AOPA Pilot Magazine - February 2022 - 90

RUDDER & WRENCH
originally expected. The FAA had instead
planned for candidate fuels to go through
a series of tests overseen by the agency and
with oversight from others in the industry
through the Piston Aviation Fuels Initiative
(PAFI) process. Both GAMI and Swift
elected to have their fuels approved outside
the PAFI process.
At the roundtable, FAA Executive
Director for Aircraft Certification Service
Earl Lawrence explained that " technically "
it would be possible for the FAA
to approve the STC candidates from
GAMI or Swift as that fleetwide solution.
But, administratively, the FAA has never
made an approval like that, and it could
take years to work out the regulatory process
by which such a determination might
be made. So even if someone makes a fuel
that is FAA approved for every aircraft
and engine in the fleet, you can't call it
a " fleetwide solution " because that term
only applies to fuels approved via a specific
process. The confusion is likely to
continue, as both GAMI and Swift refer
to their fuels as fleetwide solutions, without
the FAA quotation marks.
There was some discussion of
Lycoming's recent approvals for use of
" 100 unleaded " fuels that comply with
Update on the five
contenders /
GAMI (General Aviation Modifications
Inc.) announced at Oshkosh in July
2021 that the FAA had granted STC
approval for its 100-octane unleaded
fuel. In October, the FAA extended
that approval to another 611 lowcompression
aircraft engines. GAMI
expects approval for every engine
and airframe in the FAA's database
by second quarter of 2022. GAMI
and their distribution partner, Avfuel,
are working to establish commercial
arrangements to provide blending of
G100UL nationwide, although that
process may take a year or two to
complete entirely. GAMI and Avfuel
have offered open, nondiscriminatory
licensing terms to any provider that
might wish to blend their fuel.
GAMI points out that it has provided
transparency by allowing staff from
the General Aviation Manufacturers
Association to come to GAMI's Ada,
Oklahoma, headquarters, and review
the original FAA certification test
plans, reports, and FAA approvals.
That same offer was also extended
to Lycoming. In addition, GAMI has
hosted test pilots from Continental,
Lycoming, and Cirrus who came to
GAMI's facility for extensive flight
testing of G100UL avgas, with in-flight
back-to-back comparison to 100LL.
Cirrus performed its own independent
materials compatibility testing. EmbryRiddle
Aeronautical University did a
complete FAA engine durability test
90
AOPA PILOT / February 2022
of GAMI's unleaded avgas, combined
with 170 hours of in-flight functionality
and reliability testing as a part of the
FAA certification program. EmbryRiddle
found G100UL to be acceptable
on all accounts. GAMI says that the
FAA has accepted GAMI's detonation
testing as demonstrating the suitability
of G100UL for every aircraft and every
engine in the GA fleet.
Meanwhile, Swift Fuels has been
selling its unleaded 94UL for
several years now and is expanding
distribution, particularly in the West
where leaded sales are being banned.
A 94-octane unleaded meets the
demand of many aircraft with lowcompression
engines, but 75 percent
of avgas demand is by aircraft that
require 100 octane fuel. Swift has
developed a 100R unleaded fuel that
is in the STC certification process now.
The R stands for renewable, as the fuel
is more than 10-percent renewable
content. Swift anticipates certification
in 2022 to 2023. Swift was a member
of PAFI (the FAA's Piston Aircraft Fuels
Initiative), but exited when the PAFI
protocol restricted the company's
ability to develop its fuel.
Phillips/Afton reports via the publicly
accessible ASTM Piston Engine
Aviation Fuels Section (PEAFS) that
they are working on an unleaded avgas
that uses methylcyclopentadienyl
manganese tricarbonyl. MMT was
used in mogas in the United States
and Canada but at much lower
concentrations than proposed for
unleaded avgas. There were reports of
engine deposit issues in cars, and such
reports continue in developing nations
where MMT is still used at even higher
concentrations. The timelines on
Phillips' website show certification in
2025 to 2026. Phillips partner Afton is
a producer of MMT and also an agent
for Octel in selling TEL in the U.S.
marketplace, so it has experience in
supporting avgas blending.
Lyondell/VP-Racing reports via
PEAFS that it is entering FAA PAFI
prescreening. Lyondell includes the
former ARCO Chemical. VP-Racing
is a blender of specialty gasolines.
Their fuel contains MMT, but also
oxygenates. Each of those additives
presents challenges. Lyondell believes
it can overcome those challenges
in the multi-year fuel development
process. In an early December email
to AOPA, the companies indicated
that they remain " committed to
developing an unleaded AVGAS fuel
within the PAFI framework and expect
to complete qualification for the FAA
PAFI program in early 2022. "
Shell Global Solutions was a member
of PAFI, but exited in January 2021.
A Shell spokesperson shared that the
company is awaiting EPA action on
lead in avgas to support a business
case for further fuel development. In
other words, the company requires a
mandate or deadline for the phase-out
of lead before investing more in the
project. Shell no longer blends avgas
in the United States but has stated
it plans to license its technology to
others. -PM
AOPA Pilot Magazine - February 2022

Table of Contents for the Digital Edition of AOPA Pilot Magazine - February 2022
