AOPA Pilot Magazine - July 2013 - 62

PROPULSION / PISTON

WHERE DO WE GO
FROM HERE?

“It’s appalling that after three decades
of automotive use, electronic ignition
hasn’t become standard equipment in
aircraft engines.”
—KLAUS SAVIER, LIGHT SPEED ENGINEERING

whether an airplane is at sea level or cruising at high altitude. Electronic ignition
systems have variable timing, so they both
start easier and run more efficiently at altitude. Unlike magnetos, electronic ignition
systems have always required external electrical power to keep running. (ElectroAir
got its first STC for its electronic ignition
and single-magneto combination last year;
E-Mag has applied for FAA certification of
its electronic ignition systems with self-generating internal alternators; Lycoming uses
a Champion-designed electronic ignition

system on some of its non-certified engines;
and GAMI is developing its “PRISM” electronic engine controls—see page 64.)
Most piston aircraft engines use about
0.6 pounds of fuel per horsepower per hour.
That figure drops to about 0.54 pounds per
horsepower per hour (according to the
Lycoming manual) for an IO-360 properly
leaned at peak horsepower, and 0.43 at 60
percent power. Savier’s highly modified
IO-360 burns about 0.36 pounds of fuel per
hour, a 40-percent efficiency gain over traditional aircraft engines, and a 16-percent

FUTURE FUEL

UNLEADED ALTERNATIVES
HE “IMMINENT” DEMISE OF LEADED AVIATION FUEL HAS BEEN discussed, debated, and
planned for more than 30 years; current efforts focus on ensuring that we will
continue to have 100LL for the near future, while also implementing a program to
transition the industry to an unleaded fuel with the least impact on the existing
fleet. Our current leaded fuel eventually will go away, and when it does go, the
goal is to have it replaced by other high-octane fuels capable of safely powering highcompression, turbocharged piston aircraft engines.
“Avgas will continue to be available for the near term, but the need to transition to an
unleaded fuel is being driven by economic and environmental concerns,” said Rob Hackman, AOPA vice president for regulatory affairs and a member of the FAA and industry group sponsoring the establishment of a Piston Aviation Fuels Initiative (PAFI). PAFI is a five-year program for evaluating unleaded fuels and approving
the most viable replacement for 100LL avgas. “At the end of that process, a high-octane fuel that can satisfy the needs
of the GA fleet is anticipated,” Hackman said. “Even though it will not be an exact drop-in replacement for leaded avgas,
this initiative will provide the data required to support FAA certification of the general aviation fleet to operate safely on
the new fuel.” According to the PAFI road map, the FAA will gather data and identify potential replacement fuels by 2018.
The agency will evaluate and develop data to be used for certification of the most promising fuels to be used for fleetwide
approval. The replacement fuels may have slightly different weights, vapor pressures, or other characteristics, but extensive testing is meant to ensure the fuels are safe for wide use by the entire GA piston fleet. And the FAA will streamline its
fuel evaluation and aircraft certification process so that each engine and aircraft model doesn’t have to undergo separate
certification with the new fuel. Several promising new high-octane fuels—including those produced by Swift Enterprises
and GAMI—have been proposed as alternatives. Also, while lawsuits by a few environmental groups and regulatory changes
within the federal Environmental Protection Agency have attracted a great deal of attention in recent years, ultimately, it is
the FAA that will set avgas standards, and it’s set out on a deliberate course to do that.
“We continue to work with the FAA and industry to implement PAFI to provide the path for the fleetwide evaluation,
certification, and deployment of a new, unleaded aviation fuel,” Hackman said. “The Initiative is working to remove as many
hurdles as possible to get there.”
—DMH

62 | AOPA PILOT July 2013

ILLUSTRATION BY KYLE HILTON

hours (and which still resides in his hangar
at California’s Santa Paula Airport). The
Long-EZ engine is a parallel-valve IO-360
with high-compression pistons, dual electronic ignition, automotive spark plugs,
electronic fuel injection, and a fixed-pitch
propeller of Savier’s own design that turns
about 2,600 rpm in cruise.
A flight from California to Florida
required one fuel stop—as did Savier’s
return into the prevailing wind. (The
Long-EZ holds up to 47 gallons of avgas.)
“Air-cooled aircraft engines can be surprisingly efficient once we free them from
magnetos and other ancient technology,”
he said. “It’s appalling that after three
decades of automotive use, electronic ignition hasn’t become standard equipment in
aircraft engines. Electronic ignition provides an immediate 10-percent reduction
in fuel consumption with a single-digit
increase in power.”
Magnetos have fixed timing and fire
at the same point in the combustion cycle
AOPA Pilot Magazine - July 2013

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