April 20, 1998 Design News
Up close and personal
Engineer continues quest for flapping
by Charles J. Murray, Senior Regional
Cannon Falls, MN--In his daydreams, Jim Theis sees
small personal aircraft that can dip, turn, and hover
like dragonflies. He envisions teenagers soaring across
town, dropping in on friends. And he foresees the day
when soldiers will fly bird-like aircraft across enemy
lines, swooping in on their targets as they do their
Theis knows that his vision won't take shape soon.
But he can't help working on it. Surrounded by fluid
dynamics textbooks and reams of spreadsheets that contain
4,000 rows of propulsion calculations, Theis continues
investigating his dream: the creation of a flapping-wing
He's been at it for more than 20 years now. In the
more than two intervening decades, he has taken time
off to start his own company, New Product Design Inc.,
which he runs with his brother, Charley, who is the
company president. Working in a converted barn in the
tiny town of Cannon Falls (population 3,232), he has
churned out ideas ranging from the theoretically esoteric
to the purely practical. In all, he has more than 20
patents and countless unpatented inventions. Many of
those involve turbines, stemming from work he did for
the Hollymatic Corp. in the 1970s and Air Turbine Technology
in the '80s.
But the flapping-wing concept is still the one that
stirs Theis' inventive passions. He knows that its chances
of near-term commercial success are slim, but that doesn't
stop him. "Don't think I don't know what it sounds
like when I talk about flapping-wing aircraft,"
Theis says."People think it's a waste of time.
But I would ask you to think about what it would be
like if we could use aircraft locally. I can foresee
a time in the future when people will climb into their
'flappers,' punch a button, and a pair of wings will
That Theis can work on such experimental concepts is
amazing in itself. Nineteen years ago, while flying
an ultralight of his own design, Theis' aircraft clipped
the edge of a steel tower and crashed 35 ft to the ground,
breaking his back. He's still in a wheelchair.
In typical Theis fashion, however, his spirit was unbroken.
His physical confinement gave him the opportunity to
design better wheelchairs. In the past decade, he has
designed steerable wheelchairs, hand-crank wheelchairs,
and wheelchairs that fold up. His hand-crank chair is
currently licensed to Ultimate Support Systems (Fort
Collins, CO). The chair's hand crank is said to help
eliminate serious hand, shoulder, and elbow injuries
that often plague those in wheelchairs.
Whether or not the flapping wing enjoys similar commercial
success isn't an issue for Theis. "You have to
have faith in the process," he says. And because
he has a rare abundance of faith, he continues his work,
which is sponsored mostly by his wife, Linda. He has
already laid out the design of a 420--lb piloted prototype
with a 45-ft wingspan and a 15 hp motor. He plans plans
to fly the prototype before the year 2000.
This year, he will again give a forum presentation
at the world-renowned Experimental Aircraft Association
Fly-In Convention in Oshkosh, WI, in August. The forum,
he says, may not lead to the near-term development of
a product, but it will add to the foundation of knowledge
that's being built."The Wright brothers did all
their work because they were driven by curiosity,"
Theis concludes. "When you invent, the passion
has to be there. You can't pay for that kind of emotion."