BY DICK SARPOLUS AND LARRY CRESSMAN PHOTOS BY DICK SARPOLUS
EO SPORT BOAT
An unusual flying boat biplane design that makes a great sport-scale flyer
WHAT IS IT? That’s the most common
question asked of my friend Larry whenever
he brings his Aeromarine Tractor Sport Boat
to the flying field. Larry is used to the question, though, as he has been
scratch-building his own scale projects for
years. He loves unusual, seldom seen airplanes and this one is no exception.
Although the Aeromarine is close to scale,
Larry builds his planes for casual sport/fun
flying and not for serious scale competition. One thing is for sure: you’re likely
never to run into another Aeromarine EO
Tractor Sport Boat at the flying field!
This little known two-place biplane sea-
plane was built by an aircraft company
located in Keyport, NJ, called the “
Aeromarine Plane and Motor Company.” The
company built early passenger-carrying seaplanes and offshoots of the company went
on to become small airlines such as the
Aeromarine West Indies Airways and others.
The original aircraft was designed by B.V.
Korvin, a design engineer who worked at
Aeromarine from 1921 to 1924. It had a 38-
foot wingspan, was powered by a 6-cylinder
80hp Anzani radial engine and had an aluminum hull. It was built in 1924 and only
one was ever produced. Its flying days ended
in 1931 when it crashed at Cape May, NJ.
The model’s outline is very close to scale
and it has a flat bottom airfoil for both
wings. There’s plenty of lift available for
easy, slow flying. A home-converted 30cc
gas engine powered the prototype turning a
16x8 prop. Larry has designed and built
enough original scale planes over the years
that he doesn’t need much in the way of
construction details. He works out the outlines, sketches in the structure, and
scratch-builds the model. This doesn’t
make it very easy for the guy who has to
trace his drawing to produce the plans for
publication—that would be my job and I’ve
included all the details you’ll need to build
your own version.
The prototype has not yet flown off of
water, but if you waterproof the model it
should perform as expected. Larry uses
removable, plug-in wire landing gear for
flying off of grass. Photos have been found
of the plane while equipped with wheels, so
“ground operation” is a scale function.