Avionics News July 2022 - 39

where a third of all avgas is consumed, " he said.
The key to the timing of EAGLE seems to be that the
U.S. Environmental Protection Agency may soon make
a move against 100LL avgas. The EPA issued a press
release Jan. 12 stating it will evaluate whether emissions
from piston-engine aircraft using leaded fuel " contributes
to air pollution that endangers public health and welfare. "
The agency plans to issue a proposal for review and
comment this year and take final action by 2023.
EPA Administrator Michael S. Regan said, " EPA
has been investigating the air quality impact of lead
emissions from piston-engine aircraft near airports for
years, and now we're going to apply that information
to determine whether this pollution endangers human
health and welfare. " Airborne lead in the atmosphere
in the United States has declined 99% since 1980, but
piston-engine aircraft that operate on leaded fuel are the
largest remaining source of lead emissions into the air.
Industry officials see the possible EPA endangerment
ruling as a liability for the makers of avgas and the
single maker of TEL in Britain. The EPA could make life
difficult for fuel manufacturers and aircraft owners even
though it's the FAA that has authority over aircraft.
Roehl said the 2030 deadline established by the FAA
and general aviation industry groups may be designed to
stave off any near-term ban on lead.
In West Lafayette, Indiana, Swift Fuels has conducted
extensive research and fuel, engine and flight testing
since 2012 of 100-octane unleaded avgas, which is now
undergoing test and certification with the FAA. Swift
left the PAFI fuel test program in 2018 while continuing
to work with the FAA and OEMs. Swift didn't like the
rule that the fuel couldn't be altered once it entered PAFI
testing, a rule that has since been changed.
This new Swift 100-octane fuel, once FAA approved,
can be comingled with 100LL either in the tank
distributing 100LL at an airfield or in aircraft fuel tanks.
The new fuel is designated 100R with the R standing for
renewable since a portion of the ingredients for the fuel
comes from renewable resources. Customers can also
buy a " forever STC " from Swift Fuels for a limited time
for $100, which represents a 75% discount. This will
entitle them to all STCs for the 100-octane fuel when it
becomes available.
Swift is producing and distributing UL94, which is a
94-plus octane aviation fuel without TEL. It is suitable
for use with STC'd low-compression piston engines
but not in high-compression ones. It is drop-in ready,
meaning no mechanical parts, hardware modifications
or adjustments are needed. UL94 can be mixed in an
aircraft's tank with 100LL, but UL94 has to be dispensed
at an airfield from a separate tank. Swift has a map of
the United States on its website showing two-dozen
public airports where the fuel is currently available.
There are also private users of the fuel at other locations.
Under the " frequently asked questions " page on the
Swift Fuels website, there are lists of Lycoming Engines,
Textron Aviation Beechcraft and Cessna aircraft and
Continental engines approved by STC for use of UL94.
UL94 STCs are sold online by Swift Fuels, and buyers
receive a Forever STC entitling them to any future avgas
STCs issued by the FAA to Swift Fuels. To minimize
refueling errors, aircraft have to display an FAAapproved
fuel placard. Swift sells two UL94 placards
for $20 that should be installed by an airframe and
powerplant mechanic who can confirm in the logbook
that UL94 is approved for the engine and airframe
combination.
Swift noted that UL94 contains neither TEL nor
ethylene dibromide (a lead scavenger). This eliminated
lead-fouled spark plugs and corrosion caused by lead
from the oil in the engine and fuel system. UL94 also
allows pilots flying Lycoming and Rotax engines to
save money by increasing oil change intervals up to 100
hours. Aircraft and spacecraft designer Burt Rutan, in a
testimonial video on the Swift Fuels website, said he has
been using UL94 on two Rotax-powered aircraft for five
years. Rutan said the fuel runs clean, and " we don't have
to scrub gunk out of the oil tank. "
Now that the FAA and industry have finally put a
deadline on developing an alternative to 100LL without
the lead, the proof will be in a final approval for the
entire fleet of 200,000 general aviation aircraft. There is
no regulation in place that says it has to happen by 2030.
On March 17, 170 stakeholders gathered in Washington,
D.C., 60 of them over the internet, for the first EAGLE
meeting, including general aviation associations, airframe
and engine manufacturers, fuel suppliers, airport groups,
community organizations and the EPA.
Dr Amy Pritchett, an MIT graduate, who leads the
Penn State aerospace engineering department, led
off the stakeholder meeting summing up a report on
replacement fuels for general aviation. Last year, she
chaired a volunteer committee of experts who studied
replacements for 100LL at the direction of Congress.
The National Academies of Sciences, Engineering, and
Medicine's report issued last year is titled " Options for
Reducing Lead Emissions from Piston-Engine Aircraft. "
It is available for free download from the National
Academies Press.
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