Last week’s blog was more of an update on progress so far on the replacement of 100LL with unleaded high-octane aviation fuels. In the comments section, a reader who uses the title BestGlideSpeed gave a long list of questions and criticisms of General Aviation Modifications Inc.’s (GAMI’s) G100UL.

Many of the points made by BestGlideSpeed have been made by others, and somes we haven’t heard before. GAMI founder and chief engineer George Braly has addressed them in a point-by-point response to the post.

His intent was to post it as a reply to BestGlideSpeed in the comment section, but he agreed to allow us to run it as this week’s AVweb Insider. Here is his intended reply without any editing except to add formatting to make the replies distinct from the assertions made by BestGlideSpeed.

We at AVweb believe this to be the fundamental issue affecting the future of light aviation, and we welcome all comments made with the good faith intention of furthering the discussion. That means we’re inviting any of the players and stakeholders in this issue to use this space to make their views known, with the knowledge that whatever they put forth is open to rebuttal and debate.

Some of what Braly has to say is provocative, and we expect it to bring reaction. Let’s have it.

Russ Niles, AVweb editor-in-chief

BestGlideSpeed posted the long message critical of G100UL Avgas, which is requoted below. On behalf of GAMI, I (George Braly, head of engineering) am commenting on his message. 

                                              ************

I’m not certain if this is a news story, or if Russ just enjoys throwing rocks at a hornets’ nests to see all of the commenters get riled up. At this point no news is simply, well, no news. As an engineer developing new products for market, I understand that a typical, successful development project always includes the following:

1.   Unrealistic demands of what the new product must be able to do.

Not in the case of G100UL. The original design criteria, set out in writing to the FAA in the spring of 2011, were each fully met, and even exceeded.

2.   A never ending system of hurry up and wait. 

Yes. There has been a lot FAA imposed “waiting” and not a lot of “hurry up”

• READ MORE: GAMI Responds To Cirrus G100UL Service Advisory

3.   Unrealistic demands that after everyone sat on their hands burning up the clock, you must now save everyone else’s bacon and get the ball across the finish line in record time.   

No such urgency from the FAA has yet come to light.

4.   Individuals who have no understanding of the science, industry, or use case are the ones setting the project priorities.  

There has, at times, been some of that from the FAA. But mostly the impediments have been designed by the proponents to simply slow the G100UL avgas project down or to stop it, completely.

5.   Self interested individuals continually ignore realities and proclaim “just go with my favorite answer now” because the unresolved concerns fall outside of their very limited set of priorities.  

A lot of that very recently with respect to the coverage of the last 2 percent of the fleet of aircraft—rotorcraft.

6.   The list goes on ad nauseam—and that is when things go well.   

Things went “well” from 2012 to 2015. Then stagnated for four years.  Then went backwards for 6 months. Then, beginning in July, 2020, the Washington AIR-1 assigned a really GREAT new team of engineers and we managed to finish the project in 24 months.

A project that the government gave 10 years to resolve is only four years along. 

The scope of that government project included TWO PATHWAYS TO SUCCESS:  a) The PAFI / EAGLE project and b) The STC pathway. The second of those two pathways is now a resounding success with every single spark ignition engine in the FAA database approved to use G100UL Avgas. No exceptions!

• READ MORE: GAMI’s G100UL Unleaded Fuel Successfully Powers Historic WWII Aircraft

From my perspective, I am impressed with the progress that has been made in that amount of time.    

Respectfully, I would suggest that almost no person in the FAA who is not financially or career “motivated” with affiliation to the manifestly failed PAFI / EAGLE program would agree with you. The taxpayers have spent nearly a quarter of a billion dollars on the failed UL AvGas/PAFI/EAGLE programs over the last 20 years. The taxpayers have absolutely ZERO to show for that expenditure. Ronald Reagan once observed that there is nothing that lasts so long in Washington as a “temporary program.” 

The fact that Russ is proclaiming all to be lost and we need a complete reboot with the FAA jack boot on the neck of fuel manufacturers to obtain it is just adding himself to the list as another obstacle to getting anything done.

On the contrary. Russ’ observations, and Paul Bertorelli’s from 18 months ago, are precisely on point.

• READ MORE: Stains Reported on Wing of AOPA Aircraft Fueled by GAMI G100UL

I give kudos to at least one organization being honest enough to say that a “drop-in” replacement is not possible. 

That statement calls to mind the old Chinese Proverb: One should not tell the Chinaman that he cannot do something he has already done! A full “drop-in” replacement has already been approved by the FAA. Any statement to the contrary is either based on a lack of knowledge, or some hugely contorted definition of the phrase “drop-in” to mean something very different than the meaning given to that term by the FAA and most other participants.

To accept that statement we have to understand what a “drop-in” replacement entails. It is easy to say “I fly behind a Jabiru engine and I don’t need the same octane as some of the big block engines, so let’s just go with XXX”, but that is not a drop-in replacement for the industry. Whatever replacement we ultimately come to will be a system of compromises. 

There is no compromise with the use of G100UL Avgas. In fact, G100UL Avgas is able to allow enhanced performance of the existing fleet of high powered radial engines—by allowing those engines to be up-rated in BHP back to their original war time military ratings.

Some of us will come out of this perfectly pleased, and some of us will be left out in the cold.

No one is left out in the cold—except the major producers of 100LL who have tried to obstruct and delay any development of a “drop-in” replacement for 100LL.

Consider: GAMI’s fuel is not approved for rotary wing. You cannot get rid of 100LL and leave all of the rotary wing aircraft grounded. News helicopters, med-evac, offshore platform, 

Wrong. Every single rotary wing [gasoline] engine is already approved for use with G100UL Avgas. Robinson Helicopter (which makes 80 percent of all of the helicopters) has fully tested G100UL avgas using their independent test protocols that they developed for their testing of PAFI/EAGLE fuels. Robinson has told GAMI that G100UL Avgas is the only unleaded fuel to ever pass their rigorous flight test helicopter profile.  Robinson has written a complete engineering report and that has been submitted to the FAA to facilitate the early addition of the rotorcraft airframes (the engines are already approved) to the Approved Model List.

. . . the list goes on and on.  [If the “list goes on….” Then, please, send me an email and let me know what other items are “on the list.” gwbraly@gami.com.

GAMI’s fuel is approved by the FAA via STC—this approval only means that if I fly a certificated fixed wing aircraft, I am allowed to use it and not get busted by the FAA.   

That is false. The FAA approval means the FAA has found the use of G100UL Avgas to be equally safe, or actually safer than the use of 100LL.  Their words were:  “… as good as or better” than 100LL.

It is not an industry approval, and it by no means is a blanket mandate, indemnification, or adoption. 

There is no such thing as an “industry approval.” Period. Parade Rest.  Nor has there ever been. The purpose of an ASTM specification (by its own terms, in paragraph 1.1, is to facilitate the sale and purchase of 100LL by “purchasing agents.”

It is not approved by the engine manufacturers, it is not approved by the airframe manufacturers,    

Actually, Cirrus has fully tested G100UL Avgas. Recently, the senior manager at Cirrus has told his staff and has told one of the industry groups that “Cirrus has no technical objection” to the use of G100UL Avgas.” 

… it is not approved by the insurance companies.   

Wow. What complete nonsense! You have been reading too many “statements” from Curt Castagna at NATA. 

FACT:  Each of the major distributors has directly advised GAMI directly, that they have obtained the same product liability insurance for their sale of G100UL Avgas as they have for 100LL. Two years ago, the insurers told one of the two largest distributors the following (at Lloyds, in London): “If the FAA approves G100UL Avgas, then Lloyds will insure it.  No additional charge for the premium. FURTHER MORE, Vitol Aviation was able to add G100UL Avgas to its policy with no increase in premium.

… , and it is not approved by the fuel distributors/sellers.  

Actually, each of the major distributors has reviewed the G100UL Avgas FAA approved specification and told GAMI that they had no objection to that specification. Note, distributors and sellers do not approve or disapprove of fuels. And none of them have stated to GAMI that they have any reason to ‘disapprove’ of G100UL Avgas.

The FAA has no authority to mandate via STC that Lycoming engines must run on GAMI fuel that distributors must sell it, and insurance companies must indemnify it. The STC only gives permission to the pilot to buy it.

Correct. Nor does the FAA mandate that Lycoming must approve the use of 100LL or UL94 or UL82. THAT is not the FAA’s job.

We have one fuel that proclaims itself the elixir of all aviation engines, but refuses to allow the industry to examine it. 

WRONG. Wrong, again. And Again. From your series of false statements, it appears that you may be reading too many press releases from NATA and GAMA, and similar organizations. GAMI has in fact allowed the industry to examine G100UL avgas. Lycoming and Continental have each sent engineers to GAMI and have flown G100UL avgas and compared it back to back with 100LL and have each stated to GAMI that they cannot tell the difference in operation when compared to the use of 100LL.

We have another manufacturer that says we are working on the best solution we can, but there is no silver bullet and our solution will not be a drop-in replacement for 100LL. We have a third that is working on it but is keeping their efforts close to the vest.  

That would be LyondellBasel/VP Racing and Swift Fuel. Both of the sponsors of each of those two fuels have acknowledged, publicly, that neither of those two fuels will be able to be used on the higher performance portion of the fleet (8.5:1 CR N.A. engines and turbocharged engines) without substantial engine modifications and/or limitations added to the operating instructions.

I doubt that GAMI’s fuel is as perfect as they claim. 

GAMI has never claimed it is “perfect.” Please do not make false accusations.

There are too many red flags. In the end, there will be compromises.

Please elaborate and identify the “red flags” and the necessary “compromises” which you, in good faith, believe to exist?

We may need to move to multiple fuels to provide a simple well performing fuel to those who do not need such high octane, and a “compromise” version of 100LL that the EPA can live with in smaller quantities for the larger engines, rotary wing engines, and any others that absolutely require the higher octane.

We may need to choose a boutique fuel that gets us most of the way there, but only after modifications to the engines that require higher octane.

The thought embodied in the previous two paragraphs may well be some of the worst proposals and/or concepts for a “solution” to the TEL lead problem ever articulated in public. Either or both would be a disaster for general aviation piston powered aircraft owners.

Likely, we will need to kick the can down the road and extend the 10 years. The amount of lead contributed to the environment by aviation fuel is infinitesimally small when compared to the world’s annual consumption of lead—so small that is not measurable in the environment.

Yes, the lead contribution is small. But continuing to be a “lead denier” will likely not work out well. In addition, the benefits we have all enjoyed in the automotive world from getting rid of the lead will also take place in aircraft engines. Double or triple the oil change intervals.  No more routine cleaning of spark plugs. Likely, in our future, greatly extended TBOs. All of those are likely to occur.

There is no perfect solution, and typically it is not the first suitor to knock on your door. We have 10 years to fully develop every option and then make a well informed decision about the compromises that we will need to make as an industry.

Respectfully, if you think the States of California, Oregon, Washington, Colorado, Wisconsin, New York, and a number of others are going to wait more than another 12 to 24 months, then you are not well informed with the activity going on in those states.

For those who want to see GAMI be central to that solution, my recommendation is that GAMI take advantage of the next few years to continue to perfect their product and completely satisfy the testing requirements of every industry group out there. 

A) No “industry group” has even come to GAMI to make any suggestion for any further “testing”. B) Please provide some details as to what aspect of G100UL you believe needs to be improved upon?

They should resolve the limitation that excluded rotary wing. 

The addition of helicopters to the AML STC is nearly completed. See the previous comments on that subject about Robinson.

They should be testing their fuel with Lycoming, with Continental, with Jabiru, with Rotax, with ASTM, with Cessna, and with Piper.   

G100UL Avgas has already been rigorously tested to the FAA’s highest standards. Lycoming and Continental have both tested G100UL and found no deficiencies. Nor have they pointed out any to GAMI.  

NOW HEAR THIS: ASTM DOES NOT TEST FUEL! ASTM considers testing done by fuel sponsors—just like the FAA—and then only writes a specification. Which is not approval to even put one drop of fuel in the wing of an aircraft.

They should include representatives of insurers and distributors in those efforts.    

GAMI has done that for distributors. Insurers do not get involved in any such activity. Where on earth did you come up with THAT concept?

Sitting on their secret formula and saying “we don’t trust anyone” is doing themselves no favors while their competitors work diligently for a solution that the industry can openly embrace.

Obviously, once again in the long series in this response, you are not well informed. The complete specification for G100UL Avgas, Revision-12C9 has been posted on GAMI’s web site www.g100ul.com and, more specifically, https://www.g100ul.com/faq#specification since before Oshkosh. In addition, any of the distributors and/or OEMs that has asked to see that document have been furnished that document, over the course of the last several years.

The post GAMI Answers G100UL Criticisms, Point By Point appeared first on FLYING Magazine.

Today’s Top Pick is a 2007 Fantasy Air Allegro LSA.

The arrival 20 years ago of the FAA regulations establishing the LSA category sparked a wave of new aircraft designs in the U.S. from established manufacturers and a number of startups. The new rules also opened the door to many aircraft that already were on the market in other countries, such as the Fantasy Air Allegro for sale here.

Designed and built in the Czech Republic, the Allegro had an established following and a reputation for quality that attracted prospective business partners in the U.S. Arranging to import complete, ready-to-fly LSAs such as the Allegro looked like a faster route to market than starting an aircraft business from scratch. While that theory made sense, the process of bringing the Allegro to the U.S. market was complicated and lengthy. Still, the aircraft has sold well with pilots who want an LSA with strong performance for the category and the ability to travel cross-country with reasonable comfort and speed.

The Allegro’s fuselage is built with Kevlar-reinforced composite around a steel-framed cockpit. Its wing and tail are aluminum. As LSAs go, the Allegro is known for its relatively roomy two-seat cabin and engaging, sporty flight characteristics. The airplane can climb at 1,000 fpm and cruise at more than 100 mph while burning about 3.5 gph.      

This 2007 Allegro has 375 hours since new on the airframe and its 80 hp Rotax 912 engine. The aircraft holds 16.5 gallons of usable fuel and can operate on 100LL or automotive gasoline. Its basic “steam gauge” panel includes a Garmin 396 GPS and a transponder with ADS-B Out.     

Pilots interested in owning a light sport aircraft with impressive climb performance and good cross-country cruise speeds should consider this 2007 Fantasy Air Allegro, which is available for $55,000 on AircraftForSale.

You can arrange financing of the aircraft through FLYING Finance. For more information, email info@flyingfinance.com.

• FLYING Magazine: Avionics for Your LSA
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• AVweb: Video: Allegro Comes to the U.S.
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• AVweb: Sport Pilot: An Option for Seniors

The post This 2007 Fantasy Air Allegro LSA Is a Performance-Minded ‘AircraftForSale’ Top Pick appeared first on FLYING Magazine.

In an online forum Tuesday, GAMA provided an industry update on the initiative to Eliminate Aviation Gasoline Lead Emissions, or EAGLE.

The forum included representatives from the FAA and GAMA.  Eric Blinderman, senior director of communications for the Aircraft Owners and Pilots Association (AOPA), acted as moderator, introducing the co-chairs of the EAGLE initiative that represent supply chain infrastructure and deployment; research, development and innovation; unleaded fuel evaluation and authorization; regulation policy; and programmatic activities.

• READ MORE: EAGLE Initiative Shows Measured Progress, Fuel Contenders Say at Oshkosh

Curt Castagna of the National Air Transportation Association (NATA) said fulfilling the EAGLE initiative will require a continued effort to educate users and other stakeholders— including the FAA—”to work as fast and as safely as we can.” Castagna said the goal is “to eliminate the use of leaded aviation fuels for piston engine aircraft in the United States by the end of 2030 without adversely impacting the general aviation fleet.”

Several speakers noted that the safety considerations and liability involved with the production of aviation fuel dictates that a considerable amount of testing be involved in the creation of unleaded (UL) products.

The UL100E unleaded fuel testing protocols include:

• Determining fuel compatibility with materials used in aviation, from the metal of the wings to fuel bladders, hoses, aircraft sealants, and elastomers.
• Determining engine performance for rated power as compared to the same engines running on 100LL and determining if detonation is a factor. The tests involve hundreds of engines. The impact of vibration of the aircraft propellers attached to those engines is also being studied.
• Determining the durability of the fuel and its effect on engine parts, especially testing for deposits that may form after hundreds of hours of operation.

The fuel tests will take place both on the ground and in the air under a variety of conditions, including cold soak and high temperatures and humidity.

The testing will involve multiple engines and multiple aircrafts. According to a graphic provided during the stakeholder meeting, this work has just begun, with the exception of the testing involving a Continental TSIO-550K.

“After testing, the engines are torn down to look for damage,” said Tim Owen, who has spent several years in product development at Continental Motors Inc. and been part of the Piston Aviation Fuels Initiative (PAFI).

Supply Chain

In addition to the development of a replacement fuel for 100LL, a seamless transition to UL fuel must also be developed. A support policy and regulatory proposal for maintaining 100LL availability is also needed, as are safety measures to prevent improper fueling during the transition.

Stakeholders noted during the meeting that many FBOs are already looking into means to accommodate both 100LL and UL fuels, such as acquiring a fuel truck for UL. In addition, there will be more training required for line crew and placards in aircraft to prevent accidental misfueling.

• READ MORE: The EAGLE Has Launched to Get Lead Out of Avgas

Discussions are underway with FBOs in remote areas, such as in Alaska, Hawaii, and Puerto Rico, to determine how fuel can be economically delivered to these locations.

It is still incumbent on the FAA to authorize the use of a new unleaded fuel in GA aircraft.

That can be done one of two ways: through the fleet authorization process established by Congress and in conjunction with the PAFI, or through the FAA’s traditional aircraft type certification/supplemental type certification (STC) process.

In March 2023, the FAA issued a Fleet Authorization Policy Statement, which describes the process to obtain a fleet authorization of a qualified unleaded fuel candidate.

“The FAA anticipates that approximately 68 percent of the [GA] fleet will be eligible to use UL 94/UL 91 fuels,” according to the EAGLE industry partnership.

Stakeholders also noted that the adoption of unleaded fuels will likely require extra placards on aircraft and extra pages in the pilot’s operating handbook (POH) to advise pilots of the changes, but that is likely years away.

The FAA is expected to issue a notice of proposed rulemaking (NPRM) and accept industry comments before EAGLE becomes law.

The post Forum Stresses More Work Needed to Meet GA Unleaded Fuel Goals appeared first on FLYING Magazine.

Lycoming Engines has released the results of a study undertaken after receiving reports from the University of North Dakota (UND) about abnormal valve seat recession in the company’s powerplants that were using UL94.

Throughout the country, several GA fleets have been converted so that they can use unleaded fuel. One of those fleets belongs to UND, which made the switch in June. The UND fleet consists of Piper PA-28-181 Archers and PA-44-180 Seminoles.

Over the summer, the fleet of 120 aircraft logged some 46,000 flight hours. Routine maintenance discovered what was described as “abnormal exhaust valve recession,” and in October the university switched back to 100LL.

According to a media statement from Lycoming Engines, a root cause analysis of the issue was undertaken, including further testing of UL94.

• READ MORE: University of North Dakota Stops UL94 Use Following Valve Recession Concerns

“This analysis has determined that the engine components and airframe components conform to specification and are not believed to contribute to valve seat recession,” the statement read. “However, testing has also demonstrated that, under certain conditions, use of UL94 may impact valve seat recession. Analysis indicates that aromatic concentration tolerances for UL94 may contribute to valve seat recession in certain flight profiles.”

According to Lycoming, “aromatic limits are not directly specified by ASTM D7547, and elevated aromatic concentration may result in slower flame speed, radiant heat from particulates, and particulate abrasiveness to valve seats that may contribute to valve seat recession.”

What Is Valve Recession?

Exhaust valve recession occurs when the valve sits too low in the seat, according to Richard Scarbrough, an A&P mechanic and FLYING contributor. It results in valve discoloration—first red, green, then purple. It can also erode the guide. If the valve is not properly seated, there can be “blow-by” that can result in an uncommanded loss of engine power and compression and, in worst cases, valve failure.

“The aircraft were flown to POH procedures and the UL94 fuel was on spec,” UND chief instructor Jeremy Roesler told FLYING in a previous interview.

When routine maintenance detected abnormal exhaust valve recession, Roesler said the decision was made to revert back to 100LL while the issue was investigated.

“We have been running 100LL since then,” Roesler said. “To date we have replaced 126 cylinders. We flew 46,000 hours on UL94. We are submitting a technical paper on our experience and findings.”

Roeslser added that the university flies approximately 107,000 hours a year.

Lycoming is working with the FAA to evaluate the sensitivity of piston engines to aromatics in fuels.

“If indicated by this further analysis, we will work with industry to further define ASTM D7547 and provide appropriate guidance to operators regarding how leaning techniques can impact valve seat recession with high aromatic fuels,” the company said.

Lycoming Engines said it remains committed to the FAA’s Eliminate Aviation Gasoline Lead Emissions (EAGLE) initiative, a cross-functional industry effort to identify and deploy a high-octane unleaded replacement for 100LL for piston-engine aircraft by the end of 2030.

The FAA did not respond to FLYING’s request for comment.

The post Lycoming Claims Fuel Aromatics May Be at Root of UND Fleet Valve Problems appeared first on FLYING Magazine.

As reported by FLYING last week, UND resumed the use of 100LL after noting “exhaust valve recession” in the Lycoming engines that power its fleet of Piper PA-28-181 Archers and PA-44-180 Seminoles.

According to UND chief instructor Jeremy Roesler, the school’s 120 aircraft used unleaded fuel between June and October, logging more than 46,000 flight hours. When routine maintenance detected abnormal exhaust valve recession, Roesler said the decision was made to revert back to 100LL as a precaution while the issue was investigated. UND is working with Lycoming and Swift Fuels to address the concern.

“We appreciate feedback from all customers related to the use of fuels in Lycoming engines,” Lycoming told FLYING. “Our team is proactively evaluating the data received from the University of North Dakota Aerospace related to the use of UL94 Fuels, and we will provide appropriate guidance to the industry based on our analysis of this data. Lycoming remains committed to the FAA EAGLE initiative of eliminating lead emissions from piston-engine aircraft by the end of 2030.”

According to Chris D’Acosta, CEO of Swift Fuels, the company became aware of the issue at UND when it was contacted by Lycoming Engines. Immediately, the fuel manufacturer and supplier “went through an audit check.” This means testing fuel from the production facility and all the tanks, both stationary and used in transport, to make sure there was no contamination. None was found, D’Acosta said, adding, “The fuel was on spec.”

The investigation is very thorough, according to D’Acosta, adding that Lycoming is running it and will be “looking at the materials used in the valves, the valve seat, the head of the valve stem, the flight operations telemetry—that’s a fancy way of saying the conditions the flight was operated under.“

Swift Fuels holds an AML-STC FAA approval for UL94 fuel, which each owner-operator can purchase and install on their individual eligible aircraft and engines allowing them to use UL94. Aircraft that require a higher octane, with such higher-performance designs making up approximately 30 percent of the general aviation fleet, are still having to use 100LL.

While UND has the option to revert back to 100LL, other schools are not so lucky. Flight schools at Reid-Hillview Airport (KRHV) in San Jose, California, don’t have that option because the facility is owned by Santa Clara County. In January 2022 the Santa Clara County Board of Supervisors enacted a ban on leaded fuel sales at the county-sponsored airport,  located on 180 acres in east San Jose. For several years, politicians in the region have called for the airport’s closure, citing alleged safety issues such as lead poisoning from the use of leaded aviation fuel.

The owners of the flight schools at KRHV saw the ban coming. In 2021, a county-funded study into blood lead levels (BLL) of local children allegedly indicated that the BLL of children who live near the airport is attributed in large part to air pollution from piston-powered aircraft that utilize 100LL. In August 2021 the board of supervisors banned the sale of 100LL in Santa Clara County, effectively removing it from both KRHV and San Martin Airport (E16) south of San Jose.

• READ MORE: Aviation Community Livid With Santa Clara County Over Looming 100LL Ban

When the ban went into effect in 2022, the flight schools were already using unleaded fuel, having made the switch to UL94 that summer.

Walt Gyger, the recently retired owner and operator of Trade Winds Aviation, one of the schools at KRHV, was skeptical of the study, noting that it did not take into account lead contamination coming from building materials such as paint and pipes used in the construction of the homes and business in the San Jose area. Many of those were built at a time when the dangers of lead exposure were unknown.

Gyger, who spent 16 years as an FBO owner, said rather than fighting the county on the study results, the flight schools obtained STCs to allow their aircraft to operate on unleaded fuel and made arrangements for Swift Fuels to deliver to the airport.

According to Josh Watson, co-owner of AeroDynamic Aviation at KRHV, the aircraft powered by Lycoming engines were designed to use lower-octane fuel, so putting them on a diet of UL94 was as simple as obtaining the STC and replacarding the aircraft. That was the easy part.

There were logistical challenges transporting fuel from the refinery in Indiana, said Gyger. “The options are by truck or by rail car, which brings it to a terminal and from there to the FBOs,” said Gyger. “A truck can carry eight to 10,000 gallons. A rail car carried 28,000 gallons.”

Unleaded fuel is also more expensive than 100LL, said Gyger, by about $1 per gallon.

“But the flight schools at Reid-Hillview didn’t really have a choice,” said Watson, who in addition to being a pilot holds an A/P/IA certificate. He says his business has also noticed some issues with the valves since the switch to unleaded fuel. The school runs a fleet of 22 aircraft, ranging from Cessna single-engine trainers to Citabrias. It also has a robust maintenance shop and does its maintenance in-house.

“We have to monitor the engine condition very closely,” Watson said. :Around the 1,800-hour range is when the valve issues happen, [and] that’s over the lifespan of the engine. We have noticed some valve recession and some valve deformation and discoloration, and it has made it a little more difficult to run in new cylinders. Typically, the cylinder makes it to TBO (time between overhauls), and we are able to reuse the valve. We can no longer reuse the valve due to valve recession and malformation. When the valve goes out of tolerance, it has to be replaced. We noticed it on a set of brand new cylinders. It is odd for a first run set of cylinders to have a problem like that.”

Other Flight Schools

Gyger recently sold Trade Winds Aviation to American Flight Schools (AFS), which owns several FBOs in California, and ones in Portland, Oregon; Carney, Nebraska; and Centennial, Colorado. All of them are using UL94, according to Danny Smith, chief operating officer for AFS. The fleet is made up of more than 125 aircraft, flying on average 6,000 hours  per month. “Centennial, KAPA, is our largest operation,” Smith said.

According to Smith, when AFS made the switch to unleaded fuel in May, it was very cautious about how it would impact aircraft operations.

“At Centennial, especially in the summer, we experience very high density altitude, sometimes more than 9,000 feet,” Smith said. “We were concerned about performance, but we had no reports of degraded performance from pilots or instructors in aircraft burning UL94. They were still reporting 1,000- to 1,200-feet-per-minute climbs on takeoff.”

In addition, Smith said the aircraft are experiencing lower engine temperatures and less deposits on spark plugs. “The engines are burning cleaner,” he said. “We have not had the experience of UND. There have been no valve recessions.”

Smith noted that, although AFS is paying more for a gallon of UL94 than it did for 100LL, “the operating cost of the fuel is reduced by not having to replace six to eight spark plugs every 100 hours. Spark plugs run about $40 to $60 each, so the cost of maintenance has come down because we don’t have to replace spark plugs contaminated by lead.”

In the meantime, Swift Fuels continues development on a replacement fuel for the higher-performance general aviation engines that require a higher octane for safe and efficient operation. According to D’Acosta, “100R, the 100 octane replacement fuel for 100LL, is going through the steps and stages for approval from the FAA,” adding that the FAA and ASTM international have a long list that you must comply with and specific methods that must be used to show compliance.

Swift Fuels is hopeful 100R will be certified by the end of 2024.

“It is challenging,” D’Acosta said. “There is lots of collaboration and diligence, and safety matters. We are working with county governments, FBOs, pilots, technicians, and mechanics. There are lots of dimensions to get it going. We have been working on 100R for three or four years through a variety of channels. We move at the speed of the FAA and the speed industry. Our goal is to be the global leader in unleaded fuels.”

The post Flight Schools Discuss Getting the Lead Out appeared first on FLYING Magazine.

What Is Valve Recession?

According to Richard Scarbrough, A&P mechanic and contributor to FLYING, “exhaust valve recession is when the valve sits too low in the seat.” If the valve is not properly seated, there can be “blow-by” that can result in an uncommanded loss of engine power and compression and, in worst cases, valve failure.

“Exhaust valve recession can result in valve discoloration—first red, green, then purple. It can also erode the guide,” said Scarbrough, adding that at this time no one has attributed exhaust valve recession to a lack of lead in the fuel.

The Details

According to UND chief instructor Jeremy Roesler, the school switched the fleet back to unleaded fuel over the summer. UND boasts a robust flight training program, with the fleet of more than 120 aircraft logging more than 46,000 flight hours between June and October.

“The aircraft were flown to POH procedures,” Roseler said. “The UL94 fuel was on spec.”

When routine maintenance detected abnormal exhaust valve recession, Roesler said the decision was made to revert back to 100LL while the issue was investigated.

• READ MORE: UND Aerospace Transitions Full Fleet to Unleaded Avgas

“UND is working closely with Lycoming and Swift Fuels, providing them with data for their own evaluation,” he said. “We have sent cylinders to Lycoming for their analysis. Everything is being looked at. The analysis requires time, and we are hopeful good information will result to [facilitate] the move to unleaded avgas.”

According to an article on AVweb by Paul Bertorelli, UND set up a maintenance monitoring program to track any potential challenges with the use of UL94 prior to making the switch. To monitor for cylinder wear, the school conducted regular compression checks on its fleet of Archers and inspected the clearance between the rocker arm and valve stem. If the valve seat is recessing, this clearance will progressively diminish as the valve recedes farther into the cylinder head. If the recession becomes deep enough, the valve won’t close properly against the seat, and power loss or burned valves can result. 

UND director of maintenance Dan Kasowski said the Lycoming-specified minimum clearance is 0.028 inch, and some of the cylinders exceeded this limit.

According to Roesler, when the school started to find issues, it decided to switch back to 100LL because having a potential problem resulting in aircraft down for maintenance in a busy aviation program like UND’s creates an untenable situation.

FLYING reached out to Lycoming for a comment but did not hear back by press time.

UND is not the only busy school to utilize Swift’s UL94. In summer 2021, Walt Gyger, the longtime owner of Trade Winds Aviation at Reid-Hillview Airport (KRHV) in San Jose, California, switched his fleet of Cessna 172s to Swift UL94 in anticipation of a ban on 100LL. Gyger was ahead of the curve, because in August of that year the Santa Clara County Board of Supervisors voted to ban leaded fuel at county-owned airports as a means of reducing lead pollution allegedly suspected of coming from the airports. The allegations were triggered by a county-commissioned, peer-reviewed study that linked the ongoing use of leaded fuel with elevated blood lead levels (BLL) in children living near Reid-Hillview. For decades, the medical community has known that lead exposure, especially for children, can lead to cognitive and developmental challenges.

• READ MORE: Aviation Community Livid With Santa Clara County Over Looming 100LL Ban

The ban on the sale of leaded fuel went into effect on January 1, 2022, and NOTAMs were issued for both Reid-Hillview and San Martin (E16), warning pilots that the airports no longer had 100LL for sale. At present, the airnav.com page for KRHV notes “Fuel available: A UL94 and beginning January 1, 2022, 100LL unavailable.”

Gyger and many other pilots expressed skepticism of the board’s interpretation of the lead study, suggesting it really isn’t about the health of local children but rather “the goal of the county to close the airport.” He pointed out that the study did not take into account the lead present in the paint and pipes used in the construction of many of San Jose’s older neighborhoods before the dangers of exposure were fully understood.

Aviation advocacy groups, airport businesses, and pilots, in particular, called the study a “manufactured health crisis” and “political move.”

FLYING contacted both Trade Winds Aviation and AeroDynamic Aviation, the flight schools located at KRHV, and neither reported issues attributed to the use of UL94 in their fleets. FLYING will continue to follow this story.

The post University of North Dakota Stops UL94 Use Following Valve Recession Concerns appeared first on FLYING Magazine.

Because of the way the U.S. government operates, particularly under the Clean Air Act of 1970, certain processes within the associated agencies, including the FAA, could not begin without the finding.

Now leadership from within the industry’s manufacturers, distributors, associations, and users (that’s us, the pilot community) can act on the commitment to getting the lead out of our avgas—specifically the high octane fuel required by high-performance piston engines currently served by 100LL.

But what happens now? I spoke with Walter Desrosier, vice president of engineering and maintenance for the General Aviation Manufacturers Association, this week about the finding and what it triggers. “We have significant progress,” said Desrosier. “There is a broad, collective community commitment from the entire GA industry in cooperation with the government and the FAA to move to no lead. So the EPA action that came out is part of that transition process. It actually puts into the Clean Air Act process how they will mandate a transition. So this is not something that we continue to talk about, that we hope to find solutions—this is a commitment  from the industry that continues to work towards the best solutions.”

The timeline has officially begun, but it will take a couple of years for the mandate and the associated guidance to come into play. In the meantime, the industry is already working hard toward fielding the solutions.

Fuels in Process

Those solutions include four candidate fuels in the works from different providers in varying states of development, testing, and acceptance. “Part of our transition will also be what’s the best available fuel,” said Desrosier.

By most measures, the furthest along comes from GAMI Inc., whose G100UL has attained supplemental type certification from the FAA. GAMI works with at least one producer, VTOL, to manufacture the fuel in enough quantity to reach those who need to test it and develop its distribution in the field. The STC means the FAA considers the fuel safe for the applications covered in that approval.

While the STC includes broad fixed-wing piston aircraft acceptance, testing continues for rotorcraft with Robinson deep into its program with the fuel. Cirrus Aircraft is also testing the fuel within its fleet.

But any fuel that makes it to market must also demonstrate commercial viability. It must make it from the manufacturer through the distribution channels—pipeline or trucking—to the airport where it goes into a tank, and then into our fuel tanks on aircraft. That means the fuel must be acceptable in each of those steps by the businesses involved, as well as the end user burning it in flight.

“With the GAMI fuel, the path that they chose to take is to do their proprietary STC approval, which is perfectly fine on the safety side with the FAA, but they also chose not to enter into an ASTM consensus specification process,” said Desrosier. “Typically that’s how all the other stakeholders in the community become familiar with a fuel…the content of the fuel, the understanding of the evaluation and the assessments of the fuel, and the understanding of the components, and the understanding of the business risks related to being a stakeholder who might purchase, who might produce, who might distribute, who might dispense, and who might put it into people’s tanks.

“There’s a lot of business decisions in this, and a lot of risk.”

Swift Fuels has already entered the market with a lower octane unleaded fuel, 94UL, with limited distribution now but a growing foothold, especially in states and at airports where there is more pressure to get away from leaded avgas.

Swift is pursuing both an STC and ASTM path with its high octane fuel, 100UL, and it has chosen a clever way to gain market acceptance—and perhaps reach commercial viability—with the new fuel. For its current 94UL, Swift offers a “Forever STC,” through which an operator purchasing the STC for the lower octane fuel is promised that the STC for the 100UL fuel will be  included in that purchase when it’s available.

Swift will be able to deliver the fuel through the existing infrastructure to the existing tanks it has put in place for 94UL. According to Desrosier, Swift has already started the consensus standard and is going through the STC process. Critically, the manufacturer will share the results through the consensus process, and when it obtains FAA approval, it will share that data with all the stakeholders.

Two other fuels are pursuing approval through the PAFI (Piston Aviation Fuels Initiative) program. One already has the ASTM test specification, produced by Afton Chemical/Phillips 66, and it is continuing to share information, according to Desrosier. It has to go through the full ASTM testing process, but it has “the roadmap” to do it.

The other candidate fuel (Lyondell/VP Racing) is close behind. The consortium has entered into the specification process and expects to also share its progress.

More than One?

One big question in my mind: Will we end up with more than one fuel, and will they be intermixable? I asked Desroiser, along with the follow-up question: Is this testing pathway defined or is it wait and see?

No, said Desrosier, the fuels are not allowed to intermix and co-mingle. All of the candidate producers are testing to comingle with 100LL—because that is part of the transition process and very likely to occur in the field.

“In terms of ‘could be,’ it depends on the final composition of the fuels,” he said. “We do know some of the key components,” and some fuels will not be able to mix because they are too different.

In the end, having two fuels make it through the process means that the market will decide—and we will have a backup in case of an unforeseen issue with a producer or fuel. “We think it’s going to have to be a market decision,” said Desrosier. “I’m not expecting a significant market penetration, dividing the market in half” with different fuels regionally available.

“Once you have the acceptance by FAA, ultimately the consumer is the very last in the supply chain,” he concluded. 

With the pilot or owner-operator, it often boils down to price—and that won’t likely change with 100UL.

The post Time to Get Serious About Unleaded Fuel appeared first on FLYING Magazine.

According to the EPA statement: “EPA and FAA have already begun work to consider regulatory options to address lead emissions from aircraft engines and will announce timelines as soon as possible. EPA and FAA will work in partnership and engage all interested stakeholders and the general public as the two agencies develop their separate regulatory actions.” 

Representatives of the Eliminate Aviation Gasoline Lead Emissions (EAGLE) working group held a media briefing directly following the release of the EPA finding. During the online webinar, Liu joined several industry stakeholder participants in stressing – multiple times – that EAGLE and the FAA are firmly committed to ensuring the continued availability of 100LL until a safe and practical replacement can be made universally available. In essence, the message was that ensuring flight safety for aircraft that require higher-octane fuel takes precedence over the risk of prematurely eliminating the availability of 100LL.

• READ MORE: EAGLE Initiative Shows Measured Progress, Fuel Contenders Say at Oshkosh

Curt Castagna, president and CEO of the National Air Transportation Association, which represents the interests of “a broad array” of aviation service providers, including fuel providers, airports and FBOs, laid out three priorities going forward: developing a suitable fuel; keeping 100LL available in the meantime; and helping airports and airport operators effect a smooth transition.

Stakeholders represented at the webinar included:

• Mark Baker, president and CEO, Aircraft Owners and Pilots Association (AOPA)
• Todd Hauptli, president and CEO, American Association of Airport Executives (AAAE)
• Prentiss Searles, director of fuels, marketing and vehicle policy, American Petroleum Institute (API)
• Jack Pelton CEO and chairman, Experimental Aircraft Association (EAA)
• Pete Bunce, president and CEO, General Aviation Manufacturers Association (GAMA)
• James Viola, president and CEO, Helicopter Association International (HAI)
• Curt Castagna, president and CEO, National Air Transportation Association (NATA)
• Greg Pecoraro, president, National Association of State Aviation Officials (NASAO)

The next steps involve establishing aircraft emissions standards under the Clean Air Act. Liu said, “The EPA can find that a component causes harm [which is what the endangerment finding is]. The FAA will define the standards.” She reiterated that the FAA approach is focused on safe operation, while the EPA focuses on eliminating harmful emissions. Liu described the timeline going forward as a cooperative effort between the FAA and EPA. “We really have to work in harmony here,” she said.

Editor’s Note: This article first appeared on AVweb.com.

The post EPA Releases Endangerment Finding on 100LL appeared first on FLYING Magazine.

Representatives from GAMA, the Aircraft Owners and Pilots Association (AOPA), Experimental Aircraft Association (EAA), and the National Air Transportation Association (NATA) participated in the discussion.

The panelists cited progress toward fielding a replacement for 100 Low Lead (100LL) high octane gasoline that would be suitable for fleetwide use. While an estimated 70 percent of the current piston-aircraft fleet can safely use available lower-octane lead-free fuels, the remaining 30 percent that require higher-octane fuel to operate safely fly an estimated 70 percent of the hours flown by the entire GA fleet.

• READ MORE: EPA Releases Proposed Finding on Leaded AvGas

The panelists noted that the expected EPA endangerment finding, in itself, does not constitute a ban on continued use of 100LL fuel. In fact, the group stressed the priority of retaining the right to distribute and use 100LL until and acceptable replacement is in place.

However, the panelists did acknowledge that the EPA endangerment ruling does set a “pathway” to future rulemaking related to lead emissions in aviation fuels.

There was extended discussion on the difference between the supplemental type certificate (STC) route to acceptance of a replacement unleaded fuel, and the so-called ASTM (American Society for Testing and Materials) route, involving a “collaborative government FAA program to test candidate fuels, generate report and data, and distribute to fuel providers” enabling the FAA to gain “industry consensus” and issue a fleetwide approval.

• READ MORE: G100UL Avgas Replacement Set to Soon Hit Pumps

The panelists were careful to assure that the FAA, as the arbiter of safe aviation operations, is the final authority on approving a replacement for 100LL; not the EPA. That said, the discussion revealed that – for the first time – regulatory standards for lead emissions in aviation fuel will be established as a result of the expected EPA endangerment finding. GAMA assured the participating journalists that there would be further briefings once the EPA endangerment finding is finalized.

Editor’s Note: This article first appeared on AVweb.com.

The post GAMA Hosts Pre-Brief on Life After EPA’s Ruling on Leaded Aviation Fuel appeared first on FLYING Magazine.

This year marks the first time GA has a seat at the table as the committee has announced its intention to include a general aviation section in the bill.

Leaders from several GA organizations including the Aircraft Owners and Pilots Association (AOPA), Experimental Aircraft Association (EAA), American Association of Airport Executives (AAAE), and National Air Transportation Association (NATA), testified before the committee during the March 9 hearing.

FAA Reauthorization comes up every four or five years, setting the stage for the FAA and aviation for the coming years. The bill includes all programs and policies by the FAA including airports, airlines, general aviation, business aviation, manufacturers, air traffic controllers, and autonomous vehicles.

• READ MORE: FAA Safety, Aircraft Certification Focus of Senate Hearing

A number of topics including the transition to unleaded fuels, workforce development, staffing shortages, airport funding, and aviation safety were discussed in Thursday’s testimony.

Much of the hearing focused on the overwhelming support of the Eliminate Aviation Gasoline Lead Emissions (EAGLE) initiative—a major priority for the sector. During the testimony, concerns were raised about the rushed ban of 100 low lead (100LL) fuel before a universal alternative is widely available—as was the case at Santa Clara County. Delays in the availability of the currently promoted alternative fuels have created a gap between the supply and demand for those fuels.

• READ MORE: FAA Halts Investigation of Santa Clara County Fuel Ban

During his questioning, Rep. Scott Perry (R-Penn.) took issue with Santa Clara County’s decision to ban 100LL while accepting federal funds, calling it “offensive.” He argued that any airport taking federal funds should provide necessary services for pilots and shouldn’t compromise safety for what he described as “woke ideology.”

When asked what Congress can do to ensure more instances like Santa Clara County aren’t part of a wider trend, AOPA’s president Mark Baker insisted Congress can make sure airports don’t lose the availability of 100LL until there is a suitable, affordable replacement. He also encouraged Congress to allocate funds for supplemental type certificate (STC) holders in order to get fuel in the market faster. Baker also noted that the industry is on track to meet its goal to safely eliminate the use of leaded aviation fuel by the end of 2030.

Thursday’s testimony also addressed staffing shortages, most notably affecting the FAA, which has caused backlogs for things like aircraft certification, medicals, rulemaking, and designated pilot examiner (DPE) availability—a major setback in issuing new pilot certificates.

In his testimony, EAA CEO Jack Pelton called the DPE shortage a “crisis that needs to be addressed” and suggested Congress implement the DPE Reforms working group’s recommendation that DPE’s go to national oversight level rather than at the local flight standards district office level.

Another major takeaway from Thursday’s hearing was the aviation industry’s workforce challenges and how to recruit both qualified and underrepresented groups. Baker took the opportunity to tout the success of AOPA’s high school aviation STEM curriculum which is currently being utilized by 400 schools across the country and consists of 50 percent people of color and 25 percent females. Additionally, Baker noted that 70 percent of the first graduates of the program are actively pursuing an aviation career.

EAA has also been successful with its own Young Eagles program which has flown more than 2.3 million young people—introducing them to their first flights in general aviation.

Additionally, the National Center for the Advancement of Aviation (NCAA) bill was brought up during the hearing which would be instrumental in addressing workforce challenges. The NCAA would help shape a generation of new pilots, maintenance technicians, and aerospace engineers to promote aviation within the United States.

The House and Senate have until September 30 to draft a comprehensive new FAA Reauthorization bill.

The post Transition Away From Leaded AvGas on Track, GA Stakeholders Tell Congress appeared first on FLYING Magazine.