March-April 2023 - 21

Two candidates for unleaded fuel are
currently in the trial process.
WALKER JAROCH
AMT: What have been some of the challenges with
getting these fuels to market? What might people
not be understanding about the process and why
it needs the time it does?
Olislagers: Number one, the average age of aircraft
today is roughly 50 years. The average age of
an automobile is about 13 years, according to the
latest statistics that I've seen. So, the turnover in
the automobile industry is much faster than in aircraft.
We still have airplanes that are exceedingly
old. I've had the pleasure of flying some very old
aircraft from the late '20s on, and so, that's part of
the challenge. We don't have that kind of turnover
that we've seen in the automobile industry.
The other big challenge I think is really finding
a proper solution to prevent engine knocking and
bring up the octane high enough to where - with the
especially more modern high compression engines
- we can get the proper performance out of those
aircraft. So blending those fuels without lead but
using other additives.
[Then there's the] challenge of making sure we
having to put 94 in when that is not recommended
for especially the high compression engine aircraft.
So we really wanted to focus on making sure that
100LL remained available until we had a unleaded
fuel, not just a 94 octane, but a high octane unleaded
fuel available nationwide. So that is the goal.
AMT: What candidate unleaded fuels are there currently
and where in the approval process are they?
Olislagers: We've got two fuels in the PAFI (Piston
Engine Aviation Fuels Initiative) program and then
also in the STC program. GAMI received its STC
back in September of 2022, and Swift is still working
on theirs and they anticipate that they will get their
STC as well in 2023. So we're making some progress.
The PAFI fuels are going through the various
gates and currently we are in the mini detonation
and mini durability tests. I'm not sure where Swift
is within the STC program and obviously GAMI
has got the fuel out there already, although it's not
being marketed commercially just yet. They're still
working on some refining issues, and I think they've
addressed the distribution questions, and there are
certainly airports already looking to get that fuel
out as soon as possible.
www.AviationPros.com 21
don't end up with deposits and problems with seals
and whatnot. It's got to be compatible with everything
that the fuel touches from beginning to end.
And so that has been a real challenge, and I think
that's driven a lot in large part because of the constantly
changing altitudes that aircraft fly at. And
so, it's always been in my mind, is why have we not
developed, for example, some fuel management systems,
automated fuel management systems that can
handle that as opposed to us having to constantly
change mixture settings and so on and so forth.
So, we're still dealing with some older technology.
Lead poses a serious
health risk and those
who handle leaded
fuel regularly should
be tested to know their
level of exposure.
WALKER JAROCH
http://www.AviationPros.com
March-April 2023

Table of Contents for the Digital Edition of March-April 2023
