top side mount for Sonex (low wing) aircraft is also available.” The instrument is easily removable to prevent skewering your next Young Eagles ride. (Mom says thanks.) Weibe includes a demo video for your consideration.

AOPA To Get New Prez in 2025

By Marc Cook || September 25, 2024 4 Comments (Edit)

The Aircraft Owners and Pilots Association has announced a successor to current president Mark Baker, who is set to retire at year’s end. In his place comes Darren Pleasance. The association notes that this is only the sixth president in its history, dating back to 1939. Baker has been on the job for more than 11 years. Somebody buy that man a beer! AOPA notes that Pleasance has more than 8000 hours in 50 different types and currently owns three airplanes: A Piper Meridian, a Van’s RV-6 and a Progressive Aerodyne SeaRey. “I'm honored with the opportunity I'm being given to help steward AOPA forward into the future, and I'm inspired by the role AOPA will continue to play in protecting our freedom to fly,” says Pleasance. “I'm grateful for the privilege I'm being given to lead this incredible organization that has had such a positive impact on my life and the lives of all of us who love aviation.” Pleasance joins AOPA at a time when there are pressures across the spectrum, from finding a leaded-fuel replacement to rapidly rising aircraft-ownership costs. But there are opportunities, too, such as with the MOSAIC program expected to become a reality sometime in 2025. For his part, outgoing president Baker says, “I’m confident that Darren is the right person to lead AOPA into its next chapter. He is a pilot’s pilot with a genuine passion for flying. He combines that excitement about aviation with leadership experience at some of this country’s top consulting and tech firms, giving him the right balance of business skills and kinship with our members.”

Kitfox’s Reasons for De-Emphasizing the SLSA

By Marc Cook || September 19, 2024 6 Comments (Edit)

In the normal order of things, a successful product will probably remain in production until demand slackens, technology changes or it can’t be built effectively. But there are other reasons, some not so obvious. Case in point? Kitfox Aircraft. Since 2009, when the company began selling the Series 7 Sport, it’s cranked out roughly 40 of the factory-built LSAs, with sales always outpacing the company’s ability to produce for the first few years. Eventually, Kitfox began selling the S7 Sport with various engine options, up to the Rotax 914. Sales over the last few years have slowed to a relative trickle, but not really for reasons you’d think. First of all, the company’s bread-and-butter is the kitbuilt side of the market, so when the factory buildings are busy and full to overflowing and the order book is growing, company owner John McBean elected to prioritize the kit side of the business over the ready-made side. He describes it as a balancing act but understandably so; you want to keep your core customer happy. And so this partly explains why Kitfox is quietly putting the SLSA business on hold. But it’s not the only excuse. According to McBean, the simple fact is that today’s customers demand better equipped airplanes. They want really nice paint. They want two-screen EFISes and the most powerful engine available, which, today, is the 160-hp Rotax 916. They want nice interiors and all the options.

Such niceties add not just cost but weight. And in the SLSA rules, there’s a minimum useful load of 430 pounds, which means an empty weight of 890 pounds or less. In the robust Kitfox, you can get there with a lightweight avionics package and the lighter-weight Rotax 912 ULS or iS, but once you start ticking off the options boxes and pop for the 916, it’s much more difficult to do. And the simple fact is that a fully equipped, highly optioned airplane is what customers want. So what’s McBean’s solution? Shift those resources from the SLSA whole-build to a program of factory builder assistance, much like some of the other types where the builder comes to the factory to participate in the build. The resulting Experimental/Amateur-Built aircraft has a lot more flexibility in content and maintenance. What of MOSAIC, you ask? The current Kitfox Series 7 models all are engineered for a 1550-pound maximum gross weight, which would fall well into the current MOSAIC proposal, and so would the stall speed. There are no reasons the highest-spec Series 7 won’t be a good MOSAIC airplane to be flown by Sport Pilots under the new rules. Whether Kitfox resumes building SLSA models is more a matter of what the market demands than what can be produced out of the Homedale, Idaho, factory.

Why is Angle of Attack Important? Let’s Ask Someone With Experience

By Marc Cook || August 29, 2024 4 Comments (Edit)

As part of our parent company's coverage of AirVenture this year, I had a chance to sit with several in the industry and talk about what's happening generally and about new (and even re-emerging) technologies. One of those talks was with KITPLANES editor at large Paul Dye, who is working hard to educate pilots of LSA and homebuilt aircraft about the value of AoA and how easily it can be implemented with today's instrument packages. https://youtu.be/hkS1Kw_k2-E

As part of our parent company’s coverage of AirVenture this year, I had a chance to sit with several in the industry and talk about what’s happening generally and about new (and even re-emerging) technologies. One of those talks was with KITPLANES editor at large Paul Dye, who is working hard to educate pilots of LSA and homebuilt aircraft about the value of AoA and how easily it can be implemented with today’s instrument packages.

Let’s Talk Strategies for the Rare Ones – When We Can’t Answer Your Questions, Research Can!

By Marc Cook || August 27, 2024 1 Comment (Edit)

Here at the ByDanJohnson.com site, we get questions all the time related to aircraft whose companies are defunct or have gone on to something else. "Where can I find this part?" "How do I get documentation?" Sometimes we have the answers and sometimes we don't. But it's something we talk about every week, so in this video we discuss tactics for owners and potential owners of "rare" LSAs. What are the resources available to you? How can you get those parts you need? Let's discuss! https://youtu.be/aZrMJFDFsZc

Here at the ByDanJohnson.com site, we get questions all the time related to aircraft whose companies are defunct or have gone on to something else. “Where can I find this part?” “How do I get documentation?” Sometimes we have the answers and sometimes we don’t. But it’s something we talk about every week, so in this video we discuss tactics for owners and potential owners of “rare” LSAs. What are the resources available to you? How can you get those parts you need? Let’s discuss!

MOSAIC Next Steps—An Interview with Rian Johnson

By Marc Cook || August 13, 2024 11 Comments (Edit)

As part of the Oshkosh Live streaming television the Firecrown aviation division (which includes this site as well as KITPLANES) did from AirVenture, I sat down with Rian Johnson, who is, in addition to his role as head of design engineering at Van's Aircraft, the chair of the ASTM F37 committee working on MOSAIC industry-consensus standards. In this interview, he looks ahead at the next steps for MOSAIC and offers his perspective for what might come out of the FAA next year when the new rules package is announced. https://youtu.be/9FfylxAuK3c

As part of the Oshkosh Live streaming television the Firecrown aviation division (which includes this site as well as KITPLANES) did from AirVenture, I sat down with Rian Johnson, who is, in addition to his role as head of design engineering at Van’s Aircraft, the chair of the ASTM F37 committee working on MOSAIC industry-consensus standards. In this interview, he looks ahead at the next steps for MOSAIC and offers his perspective for what might come out of the FAA next year when the new rules package is announced.

Gas Pains — The Latest Mayhem Surrounding a High-Octane Avgas Replacement

By Marc Cook || July 3, 2024 4 Comments (Edit)

The ongoing issue of finding a replacement for leaded avgas took an ugly turn recently after Cirrus advised owners that use of anything other than an “approved” fuel would likely invalidate the engine warranty. “Per Continental and Lycoming, only approved fuels may be used for an engine to be covered by warranty. As the GAMI G100UL fuel is a non-approved fuel per Continental and Lycoming, engines known to have run this fuel may not be covered by the OEM engine warranty. For specific details, please refer to the respective Continental and Lycoming engine warranty documents,” Cirrus said in a statement. “While some aspects of the initial Cirrus testing of the GAMI G100UL fuel are encouraging, other areas, including materials compatibility, remain inconclusive.” At issue is that the GAMI fuel has not been submitted to the ASTM for “approval” but has received FAA approval in the form of a Supplemental Type Certificate that applies to virtually every spark-ignition aviation engine made. Cirrus’ stance is that this is, therefore, not an approved fuel by way of ASTM.

Soon after, GAMI responded by noting that an SR22 has been flying on GAMI fuel since 2010. In its statement, GAMI said: “G100UL Avgas is fully approved for use in all Cirrus Aircraft and in all Continental and Lycoming engines!” In the case cited by Cirrus regarding fuels compatibility, GAMI says that “Cirrus failed to inspect the condition of the fuel tank before use of 100UL Avgas in the wing of their model year 2014, company owned, ‘R & D’ aircraft, an SR22T, N72DF. Therefore, Cirrus does not know that the fuel tank sealant had not already ‘failed,’ i.e., partially de-bonded, before Cirrus first began to use 100UL avgas in one wing of N72DF.” Moreover, GAMI says that “in 2013, Cirrus engineers fully tested G100UL Avgas at Cirrus in their fiberglass/epoxy wing fuel tanks and wrote a favorable report which was formally approved by the FAA. A few weeks after Cirrus first observed the condition of the PTE sealant in the wing of N72DF, Cirrus told GAMI that Cirrus had reverted back to the exclusive use of the industry standard polysulfide (PSD) sealant in the Cirrus tanks on their production line.” The company concludes by saying, “The FAA has fully investigated this matter, for nearly a year. To date, the FAA has found no 'safety of flight' issue associated with the single adverse report from Cirrus.” Hot on the heels of the GAMI rebuttal, Lycoming chimed in with this statement: “Lycoming Engines provides a Limited Warranty against defects in material or workmanship. Lycoming’s Limited Warranty does not cover damage caused by operation outside of Lycoming’s published specifications or the use of non-approved fuels or lubricants. Lycoming publishes specifications for approved fuels in Service Instruction 1070. G100UL is not listed as an approved fuel in Service Instruction 1070. Lycoming evaluates warranty claims on a case-by-case [basis] in accordance with the terms of its Limited Warranty. However, customers should be aware that use of fuels not approved in Service Instruction 1070 would constitute operation outside of Lycoming’s published specifications.” The FAA followed by saying that warranty issues were between the manufacturer and the customer; it’s not in that chain at all.

And then came word that the key player in the EAGLE program for an unleaded avgas alternative had pulled its ASTM application. “Lyondell had balloted its ASTM Test Spec and had received some negative comments, so have pulled it and are addressing the feedback and plan to re-ballot in the near term,” Castagna quoted an FAA official as telling him, as reported on AVweb. Which now leaves Swift to complete its work on a 100-octane unleaded fuel and the already FAA-approved GAMI G100UL on the table, though it’s broadly considered that Lyondell/VP Racing will go back to work on remedying the unstated issues found in early testing. It’s unclear what those were, though it’s reasonable to assume they related to either the fuel’s ability to suppress harmful engine detonation or materials compatibility, or both. In the days since that reporting, Lyondell clarified the status of its unleaded avgas, per reporting in AVweb. “LyondellBasell has not paused or suspended our efforts to obtain an ASTM test fuel specification. We continue to pursue ASTM certification for our UL100E unleaded fuel through the normal balloting process. We balloted a test fuel specification and research report on UL100E in May for the first time and the ballot closed on June 9, a week before the ASTM meeting. The ballot received 65 affirmative votes, 5 negative votes and 228 abstentions for a 93% affirmative rate. Since our first ballot received a negative comment on our proposed color method that we found persuasive and others we are still reviewing, we withdrew the ballot to make the correction and reach out to the other commenters. This is the standard procedure for making even minor changes to specifications. We will ballot a revised test fuel specification and research report for additional review and comment from the ASTM community as soon as we review the other comments and reach out to their authors. Since an ASTM specification is a required element of PAFI fleet authorization, we are committed to obtaining both as expeditiously as possible.” Parsing this, the "others we are still reviewing" is, again, unclear: Are the complaints of a similarly minor nature as the color of the fuel or is there more?

LSAs running the 900-series Rotax engines might be in a far better place than many should there be more trouble finding a true 100-octane unleaded replacement for avgas.

Since you’re reading this on ByDanJohnson, you’re probably wondering how this applies to you. Since most of the LSA market is powered by Rotax engines, it’s good to consider their guidance, which is relatively straightforward. In the current set of Service Instructions, Rotax defines the leaded option as our conventional avgas that conforms to ASTM D910, but also lists a number of other global standards including unleaded fuels that comply with ASTM D4814 as well as the UL94 conforming to ASTM D7547. According to Rotax, “In addition to AVGAS, various automotive fuel types with different quality are available. Due to various environmental, economic and political reasons a number of fuel types with different amounts of ethanol blend are available.” Rotax then allows use of auto fuel with as much as 10% ethanol, though it notes that “it is the responsibility of the aircraft manufacturer to test their fuel system components and supply any further information on techniques, procedures and limitations of using ethanol blended fuel.” Some airframe manufacturers fall back on Rotax’s fuel recommendations rather than make their own, though the ASTM process theoretically puts that definition on the airframe manufacturer. At this point, Rotax doesn’t explicitly say the GAMI fuel can or cannot be used. For now it’s an academic point because while GAMI says that it has had fuel produced—making it “commercially viable”—it is not yet widely available. What’s more, the STC held by GAMI does not include Rotax engines, though, technically, if G100UL works on old-technology highly turbocharged powerplants there’s no reason to believe it won’t also work with Rotaxes. And remember back at the beginning that Cirrus’ prime argument wasn’t that the engine wouldn’t run well on G100UL but that there may be materials issues with the airframe and systems. For now, if you’re flying behind (or in front of) a Rotax, you’re relatively well protected. Commonly available auto fuel is, in fact, the preferred fuel for most applications. Should there be continued issues with a candidate avgas replacement—say, one that doesn’t quite get to 100 octane, as required by the big engines—there's also a viable path to using 94UL exists. Overall, then, for most airplanes in the LSA sector, fuel will continue to be an issue—something we all watch like a slow-motion train wreck—but primarily an economic one.

Inside the Transatlantic Crossing of the Risen

By Marc Cook || June 27, 2024 16 Comments (Edit)

Ready to depart Voghera in Italy.

It all started last December, with a phone call I received from Alberto Porto. At the time, I was in Australia doing a report at the Gliding World Championship for theItalianTeam. Onthephone Alberto, designer and builder of the fastest ultralight in the world (430 kph/232 knots), with the simplicity that always distinguishes him, says: ”Andrea, keep yourself free for next June, I'll detail everything when you return to Italy.” You can imagine my curiosity in the meantime. A few weeks later, the mystery was revealed: the Risen Superveloce with the brand new Rotax 916 iS must be brought to Oshkosh, to AirVenture, the largest and the most important aviation fair ‘of the Universe.’ I knew well what Oshkosh meant. A strange word in Italian; it’s the headquarters of the EAA, basically an immense display of aircrafts with thousands of people camped under their wings for about a week. The show comprises hundreds of aeronautical displays that take place from 6am until deep into the night. I still remember the flames from a show with a squadron of A10s that made a low-pass. The napalm explosions made my face hot from hundreds of meters away, a huge fireball raised in the night sky. As I have always said, every pilot, at least once in his life, must visit Oshkosh.

The planned routing.

So, if I understand correctly, Alberto wants me to accompany him on the Risen to Wisconsin. Mmm, but which way do we actually go? I know well that the year before he delivered a Risen Superveloce to the States but he then passed through the “classic” North Atlantic route Scotland, Iceland, Greenland, Canada. This time, however, the plans are way more ambitious: The idea is to fly the new Risen Superveloce, with a Rotax 916i without stopping to refuel, leaving from Stornoway, Scotland. Basically doing something that only the Risen Superfast can do—fly at speed beyond 300 km/h, with 20 knots of headwind consuming only an average of 18 liters (4.5 gallons) per hour.

Andrea, foreground, dons the survival suit before crossing the Atlantic.

First comments I heard were: "It is not possible.” Instead I thought: Well, let's see if it's really impossible. The plane is here, the two "crazy" pilots are here, for me the mission it's already done.... We still have to do the math properly and analyze the flight data in detail, but the approximate summary is this: we left from Voghera [near Genoa, Italy] with only one straight route, landed at the Outer Hebridean islands, Scotland, to the only refuel before the second important leg. The ocean route, directly from the Hebrides to Canada, was approximately 3300 km flown in 11 hours. As I said before, at the moment we are still gathering the data, but the average speed estimated in the various sectors for each leg, was between 165 knots (305 kph) and 200 knots (370 kph), covering a total of 4050 nautical miles (7500 km), all of this using just over 100 gallons!

The first sign of civilization after 10 hours over nothing but water.

The ocean crossing, against the wind toward the west, with an aircraft that is truly an ultralight and without stops either in Greenland or Iceland for refueling—it’s now a reality. An incredible flight has just been completed with a recreational aircraft, all this thanks to extremely efficient parameters of the plane. The secret of the Risen relies precisely on this: efficient and clean aerodynamics, like no other aircraft, which allow you to make the best use of the engine. All of this is available to pilots whether you want to break a speed record or just cruise along at 2.1 gallon an hour at speed. The two-seat all-composite Risen has proven itself a speedster with the normally aspirated 912 and even more so with the turbocharged 915 previously fitted. With the new, more powerful Rotax 916 iS available, this is the first of the Risen to use it. This airplane will be on display at AirVenture next month.

An escort into Canada.

From the customs office in Appleton... success!

We recently reported that the newest version of the sleek, retractable-gear Risen had made a successful transatlantic crossing. From what we could piece together from outside accounts and posts on social media, it went well. But here’s a more first-person look at the crossing, from the perspective of the right seat. Andrea Venturini accompanied designer Alberto Porto on the epic journey across the pond. Here’s his account. It all started last December, with a phone call I received from Alberto Porto. At the time, I was in Australia doing a report at the Gliding World Championship for theItalianTeam. Onthephone Alberto, designer and builder of the fastest ultralight in the world (430 kph/232 knots), with the simplicity that always distinguishes him, says: ”Andrea, keep yourself free for next June, I’ll detail everything when you return to Italy.” You can imagine my curiosity in the meantime. A few weeks later, the mystery was revealed: the Risen Superveloce with the brand new Rotax 916 iS must be brought to Oshkosh, to AirVenture, the largest and the most important aviation fair ‘of the Universe.’ I knew well what Oshkosh meant.

Risen Completes Transatlantic Leg

By Marc Cook || June 19, 2024 5 Comments (Edit)

On June 14, a Porto Aviation’s Risen completed the transatlantic leg of its journey from Milan, Italy, to Oshkosh, Wisconsin. The company posted on social media: “We made it!!! I have been reluctant to post anything here before accomplishing this epic flight , being Italian I guess makes me more superstitious.A page in aviation history has been written by Alberto Porto and Andrea Florence (Venturini). 1900 nautical miles, average speed [of] 165 kts, with just over 43 gallons of fuel!!! We left this morning early in rainy Scotland and landed in the afternoon at Goose Bay the same day without refueling.” The company announced its cross-the-pond plans this May to bring the newly re-engined Risen to the U.S. While many versions of the retractable-gear Risen use the Rotax 912, the company had been fitting the turbocharged 915 iS. But this example has the newer, more powerful Rotax 916 iS. The turbo Risen normally carries around 32 gallons of gas (120 liters) but this example has longer-range integrated tanks with 50 gallons' capacity; Porto and Florence did not carry special auxiliary fuel tanks. The total distance is more than 5100 nm from Milan to AirVenture, but the Risen seen here has only 1200 nm to go, all of it with land beneath the slender, efficient wings. https://www.youtube.com/watch?v=FPQrgmSPzgU&pp=ygUOcG9ydG8gYXZpYXRpb24%3D https://www.youtube.com/watch?v=g_H220j2MVQ&pp=ygUOcG9ydG8gYXZpYXRpb24%3D

Checking in With Sonex’s Mark Schaible — Update on the High Wing and Will it Be a MOSAIC Design?

By Marc Cook || June 11, 2024 Leave a Comment (Edit)

Light Sport enthusiasts who appreciate light, simple, inexpensive airplanes have been watching Sonex Aircraft develop the High Wing model for a couple of years now. It'll first come out as an Experimental/Amateur-Built version but the company is very much open to considering an E-LSA and even, with some outside help, an S-LSA version. (Or whatever we're going to call that once MOSAIC is real.)

Company owner Mark Schaible joins us to talk about the airplane's gestation and expectations for performance and when it might fly. Hint: You'll be able to see a cabin mockup at AirVenture this year at the least. In general, Sonex is hoping for performance similar to the low-wing Sonex designs and will be building the first example as a taildragger with a 130-hp ULPower engine. Schaible also discusses changes to the design now that MOSAIC is closer to reality. Expanded Sport Pilot rules could allow Sonex to give the High Wing a gross weight above the current 1320-pound maximum for LSA.

By expanding the max-weight envelope, Schaible hopes that the High Wing will have even better useful load and will be a better option for those owners and builders who inevitably want more stuff in the airplane that ultimately adds weight. https://youtu.be/bV9WZkYxE6A

Light Sport enthusiasts who appreciate light, simple, inexpensive airplanes have been watching Sonex Aircraft develop the High Wing model for a couple of years now. It’ll first come out as an Experimental/Amateur-Built version but the company is very much open to considering an E-LSA and even, with some outside help, an S-LSA version. (Or whatever we’re going to call that once MOSAIC is real.) Company owner Mark Schaible joins us to talk about the airplane’s gestation and expectations for performance and when it might fly. Hint: You’ll be able to see a cabin mockup at AirVenture this year at the least. In general, Sonex is hoping for performance similar to the low-wing Sonex designs and will be building the first example as a taildragger with a 130-hp ULPower engine. Schaible also discusses changes to the design now that MOSAIC is closer to reality. Expanded Sport Pilot rules could allow Sonex to give the High Wing a gross weight above the current 1320-pound maximum for LSA.

Chip Erwin and the TrueLite Mow the Lawn — And Then Go Flying! (UPDATED AGAIN!)

By Marc Cook || June 4, 2024 2 Comments (Edit)

In our original post, we linked to video of the TrueLite performing taxi tests. Now it's done better: flying! See the new videos below as Chip Erwin documents the first flights of the TrueLite happening now in Florida. Those of us looking for pure flying in lightweight form can't help but be intrigued by the TrueLite ultralight, marketed here by Chip Erwin's Aeromarine company. "The taxi test went fine. I didn't have any airspeed reading so I'll have to see what's going on there," Erwin says in the video. While the 36 hp Vittorazzi Cosmos 300 ran a bit hot during the taxi tests, he feels it was because it sat idling for 5 minutes before the test, saying that it cooled down once he got moving. Here's a sampling of videos related to the TrueLite. https://youtu.be/udNuA0XnMtw?si=WsK6fHzYeF-SlfFY https://youtu.be/Lz522pGiTbk?si=0r7QGQLvgvffu4jo https://www.youtube.com/watch?v=NrrHSNex-Tw https://www.youtube.com/watch?v=GKrWp03yJHw https://www.youtube.com/watch?v=VbiCJYyQBhE

In our original post, we linked to video of the TrueLite performing taxi tests. Now it’s done better: flying! See the new videos below as Chip Erwin documents the first flights of the TrueLite happening now in Florida. Those of us looking for pure flying in lightweight form can’t help but be intrigued by the TrueLite ultralight, marketed here by Chip Erwin’s Aeromarine company. “The taxi test went fine. I didn’t have any airspeed reading so I’ll have to see what’s going on there,” Erwin says in the video. While the 36 hp Vittorazzi Cosmos 300 ran a bit hot during the taxi tests, he feels it was because it sat idling for 5 minutes before the test, saying that it cooled down once he got moving. Here’s a sampling of videos related to the TrueLite.

Crystal Balling — What Will Rotax Do Next?

By Marc Cook || May 30, 2024 19 Comments (Edit)

The Rotax 916 on the Carbon Cub UL (Jon Bliss photo).

Untethered prognostication is what you do waiting for the rain showers to blow through and the sun to reemerge on your long cross country. Me? I sorta do it for a living. (Such as that is.) And I get to do it often enough in front of people who work deep in the industry to see if I’ve landed close to the truth. Like playing Battleship with engineers and PR people. My latest prognostication jag centers on what’s next for Rotax. And it’s driven by a feeling that there’s no time to waste moving up the horsepower ladder. Here’s my argument. First, the traditional engine manufacturers have still not recovered from what they say are pandemic-related supply-chain issues, which causes huge delays in deliveries and helps drive prices quite high. In the Experimental realm, where I also live, new engines have become exceptionally more expensive, leading some builders to reassess their budgets and stop their projects where they stand. Second, Rotax has scored a big hit with the 916. Yes, it’s also expensive, but that extra increment from 141 to 160 hp has opened the door to new performance in several designs that were good on the 915 but are significantly better with the newer engine. Some of those airplanes would be even better with more power. Third, Rotax takes the world view that its products have to work around the globe, which means they can’t depend on 100-octane fuel. In the next slot up, which I’ll call the 200-220 hp range, we basically have traditional aircraft engines that require big octane to make power. You could, of course, run an even bigger Lyconsaurus at a lower compression ratio but the power-to-weight figures get even uglier. So a Rotax product at this power level that could use, say, the equivalent of a high-octane auto gas (as the 916 does) would be a huge win and provide owners with the option of using auto gas, the currently available 94-octane unleaded avgas that’s sparsely available or something else. Point being that any future engine should be not designed to require 100LL. Some Perspective It’s worth looking at where the Rotax line currently fits to help see a potential future. Of course, the 900-series engines are small four-stroke, flat-four engines with a gear reduction drive and liquid-cooled heads. The gear drive allows these small engines, which displace just under 83 cubic inches, to rev higher and make more horsepower. Our traditional engines, unburdened by gearboxes are, in effect, burdened by the inability to rev much higher than 2700-2900 rpm with any usefully sized propeller. As anyone who bases at an airport with a Cessna 185 present, as I am, you know that a big Continental spinning 2850 rpm for takeoff with a large propeller is a gloriously noisy thing. But it’s not something you’d aim for with modern sensibilities or worldwide acceptance in mind.

Continental's IO-520: Big, slow turning.

By gearing the 900-series engines, Rotax allowed them to make more power than their displacement suggests but also to turn their propellers more slowly, which is good for noise and, to some extent, aerodynamics. The downside is weight and complexity, but the relative simplicity of the 900-series engines and their small size more than makes up for it. More advantages to the 900-series designs include modern combustion chambers—especially compared to the ancient chambers found in parallel-valve Continental and Lycoming engines, a good reason these engines need high-octane fuel to make decent power—and liquid cooling. In short, you can run a modern design harder—more compression ratio, more turbo boost—before destructive detonation begins to impact power and the liquid cooling further adds to the detonation margin. So, What Should Rotax Build? Let’s get back to the assumption that Rotax needs to build an engine in the 200-220 hp range. (I’ll set aside for now the need for a 300-hp-class engine but not completely ignore it.) I believe the 900 series as we know it has reached its limits. Consider this: The 912 iS makes 100 hp without a turbo on just under 83 cubic inches, which is 1.2 hp per cubic inch—itself more than double the power density of a Lycoming. It needs to make 91 pound-feet of torque at 5800 rpm to do so, and that requires a BMEP (brake mean effective pressure) in the combustion chamber of 165 psi to get there. While the horsepower-per-displacement number seems impressive, that’s actually a modest BMEP, or about what a 180-hp Lycoming runs. Clearly the 912 iS isn’t working all that hard.

Everyone's fave: The 100-hp Rotax 912 iS.

But the 916 is. With 160 hp on tap for takeoff (limited to 5 minutes, then it’s 137 continuous), it’s working really hard. First of all, power-per-cube is a really impressive 1.93 hp/cubic inch. For that power, the engine has to make 145 foot-pounds of torque at 5800 rpm, a big jump from the 912’s figures, and that requires a BMEP of 263 psi. That is a huge number, one that really stresses the engine’s ability to resist detonation, which it surely only does through strict electronic control. If you’re old enough to remember the Cosworth DFV Formula 1 engine, you may be surprised to know it made its 500-ish-hp on a BMEP of just 230 psi. Oh, how our heroes have fallen. (And, yes, I know the DFV was not turbocharged…) Where do we go from here if the current 916 is right on the hairy edge of power production from its displacement? Well, you make it bigger. We’ve all seen the April Fool’s photos of the 912 Photoshopped into a six-cylinder but I personally think Rotax will go with a bigger four. Why? Parts count, mainly. Yes, there are good reasons to have six smaller instead of four larger cylinders, mainly for smoothness. But the manufacturing cost difference in cylinder assemblies of different dimensions is virtually zero. So the fact that the six-banger has one-third more of them only adds to weight and cost. (Though it should be said that if you’re thinking of retrofitting aircraft originally designed for Lycoming engines, weight isn’t quite the enemy you think it is.)

The Lockwood 915-powered RV-9A required a long nose for weight and balance.

No, I think it’s going to be a bigger four. And knowing that Rotax is a naturally conservative company, I’m thinking incremental from the 900 series. Back-of-the-napkin thinking has a four-cylinder flat engine with a 4.0-inch bore and 2.85-inch stroke. Why? Because this is close to the bore/stroke ratio Rotax uses in the 912 and because the shorter stroke allows the engine to continue to be geared. And if you take the average piston speed seen in the 900-series and apply that to our hypothetical 143 cubic inch engine, you’d have to limit max rpm to 5200. I’m already way out on the limb so I might as well continue. This hypothetical engine could make 180 hp naturally aspirated on a bit more BMEP than the 912 iS musters. But turbocharged, 220 hp seems easily achievable and even, if you ran this engine as hard as Rotax does the 916, it could theoretically make 250 hp running the same BMEP of 263 psi. Of course, not everything scales the same way. There’s more internal friction in a larger engine even if the average piston speed is the same—you have more ring area to drag around. And there are countless other interactions that people who do this for a living know about, can predict with the help of a computer and eventually discover when they actually build and test prototypes. It’s worth noting that Rotax is not the only player in this space. The ULPower 520T engine is impressive in its own right. It’s a 321 cubic inch six-cylinder engine with, like the Rotax, two pushrod-operated valves per cylinder. (Truly, until you decide you need high revs, a two-valve head is plenty; until then, you’re just adding weight and complexity.) The 520T uses a modest amount of boost, just 38 inches for takeoff, and makes 220 hp at 2700 rpm. To do so, it’s making a phenomenal 428 pound-feet of torque from an almost-square bore/stroke ratio of 1.056:1. Heck, even a Lycoming is more “over square” than that, with a bore/stroke ratio of 1.717:1.

The ULPower’s BMEP is a modest 201 psi, above the naturally aspirated Rotax 912’s but well short of the turbo Rotaxes. I think in part this has to do with the ULPower being air cooled. No matter how nice the fins and effective your air-cooling scheme is, it’s really hard to beat the efficiency of liquid cooling. The offset is the weight and complexity of a cooling system, of course, but you have the opportunity to make much more power from any given displacement. All this discussion is merely educated guessing. I’m 100% sure Rotax is working on an engine in the next horsepower class up. Maybe two classes up. And for all I know they could design the next engine with a more conventional up/down intake and exhaust system that would allow them to make both four- and six-cylinder versions with the same cylinders. I’m also fairly sure Rotax will take a careful approach. The 900 series has been around for more than three decades, carefully developed and curated in that time to double the power output. I don’t see a 400-hp, fire-breathing, flat-eight breaking cover, but I’d be mighty impressed if they did it. What are your thoughts?

Looking Back to See Ahead — Dan Johnson Recalls the Beginning of the LSA Movement

By Marc Cook || May 30, 2024 7 Comments (Edit)

As we move toward MOSAIC as a new reality in the Light Sport/Sport Pilot world, it's worth knowing how we got here. MOSAIC does, after all, leverage right off of the success of the LSA category. In this casual conversation, I chat with Dan Johnson about the early days of LSA and get some questions answered on how some decisions came to be made. https://youtu.be/ydXCTTbV_rM

As we move toward MOSAIC as a new reality in the Light Sport/Sport Pilot world, it’s worth knowing how we got here. MOSAIC does, after all, leverage right off of the success of the LSA category. In this casual conversation, I chat with Dan Johnson about the early days of LSA and get some questions answered on how some decisions came to be made.

Amphib Dreams — Aero Adventure To Get New Leadership

By Marc Cook || May 22, 2024 8 Comments (Edit)

Editor’s Note: This news release came across our (virtual) desks today and we feel it’s of interest to provide this update now. However, our man Dan Johnson has arranged to speak with current CEO Alex Rolinski in the next few days to get more detail on these changes and what to look for from Aero Adventure in the near future. Change is coming to Aero Adventure, maker of the Aventura amphibs. According to the company, “this month, our company will be under…new leadership. With a highly experienced and respected professional team, the company is about to enter a new era of innovation and expansion.” The company has already been making progress. “Since the beginning of 2022, we have focused on solidifying and accelerating our production process, our new team has taken us to the next level. We changed the production process, adding state-of-the-art CNC equipment. Today, we have a production capacity of 18 kits per year and plan to expand to 24 kits by 2025.” Modifications to the Aventura are on the way as well. “We will soon be launching updates such as: a new wing for the AVENTURA SLSA version, with ribs, a fiberglass leading edge, and complete covering,” the company says. “This will increase aerodynamic efficiency by reducing drag. The tail will also undergo significant modifications, as well as the windshield!” Aero Adventure has also "expanded our operations around the world, with representatives in Europe (Poland), Asia/Oceania (Australia), and South America (Brazil)."

Reorganization Approved: Van’s Emerges From Chapter 11

By Marc Cook || May 16, 2024 3 Comments (Edit)

While the world of LSAs is diverse enough that the trials of Van’s Aircraft, which put itself into Chapter 11 bankruptcy protection late last year, aren’t quite the foundational matters they are among the homebuilt crowd, the fact that Van’s is represented with the popular RV-12 and companies that support it are also part of the LSA ecosystem suggests more than a little spillover. In the background, Van’s has been working hard to reset its business and emerge from Chapter 11. And on May 15 the company received good news in the form of an Oregon judge approving the company’s reorganization plan. While it seemed unlikely, there was always the possibility that the court would reject or modify the company’s proposal. In the proposal, Van’s has agreed to repay unsecured creditors 55% of the money they’re owed over three years on top of an “immediate” repayment of $3350 for those in the unsecured creditor class. It’s important to note that this class of creditor mainly includes customers who had deposits with the company when it began Chapter 11 protection and who also declined revised purchase agreements that came with an increase in kit and component costs of about 30%. According to filed documents, around 82% of those affected builders agreed to the new agreement, which dramatically reduced the pool of unsecured creditors. In the reorganization plan submitted to the court, Van’s said it “must show that it will have enough cash over the life of the Plan to make the required Plan payments and operate its business. Debtor’s [Van’s] primary revenue sources for the next three years will come from the sale of its eight different kit airplanes, one model of production ready-to-fly plane, and one future backcountry airplane kit.” The ready-to-fly airplane is the RV-12, of course, and the backcountry model is the RV-15, which the company also feels could make an excellent MOSAIC airplane down the road. Van’s has also committed to a corporate reorganization and implementation of a scalable MRP (material requirements planning) software suite that will give it much better visibility to real costs than it had before—all key requirements of a company projecting gross revenues of $69.5 million to $73.5 million per year between now and mid-2027. It’s interesting to note that Van’s had begun increasing the RV-12’s production rate through the 2021-23 time period (it filed for Chapter 11 in October 2023), fr https://youtu.be/vHt7duxQUzs?feature=sharedom 11 units in ‘21 to 20 aircraft in ‘22 to 28 in ‘23. Looking at registrations so far in 2024, the RV-12 has 25, trailing the Zenith CH 750 at 30 and ahead of the RANS S-21 at 24 and the Kitfox S-7 Sport at 17. https://youtu.be/vHt7duxQUzs?feature=shared

Not Bent — Whisper Sling Special Prop Breaks Cover

By Marc Cook || May 8, 2024 9 Comments (Edit)

Not just any prop. This special “non-planar” three-blade prop designed by Craig Catto features an unusual bit of blade shape near the tips, all aimed at reducing noise while retaining or, even better, increasing efficiency. As tested on the Whisper Sling, the Catto prop showed strong thrust measurements (as seen in the video) and appears to have reduced noise, both on the ground and in the aircraft. The key to reducing noise is to control the tip vortices. According to CFD analysis done by Catto, the non-planar tips split the vortex in two, which helps clear the path for the next blade as it comes around. Catto says testing showed that lift at the tip was zero, “which is what you want.” Another interesting aspect of the Catto ground-adjustable prop is its use of shims to set pitch. There’s an internal pitch-setting pin that allows the shanks to rotate through the desired pitch range by shimming a central pitch block that contacts pins on the blade shanks. All pins ride on the same block, which is a clever way to reduce the chances of blade-to-blade differences. It also means there’s no need to use a digital protractor to set pitch as is common with other ground-adjustable props. (Sensenich uses a different kind of pitch pin to set blade angle on its two-blade ground-adjustable props.) Sling is continuing to test the unusual prop, but early results are promising.

Craig Catto explains how the tip vortices react with the non-planar tip.

https://www.youtube.com/watch?v=4YIRRotxv8g

When we last wrote about the Whisper Sling, a version of the Sling LSA used in the Sling Pilot Training Academy in Torrance, California, one teeny tiny detail was left out of the story by request. It was the next piece of the puzzle, so to speak, to reduce the airplane’s sound signature and one of the places most airframers go to help reduce noise: the prop. Not just any prop. This special “non-planar” three-blade prop designed by Craig Catto features an unusual bit of blade shape near the tips, all aimed at reducing noise while retaining or, even better, increasing efficiency. As tested on the Whisper Sling, the Catto prop showed strong thrust measurements (as seen in the video) and appears to have reduced noise, both on the ground and in the aircraft. The key to reducing noise is to control the tip vortices.