In an update posted on the agency’s website, the FAA said although two unleaded replacement fuels have been chosen for the Piston Aviation Fuels Initiative (PAFI), flight and some engine testing has been paused to assess the effects they will have on the larger GA fuel producing industry and the GA fleet.
Both fuel producers, Shell and Swift, are “currently evaluating options to mitigate the impacts these differences will present in fuel production, distribution and operation in the GA fleet,” the agency said. “These evaluations will take time and ultimately affect the schedule of the test program.”
PAFI was established by a wide range of sectors in the aviation and petroleum industries, as well as consumers, to find an unleaded replacement for 100LL aviation gasoline, currently the only fuel in the United States that still contains lead to protect engines against knock and detonation. However, lead is toxic and can be inhaled or absorbed into the bloodstream. Avgas is the largest contributor of low levels of lead emissions in the United States, according to the Environmental Protection Agency.
The FAA also announced that due to the delays, the new testing completion date for PAFI has been extended to December 2019 after previously being projected for December of this year.