Planes, Trains, Bots & Games (and a few gadgets too)

The Hobby Guy

March 29th, 2007 at 8:15 am

The origins of the Kline-Fogleman airfoil, by Dick Kline


The following was written by Dick Kline, inventor of the Kline-Fogleman airfoil. Dick has graciously written this great piece for all of us. Thank you Dick!

I have been asked a number of times, “How did you come up with the
Kline-Fogleman airfoil?”

Back in the early 1960s, I was working as an art director for an
advertising agency in mid-town Manhattan. My office was on the 24th
floor, overlooking 42nd Street, the New York Public Library and Bryant
Park. I had no knowledge of aerodynamics back then, but I loved to make
paper airplanes and would occasionally sail one out the window and
watch it fly over the park and the library.

KF Flight Over Bryant Park 1

On weekends, I would take my young son out to a ball field to fly paper
planes. But it could get windy outdoors, and the paper airplanes
couldn’t handle the conditions very well. I couldn’t throw them very
hard without having them collapse. So I asked myself, “How can I make a
paper airplane that I can throw hard into the wind, have it climb up
and when it reached the apogee automatically level off by itself and go
into a nice long glide?”

Once you pose a question to your mind, it will begin to work on the
problem. You will get impressions – often visual – that suggest you try
this or try that. One of the first things I tried was to make a
more-rigid paper airplane – one that could stand up to a strong throw.
By making an extra fold on each wing running from leading edge to
trailing edge and then taping them tightly together, I created a
fuselage. This made the paper plane much stronger, and the wings held
together even with a hard overhand throw.

KF Flight Over Bryant Park 2

But I still wasn’t getting the height that I wanted. I could see it
happening in my mind, but not in the real world. Then one day, I looked
at the extra fold of paper that one makes when first folding a paper
airplane. This is done because you want more weight up front to carry
the plane forward. I opened up the folded-over piece on each wing,
creating pockets. Now each wing had a step about half-way back from the
leading edge on the underside of the wing. I gave the plane my best
pitch. It took off directly into the wind and climbed up about as high
as a telephone pole, then leveled off and went into a nice long glide.
That’s exactly what I was looking for. It’s what I had imagined. Mind
you, this did not happen overnight. It took many attempts until I was
able to get it to perform the way I wanted it to. For example, the
depth of the steps on both wings had to be equal . If one step was
deeper than the other, it would affect the flight, and the plane would
not fly straight and true. Or, if the folds did not meet where the
fuselage started in exactly the same position on each side, it would
also cause the plane to fly poorly. I had probably made over 100 paper
airplanes before finding my solution. Equal pockets on both wings and
perfect alignment of both wings. That combination made for the perfect
flight.

KF Flight Over Bryant Park 3

For the next four years, I tried to interest toy companies, but without
success. Then, one day a photo-retoucher who was doing work for me came
into my office. Floyd Fogleman was a pilot and model-airplane builder
as well as a retoucher, and I gave him a demonstration of my paper
airplane, launching one down the hallway. He went running after it and
came back, saying “I think you’ve got a whole new concept in
aerodynamics here.” He noted that the paper airplane appeared not to
stall, but continue flying and was extremely stable in flight. We
decided to apply for a patent after he took one of the planes home and
translated it to balsa wood. It flew with the same characteristics as
the paper models. Two years later, we had our first US patent,
#3,706,430.

I now believe that every discovery starts with a question. Imagine some
guy – maybe an accountant – in an office a long time ago. And he made
mistakes as he wrote down his numbers. He was using a wooden pencil,
but was always misplacing his rubber eraser. He probably asked himself,
“Why can’t I find that eraser when I need it?” One day, it occurred to
him to put the rubber eraser on the end of the wooden pencil. Today,
almost every wooden pencil comes with a rubber eraser on its end.

So if you want to begin an interesting adventure, start by making an
observation and then asking yourself a question.

 

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