3 March 2025
A state agency in California is trying to force leaded avgas off the market before a satisfactory unleaded alternative is available, according to the General Aviation Manufacturers Association (GAMA).
The California Center for Environmental Health (CEH) has filed a motion with a Californian court to force several fixed base operators (FBOs) and general aviation fuel distributors to transition to solely offering a new unleaded avgas.
The motion will be heard on Wednesday, 5 March. If carried, anyone operating an aircraft requiring 100LL avags will effectively be grounded.
GAMA says it is actively working to support a safe transition to an unleaded future for piston-engine aircraft through the Eliminate Aviation Gasoline Lead Emissions (EAGLE) initiative.
“There is a concerted effort currently underway to ensure that there is a safe and efficient transition to an unleaded future for piston-engine aircraft,” said Pete Bunce, president of GAMA.
“There is still significant work needed before a full-scale transition can take place. The CEH motion is based on a brand new high-octane unleaded fuel, which is currently available at just two California airports.
“Although the FAA issued an STC allowing for its use in airplanes, this is the only aviation fuel that has not been subject to a stakeholder consensus peer review process and does not have the endorsement for use by piston-engine and aircraft Original Equipment Manufacturers (OEMs) or other stakeholders such as distributors and FBOs due to lack of transparency and understanding of the new fuel’s composition and performance properties.
“Additionally, this fuel cannot be used in piston helicopters. There are also questions and a need for additional information about materials compatibility and safety in both aircraft and fuel distribution infrastructure.
“The general aviation industry is committed to supporting a viable unleaded avgas solution, but a forced and premature transition will not be in the interest of the aviation community or public in the long run.”
There have been notices to the public, from Cirrus Aircraft, Lycoming, Piper Aircraft and Textron Aviation, citing concerns about the specified unleaded avgas product (believed to be GAMI G100UL).
In addition to these warnings, aircraft manufacturers Aviat Aircraft, Diamond Aircraft, Enstrom Helicopter Corp, Piper Aircraft, Schweizer and Robinson Helicopters each submitted information to the Court that stated the new unleaded avgas variant was not approved or supported by manufacturers for use in their models, given their companies lacked the information necessary to verify its safety and material compatibility.
According to court documents, several individual aircraft owners in California have filed declarations related to adverse issues potentially encountered by using G100UL.
Additionally, according to court documents, a California-based FAA Flight Standards District Office has initiated an investigation into some of these possible material incompatibility issues identified in several piston airplanes.
In the interest of aviation safety, GAMA calls for transparency and openness in a manner consistent with established industry practices for all transportation fuels.
GAMA further calls on the FAA to issue a Special Airworthiness Information Bulletin or other notice to inform the general aviation community of potential issues and possible airworthiness impacts.
The public statements and court submitted documents can be found HERE.
