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 Diamond DA42.

Ever since its debut in the early 2000s, the Diamond DA42 light twin has attracted the interest of flight schools seeking economical multiengine trainers. They are also attractive to individual private pilots who wish to move up to the light twin category while keeping operating costs under control.

The aircraft’s diesel engines are a focal point, especially for operators who prefer jet fuel over avgas. The DA42, with its composite structure, advanced avionics, and other modern features, also offers pilots the added sense of security that comes with a relatively new airframe and low hours.

For private pilots who regularly use their aircraft for business or long-distance family travel, possibly over long stretches of water or mountainous terrain, having a second engine can be an added measure of security worth contemplating. The DA42’s relative fuel efficiency, forgiving handling characteristics and impressive all-around performance make it a strong candidate for anyone seeking a capable personal aircraft.        

This 2007 DA42 has 950 hours on the airframe and on both Continental CD135 engines and MT composite propellers since new.

The panel features the Garmin G1000-integrated glass cockpit with dual GDU 1040s with 10-inch screens for PFD and MFD, GEA 71 airframe/engine interface unit, dual GIA 63 Nav/Com/GPS radios, GMA 1347 digital audio system, GTX 345R transponder with ADS-B In and Out, GRS 77 AHRS, GMU 44 magnetometer, GDC 74 air data computer, WX500 StormScope, and Avidyne TAS 60X active traffic.

Additional equipment includes a TKS deicing system, oxygen system, long-range fuel tanks, lightning protection system, HID landing and taxi lights, and automatic three-point safety belts on all four seats.

Pilots looking for a modern, economical light twin for travel or training should consider this 2007 Diamond DA42, which is available for $495,000 on AircraftForSale.

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

• FLYING Magazine: Diamond DA42 Twin Makes First SAF Flight
• FLYING Magazine: Lufthansa Commits to Eco-Friendly Training with Diamond DA42 Twins
• FLYING Magazine: Emirates Expands Training Fleet With Diamond DA42-VI
• Plane & Pilot: Plane & Pilot 2017 Buyer’s Guide: Piston Twins
• AVweb: FAA: Diamond DA42 Twin Star OK for Known Icing
• AVweb: Lyc-Powered DA42 Certified in Canada
• AVweb: Diamond Offers Continental Option for DA42

The post This 2007 Diamond DA42 Is Fuel Efficient ‘AircraftForSale’ Top Pick appeared first on FLYING Magazine.

“We were the first U.S. dealer to deliver a new DA50 RG to a customer during last year’s Oshkosh AirVenture, and now, becoming the first dealer to take delivery of our own DA50 RG demonstrator is another milestone for Premier Aircraft Sales,” said Travis Peffer, CEO of Premier Aircraft Sales. “We are extremely proud that our long relationship with Diamond Aircraft has allowed us to be the first Diamond dealer to offer our customers the opportunity to

fly and buy this incredibly efficient, comfortable, and beautiful airplane.”

The DA50 RG is powered by a 6-cylinder, 300 hp Continental Aerospace

Technologies CD-300 engine that runs on jet-A fuel, which has advantages including lower fuel consumption, reduced emissions, and more reliable worldwide fuel availability compared with avgas.

• WATCH: We Fly: The Diamond DA50 RG

The aircraft’s geared, turbocharged, and liquid-cooled powerplant is controlled by two redundant FADEC units. Performance figures include a maximum airspeed of 181 ktas, cruise speed of 172 ktas, maximum range of 754 nm, and useful load of 1,210 pounds. 

• READ MORE: Diamond Aircraft Receives FAA Type Certification for DA50 RG

“Ever since the DA50 RG’s introduction in 2020, it has arguably been the most anticipated new single-engine piston aircraft in history,” said Jeff Owen, vice president of sales for Premier Aircraft Sales. “Now that we have our demonstrator available, we’re excited to give prospective owners a chance to experience for themselves why it’s earned its place as a truly aspirational airplane.”

The company said the aircraft will be on display during the U.S. Aircraft Expo at the Pompano Beach Airpark (KPMP) in Florida on February 2-3.

The post Premier Aircraft Sales Takes First U.S. Retail Delivery of Diamond DA50 RG appeared first on FLYING Magazine.

Actually, I started out already feeling somewhat bummed. I’ve been licking my wounds ever since selling our Cessna Citation CJ1 jet. Insurance costs have increased dramatically, especially for older single-pilot ops in jets. Looking for a new (to me) airplane has been depressing. I’ve had it with the ominous, threatening letters from the Manager, Aerospace Medical Certification Division in Oklahoma City, Oklahoma (“You must promptly report any adverse changes…You are cautioned to abide by Title 14 of the Code of Federal Regulations…”), and have decided to transition to Basic Med. This limits the maximum takeoff weight (MTOW) to 6,000 pounds. I don’t remember meeting this doctor when I took the AME course several years ago, but I do remember the vibe of the class.

My thoughts turned to finding a Cessna 340 with fond memories of “6828 Charlie,” a beautiful 340 that my wife, Cathy, and I enjoyed from 1995 to 2000. The original certified MTOW was 5,990 pounds, which should qualify. The only trouble is almost all 340s have been improved with RAM programs that increase the MTOW to about 6,300 pounds. Is it the improved MTOW that counts or the originally certified weight? I am not going to be the guy to test that theory. Some A&Ps have suggested that the vortex generators installed to improve stall speed and increase MTOW could be removed and make a 340 eligible for Basic Med. What a thought.

Some friends have recommended the Beechcraft Baron. Though the airplane would have to be flown below 18,000 feet to qualify for Basic Med, a “kit” from Textron makes the slightly overweight airplane eligible for the program. Why Textron hasn’t provided a similar kit for the 340 is a puzzle. It is also clear that there are Baron lovers and there are 340 lovers.

The fact is, the insurance industry and the FAA have stimulated me to abandon a really safe turbine engine jet for a piston twin with the attendant excitement that comes with engines that have parts changing directions more than 30 times per second. Add to that the removal of the vortex generators designed to enhance safety. Now I’ll be plowing around in lower altitudes in weather with less reliable engines. How this improves the fortunes of my insurance company is not clear to me.

Armed with these ruminations, I joined Tom for the short flight. More grim news was immediately evident. Tom’s hangar lease at KVDF is not being renewed. Hangar space is scarce around these parts (the Tampa-St. Petersburg metro area), and losing a slot is a blow. Apparently, he parked a car in the hangar against the rules. I know from personal experience that the FBO at KVDF is big on rules.

Tom’s longtime repair shop, Aeromech at KLAL, is closing after 30 years. Kenny, the owner, told us, “I can’t get parts. I can’t get grease for bearings. Cylinder repair shops can’t get valves, can’t get vanes. There’s a shop in Indiana with hundreds of cylinders sitting on the bench (starving for) parts. Add to that my hangar rent is tripling. I’m going to go home and raise strawberries.”

He agreed to fit Tom in for an annual before closing day. His staff members were unsure as to what they planned to do next.

Many Cessna 340s and Barons are more than 40 years old. What about parts in the future, and what about the fate of avgas? I haven’t even begun to examine all the forces that seem to be wishing me to drive, not fly, into the sunset—in a recreational vehicle, not an airplane.

But the primitive desire to own an airplane is rearing its not-to-be-denied-or-disrespected head. At the moment, I am a hangarless, airplaneless 77-year-old who has enjoyed airplane ownership virtually without interruption for more than 50 years. There have been times when I could barely afford an airplane. There have been times when I just couldn’t fly very often. There have been times when I thought it was time to quit. Somehow, though, I just can’t see it ending now. I think back to that first airplane, a Musketeer, and its subsequent siblings: the Arrow, the Cessna 210, the P210, the 340, the Piper Cheyenne, the Raytheon Premier, and the CJ1. Each of these airplanes gave me purpose and pride. They coaxed me into relationships with amazing mechanics possessed of accumulated wisdom and, oftentimes, a gentle perspective on life. These airplanes and their A&Ps, the line guys and the ATC controllers, held my hand in times of woe.

There certainly is rich irony here. Just as my day job as a surgeon and my retirement job as a Part 135 Citation CJ3 pilot provided me with the money to own, and experience to fly, a CJ1, I’m being elbowed out of my dream airplane. I get the same sense of wistfulness at a high-end steakhouse. I can finally afford that 12-ounce filet mignon, but I can’t possibly eat it. Ain’t that something?

Tom offered to let me fly his other Aerostar back to KVDF, but I just didn’t have the heart to accept this kindness. Flying is joyful, and I wasn’t feeling that way. So I looked out the window at the cows and homes and listened to the AWOS. I watched as a high-time airline pilot and Aerostar guru chirped his airplane safely home. We tugged the airplane into the hangar, and I watched with alarm as the hangar door cleared the nose by an inch. We agreed that we’d both live to fight another day.

The post Should We All Be Frightened of the GA Future Ahead? appeared first on FLYING Magazine.

The announcement came after the fuel passed a 150-hour engine durability test under the Piston Aviation Fuels Initiative (PAFI), a collaborative industry and government testing program established in 2014. The FAA noted that the LyondellBasell/VP Racing UL100E is the first unleaded fuel to pass this phase of PAFI testing. The program’s signatories are working towards a replacement for 100LL avgas for aircraft requiring higher octane than the currently available 94UL unleaded fuels.

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

“This is another important milestone for a safe general aviation transition to unleaded fuel and for our goal to eliminate lead emissions by the end of 2030,” said Lirio Liu, FAA executive director of aircraft certification service and government co-chair of the Eliminate Aviation Gasoline Lead Emissions (EAGLE) government-industry partnership. “The joint industry/government effort continues to make strong progress.”

The General Aviation Manufacturers Association (GAMA) and Aircraft Owners and Pilots Association (AOPA), both members of EAGLE, said they are “applauding the news of the first unleaded fuel candidate to successfully pass the most rigorous Piston Aviation Fuels Initiative initial detonation and 150-hour engine durability test phase, and continued progress toward an unleaded future.” 

• READ MORE: Time to Get Serious About Unleaded Fuel

Overall, the PAFI test program evaluates fuel on numerous characteristics including engine durability and detonation, aircraft performance, material compatibility and environmental factors.

“The LyondellBasell/VP Racing’s achievement marks an important waypoint on the path to a more environmentally friendly future for aviation fuel and demonstrates the progress we’ve made through our government and aviation community partnership,” said Curt Castagna, president of the National Air Transport Association (NATA) and industry co-chair of the EAGLE initiative. “EAGLE celebrates this milestone and looks forward to more opportunities to recognize industry ingenuity and innovation.”

The next step for the LyondellBasell/VP Racing fuel includes engine and airframe testing with 10 engines and eight aircraft, which is expected to take 12 to 18 months. The UL100E fuel is one of four unleaded fuel candidates in the test program. If a fuel successfully completes testing, and the American Society for Testing and Materials (ASTM) publishes a production specification, the FAA would issue a fleet authorization.

The post Unleaded Avgas Candidate Passes Critical Engine Tests, Moves Ahead 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.

The project launched this week with the introduction of GAMI’s G100UL during initial flights in Ada, Oklahoma. Beginning with a baseline of two freshly overhauled Continental IO-520 engines, the Baron will be operated under AOPA management, with the cooperation of Savvy Maintenance founder and technician guru Mike Busch, using the company’s computerized diagnostic tools to analyze engine data and compare it against the information it has collected from “hundreds of thousands of hours of GA flights,” according to an AOPA release.

• READ MORE: Time to Get Serious About Unleaded Fuel

An AOPA spokesperson told FLYING that the association is staging in Ada right now “since that is where the majority of the fuel is, and it makes sense to use [it] as a geographically appealing hub.” Presumably this will allow AOPA the “best efficiency in demonstrating the fuel to a wide range of people.” GAMI’s fuel obtained a supplemental type certificate, covering a broad range of piston aircraft, from the FAA in September 2022. The initial STC for Lycoming O-320, O-360, and IO-360 engines came in July 2021. 

• READ MORE: GAMI Gaines Avgas STC for Pistons on Unleaded Fuel

AOPA president Mark Baker was at the controls for the demonstration flight to kick off the program on October 31. For one hour, Baker flew with G100UL feeding the left engine and standard 100LL powering the right one.

“We wanted to get some actual experience with a 100-octane unleaded fuel in the kinds of airplanes and engines that our members own and fly,” said Baker. “This fuel has been tested extensively in labs and received an FAA STC. Should the FAA approve additional fuels, we’ll test them, too, so we can see what they’re like to use out on the airways.

• READ MORE: GAMI Now Selling STCs for G100UL

“George Braly and GAMI have done a great deal of pioneering work preparing for general aviation’s unleaded future. We’re staging the AOPA Baron at GAMI’s headquarters in Ada first to try out its G100UL.”

The post Long-Term Unleaded Fuel Test Begins in AOPA Baron 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.

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.