MAKE CHAPTER 288 YOUR AVIATION HOME! E-AB, TYPE CERTIFIED, VINTAGE, WARBIRD, ETC.
MAKE CHAPTER 288 YOUR AVIATION HOME! E-AB, TYPE CERTIFIED, VINTAGE, WARBIRD, ETC.
A yearslong investigation determined that cold-bending a metal wing spar to create a dihedral also creates the risk of future fatigue and failure, and more than 21,000 Piper aircraft will have new wing spar life limits and recurring inspections required under a pair of proposed airworthiness directives.
The FAA published two new proposed ADs in recent weeks that continue a series of actions and investigations the FAA began following a 2018 wing separation accident involving a Piper Arrow that killed a commercial pilot applicant and designated pilot examiner. The agency has since noted fatigue cracks of the main spar were also found in two additional accidents involving PA–28 series Pipers, in 1987 and 1993.
The FAA published AD 2020-26-16 a little more than two years later, updating guidance and directives dating back to 2018, and requiring eddy current inspections of thousands of Piper wing spars, including various PA–28 and PA–32 series models.
The results of those inspections informed a new directive, AD 2024-00008-A, published on September 19, followed by AD 2024-00033-A, published on September 23.
The new directives establish or expand a wing spar inspection regime to include all PA–28 and PA–32 series single-engine Piper aircraft. The FAA noted that all of these aircraft have a common spar design, with varying degrees of reinforcement in the original structure.
The FAA noted that a redesigned wing spar assembly is available from Piper, as well as a reinforcing kit that can be installed on many newer PA–28s including the Cherokee, Warrior, Archer, and Piper Pilot models. The spar reinforcement kit enables longer inspection intervals, and a longer life limit—up to 25,000 hours for a reinforced spar, instead of 12,000 hours or 13,499 hours for an unmodified wing spar.
The FAA also updated the formula for calculating service time that enables risk-based grouping of aircraft (the same formula for calculated service hours, or CSH, that was previously detailed in Piper Service Bulletin 1372 published on April 3) to determine required inspection intervals, and establish life limits for wing spars made with a particular process that Piper has now discontinued: bending the cold spar to create the dihedral.
“In an attempt to support less onerous inspections and to understand the causal factors, Piper investigated the residual stresses in the critical bolt-hole area. That investigation showed that the residual stress due to the spar cold bending process is a significant contributing factor in reducing the fatigue life of the spar bolt holes,” the FAA wrote in the AD published September 23 that applies to an estimated 10,665 aircraft previously subject to required spar inspections under the 2020 directive. “An additional outcome of this investigation is a change to all new manufactured spars having machined dihedral bends to eliminate the residual stresses in the critical area.”
An identical paragraph appears in the AD published on September 19, which applies to an estimated 10,927 PA–28 and PA–32 series aircraft that will now be subject to initial and recurring eddy current spar inspections based on the aircraft’s history, including (calculated) time in service and other factors.
Comments on both directives will be accepted into early November.
“We’re relieved to see that Piper has designed a reinforcing kit that will help ease the burden on owners and mitigate the safety concern for many aircraft,” said AOPA Vice President of Regulatory Affairs Murray Huling. “We’re also glad to see a spar replacement option now exists that eliminates the need for recurring inspections and corrects the original defect. That said, these directives pertain to a very large number of aircraft and implement a complex formula for assessing risk that we’ll need to look at closely before making our formal comments on these proposed directives.”
The FAA and Piper received more than 2,800 bolt-hole eddy current inspection reports as required by the 2020 directive (that was published in 2021, and estimated to apply to 5,440 airplanes), and more than 100 of these “reported a positive eddy current indication, with several including pictures of the bolt hole showing the source of the indication.”
While positive findings included various anomalies other than fatigue cracks, the FAA noted that six fatigue cracks were found in and around bolt holes, three of them verified as fatigue cracks by the NTSB and Piper.
“Other known cracks include those found in an airplane in the same fleet as the 2018 accident airplane, a separately submitted crack finding confirmed with dye penetrant, and a crack located on the lower spar cap surface running alongside the inspection bolt holes,” the FAA wrote. “Given these findings, additional cracks may be present among the other unconfirmed reported indications.”
The FAA noted that fatigue was not the only cause of cracks discovered during the investigations:
“Other cracks have been discovered that may be caused by overload rather than by fatigue. While use of the airplane within its limits should not cause an overload crack, some crack findings have revealed that airplanes have been operated outside their limits. Though cracks due to overload are not the primary source of this corrective action, this emphasizes the need for and importance of inspecting the spar bolt holes for evidence of any cracking.”
The FAA estimates that replacing the wing spar is less expensive than installation of the reinforcement kit, though the agency acknowledged it has no way to know how many aircraft might require either alteration. Spar replacement is estimated to cost $14,383 per wing (including 40 hours of labor), while reinforcing the wing via installation of the $4,000 kit is estimated to cost $20,150 installed, per wing, including 190 hours of labor. (AOPA contacted the FAA, Piper, and maintenance providers seeking clarification on why the spar reinforcement kit installation requires significantly more shop time than a spar replacement.)
While much of the September 23 AD references the Piper Service Bulletin that details the inspection process, the agency did establish a different inspection schedule for the “Group 1” and “Group 2” aircraft than what Piper previously stipulated.
For Group 1 aircraft (generally newer PA–28s) initial inspections are required at 3,000 CSH, and thereafter at intervals ranging from 1,750 CSH down to 500 CSH, up to 13,499 hours, at which point the spar must be replaced, or a reinforcement kit installed. (Piper’s service bulletin called for an initial inspection at 5,000 CSH.)
Aircraft in this group with kits installed are inspected upon kit installation, and thereafter every 4,800 CSH up to 13,499 hours, and not to exceed every 3,700 hours thereafter, with a 25,000-hour limit on the spar.
The FAA established the same compliance times and inspection intervals for Group 2 aircraft that Piper set forth in Service Bulletin 1372, starting with an initial inspection at 4,500 CSH, and repetitive inspections every 400 CSH thereafter up to 11,999 CSH, when the spar must be replaced or reinforced (if a kit becomes available for Group 2 aircraft).
“Both the FAA and Piper attempted to determine an inspection program that would manage risk to an acceptable level using inspection alone; however, no method could be found that did not eventually require spar replacement,” the FAA noted. The agency, like Piper, also emphasized the importance of following the prescribed procedures precisely to avoid damaging the wing spar assembly during inspection, which would then require spar replacement: “Ensuring further damage is not caused by the inspection itself is important, especially with repetitive inspections; however, inspecting for fatigue cracks as well as other hole anomalies is critical and outweighs the risk associated with repetitive inspections.”
EAA UPDATE 11/07:
EAA Submits Comments to FAA Concerning Proposed Piper ADs
EAA, supporting the concerns raised by Piper Aircraft and many commenters, this week submitted comments asking the FAA to rescind two proposed airworthiness directives (AD) that would affect certain PA-28 and PA-32 series aircraft. If implemented, the two ADs would expand the main wing spar inspections already mandated by previous FAA action. EAA and others are concerned that the FAA has failed to properly consider the safety risk and financial burden of the proposed additional inspections.
EAA is concerned that neither proposed AD, as put forward by the FAA, addresses all technical aspects regarding the hazards of expanded inspections and that inspection data gained from AD FAA-2020-26-16 does not support the conclusions drawn by the FAA.
Proposed AD FAA-2024-2142 modifies the formula for calculating the applicable time for eddy current inspections of the lower main wing spar bolt holes, affecting 10,665 airplanes. Damaged wing spars would require repair or replacement. Proposed AD FAA-2024-2143 would require reviewing airplane maintenance records to determine if an eddy current inspection of the lower main wing spar bolt holes was completed. If no previous inspection has been completed, a one-time eddy current inspection of the lower wing spar bolt holes would be required at 12,000 hours. This second AD would affect an additional 10,927 airplanes.
These proposals arise from the findings of inspections required by AD 2020-26-16, which mandate wing spar inspections on some Piper aircraft models. Based on these findings, the FAA is proposing to expand the scope of aircraft needing inspections, modify the inspection intervals, and amend the formula used to calculate aircraft time triggering the inspections.
We also strongly urge the FAA to utilize the data and information provided in Piper’s comments to reconsider the proposed inspections and the scope of aircraft to which they apply.
Aug 20, 2024: Cracks found in 24 other aircraft
A Cirrus SR20 power lever fractured during takeoff and forced the pilot to abort. Further investigation revealed cracks in 24 other Cirrus piston airplanes, prompting the FAA to notify operators and seek additional information.
The findings suggest that the double-drilled bolt hole in the rear wing spar attachment fitting significantly reduces the strength of the fitting below its limit load. If left unaddressed, this could lead to the separation of the wing and loss of control of the aircraft. Given that these aircraft are frequently used in training and quickly accumulate flight hours, inspecting for this condition before further flight is critical, according to the FAA.
For complete information click the link below:
The FAA has signed supplemental type certificates to allow General Aviation Modifications Inc.’s 100-octane unleaded fuel (G100UL) to be used in every general spark-ignition engine and every airframe powered by those engines. The move was hailed by the GA industry as a major step in the transition to an unleaded future. The FAA’s approval of the use of G100UL fuel in all piston aircraft directly addresses the industry's long-standing goal of finding unleaded solutions that can be used for the entire GA piston fleet.
“Congratulations to GAMI on this achievement, which is another initial step toward a goal we all want – an unleaded fuel for general aviation,” said Jack J. Pelton, EAA CEO and Chairman of the Board. “This is a significant accomplishment that opens the door to the hard work that remains to create a commercial pathway and acceptance across the broad spectrum of GA aircraft.”
In 2021 the FAA approved STCs for GAMI covering a smaller number of Cessna 172 engines and airframes, and then expanded those STC approved model list (AML) to include essentially all lower-compression engines. Though that was seen as an encouraging step forward in the years-long path to supply unleaded aviation fuel to the piston aircraft fleet, the STC’s did not include aircraft needing the higher-octane fuel that accounts for approximately two-thirds of avgas consumption. Today’s announcement by the FAA addresses the needs of those higher-compression engines.
GAMI co-founder George Braly said, “This is a big day for the industry. It means that for a lot of our general aviation communities, and especially for a high fraction on the West Coast, relief is on the way. And it means that our industry will be able to go into the future and prosper, and provide the essential infrastructure for this country for everything from Angel Flights to critical training of our future airline pilots.”
Braly thanked the GA community for its support through this long process. “Without it we couldn’t have gotten this done,” he said. GAMI’s Braly has said that Ann Arbor, Michigan-based fuel supplier AvFuel is standing by to manage the logistics and distribution of G100UL, and said he is open to partnerships. “Our arrangement is that any qualified refiner or blender of existing aviation fuels will be eligible to produce and sell it subject to the quality assurance requirements that the FAA has approved,” he said.
The timing for when G100UL will reach airports is still uncertain. “It’s going to take a while to manage the infrastructure including manufacturing and distribution," Braly said. The supply chain “is still a very wounded infrastructure and that’s not going to make the process any easier, but we have a handle on how to do this, and with the support of the major players I think we can do that. It’s going to be limited to begin with, but it can be ramped up rapidly,” he said.
Pelton noted that certain regions, such as the West Coast, are priorities to receive approval as soon as practical. Some California municipalities, for instance, prematurely banned the sale of leaded avgas and threatened a safe and smart transition to unleaded. “There is a process in place for a safe transition to unleaded fuel for the GA fleet,” Pelton said. “Let’s keep forging ahead on that path in a unified fashion, rather than a patchwork of local ordinances that will only set political hurdles in front of the ultimate goal.”
While the cost of the fuel has not been determined, Braly said the small batch production process that will initially mark the arrival of G100UL at airports means that the fuel will cost slightly more than leaded avgas. “Small volume batches cost money,” he said. “Until we can get [production] revved up that we’re making millions of gallons at a time, there will be an incremental cost," he said.
“It’s not going to be unreasonable,” Braly added. “Pilots in America will not be paying what they’re paying for avgas in Europe today.” Owners can also expect to see engines that operate more efficiently. “I think the days of cleaning spark plugs every 50 hours are going to be behind us for good,” Braly said.
Swift Fuels Inc., an Indiana based company, has received FAA approval for its 94-octane unleaded fuel, and has expanded its distribution, particularly to the West Coast. Swift Fuels’ 94-octane fuel meets some, but not all, of the demand of aircraft with lower-compression engines. The company is developing a 100R unleaded fuel with more than 10 percent renewable content.
In addition, two fuel candidates are currently in the EAGLE/PAFI testing process.
All fuel manufacturers continue to be encouraged to follow through with their own formulations, Pelton said. “Innovation and multiple options have always been a key to ultimate success, so we welcome any and all ideas to bring unleaded fuel to the marketplace for general aviation.”
It works hard at a number of important jobs, including cooling, lubricating, and, believe it or not, cleaning away the nasty debris. Cleaning the oil is the job of a metal screen, or in some cases, a paper filter.
Oil screens are an older technology, but still in use as the primary method of filtering the oil in many engines. How many screens an engine has, and their purposes depend on the model, but there are two basic types: the pressure screen and the suction screen.
The suction screen is prior to the oil pump and filters out the really bad stuff. Imagine a mechanic accidentally drops something into the engine and it passes through without damaging anything. It would end up in the oil pan and stay there thanks to the screen. More commonly, the suction screen blocks bigger pieces of aluminum and rubber that could be shed from use or internal damage. In a Lycoming engine these screens can be removed, cleaned, and inspected at each oil change. In a Continental engine they are fixed, so owners hope for the best.
Oil pressure screens are small cylinders about the size of a mini can of Coke that filter out the smaller stuff. These are removable on all engines in which they are installed, and cleaned with mineral spirits, inspected, and reinstalled as part of every oil change. Because oil filters can stop particles down to about 40 microns, and oil screens only filter down to about 60 microns, oil filters are generally considered superior. A 20-micron difference might not sound like much, but those particles floating around in the engine’s bottom end and cylinders can cause premature wear. Many pilots argue that an oil screen is just fine, and more regular oil changes make up for the difference.
Inspecting the screen is a bit of a dirty job, as the gooey oil must be brushed or wiped off in mineral spirits, and the resulting liquid drained through a coffee filter. From there it’s easy to see flecks of metal that can be analyzed for more information.
The aviation community has long recognized the need to eliminate lead emissions from piston-engine aircraft, a goal set to be achieved by the end of 2030 through the leadership of the Eliminate Aviation Gasoline Lead Emissions (EAGLE) initiative. This ambitious endeavor brings together government and industry partners committed to finding a safe and reliable unleaded aviation fuel that is viable throughout the aviation supply chain.
As the general aviation community works toward this goal, the role of aircraft owners cannot be overstated. They are, after all, the ultimate end-users of any new fuel, and their buy-in will be critical to its success.
This transition is about more than meeting regulatory requirements—it’s about ensuring that aircraft owners feel confident in the safety and reliability and availability of the new fuel. The solution must be robust enough to meet the diverse needs of the piston-engine fleet, ranging from the World War II era planes to modern helicopters.
Currently, there are three promising unleaded fuel candidates. Their developers are pursuing either the Fleet Authorization (FA) under the Piston Aviation Fuels Initiative (PAFI) or the traditional Supplemental Type Certification (STC) process via an approved model list (AML). Both pathways ensure that engines and aircraft can safely operate on the new fuel, however, regardless of the path to approval to use in the aircraft, consumer acceptance will hinge on more than FAA approval.
Fuel developers must not only prove their products’ safety and compatibility with the existing fleet but also demonstrate to key industry stakeholders that their product is reliable. Aircraft owners need assurance that switching to a new fuel won’t void manufacturer warranties. They also need to be confident that it won’t cause damage to paint, electronics, engine components or fuel systems. The aviation supply chain will need assurances as well. This next fuel must be produced, distributed, stored, possibly comingled with other fuels, pumped, and consumed without causing damage or requiring significant equipment modifications. Industry stakeholders understand that any new fuels must meet the needs of aircraft owners and be compatible with production, distribution and dispensing systems.
EAGLE has worked diligently over the past 18 months to keep stakeholders informed, providing updates on the progress of key unleaded fuel developers. General Aviation Modifications Inc.’s (GAMI) G100UL and Swift Fuels’ 100R are advancing through the STC process. GAMI has already secured a broad Approved Model List (AML) STC for its fuel in 2022 for piston engines and airplanes. Recently, the FAA granted Swift Fuels its first STC for the use of its 100R in Cessna 172 R & S model aircraft powered by Eliminate Aviation Gasoline Lead Emissions (EAGLE) Lycoming IO-360-L2A engines, with many additional engines and airframes being evaluated for approval in the weeks ahead. LyondellBasell/VP Racing’s UL100E is progressing through the PAFI pathway, having completed about 25 percent of critical materials compatibility and full-scale engine detonation and performance testing. Both Swift Fuels and LyondellBasell/VP Racing have also begun working through ASTM International on the development of an industry consensus production specification for their respective fuels.
The recent updates from EAGLE provide optimism. To learn more visit: flyEAGLE.org (See Stakeholder Meetings). Progress is being made, and general aviation’s path to acceptance of unleaded fuel continues.
Congress and the FAA’s commitment to this initiative is underscored by the 2024 FAA Reauthorization, which supports the continued availability of 100-octane low-lead (100LL) avgas until the end of 2030, or when a certified unleaded alternative is available at airports. (Alaska, a state heavily reliant on piston-engine aircraft, has been given a slightly extended timeline protecting continued availability of 100LL through the end of 2032). However, the collaborative industry/government EAGLE goal is clear: the elimination of leaded aviation fuel by the end of 2030.
General aviation is moving to ensure a safe, reliable transition to unleaded avgas without jeopardizing the operational safety of the piston-engine fleet. Aircraft owners must stay informed and engaged as this transition unfolds. It is important that they educate themselves on any restrictions that may accompany an STC and comply with any OEM directives that may be issued. They are the key players in this process, and their comfort with these new fuels will drive this monumental shift.
It is not enough for the FAA to approve these new fuels. The industry—from aircraft owners to fuel distributors to FBOs that dispense fuel and aircraft manufacturers that provide continued operational support—must accept them. Safety, reliability, and commercial viability must guide this transition, ensuring that by the end of 2030, piston-engine aircraft can take to the skies with unleaded fuel that is dependable. The future of general aviation depends on it.
The Eliminate Aviation Gasoline Lead Emissions (EAGLE) initiative is a comprehensive public-private partnership consisting of the aviation and petroleum industries and U.S. government stakeholders, and a wide range of other constituents and interested parties, all working toward the transition to lead-free aviation fuels for piston-engine aircraft by the end of 2030 without compromising the safety or economic health of the general aviation industry. To learn more, visit: https://flyEAGLE.org
California has passed the U.S.’s first leaded avgas ban effective in 2031.
California is a governor's signature away from banning leaded aviation gasoline statewide. Politico Pro is reporting the California state Senate on Thursday passed bill that would outlaw the fuel starting in 2031. California is the first state to pass a leaded fuel ban. Several other states have similar legislation moving through their legislatures. The Senate vote passed 30-8. The day before, the House passed the bill, SB1193, sponsored by Democratic Sen. Caroline Menjivar, by 59-11. It now goes to Gov. Gavin Newsom to sign. He could veto it but based on the two votes it would pass anyway with the required two-thirds majority to defeat a veto. Newsom has until Sept. 30 to sign or veto the bill.
The bill was a compromise in that Menjivar's bill proposed a phase-out starting in 2026 based on a complicated formula for determining health risk. The amended measure is an unequivocal measure that would "ban airport operators and any public or private entity that offer aviation gasoline from selling or distributing leaded fuel starting in 2031." The delay resulted from pushback from aviation groups who argued an earlier deadline would threaten safety because a substitute fuel would not be widely available in time. The End Aviation Gasoline Lead Emissions (EAGLE) initiative has been given until 2030 to come up with a drop-in replacement fuel that completely satisfies the fuel requirements for piston aircraft.
Updated August 26, 2024
These statements are in response to comments by Russ Niles of AvWeb
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”
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% 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 ten 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!
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’s observations, and Paul Bertorelli’s from 18 months ago, are precisely on point.
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% 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 TBO’s. 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, WA, CO. WI. NY, 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.
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General Aviation Modifications Inc. (GAMI) says it will issue a detailed response to Cirrus Aircraft’s recent service advisory discouraging the use of GAMI’s G100UL unleaded fuel in its SR series aircraft.
In a statement to AVweb, GAMI said the service advisory appears to be linked to a single incident in which the sealant used in the fuel tank had unbonded in a company aircraft that had been fueled with G100UL. GAMI says there are indications the unbonded sealant had nothing to do with the fuel, but because the tank was not inspected before the unleaded fuel was introduced there’s no way to prove whether the fuel was a factor.
In its service advisory, Cirrus said the materials compatibility of the fuel is “inconclusive.”
GAMI also noted that the fuel has been used in other aircraft with the same sealant with no issues.
“GAMI’s SR22 has had G100UL in the fuel tanks for most of the last 14 years. Recently, Cirrus engineers and management inspected the interior of those tanks, in person, using a borescope and found no evidence of any debonding by any of the factory applied sealant in that aircraft,” the company said in its statement.
GAMI is also disputing Cirrus’s claim that use of G100UL voids the warranties on engines supplied by Lycoming and Continental and used in its aircraft. The engine warranties both state that they will not cover damage from the use of “non-approved fuel,” but GAMI noted the FAA has approved G100UL for all models of Lycoming and Continental gasoline engines.
Cirrus Service Advisory Cites GAMI G100UL As ‘Unapproved’ For SR Series
In a blow to the General Aviation Modifications Inc.’s (GAMI’s) G100UL unleaded aviation fuel program, Cirrus Aircraft posted Service Advisory SA24-14 Tuesday (June 18). The advisory informs operators of Cirrus SR-series aircraft (SR20, SR22 and SR22T) that the manufacturer “does not approve the use of GAMI G100LL fuel in Cirrus SR Series airplanes. Additionally, Cirrus does not warrant or represent in any way an operator’s use of the GAMI G100UL fuel in Cirrus SR Series airplanes.”
Cirrus further advised operators: “Per Continental and Lycoming, only approved fuels may be used for an engine to be covered by warranty. As the GAMI G100UL fuel is a non-approved fuel per Continental and Lycoming, engines known to have run this fuel may not be covered by the OEM engine warranty. For specific details, please refer to the respective Continental and Lycoming engine warranty documents.”
Those advisories were preceded in the statement by a description of Cirrus’s efforts to promote the development of unleaded aviation fuel that would serve as a drop-in replacement for 100LL. “These efforts include working directly with industry associations and all stakeholders including AOPA, GAMA, the FAA, and the FAA-Industry EAGLE [Eliminate Aviation Gasoline Lead Emissions] program through the PAFI [Piston-Engine Aircraft Fuel Initiative] certification program. As of June 2024, EAGLE is actively pursuing three potentially viable alternatives/replacements for 100LL: GAMI G100UL, LyondellBasell/VP Racing UL100E, and Swift 100R.”
Cirrus described its testing programs with GAMI’s G100UL, citing more than a decade of performance testing on materials compatibility and performance. However, Cirrus wrote, “While some aspects of the initial Cirrus testing of the GAMI G100UL fuel are encouraging, other areas, including materials compatibility, remain inconclusive.”
Controversially, while G100UL has received an FAA Supplemental Type Certificate covering virtually all aircraft piston engines, GAMI has chosen not to participate in the PAFI program to achieve ASTM International approval for its fuel.
Lycoming Clarifies G100UL Warranty Impact
he world’s largest piston aircraft engine manufacturer has confirmed it may not honor warranty claims on engines that have been run on GAMI G100UL unleaded fuel. In a statement to AVweb, Lycoming said that G100UL is not on its list of approved fuels and while warranty claims are assessed individually, the warranty “does not cover damage caused by operation outside of Lycoming’s published specifications or the use of non-approved fuels or lubricants.”
The full statement is copied below. The company did not say what is required to make that list but it includes leaded and unleaded aviation fuels and some unleaded automotive fuels. Its highest performance engines are generally restricted to 100LL in North America.
Lycoming was responding to a legal opinionoffered by an AVweb reader who is a lawyer and high-performance single owner who disputes that claim. He said that since G100UL is approved by the FAA through an STC, engine manufacturers can’t reject warranty claims based on use of the fuel. Lycoming’s full unedited statement follows.
WILLIAMSPORT, PA – Lycoming Engines provides a Limited Warranty against defects in material or workmanship. Lycoming’s Limited Warranty does not cover damage caused by operation outside of Lycoming’s published specifications or the use of non-approved fuels or lubricants.
Lycoming publishes specifications for approved fuels in Service Instruction 1070. G100UL is not listed as an approved fuel in Service Instruction 1070.
Lycoming evaluates warranty claims on a case-by-case bases in accordance with the terms of its Limited Warranty. However, customers should be aware that use of fuels not approved in Service Instruction 1070 would constitute operation outside of Lycoming’s published specifications.
Credit to : Russ Niles is Editor-in-Chief of AVweb.
Pilots and A&P mechanics can bond over setting spark plug gaps or tossing them if they fail to meet muster.
Diving deeper into the world of aviation spark plugs, we will pull back the cowling and affix our inspection mirror to discuss the types commonly used in different aircraft models, insights into their maintenance, and recommendations for their replacement.
At their core, spark plugs are devices that deliver electric current from an ignition system to the combustion chamber of an engine, igniting the compressed fuel/air mixture by an electric spark. Properly functioning spark plugs are essential for smooth engine operation and optimal performance.
“The two major types of electrodes in today’s spark plugs include the dual nickel alloy massive electrode and the single Iridium fine-wire electrode," saidAlan Woods, sales manager for piston and power at Champion Aerospacein Liberty, South Carolina. "The nickel alloy electrode design allows for a long-lasting spark plug [300 to 500 hours] at an affordable price. The Iridium fine-wire electrode design offers TBO life [2,000 hours plus] but at a higher cost due to the high cost of Iridium [$4,000 per ounce].”
Massive Electrode Spark Plugs
Massive electrode spark plugs are the most commonly used type in general aviation. They feature large electrodes designed for durability and extended use.
Massive electrode plugs are critical features in terms of durability. They can withstand significant wear and tear, making them ideal for aircraft that undergo frequent and long flights. Massive electrode plugs are also cost-effective. They are generally more affordable than their counterparts, the fine-wire spark plugs. Another attribute is their ease of maintenance. Due to their stout construction, massive electrode plugs are easier to clean and maintain.
There are a few downsides to massive electrode plugs. Over time, massive electrode spark plugs can suffer from performance issues due to electrode wear and increased gap size, leading to less efficient combustion. They are also heavier as the larger electrodes add to the weight, which can be a minor concern in aircraft performance calculations.
Fine-Wire Spark Plugs
Fine-wire spark plugs are designed with thinner electrodes, often made of precious metals such as platinum or Iridium, to provide superior performance and longevity.
The fine-wire plug offers improved ignition over massive electrodes, giving the fine-wire electrodes a more concentrated spark and leading to better combustion and engine performance. They also last longer because they are constructed using durable materials, such as platinum and Iridium, reducing the frequency of replacements. Fine-wire plugs are also lighter than massive electrode plugs, contributing to overall aircraft efficiency.
These enhanced attributes come with a cost. Aircraft fine-wire spark plugs are substantially more expensive than massive electrode spark plugs. They also require careful handling during maintenance to avoid damaging the fine electrodes.
The choice between massive electrode and fine-wire spark plugs often depends on the specific requirements of your aircraft and your flying activity. Massive electrode spark plugs might be more suitable if you fly frequently and cover long distances due to their durability and cost-effectiveness. Fine-wire spark plugs could be the better choice if you prioritize engine performance and are willing to invest in premium parts due to their enhanced ignition efficiency and longevity.
Fine-wire plugs provide a more efficient burn rate and last longer at a much higher purchase price, according to Vince Bechtel, director of aftermarket sales at Tempest Aero Group, which entered the aviation spark plug market in 2010 by acquiring the Autolite brand. A relatively small niche market, the company represents about 10 to 15 percent of the aviation aftermarket. Turbocharged aircraft flying at higher altitudes favor fine-wire plugs, according to Bechtel.
Proper maintenance and timely replacement of spark plugs are crucial to avoid engine misfires and ensure smooth operation. Some tips:
● Regular inspections: Conduct routine inspections every 100 hours of flight time or as your aircraft’s manufacturer recommends. Check for signs of wear, fouling, or damage. Common issues include carbon buildup, oil fouling, and electrode erosion.
● Cleaning: Use an approved spark plug cleaner to remove carbon deposits and debris. Be cautious with fine-wire spark plugs to avoid damaging the delicate electrodes.
● Gap checking: Ensure the spark plug gap meets the manufacturer’s specifications. A correct gap is crucial for optimal spark plug performance. Adjust the gap if necessary using appropriate tools.
● Replacement: Replace spark plugs at the manufacturer’s recommended intervals or if significant wear or damage is observed during inspections. Always use spark plugs that meet the specifications of your aircraft’s engine model.
“Honestly, the biggest issue I see is over-cleaning," Bechtel said. "Individuals and shops tend to clean plugs until they look brand new out of the packaging. The only thing this does is wear out your electrodes and insulator faster, preventing you from getting the full life out of a set of plugs.”
Even with regular maintenance, spark plug issues can occur. Some common problems and their potential causes include:
Engine Misfire
Hard Starting
Poor Engine Performance
The introduction of fired-in suppressor seal technology, or FISS, is a recent advancement in aircraft engine spark plugs.
"This technology eliminates the high-voltage silicon resistor, which is prone to resistance value increases over time," Woods said. "The FISS technology incorporates fired-in conducting and suppressor glasses that establish the resistance value of the spark plug. This means that the end user has a stable resistance value over the entire life of the spark plug. With the introduction of electronic ignition, spark plug designs will evolve with wider gaps to handle the increased energy being produced.”
Understanding the various types of aviation spark plugs and their benefits and limitations can help you make informed decisions about aircraft maintenance. Whether you choose massive electrode spark plugs for their durability and cost-effectiveness or fine-wire spark plugs for their superior performance and longevity, regular maintenance and timely replacements are critical to engine operation.
Please consult your aircraft’s technical publications and an A&P mechanic to ensure your spark plugs are in an airworthy condition.
Aircraft engines, for obvious reasons, are supposed to be reliable, but having one tank is a recurring nightmare for many pilots. How often does it happen? Often enough, but as AVweb’s Paul Bertorelli reveals in this video, the risk is not really as high as many of us imagine and more than half of engine failures are caused by pilot or mechanic mistakes. In this AVweb rewind, we take a look at a video examining the topic published last year.
By Vic Syracuse, EAA Lifetime 180848
This piece originally ran in the January 2024 issue of EAA Sport Aviation magazine.
In the November 2021 issue of EAA Sport Aviation I wrote a column entitled “Cooling Things Down.” It was meant to help builders solve some of their cooling problems by providing some insight into the causes. From several discussions with pilots and owners of aircraft since that column, it’s become clear that not everyone understands the differences between EGTs (exhaust gas temperatures) and CHTs (cylinder head temperatures), and whether they are or are not a problem.
Click the link below to read the article:
Thanks to years of EAA’s advocacy efforts, the FAA has unveiled a new program for the use of off-the-shelf parts in type-certificated aircraft. This is the first approval granted under the new Vintage Aircraft Replacement and Modification Article (VARMA) program, the next big step in keeping vintage aircraft flying.
Anyone who owns and operates vintage aircraft knows that finding parts can be a major challenge. This situation is especially frustrating when perfectly safe and functional alternatives are readily available, but can’t be used because there’s been no legal way to install them in a type-certificated aircraft. With VARMA in place, some aspects of vintage aircraft ownership and operation are about to get a lot simpler.
Notably, VARMA uses several existing FAA policies to create a program that requires no new regulations, orders, or advisory circulars. It applies to small (less than 12,500 pounds) type-certificated aircraft built before 1980. The program allows ordinary maintenance personnel to validate that certain low-risk replacement parts are suitable for installation on aircraft, without the need for extensive engineering analysis or complex and time-consuming design and production approvals from the FAA.
"This is great news for those of us who own and fly vintage aircraft,” said Jack Pelton, EAA’s CEO and chairman of the board. “There could easily come a time when a classic airplane that would otherwise be grounded for want of a part that’s no longer available will fly again thanks to the parts substitution enabled by VARMA.”
The program applies to parts whose failure would not “prevent continued safe flight and landing.” While this means that safety-critical components are not subject to this program, there are plenty of hard-to-find parts that meet VARMA’s criteria.
For the trial, EAA chose to apply for an off-the-shelf starter solenoid used as a substitute part in a Cessna 150, as the failure of the starter system is generally irrelevant to flight safety. The FAA granted the first Form 337 approval under the program several weeks later. Since that time, we’ve also been granted approval for alternators and voltage regulators in VFR aircraft.
There are many more parts that are eligible under VARMA. For the time being, the FAA will be primarily managing the program through its Chicago Aircraft Certification Office, which can be reached at 847-294-7357, but VARMA is supported all the way to the highest levels of the agency. At this time approvals will be considered on an individual basis, although type clubs and ownership groups are encouraged to keep track of substitute parts that have gained approval.
“EAA has had a longstanding commitment to maintainability and modernization in the legacy aircraft community,” said Tom Charpentier, EAA’s government relations director. “Our EFIS and autopilot STCs broke new ground in affordable avionics, and it is our hope that VARMA opens many new doors for easily found replacement parts. As with the STC programs, we blazed the trail with the first application. Now we’re excited to see the program grow in the GA community.”
Do you think ADs Apply to Homebuilts? Yes or No? Because you have an E-AB aircraft and you don't think you need to comply AD's you just might be wrong. Please read this article from Kitplanes Magazine. It's an excellent analysis of what needs to be considered.
Among the many effects of the supply chain problems in the summer of 2022, aviation discovered that it was having a difficult time functioning without a simple commodity—the oil filter. Lycoming and Continental engines everywhere needed spin-on, disposable oil filters to keep flying, and the supply was extremely limited. KITPLANES research found that Champion had effectively stopped production—though it is now ramping back up—while Tempest was going at their normal production rate and trying mightily to increase it to meet demand. But Tempest simply couldn’t double its production overnight, so suppliers’ shelves emptied as aircraft owners quickly bought up every filter they could find. Remember the toilet paper shortages in the early days of COVID? Yeah, it was sort of like that.
Click below to read the entire article
Care and feeding of the only things between you and the ground.
While generally round and black in color, that’s almost all the characteristics aircraft tires have in common with their automotive siblings. In fact, a major difference is the construction and materials used in their manufacture. Aircraft tires and tubes primarily incorporate natural rubber while automotive tires use synthetic compounds extensively. Aircraft tires are designed for a very specific job and are part of the landing gear system on almost every aircraft.
Credit to AvWeb for this excellent article
Following a request from EAA and AOPA, the FAA has released a policy that will make it easier for some owners of experimental aircraft to obtain special flight permits (SFPs) for their airplanes in order to reposition them for condition inspections.
The advent of the FAA's shift to an electronic airworthiness certification process can be daunting, but it need not be! DAR Arnold Holmes, our "local" DAR can explain what you need to get your aircraft certified. Arnold Holmes is a Private pilot, an A&P Mechanic with Inspection Authorization (IA), and a Designated Airworthiness Representative (DAR). He is a member of EAA and has over 25 years in aviation. Arnold runs DAR-Certification Services at the Leesburg Airport.
Check out his website at https://dar-certification.com.
ENJOY!