AOPA asks FAA to rule against California county avgas ban

The recent arrival of 100-octane unleaded fuel at Reid-Hillview Airport and the availability of a different brand of 94-octane unleaded sold at San Martin Airport "are incremental steps forward in the unleaded fuel transition, they are not a comprehensive solution," AOPA General Counsel Justine Harrison wrote in a November 22 filing. Aviation safety must be the top priority as our industry continues its transition to an unleaded future. “It is dangerous to create fragmented fuel availability for the piston fleet.”

Experimental aircraft and light sport aircraft have special airworthiness certificates and cannot use the supplemental type certificate process to approve any new unleaded fuel, including General Aviation Modifications Inc.’s G100UL, Swift Fuels’ 100R, or any others that may become available. No LSA manufacturer has authorized to date the use of either G100UL or 100R. STCs for unleaded fuel issued to date do not apply to piston rotorcraft, or allow competing brands of 100-octane unleaded fuel to be mixed. (G100UL and 100R are each authorized to be mixed with 100LL.)

Since the county's ban on aviation fuel containing lead took effect on January 1, 2022, AOPA noted in the filing, “there has been one documented aircraft accident with serious injuries due to ‘fuel starvation’ and two documented misfuelings.”

AOPA and its co-complainants challenged on both procedural and factual grounds the county’s latest legal maneuver: a motion to "further supplement the record" following what the county itself hailed in an October 31 press release (included as attachment 1 to AOPA's latest filing) as the “first in the nation” arrival of G100UL.

The new fuel may be lead-free, but it is not currently an ultimate solution that can be used in every aircraft, AOPA noted. High-compression engines that require 100-octane fuel burn 70 percent of 100LL sold nationwide. The two principal engine makers have not yet approved use of 100-octane unleaded alternatives in their engines, even in cases where the engines are listed on the Approved Model List of an STC, indicating use of fuels without the manufacturer’s approval can impact engine warranties. For example, Lycoming’s standard warranty excludes “operation outside of Lycoming’s published specifications or the use of non-approved fuels or lubricants.”

Swift Fuels’ 94-octane unleaded alternative is sold at San Martin Airport, and Swift recently gained supplemental type certificate approval to use its 100-octane unleaded fuel in Cessna 172 R and S models. However, Swift’s STC does not allow its 100-octane fuel to be mixed with GAMI G100UL, and GAMI’s STC does not allow its 100-octane fuel to be mixed with Swift’s 100R.

“This is why its continued availability of 100LL while 100 octane unleaded fuels become available is vital for safety, efficiency and airport access,” Harrison wrote.

Cirrus Aircraft, the world’s leading producer of piston engine airplanes, advised customers in June that because G100UL “is a non-approved fuel per Continental and Lycoming,” using such fuel in SR-series aircraft may impact warranty coverage.

“While some aspects of the initial Cirrus testing of the GAMI G100UL fuel are encouraging, other areas, including materials compatibility, remain inconclusive,” Cirrus wrote in the June 18 service advisory. “Engines known to have run this fuel may not be covered by the current OEM engine warranty.”

AOPA and its co-complainants argued that while the industry continues to work toward an unleaded solution available to all, that solution does not yet exist, and banning the sale of the only piston aviation fuel approved for use in all aircraft violates federal law—as the FAA itself has determined in response to other communities seeking to limit the sale of avgas.

“It remains unreasonable for a portion of the industry to be denied reasonable, and previously available, amenities that effectively limit and deny fair use of the airport,” Harrison wrote.

The training aircraft operated by San Carlos Flight Center, 23 nautical miles away, have a Swift Fuels STC and legally cannot also obtain approval to use G100UL. Similarly, there are aircraft based at both Santa Clara County airports that have an STC for one brand of unleaded fuel that precludes using the other. “These aircraft need the reasonable access they had before the ‘unprecedented ban’ was implemented,” Harrison wrote.

The FAA, which has the authority to grant itself additional time to decide the case, has given itself eight such extensions to date that have delayed by an estimated 10 months the determination of an otherwise uncomplicated case.

“Further delay in issuance of a Director’s Determination is contrary to safety, to the just administration of compliance with grant assurances, to safeguard the public’s investment in Santa Clara County’s public use airports, and to a safe and coordinated transition to unleaded fuels across the [National Plan of Integrated Airport Systems],” AOPA argued.