is a blend of materials. How does each react to normal
aviation fuel systems?
A second question relates to costs. For my company,
every chemical I buy costs at least $5 per pound. At 6
pounds per gallon, this equates to $30 per gallon for a fuel.
With the best will in the world, I can’t see how this can
be an economic replacement for avgas or 100LL, which is
about $5 a gallon at my local fixed base operator.
My third comment relates to other fuel alternatives.
BP and DuPont have been developing a butanol/gasoline
blended fuel for quite a while that they call “BioButanol,”
produced by fermentation. Here is what they say on the BP
“Laboratory and vehicle assessment of butanol blends
greater than 16 percent also have produced favorable
test results. The results show that 16 percent high octane
butanol blends have the added advantages of vapor
pressure behavior and distillation curves comparable to
regular gasoline and, unlike 10 percent ethanol, do not
phase separate in the presence of water” (my emphasis).
Butanol and its isomers have the advantage of similar
energy content to that of gasoline. Since it uses the same
process for producing ethanol, just different bugs, the cost
is very similar. This assumes that the government subsidy
for ethanol also applies to butanol.
My next comment refers to the beneficial effect lead can
have on exhaust valve seats. How will the problem of valve
seat recession be dealt with if lead is eliminated? Perhaps
metallurgy has the answer, but the answers need to be on
the table when these questions are dealt with.
Finally, the answer that works for all of us in the drive to
remove lead from 100LL may be a compromise. It seems to
me that a completely new fuel formulation is risky, however
good it looks on paper.
I like the idea of the BP/DuPont butanol to replace
ethanol; that solves the phase separation, octane, and
energy content problem, and I’m surprised that it has not
received more press. The EAA and Petersen supplemental
type certificates have a good chance of remaining in force if
such a mixture was used.
This critique is meant to be constructive, and I hope that
my comments will be taken in that spirit and will lead to
healthy debate to find the right answer for all of us. I have
no connection to Swift Enterprises, BP, or DuPont, but I
have to confess to being a chemist and chemical engineer.
Chris Lowery, EAA 603052
Your article on fuels was interesting. There is one fuel
that is being overlooked. This fuel is high-octane ( 100+),
is widely available, and can be stored indefinitely without
deterioration. Its closed fuel system prevents contamination,
burns so cleanly that oil stays clean after 50 hours of
use, is lead-free, has been shown to extend engine life in
automotive use, contains more energy per pound than
gasoline, and sells for less than one-half the cost of aviation
fuel. Modern fuel-injected systems achieve the same power
and economy as gasoline. What is this fuel? Propane.
Larry Brooks, EAA 546397
I recently finished reading the February 2009 edition from
cover to cover. I have to say that this was one of the most
informative single editions of any aviation periodical I’ve
ever read. As a certificated flight instructor, I particularly
enjoyed the article “A Flap by Any Other Name…” by
As the owner of a light piston aircraft running on
the increasingly endangered species of 100LL, I found
the “Fuels for the Future” article by Jeffrey Decker to
be very timely. The updated information on Canadian
requirements for 406 MHz emergency locator transmitters
was also thought-provoking for a guy who lives and
teaches in close proximity to the border.
David A. Hamel, EAA 697786
You Missed the GP- 4!
I am presently building a GP- 4 designed by Osprey.
This is a plans-built aircraft with a speed of 240 mph
and made of wood. This aircraft has won more awards
than any you have mentioned in your February 2009
issue (“Building From Plans”). There is not one word
of the GP- 4 in the article. I feel this is an aircraft that
deserves more acknowledgment than any in your article.
The design makes the aircraft qualified for aerobatics as
well as a fast trip to any location you desire. The GP- 4
needs more recognition.
Ralph Cristofaro, EAA 529240
Las Cruces, New Mexico
Loved Building From Plans
The “Building From Plans” article in the February issue
was a wonderful article, one of the best that I have
Davisson writes about the fact that “time comes
from somewhere” and the trade-off with family time
and the need to discuss it with them. Wow. That’s very
responsible and mature, something that our society just
doesn’t perpetuate very often. Great work!
Danny R. Schnautz, EAA 863549