APPENDIX A
Airport Summaries

This appendix provides summaries of case studies of seven airports that had already begun or were in the process of being able to supply unleaded gasoline along with 100LL gasoline during the spring and summer of 2024 when interviews were conducted. The summaries are available for the following airports, along with the results of interviews related to the transition at Alaskan airports:

• Centennial Airport in Englewood, CO
• Long Beach Airport in Long Beach, CA
• Naples Airport in Naples, FL
• Rocky Mountain Metropolitan Airport in Broomfield, CO
• South St. Paul Airport in South St. Paul, MN
• Waco Regional Airport in Waco, TX
• Watsonville Municipal Airport in Watsonville, CA

Centennial Airport

Location & Date: Centennial Airport (APA), Englewood, CO (April 10, 2024)

Contact: Michael Fronapfel, Executive Director

Airport Overview

The Centennial Airport (APA) is owned and operated by the Arapahoe County Public Airport Authority. It is a general aviation reliever airport located southeast of Denver, Colorado. It is one of the nationʼs busiest general aviation airports, accommodating 362,704 operations (takeoffs and landings) in 2023. APA consists of approximately 1,360 acres of property, more than 125 businesses, and approximately 840 based aircraft. Centennial Airport prides itself on being a leader in sustainability and social responsibility. It was the first airport in Colorado to offer unleaded fuels and is the largest user of UL94 in the country.

Fuel Service at the Airport

There are three fixed-base operators (FBOs) at the airport: jetCenters of Colorado, Signature Aviation, and Modern Aviation. There is one additional smaller FBO that focuses on helicopter refueling. All aircraft refueling is delivered by fuel trucks serviced by fuel farms owned by the FBOs.

The airport dispenses approximately 16 million gallons of fuel per year, including jet fuel. jetCenters of Colorado is the largest FBO and serves about 60% of avgas sales. At the time of the interview, this was the only FBO participating in the sale of Swift UL94. There is an effort to also work with Signature to provide UL94, but this has not happened yet.

Both 100LL and UL94 are offered to customers. The airport does not have a requirement that fuels comply with ASTM standards. This is handled by the FBOs as a requirement. However, the FBOs at Centennial were not reported to be interested in GAMI G100UL because there is no applicable ASTM standard.

Infrastructure

The fueling infrastructure at the airport includes the following tanks:

• jetCenters of Colorado – has three fuel farms with approximately 210,000-gallon capacity. The FBO converted a 30,000-gallon tank for UL94 and has also converted one fuel truck to deliver UL94.
• Signature Aviation – has two fuel farms with approximately 69,000-gallon capacity.
• Modern Aviation – has one fuel farm with approximately 40,000-gallon capacity.

Process Leading to Offering Unleaded Gasoline

The Airport Board was supportive of the unleaded fuel initiative as there was community interest in addressing the use of leaded fuels. There were ongoing discussions with Board members regarding the transition initiative and also between staff and the FBOs in advance of proposing a resolution. The Airport Board passed a resolution in March 2023 in support of the initiative, and the airport began offering UL94 through jetCenters of Colorado on May 3, 2023. From November 2023 through October 2024, 582,903 gallons of 100LL and 159,536 gallons of UL94 were dispensed. UL94 accounted for 21.49% of avgas dispensed. During that same period, 13,983,871 gallons of jet fuel were sold, with 100LL and UL94 accounting for 5.04% of overall fuel sales.

The airport has an internal goal of UL94 reaching 25% of the avgas market but would like to see that increase to 50%. If the airport can transition to all unleaded fuel before the EAGLE initiativeʼs 2030 goal, they will attempt to do so. If an appropriate unleaded replacement fuel becomes available, the airport anticipates implementing it within 2–3 years but may still need to offer 100LL for certain aircraft or to meet any FAA grant assurance requirements to provide 100LL.

Several factors influenced the decision and the Boardʼs eventual adoption of a supportive resolution. A key consideration was ensuring there was a market for UL94, with a focus on the airportʼs flight schools.

Flight Schools & Flying Club

There are three flight schools under the jetCenters of Colorado leasehold on the airport. The largest flight school, Aspen Flying Club, chose to use UL94. They operate 28 aircraft with the required STC and are currently one of the largest users of UL94. Aspen reports aircraft maintenance cost benefits.

Also under the jetCenters leasehold is ATP Flight Training, with 24 aircraft with the UL94 STC, but they are not yet using UL94 fuel. Independence Aviation flight training is not participating because their aircraft cannot use UL94.

Flights Inc., another flight school with 16 aircraft with the UL94 STC, operates under the Signature Aviation leasehold. They do not utilize UL94 because Signature does not dispense UL94 yet.

Centennial Flyers, a flying club at the airport, is also a large user of UL94. Aspen Flying Club and Centennial Flyers are the largest users of UL94 at the airport.

Secondly, the airport wanted to ensure deliveries and costs were addressed. jetCenters of Colorado, the first FBO to offer UL94, wanted the ability to support full loads of UL94 deliveries. The cost of utilizing smaller-volume totes would have significantly increased the cost and end-user pricing. jetCenters of Colorado had the tank capacity to accommodate unleaded fuel by converting an existing tank while maintaining adequate capacity for 100LL.

Thirdly, the airport desired to initiate an incentive program. Initially, they offered to financially assist the FBO with a tank installation but did not need to, as a tank was already available on site. They will likely assist Signature Aviation if they agree to provide unleaded fuel. The airport has budgeted $300,000, which could be applied to tank purchases, installation, fuel truck purchases, or retrofits.

Fourthly, the airport covers the full cost of any tenant aircraft STC. To date, approximately 103 aircraft have received STCs, costing about $10,000. There is a sunset on paying for the STCs, and this program only applies to the Swift UL94 fuel, as GAMI G100UL might have a different STC cost.

Finally, the airport subsidizes the cost of UL94 to aircraft operators. To do this, the FBO conducts a weekly analysis of the price differential between UL94 and 100LL, which has ranged from $1.13 to $1.88 per gallon. The airport then pays this difference, with the stipulation that the FBO charge program tenants the same price for both 100LL and UL94. The FBO provides the airport with a monthly price analysis.

Additionally, the airport mentioned an EPA study completed in 2015 that measured lead levels in the air near the airportʼs most common aircraft run-up area. It was stated that the study found that the lead levels were at 0.02 micrograms per cubic meter, lower than the 0.15 microgram per cubic meter EPA National Ambient Air Quality Standard.

Fuel Supplier Coordination

jetCenters of Colorado is “Avfuel branded.” Avfuel provides both 100LL and UL94 products. The airport elected not to utilize tote delivery (i.e., delivery of relatively small volumes of fuel in small transportable containers) and started with full tanker delivery, as the available tank would accommodate this, thereby lowering UL94 costs. To date, there have been no known delivery issues.

Training

The FBO provides the fuel and refueling services and is therefore responsible for the required training.

Communication with Tenants

The airport reached out to the FBOs and the flight schools initially to understand the issues and eventual demand for unleaded fuels. There were public meetings held. Additionally, there were a number of one-on-one telephone calls and meetings with tenants. The airport also advertised the program on their website and social media platforms.

Challenges and Costs

Overall, Centennial believes the UL94 program has been a success.

Currently, the airport is using airport funds for the program. The airport budget for the STC/unleaded fuel subsidy program was $250,000 for 2024, and the program was expected to continue

through the end of 2025. Centennial received a $300,000 grant from the Colorado Division of Aeronautics, paying 90% of the cost to subsidize unleaded aviation gasoline prices. Provided future grants can be obtained, Centennial plans to continue the fuel price subsidy program until a 100-octane unleaded fuel becomes available. At the time of the interview, Centennial was the only airport in Colorado dispensing unleaded avgas, so it is likely the airport may continue to receive state grants going forward. There was proposed state legislation regarding the issue (House Bill 24-1235, which was later enacted). State Aeronautics is proactive and may be providing grants ahead of the legislation.

For federal funding assistance, the airport works with a lobbyist that assists airports across the country with the transition to unleaded fuel. Areas of discussion include possibilities such as rolling back taxes on unleaded fuels and/or taxing fuel to offer FAA Airport Improvement Program funds for infrastructure and fuel subsidies.

There was mention of individual tenants who have concerns or hesitations about using UL94 due to the University of North Dakota aircraft engine situation (Lycoming Engines 2024).

Advice for Other Airports

Centennial hopes to see legislative action for federal funding to assist other airports with the transition to unleaded avgas.

Additional Information

The EPA study and the FBO contact information were provided.

Liability Risk Management

The airport did not have any liability concerns because Swift UL94 had both FAA authorization and an applicable ASTM standard, and it had been used at other airports and by flight schools for years without any issues—in fact, some users reported benefits. Neither Centennial Airport nor the FBOs would support the dispensing of any unleaded fuel that does not have both FAA authorization and an applicable ASTM standard.

Long Beach Airport

Location & Date: Long Beach Airport (LGB), Long Beach, CA (April 23, 2024)

Contact: Juan Lopez-Rios, Deputy Airport Director

Airport Overview

The Long Beach Airport (LGB or Airport) is owned and operated by the City of Long Beach, California, located in the southernmost part of Los Angeles County, adjacent to Orange County, California. It is a small-hub airport providing services for general aviation, military, cargo, and commercial passengers. The Airport supports approximately 400,000 operations (takeoffs and landings), has approximately 400 based aircraft, and services more than 2 million enplaned passengers annually. LGB consists of approximately 1,166 acres of property.

Fuel Service at the Airport

LGB is served by two FBOs, Aeroplex Aerolease Group (AAG) and Atlantic Aviation. As a subtenant, Signature Aviation provides fueling service for AAG general aviation customers.

Infrastructure

• Fuel Farm #1
  2 – 15,000-gallon tanks, Jet A
  1 – 12,000-gallon tank, 100LL
  1 – 2,000-gallon tank, diesel
• Fuel Farm #2
  1 – 15,000-gallon tank, Jet A
  1 – 12,000-gallon tank, UL94

Signature Aviation at Van Nuys Airport provides a 1,000-gallon fueling truck for transporting UL94 to LGB, which minimized the need for an additional capital investment in a dedicated fuel tank at LGB. The fuel truck facilitated UL94ʼs quick availability at LGB.

Process Leading to Offering Unleaded Gasoline

Based on data reported in EPAʼs 2017 National Emissions Inventory, LGB was identified as emitting the second highest amount of lead in the country (EPA 2017). The leaded fuel issue became a concern for the community and therefore for the Mayor and the City Council. In December of 2022, the City Council directed the Airport to develop a strategy to transition to unleaded avgas.

The Airport began an effort to educate the City Council and community on how airports operate and what is within an airportʼs purview to change. There was some community misperception regarding airport obligations under FAA grant assurances, believing the airport was obligated to provide certain fuel based on accepting federal funding assistance for airport projects. During December 2022 to August 2023, the Airport worked with the City Council, the FBO, and Swift Fuels to review options to introduce unleaded fuel at LGB. The Airport also provided educational information on airport operations to the Council and community.

In December 2022, Long Beach City Council authorized the Airport to institute a waiver of fuel flowage fees for unleaded fuel for the years 2023–2025. This was put in place as an incentive program for fuel providers at LGB to support the move towards offering unleaded fuel.

In August 2023, FBO AAG began offering UL94 and the Mayor performed the first ceremonial fueling at the FBOʼs press event. Avgas only accounts for approximately 10% of total fuel volume dispensed at LGB.

In October 2023, the EPA determination was released regarding potential health risks caused by lead aviation fuel emissions, creating greater concern.

Two additional incentive programs were subsequently developed with initial budgets of $60,000 and $200,000, respectively. In November 2023, the Airport offered a program for tenant reimbursement for the purchase of a Supplemental Type Certificate (STC), which is required to confirm that an aircraft and engine qualify for the unleaded fuel available. It was estimated that 60%-70% of aircraft based at LGB would be compatible with this STC. At the time of the interview, approximately 20 aircraft were in the application process. The Airport expected that the program would take time as pilots would need to become comfortable with converting to UL94. The Airport continued its promotional efforts. The first person to obtain an STC was featured in the Airport newsletter.

Based on the Long Beach Airportʼs experience at the time of the interview, high fuel transport costs resulted in the price of unleaded fuel ranging from $2.00 to $4.00 per gallon higher than 100LL. In January 2024, the Airport offered a third incentive program approved by the City Council, known as the Subsidized Aviation Fuel for the Environment (SAFE) program. SAFE

subsidizes the cost of UL94 so the consumer can buy UL94 at the same price as 100LL. The Airport works directly with Signature Aviation in the implementation of SAFE. The SAFE program for UL94 is available for all qualified aircraft, both LGB-based and itinerant. The negotiation and execution of the subsidy program was completed in May 2024.

On December 12, 2023, the Airport presented a comprehensive report, General Aviation Operations at Long Beach Airport, to the City Council and the community (City of Long Beach 2023a). This provided a public forum to further educate the community about airport operations in order to address misperceptions, including those related to the provision of unleaded aviation gasoline and to receive public comment on the matter (City of Long Beach 2023b).

Fuel Supplier Coordination

Signature Aviation branded but Swift provides the UL94 support.

Training

Since the FBO provides the refueling service, they are responsible for training.

Communication with Community & Tenants

There are two general aviation groups that meet to discuss concerns:

The community is concerned about the health risks associated with the continued use of lead fuel for general aviation operations. The flight schools conduct a large volume of touch-and-go operations. The flight schools, user groups, and tenants are becoming aware of the various issues and the available incentive programs. The flight schools are engaged in discussions regarding the communityʼs concerns. Transition to unleaded fuel by the flight schools would help to address the health concerns of the community.

LGB coordinated with the FAA on a Community Webinar for the Long Beach community which was held in June 2024 after the case study interview (FAA 2024). The FAA had previously provided a similar webinar for the Newport Beach community adjacent to John Wayne airport (SNA) (FAA 2022). The Long Beach webinar was designed to cover many issues including fuel concerns.

Challenges and Costs

The unleaded fuel truck utilized by Signature Aviation at LGB is not approved for public roadways. The truck is physically hauled to Van Nuys Airport, loaded with UL94 and then hauled back for use at LGB. These transport costs and other factors increased the expenses for offering unleaded fuel.

At the time of the interview, there were no complaints from the pilot community regarding the programs, but there was hesitancy in converting based on safety uncertainties in the various unleaded fuels, and as a result, limited use of UL94.

At the time of the case study interview, California Senate Bill SB 1193 was under consideration and written to ban the sale of lead fuel in California. This bill was ultimately enacted with modifications. It bans the sale of leaded aviation gasoline in California on and after January 1, 2031.

Advice for Other Airports

It takes time to develop contracts and arrangements, and one must be aware of local public sentiment and politics. Communities can be galvanized on sensitive issues, but cordial communication is essential to ensure that input from citizens and organizations is heard. Long Beach Airport found that holding public discussions in conjunction with elected officials and airport representatives was helpful in discussing the transition to unleaded fuel.

Naples Airport

Airport: Naples Airport (APF), Naples, FL (March 12, 2024)

Location & Date: Byron Gray, Director of FBO Services

Airport Overview

The Naples Airport (APF) is owned and operated by the Naples Airport Authority (NAA). In addition to the airport, the Authority also owns and operates the FBO. It is a general aviation reliever airport located in southwest Florida. During 2021–2022, the airport experienced just over 113,000 operations (takeoffs and landings) and annually services more than 200,000 visitors. APF consists of approximately 732 acres of property, two terminals, and approximately 360 based aircraft.

Fuel Service at the Airport

The NAA owns and operates the sole FBO. They offer Jet A, 100LL, and UL94. The FBO experiences approximately 36,000 fueling operations per year, dispensing approximately 350,000 gallons of 100LL and approximately 57,000 gallons of UL94 annually, or 16% of avgas sales. The fuel is delivered by mobile trucks; however, there is a self-serve option for 100LL fuel (100LL is provided by a 50/50 mix of self-serve and full service). The fuels are ASTM certified, and at this time, Naples probably will not switch to another unleaded or non-ASTM fuel.

Infrastructure

The fueling infrastructure at the airport includes the following tanks:

• Tank #1 – 30,000 gallons Jet A
• Tank #2 – 20,000 gallons Jet A
• Tank #3 – 20,000 gallons Jet A
• Tank #4 – 20,000 gallons UL94
• Tank #5 – 40,000 gallons Jet A
• Tank #6 – 40,000 gallons Jet A
• Tank #7 – 40,000 gallons Jet A
• Tank #8 – 10,000 gallons Diesel
• Tank #9 – 2,000 gallons Unleaded Gasoline
• Car rental – 12,000 gallons Unleaded Gasoline
• North Self-Serve – 12,000 gallons 100LL
• South Self-Serve – 10,000 gallons 100LL

There are two 100LL refueler trucks and one additional truck that has been dedicated to UL94.

Process Leading to Offering Unleaded Gasoline

There was growing concern from the community regarding the use of 100LL and lead emissions. The NAA considered offering UL94 and approved the transition, including subsidizing additional costs for the based tenants. Upon approval, staff proactively implemented the operation in just over two months.

NAA performed a survey of other airports* supporting and offering UL94 to the flying community. They determined if other airports were subsidizing the program and learned the details. Next, they performed a tenant survey to gauge interest in UL94. They reached out to Swift Fuels and provided them with a list of all NAA-based tenants who use 100LL to determine which aircraft qualified to use the product. NAA presented these findings and then determined how they would subsidize the program. The Board granted approval for FY23 and FY24 at a sum of $182,500. They started in June 2023, and as of November 2024, they have used $142,865 and the sales have been consistent. They plan to request that the Board renew the subsidy before it is spent.

UL94 is subsidized at about $1.30 to $1.50 per gallon in an attempt to match the 100LL rate for based aircraft; non-tenants pay the full retail price. An additional subsidy, limited to $250 per based user, is offered for the purchase and installation of the required STC for applicable based aircraft.

NAA started by using a refueler truck provided by Avfuel to store and distribute UL94. After a two-month period, they converted an existing 20,000-gallon 100LL fuel tank into a UL94 tank. They drained and cleaned out the tank and replaced the filters in the system. They leased a 1,200-gallon aviation gasoline refueler dedicated to the UL94 product. All products are ordered through Avfuel at 8,000-gallon loads compared to the initial 900-gallon orders. This reduced freight costs considerably and lowered the subsidy cost.

During this process, NAA completed some soil testing for lead levels at the airport, around the runway environment, and in residential areas near the airport (homes, tabletops, etc.). All tested levels came back well below residential limits.

Fuel Supplier Coordination

NAAʼs FBO is Avfuel branded. Avfuel provides both 100LL and UL94 products. Delivery by tote cost was estimated to be between $11.00 and $13.00 per gallon. This cost could be reduced to around $7.00 or $8.00 per gallon with full-load deliveries, allowing for reduced freight costs coming from West Lafayette, IN.

Training

NAA utilized their internal training department to develop an SOP**, then trained all line technicians and customer service representatives regarding the new procedures. X1 software developed a new product code to help prevent misfueling. In addition, they developed a tenant authorization form to record the aircraft transition to UL94. They do not offer UL94 as a self-serve product and only offer it through the mobile refueler.

NAA states, “with 37-line personnel, there is always opportunity for mishap.” NAA prioritizes training, following written SOPs, and supervisor support. The use of aircraft placards, colors (industry recently dyed UL94 purple), and color stickers on nozzles all assist with proper refueling. It was stated that NATA does offer a training program; however, it is very brief and buried in the “misfueling” section.

Communication with Tenants

NAAʼs communications department sent out emails surveying the tenants and their interest in using the product. There are 360 based aircraft and approximately 120 qualified to use UL94. Currently, there are 36 aircraft enrolled, 17 of which are flight schools that consume 96% of the monthly UL94 purchases. In addition, they contacted each qualified tenant asking if they wanted to participate, and 12 additional customers were enrolled. They continued to send out random communications inviting others to participate. A recent survey had a light response of 40 out of 360, indicating low interest.

Challenges and Costs

The addition of UL94 has been well received with positive Board support. However, there is low demand and a concern that it would not be sustainable without the subsidy. There are negative responses regarding trust in the product, and several tenants will not transition at this time. There is a concern about shelf life if the product is not sold in a timely manner. The shelf life is 6 months before recertification, or a new load of fuel equal to the current inventory may reset the clock.

Having the existing tank and ability to convert presented low implementation costs for NAA. There is a concern about compatibility with other unleaded products.

Advice for Other Airports

Based on this example, other airports could consider liability. Avfuel helps cover quality control. NAA made their insurance company aware of the additional product for sale. A primary concern is misfueling, which NAA seeks to address through training. No aircraft can be fueled if not placarded. No self-serve of UL94 is permitted.

There is a real concern regarding the compatibility of all the unleaded products coming online (GAMI G100UL, Swift UL94, and LyondellBasell & VP Racing Fuels UL100E product). Some are going the STC route while others are pursuing the ASTM route, but uncertainty exists on compatibility between products when they come online.

Naples will likely not switch from UL94 in favor of another unleaded option.

The airport owns and operates the fueling. It may be difficult to convince an FBO to implement unleaded fuel depending on equipment and support through subsidy, etc.

NAA offered an industry perspective. They would have preferred waiting for the ultimate drop-in product rather than offering an additional unleaded option (UL94). There are ongoing developments and questions on implementation.

**SOP: Training line staff on how to handle UL94 and identify aircraft and its markings.

• Training is supported by a written SOP explaining clear procedures, pictorial examples of aircraft markings (Appendix B) and a designated (purple) customer fuel order slip.
• N-number aircraft require an STC for UL94.
• Transient aircraft must have appropriate markings and complete a signed fuel order release. They pay full retail. The difference in profit between based and transient works out to be $.08 per gallon. NAA sells UL94 at cost for retail, pricing $7.00 per gallon. UL94 tenant pricing is $5.64 per gallon, which is a $1.36 per gallon subsidy for tenants.
• UL94 is now purple in color, which assists personnel in identifying fuels.
• Fuel is no longer referred to as “avgas”; must use specific identifier (100LL, UL94).
• There are some challenges with based aircraft and user pushback, and some older aircraft do not have the required fuel placards near fueling ports.
• Avoiding misfueling and procedures to address these concerns are prioritized.

Disclaimer: The information provided in this document is based on regulations and guidance available at the time of writing and is intended for general informational purposes only (and, as such, should not be construed as advice on any subject matter). The City of Naples Airport Authority (NAA) assumes no responsibility, and hereby expressly disclaims all liability, for any actions taken or not taken based on the information in this document. The content of this entire document is provided “as is,” and no express or implied representations or warranties of any kind are made, including, without limitation, any warranty that the content hereof is error-free. Note: “This entire document” refers to the Naples Airport case study of Appendix A (pages 24–27), not the full guide.

Rocky Mountain Metropolitan Airport

Location & Date: Rocky Mountain Metropolitan Airport (BJC), Broomfield, Jefferson County, CO (April 17, 2024)

Contacts:

Ben Miller, Airport Planning & Development Administrator, Project Lead Unleaded Transition

Christopher Nicholas, Airport Operations Manager

Kevin McKay, Airport Operations Specialist - Environment

Airport Overview

Rocky Mountain Metropolitan Airport (RMMA) is a county-owned general aviation reliever airport located northwest of Denver, Colorado. RMMA consists of approximately 1,700 acres of property, including nearly 50 businesses and over 400 based aircraft. RMMA is a self-supporting enterprise fund of Jefferson County. Its operations and maintenance are funded through revenues from airport ground leases and other user fees. In 2022, RMMA was the third busiest airport in Colorado in terms of operations (takeoffs and landings), with a landing or takeoff occurring every three minutes on average.

Fuel Service at the Airport

There are two FBOs at the airport that own and operate fueling systems. Signature Aviation offers self-service fueling (a 1,000-gallon tank of 100LL) and fuel trucks for both 100LL and Jet A. Sheltair utilizes fuel trucks. In addition, there are a number of privately owned fuel systems/tanks at the airport primarily for corporate jet aircraft operators. The airport is trying to phase these out as leases expire.

The airport currently does not offer unleaded fuel. However, it recently acquired a surplus 100LL truck with a 1,000-gallon capacity with the intention of adding tank/service capacity to offer unleaded fuel. This would potentially be operated by one of the FBOs under one of the airportʼs possible models to offer unleaded fuel. The airportʼs goal is to partner with one or both existing FBOs to provide unleaded fuel service rather than managing the supply and delivery themselves.

The fuel volume dispensed in 2023 was 6.3 million gallons of combined 100LL and Jet A. Fuel volume dispensed in 2022 was:

• Avgas: 541,993 gallons
• Jet A: 5,236,761 gallons

Infrastructure

The fueling infrastructure at the airport includes the following tanks:

There is one central fuel farm location that serves both FBOs. There was no mention of a requirement that dispensed fuels have an applicable ASTM standard.

At the time of the interview, RMMA anticipated installing an FAA grant-funded unleaded fuel tank in 2025.

Process Leading to Offering Unleaded Gasoline

Airport operations have increased by 50% in the last 5 years to approximately 288,000 operations per year. The increase in operations initially led to community concerns about noise impacts and a Community Noise Roundtable (CNR) was formed to address concerns. The initiative to begin providing unleaded avgas began in early 2023. Airport stakeholders, including the CNR, community members, local politicians, and County Commissioners, expressed concerns about the use of leaded aviation fuel. This led to the airport purchasing the previously mentioned surplus fuel truck with the goal of offering unleaded fuel by the end of 2024.

The Jefferson County Board of Commissioners is supportive of providing unleaded fuel.

There are four approaches being considered for the unleaded transition process:

1. The airport is looking at FAA grant options to install a large tank at the fuel farm location. This may involve an application for federal BIL funding. This tank would be used for unleaded fuel such as UL94 and would also require a fuel truck to be used by an FBO.
2. RMMA purchased a 1,000-gallon fuel truck/tank for use with unleaded avgas to be positioned at one FBO leasehold. The airport would look into donating this truck/tank if the FBO would agree to operate and dispense the unleaded fuel. The FBO believes the costs to transition this truck to unleaded are minimal. There are concerns that this capacity might not be adequate for fuel product deliveries, requiring the delivery of Swift UL94 totes rather than full loads, which would drive up UL94 costs.
3. Purchase an existing large 12,000-gallon tank located at the airport from a private party that is not being used. The tank would then have to be converted from jet fuel to unleaded fuel.
4. Purchase a large capacity tank to install at either FBO.

There is also a concern regarding demand for UL94. Flight training makes up the majority of operations at the airport. There are over one hundred total aircraft used by flight schools. They

have discussed transitioning to UL94 with the flight schools, and one of the flight schools has an interest, but also has concerns about using UL94 due to the University of North Dakota aircraft engine situation (Lycoming Engines 2024).

Currently, all the flight schools refuel aircraft by truck, so this may be a factor in choosing between a stationary fuel tank/system or a mobile refueler. Besides efficiency and convenience, they indicated the operation would have to be cost-effective as well. The pilot community appears to be supportive of unleaded fuel, but there is a question regarding cost impacts. The airport is interested in doing a more formal survey with more tenants.

There has been discussion regarding possible rent credits or tie-down credits for tenants who would use UL94 to subsidize the cost of acquiring STCs. They are gathering data on estimated cost differences between 100LL and UL94 to better understand the financial implications. The airport noted it does not have the budget to subsidize the unleaded fuel costs that Centennial Airport does under its program.

Fuel Supplier Coordination

Both FBOs use branded fuel suppliers; Signature – Shell, and Sheltair – Avfuel. As of the date of the interview, the FBOs had only been engaged in fact-finding discussions regarding costs and pricing.

Training

The airport would continue to rely on the FBOs to provide the fuel and, therefore, the required training.

Communication with Tenants

The Jefferson County Board held a press conference in October 2023 announcing their intention to transition to unleaded fuels. They continue to have ongoing discussions and updates at Airport Board meetings, CNR meetings, and County Board of Commissioners meetings. The messaging has shifted from “why we canʼt offer unleaded fuels” to “how can we implement a transition to unleaded fuels?” The Board wants more community engagement, increased transparency, and more frequent outreach.

Challenges and Costs

There is concern about the costs and the airportʼs ability to secure funding. In addition to BIL funding, a State of Colorado House Bill (HB 24-1235) was being considered at the time of the case study interview to assist aircraft owners and airports in transitioning to unleaded fuels. RMMA is seeking a $300,000 annual grant from the Colorado Division of Aeronautics to subsidize unleaded fuel costs. They are also considering details of offering credits towards STCs for tenant-based aircraft.

They are evaluating examples from other airports where unleaded fuels are sold to assess demand to determine the financial feasibility of offering unleaded fuels.

Preliminary communications with FBOs have occurred, but potential issues may arise—such as multiple FBOs being interested in providing unleaded fuel—which could require a formal request for proposals process to allocate access to airport-provided unleaded tank infrastructure.

Flight schools, particularly Spartan College, have indicated concerns about engine wear with UL94. They will closely monitor this issue.

Advice for Other Airports

RMMA noted that a checklist or guidance document, such as the one being developed under ACRP 03-73, would be helpful for supporting their transition efforts.

Liability Risk Management

The FBOs have expressed concerns about serving both unleaded and leaded customers across a ramp with over 100 aircraft. The airport will continue conversations with the FBO and tenants to develop a plan that minimizes the risk of misfueling.

South St. Paul Airport

Location & Date: South St. Paul Airport (SGS), South St. Paul, MN (March 29, 2024)

Contact: Andrew Wall, Airport Manager – City of South St. Paul

Airport Overview

South St. Paul Airport (Fleming Field) is a municipally owned general aviation reliever airport located in the Minneapolis-St. Paul metropolitan area in Minnesota. There are approximately 200 based aircraft at the airport and a number of aviation-based businesses on the field. The airport is a non-primary general aviation regional classified airport falling within the FAA Great Lakes region.

Fuel Service at the Airport

The City of South St. Paul owns and operates the airport, including fuel service to airport users. The airport offers 100LL, Swift UL94, and Jet A, which are self-serve only from underground fuel storage tanks. There are no mobile fueling trucks utilized at the airport.

Unleaded Fuel

The airport has been offering Swift UL94 for approximately the last five years and was the first airport in the state of Minnesota to offer UL94. The volume of UL94 dispensed at the airport averages approximately 5,606 gallons annually, representing about 4.6% of the total volume sold between UL94 and 100LL (Fuel data: 2021–2023). In comparison, the approximate annual volume of 100LL is 116,921 gallons, or about 95.4% of the total volume sold between the two products.

The sales of UL94 are slow compared to 100LL. The retail price of UL94 ranges from $1.00 to $1.50 higher per gallon than that of 100LL. The airport does attempt to keep the cost of UL94 down for consumers by lowering the markup relative to 100LL. The City of South St. Paul, which owns and operates the airport, does not subsidize the cost of any STCs for unleaded fuel. There are no other cost discounts or incentives offered by the airport to use UL94. The primary users of the product are two RV12 aircraft used for flight training, with usage by these customers recently decreased.

Infrastructure

The fueling infrastructure at the airport includes the following tanks:

All tanks are underground. Each system has its own tank, cabinet, pumps, hoses, etc. The 100LL and UL94 share a fueling pedestal for customers to enter payment cards and select either Pump A (100LL) or Pump B (UL94). The airport does not require that fuels offered have an applicable ASTM standard, but all fuels presently offered do have applicable ASTM standards.

Process Leading to Offering Unleaded Gasoline

The initiative to begin the service of Swift UL94 was initially researched by several airport Board members who then contacted Swift Fuels. Swift Fuels provided a presentation to the Board as a whole. The decision was driven more by finances than by tenant demand or environmental issues. It was decided that an existing 6,000-gallon tank used for UL91 fuel could be converted to UL94. Airport Management was not opposed to this in light of the low sales volume of this fuel. No other significant internal or external factors influenced this decision.

Fuel Supplier Coordination

Swift Fuels worked closely with the airport to prepare for UL94 service. Notably, Swift coordinated with the airport to empty and clean the airportʼs existing 91-octane tank to transition the system from 91-octane to UL94. Swift paid $0.50 per gallon for the old fuel and made accommodations to dispose of it. They then had the remaining fuel and any sludge pumped out of the bottom of the tank. They do not recall any extensive tank cleaning process. All decals and labeling for UL94 at the fuel farm were provided by Swift. Swift also assisted with the rollout of the product and provided the airport with a press release.

The airport cannot currently accommodate full loads of UL94 since the 6,000-gallon tank cannot accommodate a full delivery load. The airport often seeks split loads of UL94 with other airports in the area offering UL94. Swift is proactive and often contacts the airport to see if additional product or split load opportunities arise. Swift Fuels utilizes dedicated transport carriers out of Indiana. The airport takes delivery of the product consistently with all fuel delivery orders, including quality control testing, white bucket tests (a visual inspection of fuel for contamination), and API gravity verification.

Training

The airport offers self-service fueling only, so there has not been extensive training outside of making people aware of the new product. If the airport utilized fuel trucks or full-service fueling, there would be greater concern for training to avoid misfueling, STC issues, etc. The systems and type of fuel are clearly placarded. At this time, the UL94 is clear in color and has a distinct smell that sets it apart from 100LL. Self-service customers are responsible for selecting the proper fuel and being aware of and complying with any STC requirements. The airport does not, however, police this.

Communication with Tenants

When UL94 was first offered, the airport informed tenants through a variety of channels, including email, social media, flyers in the terminal, and notices posted around the fuel system. These communications included information about the STC requirement. A press release was also provided by Swift Fuels. The airport lists UL94 alongside other available fuels on pilot websites.

There was no mention of open meetings on the topic beyond the Boardʼs discussions during the decision process to begin offering UL94, which were not widely attended by tenants or users.

Challenges and Costs

There have not been complaints from airport users regarding UL94, but it is not widely used at the airport. Some UL94 users have reported that they have observed fewer deposits in the engine and cleaner spark plugs during 100-hour inspections.

Airport staff are aware of the EAGLE initiative 2030 timeline and are looking towards future infrastructure needs for the 100LL to unleaded gasoline transition. Cost may be a challenge given perceived limitations regarding availability of federal funding for tank infrastructure.

Advice for Other Airports

Talk to other airports that have transitioned to unleaded fuel—find out which fuel they offer, what incentives they provide, and how they manage the overall process.

Liability Risk Management

The fact that UL94 has an applicable ASTM standard did play a role in the airportʼs decision to offer the fuel, although it was not the driving factor. Shelf life and vapor lock issues in aircraft with UL91 unleaded were what really interested them in switching to UL94. If an unleaded fuel did not have an applicable ASTM standard, the airport may have had more conversations with the supplier, the League of MN Cities (insurance provider), and their legal staff.

Waco Regional Airport

Location & Date: Waco Regional Airport (ACT), Waco, TX (May 14, 2024)

Contact: Joel Martinez, Airport Director

Airport Overview

The Waco Regional Airport (ACT) is owned and operated by the city of Waco, Texas, and is located approximately 90 miles north of Austin, Texas. It is a regional non-hub airport providing services for both general aviation and scheduled commercial airline service. For the year ending June 30, 2022, the airport supported 66,191 operations (takeoffs and landings) and annually serves more than 54,000 enplaned passengers. ACT consists of approximately 1,369 acres of property, flight training facilities, and approximately 89 based aircraft.

Fuel Service at the Airport

The Waco Regional Airport is served by Texas Aero, the sole FBO. They offer Jet A, 100LL, and UL94. The FBO is a branded fuel distributor supported by Avfuel; however, Swift offered to support the FBO for the UL94 product. At the time of the interview, the FBO offered 100LL at $6.65 per gallon and UL94 at $6.99 per gallon.

Infrastructure

There are two fuel farm systems at the airport. All tanks are above ground, encased in concrete. The fueling infrastructure includes the following:

Process Leading to Offering Unleaded Gasoline

In 2019, Universal Flight Concepts, a flight school also operating out of Scottsdale, Arizona, entered into an agreement with the Baylor University flight training program. A portion of their fleet consists of Tecnam aircraft. Universal Flight Concepts wanted to use UL94 for these aircraft and approached the FBO. Since the flight school initiated the request and was interested, the City had no objections and, in fact, had limited awareness of or involvement in the unleaded fuel issue. There was no other driving force behind the transition to unleaded fuels.

There were two FBOs at the airport, but in 2017, one went out of business, leaving Texas Aero as the sole operator. Texas Aero took over the former FBOʼs operations and fueling infrastructure. An existing tank was available and suitable for conversion to accommodate UL94. The city had no objections to the transition and did not allocate any funding for it.

The primary user continues to be the flight school, and there is limited demand for UL94 outside of that organization.

Fuel Supplier Coordination

The FBO is Avfuel branded, but Swift provides support for UL94.

Training

Since the FBO provides the refueling service, they are responsible for training. They utilize Avfuelʼs general quality assurance training, which is not specific to unleaded fuels.

Communication with Tenants

There was not a significant outreach effort. The tenants and aircraft owners are long-term and generally do not rotate ownership over the years. The airport believes there is a general awareness of the availability of unleaded fuel. There has been no discussion from the flight school regarding lead emissions or UL94-related performance or maintenance issues.

Challenges and Costs

There were no additional costs for the city. The FBO already had a suitable tank, making the transition easy and inexpensive.

Advice for Other Airports

In this case, the flight school initiated the request, and a solution was already in place. Being supportive and accommodating was all that was required.

Watsonville Municipal Airport

Location & Date: Watsonville Municipal Airport (WVI), Watsonville, CA (April 23, 2024)

Contact: Rayvon Williams – City of Watsonville

Sam Rosas, Airport Operations Manager – City of Watsonville

Airport Overview

The Watsonville Municipal Airport is owned and operated by the city of Watsonville and is classified as a general aviation regional airport within the FAAʼs Western Pacific region. The airport is located in Santa Cruz County, California, and is home to approximately 280 based aircraft and several aviation-based businesses. The airport is self-funded, with approximately $5 million in annual revenues from sources including fuel sales, hangar rentals, and property use.

Fuel Service at the Airport

The airport owns and operates the fuel systems at the airport using fuel trucks for full-service customers. Fuel types offered include 100LL, Swift UL94, and Jet A. Airport staff provide fueling services daily, with six operations specialists working in two rotating crews.

Approximate total annual fuel volumes dispensed:

• July 2022 through July 2023:
  UL94—24,096 gallons
  100LL—105,345 gallons
• July 2023 through July 2024:
  UL94—26,975 gallons
  100LL—120,528 gallons
• July 2024 through November 2024:
  UL94—8,018 gallons
  100LL—42,263 gallons
• UL94 Annual Percentage Rate: 18%
• 100LL Annual Percentage Rate: 82%

Unleaded Fuel

WVI began offering Swift UL94 on September 20, 2021. Specialized Aviation, a flight school also providing aerial tours, operates three to four helicopters and five to six fixed-wing aircraft and is by far the largest user of UL94.

The volume of UL94 dispensed decreased from approximately 40,000 gallons in 2022 to approximately 20,000 gallons in 2023, largely due to another flight school discontinuing use of UL94. Airport staff believe this may be due to the higher cost of UL94 not resulting in the expected operational savings.

The local Experimental Aircraft Association chapter, with 30 to 40 members, is also supportive, and several members use UL94.

Infrastructure

The airport has three 12,000-gallon underground fuel storage tanks. There are four dispensers with full service provided by staff utilizing mobile fuel trucks. There are self-service options for 100LL and UL94 out of dedicated dispensers. UL94 is self-service only.

The airport converted an existing 12,000-gallon 100LL tank for UL94 storage. This involved changing out the fuel filters and preparing the system for a new product. This also involved hiring a local company to clean out the underground storage tank, dry it, and change three filters in the system at an approximate cost of $1,100.

WVI does not have a documented requirement for fuels to meet an applicable ASTM standard; however, all fuel products currently in use comply with one, and this is also a requirement imposed by the airportʼs fuel suppliers, World Fuels and Swift. WVI considers this adherence a best practice and anticipates that any decision to offer a fuel not covered by an ASTM standard would necessitate a formal risk management evaluation.

Process Leading to Offering Unleaded Gasoline

Airport management wanted to be proactive with environmental initiatives, including offering unleaded fuel. WVI were already working on LED lighting, accommodating electric vehicles, and solar power. Therefore, WVI was interested in offering unleaded fuel to get out in front of the issue and be proactive before it became a mandate from the City Council. The City Council was not involved with the initial transition process.

There were no internal or external pressures influencing the decision to move to offering unleaded fuel. The airport requested that the regional EPA office provide a letter to the City Council endorsing its recommendation to offer unleaded fuels, which the EPA office agreed to and submitted. Airport staff also checked with local regulators, including the Monterey Bay Air Resources District, the Santa Cruz Commission on the Environment, and the Certified Unified Program Agency.

The investigation and preparatory work for the transition took about nine months. The airport explored transitioning to unleaded fuels on three separate occasions:

• 2013: About four experimental category aircraft users expressed interest in unleaded fuels but offering unleaded fuel did not seem viable at the time.
• 2015: Rabbit Aviation Services in San Carlos provided input, as there was interest in using unleaded fuel with aircraft powered by the Rotax engine.
• 2020: The most recent investigation, which led to the adoption of Swift UL94.

In December of 2020, WVI began the vetting process for UL94. The airport evaluated customer demand, logistics, and potential profit margins of Swift UL94. This process involved conducting several surveys to assess demand. Once the decision was made to proceed, an existing 100LL fuel storage tank was converted for UL94 use, and the airport began offering Swift UL94 on September 20, 2021.

Fuel Supplier Coordination

Regarding supplier contracts, the airport has a five-year contract with World Fuels for 100LL and Jet A that includes minimum gallon requirements. If these minimums are not met, the contract must be extended by one year. The Swift Fuels UL94 contract is separate and can be terminated at any time. The UL94 agreement with Swift Fuels provides the same level of liability coverage as the airport has under the World Fuels agreement.

The contract received Council approval, but there was no competitive selection process because there was only one fuel under consideration.

World Fuels is the airportʼs fuel supplier, and both 100LL and Jet A fuel trucks and dispensers are branded under World Fuels. Swift UL94 is separately branded by Swift Fuels.

Swift Fuels provided labels and decals for the UL94 dispenser. Everything is labeled, including reels and hoses. They helped to ensure self-service dispensing equipment was clearly labeled to minimize the chance of misfueling. Purchasing notices, such as messages asking the customer

to confirm their selection of UL94 and reminders about the STC requirement are displayed at the dispenser. They also ensured that all fuel products are further identified by color-coding of platforms and pumps:

• Avgas (100LL)—Dark Blue
• Jet A—Black
• UL94—Purple

There were some transportation issues that needed to be resolved. Staff wanted UL94 delivery volumes to be the same as those used for World Fuels. World Fuels uses the same transport company and can be scheduled within two to three days. Initially, Swift wanted to deliver the smaller-volume totes, but they eventually began using standard delivery vehicles. To accomplish this, Swift looks for other airports to split loads with and arranges for UL94 to be delivered by rail to the area. WVI then contracts with their own carrier to transport the fuel to the airport at their expense.

Training

Staff undergoes fueling training every two years. Even though the airport is not an FAA Part 139 airport, it uses a 14 CFR Part 139 Supervisor Training program. This is not UL94-specific training. The program covers all aspects of fueling, including safety, quality control, inspection procedures, fuel truck operation, and fire extinguisher use. WVI requires all operations staff to complete supervisor training so that team members can train new hires. Training is provided by World Fuels.

Communication with Tenants

The airport made presentations regarding UL94 to user and tenant groups as part of information exchange meetings. The Watsonville Airport Advisory Committee meets monthly. Tenants were provided with information on the dos and donʼts of using UL94. Additionally, the airport website offers detailed information on UL94, including a dedicated link that directs viewers to all relevant content.

Airport staff considered offering incentives to encourage the use of UL94 but ultimately decided against it. They treat all grades of aviation fuel as products sold at defined margins, in line with the airportʼs mandate as a self-sustaining enterprise fund.

The airport also hosts a fuel promotion on the second Saturday of each month, offering discounted fuel. These events may lead to increased transient sales of UL94.

Challenges/Costs

There are some complaints from tenants having to pay for the STC and concerns that the price of UL94 is too high. Current fuel prices are:

• 100LL—$6.80 per gallon (self-service)
• 100LL—$7.30 per gallon (full service)
• UL94—$7.45 per gallon (self-service)

The airport reports that a small number of aircraft owners do not believe unleaded fuel is good for engines. However, the airport staff believe the primary barrier to broader use is the higher cost of UL94. While some pilots have shared that UL94 may offer long-term benefits, the lower price of 100LL tends to drive short-term decision-making.

The airport has also evaluated GAMI G100UL unleaded avgas as a potential replacement for UL94 and identified some potential challenges. One concern is distribution; airport staff would prefer that World Fuels be able to distribute the product. This would allow the airport to meet its minimum gallon requirements under the World Fuels contract.

WVI staff explained that there is a conundrum: They would like to be the first to offer GAMI fuel, but although the GAMI fuel is FAA-authorized, the city would likely object from a risk management perspective since the fuel is not subject to an ASTM standard. Additionally, there are concerns that GAMIʼs price point would likely exceed that of UL94.

Advice for Other Airports

It would be beneficial to mobilize the industryʼs support to fund and develop distribution pathways for unleaded fuels. WVI also indicated interest in seeing FAA funding made available to help airports acquire unleaded fuel tanks and related infrastructure.

Liability Risk Management

WVI considers fuel provisioning a key element of its service commitment and a critical component of their continued self-sustaining model. As such, the airport spent nine months vetting UL94, interviewing other airports and flight schools, and researching all available information prior to bringing the fuel on the field. As a result of this effort, they had no concerns but hedged their commitment by signing a purchase-on-demand agreement with no volume obligation.

The fact that UL94 is subject to an ASTM standard was a consideration, but not a requirement. The airport is currently considering fuels that do not have applicable ASTM standards. If such fuels are introduced at the airport, the manufacturer or distributor will be required to contractually agree to provide liability and risk management protection equivalent to that offered by the Jet A and 100LL providers.

No concerns were raised by the specialized aviation service organizations (SASOs) on the airfield regarding UL94, aside from its cost. Of the three SASOs operating at WVI, two initially converted to using UL94, however, one of the SASOs later reverted to 100LL due to pricing concerns. Specialized Aviation is currently the only SASO on the airfield using UL94.

Summary of Alaskan Issues

At this time, no airports in Alaska have transitioned to higher octane unleaded aviation gasoline, although a number of airports do offer and continue to provide non-oxygenated mogas. As a result, no Alaskan airports were included as case studies. However, two individuals, Adam White, representing the Alaska Airmanʼs Association, and Jake Matter, representing Alaska Fairbanks International Airport, were interviewed through a process analogous to the case study surveys. They reported that Alaska has approximately 240 airports, many of which are small and located in remote areas.

The primary issue raised during the interviews regarding a potential transition to unleaded fuel in Alaska was the logistical challenge of distributing more than one type of aviation gasoline, given the stateʼs airport population. Aviation gasoline in Alaska is supplied by a single fuel supplier, Crowley Fuels Alaska, which typically sources 100LL from California and delivers it via marine transport to a central terminal. From there, deliveries are made by barge, truck, or air to outlying airports, which generally lack spare tankage or infrastructure to accommodate a second

type of aviation gasoline. Non-oxygenated mogas is typically available from companies that supply gasoline for motor vehicles.

Given these constraints, the general feeling was that Alaska can realistically support only one type of aviation gasoline that must be suitable for all gasoline-fueled aircraft. A transition would likely require a lead time of several years. However, this timeline could be shortened if there was an unleaded aviation gasoline suitable for use in all aircraft that was also compatible with being commingled with 100LL. Both representatives also noted that aircraft owners and operators would likely have concerns about the cost of unleaded aviation gasoline and any issues it might raise with respect to aircraft performance and maintenance.

References

City of Long Beach. 2023a. General Aviation Operations at Long Beach Airport. Office of the City Manager. https://www.longbeach.gov/globalassets/city-manager/media-library/documents/memos-to-the-mayor-tabbed-file-list-folders/2023/october-31--2023---tff---general-aviation-at-long-beach-airport_final.

City of Long Beach. 2023b. Agenda Item 26 (23-51387): Recommendation to Receive and File a Presentation on the Operations of General Aviation at the Long Beach Airport. December 12, 2023, City of Long Beach Council Meeting. Video. https://longbeachca.new.swagit.com/videos/291188.

EPA. 2017. 2017 National Emissions Inventory (NEI) data. https://www.epa.gov/air-emissions-inventories/2017-national-emissions-inventory-nei-data.

FAA. 2022. FAA Orange County Communities Virtual Public Information Workshop #1. YouTube. https://www.youtube.com/watch?v=vsV7061-bA8.

FAA. 2024. FAA and Long Beach Airport Virtual Public Informational Webinar YouTube. https://www.youtube.com/watch?v=K35RjVTPIPY.

Lycoming Engines. 2024. Lycoming Engineʼs UL94 Valve Seat Recession Investigation Update. https://www.lycoming.com/press/lycoming-engines-ul94-valve-seat-recession-investigation-update.