Flight Training - March/April 2024 - 30

PREFLIGHT FUTURE FLIGHT
BY DAVE HIRSCHMAN
'TWO FUELS' IN A BARON
HOW AOPA IS WORKING ON AVGAS SOLUTION
THE AOPA FUEL DEMO BEECHCRAFT BARON IS NEARING 100
flight hours using unleaded fuel in one of its engines, and so far the
performance is indistinguishable from the traditional avgas being
used in the other engine. The 1966 Baron C55 has been operating
out of Ada, Oklahoma, where General Aviation Modifications Inc.
(GAMI) has been supplying unleaded G100UL for the Baron's left
engine and avgas in the right.
A half-dozen pilots have flown the airplane using this " two
fuels " arrangement, and all have found the G100UL's performance
virtually identical to avgas.
" You really can't tell the difference in the air, " said John Whitehead,
a retired FedEx pilot with extensive instructional and flight
test experience in a variety of Beech airplanes, including Bonanzas
and Barons. " If you didn't know the engines were using different
kinds of fuel, you couldn't tell by the way they perform. "
On the ground, there are obvious differences. G100UL has an
orange tint (instead of blue avgas), and it smells a bit like turpentine
or cleaning solvent. G100UL also is slightly heavier than avgas but
the weight difference is small enough that it's unnoticeable to pilots.
The AOPA Fuel Demo Baron is scheduled to undergo a series
of borescope inspections, compression tests, and oil analysis when
it reaches 100 flight hours. Engine and airframe experts will scrutinize
the results looking for unusual wear within the engines as
well as fuel lines, bladders, and other components. The AOPA fuel
demo Baron is equipped with a digital engine monitor that records
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FLIGHT TRAINING MARCH/APRIL 2024
a wide variety of data, and a team at Savvy Analysis will use their
analytical tools to compare the Baron's Continental IO-520s. The
Baron will return to AOPA headquarters in Maryland early in
2024 once G100UL is available there.
AOPA President and CEO Mark Baker intends to take GA
leaders for flights in the Washington, D.C., region to give them
first-hand experience flying with unleaded aviation fuel. G100UL
is currently the only unleaded 100-octane fuel the FAA has
approved for use in the full spectrum of piston aircraft engines.
When other unleaded fuels become available, the Baron will be
used to try them, too.
" The shift to unleaded aviation fuel is happening, and it's critical
that the change is made safely, " Baker said. " The AOPA fuel
demo Baron gives us real-world experience with unleaded aviation
fuels in the kinds of engines our members own and operate. "
dave.hirschman@aopa.org
About the issue: Most aircraft in the current general aviation fleet
were designed to operate with fuel containing a lead-based additive
to prevent damaging engine detonation. Finding a suitable substitute
that doesn't contain lead has been challenging, but AOPA and the GA
industry are committed to a safe and smart transition. That means transitioning
the entire fleet to an unleaded fuel by 2030 and ensuring the
current supply of fuel is available during the transition.
DAVID TULIS
Flight Training - March/April 2024

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