NASA’s Aviation Safety Reporting System (ASRS) has amended a report (December 2024 CALLBACK) that incorrectly attributed deterioration of cadmium-plated bolts in an aircraft’s fuel system to an approved aviation gasoline unleaded fuel, Swift Fuels’ UL94. It was later discovered that the actual cause was auto gas (mogas) and an isolated incident.
In April 2023, an aviation maintenance technician providing service to a fixed base operator (FBO) for a flight school reported that damage to cadmium-plated bolts, commonly used in aircraft carburetors, had been caused by UL94. UL94 is an unleaded fuel approved by an FAA STC, with an ASTM specification, and that supports a majority of the nation’s piston fleet. Swift is one of three fuel companies currently working with the FAA to develop a replacement fuel (Swift 100R). It is a candidate to support additional piston aircraft in the fleet as the industry’s current leaded aviation fuel is to be phased out by the end of December 2030.
After further investigation by the FAA, it was determined that auto gas (mogas) caused the issues and was an isolated incident. The amended CALLBACK report clarified that the damage to the cadmium parts was not caused by UL94.
The EAGLE initiative released the following statement to further clarify the issue:
“A recent NASA ASRS CALLBACK report noted a potential issue in 2023 between UL94 aviation fuel and cadmium components. The FAA received the same information in 2023 concerning this issue, prompting an investigation. At this time, the FAA investigation determined that the fuel in question was not UL94, but mogas from a local gas station. No incompatibility has been identified between UL94 and cadmium components.”
EAGLE urges pilots and aircraft owners to stay vigilant to prevent misfuelling incidents and be mindful of any STC or other POH limitations on mixing aviation fuel. More information on how to avoid misfuelling can be found in the November 2024 EAGLE update titled “Pilots & Aircraft Owners: Stay Vigilant as New Unleaded Aviation Fuels Roll Out” https://flyEAGLE.org/updates/.
Eliminate Aviation Gasoline Lead Emissions (EAGLE) is a comprehensive government-industry initiative 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