July 28, 2009 - Oshkosh, Wisconsin - Monday’s
panel discussion on the future of aircraft fuels offered a thorough
discussion about the threat to the continued use of leaded aviation
gasoline and a view of the process that could lead to the widespread use
of unleaded aviation gasoline in the coming years. The result of 19 years
of work to find a lead-free substitute for 100-octane, lowlead (100LL)
aviation fuel is that there is no solution that offers a seamless
transition from leaded to unleaded fuel for high-performance aircraft
engines, and viable solutions remain elusive.
the FAA, the U.S. Environmental Protection Agency (EPA) aircraft, and
engine manufacturers and fuel producers have all taken part in that
effort. At Monday’s event, about 150 spectators heard from
representatives of EAA, EPA, FAA, GAMA (General Aviation Manufacturers
Association), the Coordinating Research Council, and the FAA Technical
Center who collectively have conducted or coordinated much of the research
“We are no
longer seeking a ‘transparent’ or ‘drop-in’ replacement for 100LL—one
that wouldn’t require modifications to the aircraft or FAA approval for
each aircraft,” said Walt Desrosier, a vice president of GAMA.
under study include low- or medium-octane unleaded avgas, high-octane
synthetic fuels (mainly biofuels), and new blended fuels. The solution has
to be a worldwide standard, panel members agreed, and it has to be a
long-term solution. “A solution that lasts two to three years is no
solution,” said EPA’s Glenn Passavant.
aircraft engines— powering about 30 percent of the U.S. general aviation
fleet—are designed to use leaded fuel to control engine detonation.
potential alternative to 100LL will require extensive testing to determine
its effects on the engine and fuel system, aircraft systems and
performance, as well as engine cooling and weight. In addition,
researchers will have to identify certification issues and the costs of
the fuel, as well as needed aircraft modifications.
is running out, Passavant noted; states will need to meet the new lead air
quality standard by 2016 or 2017, and aviation gasoline may need to be
part of the solution.
a solution, panel members agreed, remains a complex problem. A forum
exploring the declining availability of fuel for light-sport aircraft and
other auto-fuel-powered aircraft will be held at 10 a.m. in the Aviation
Learning Center, Stage 2. The center is supported by Chevron.