Diseño De Planeadores

The Glider
Stelio Frati

Preface
At our Falco Builders Dinner at Oshkosh ’89, Fernando Almeida mentioned “Mr. Frati’s
book” in some context. This was the first I had heard of it, and Fernando explained that
Mr. Frati had published a book years ago on aircraft design. Then and there, I decided I
would have to get my hands on the book and get it translated into English.
Subsequently,Fernando mailed me his only copy of the book, L’Aliante (The Glider)
which was a photocopy of the original. Since then, we have slowly worked our way
through the book. The bulk of the work fell on Maurice Branzanti who translated the
original text into English. I then edited and polished the words into the copy you see
here, at times with the help of Steve Wilkinson, Jim Petty and Dave Thurston.As you might imagine, the original 1946 book contained a lot of material that is
hopelessly outdated now. The book contained many illustrative sketches of gliders
circling clouds, launching by being towed by a car, and the like. There were many
references to contemporary gliders and airfoils—indeed a large section of the book was
simply a series of charts and tables of airfoil with the usualcoordinate and aerodynamic
data.
We have not included these outdated charts and decorative illustrations, and instead we
have attempted to reproduce the original book in a form that covers the engineering and
design principals in a way that doesn’t date the book in any obvious way. Thus we must
apologize for a lack of strict fidelity to the original text, but we did this in the interest ofproducing a more immediate and interesting book.
Since Mr. Frati has no intention of reviving the book, we are happy to share it with
everyone, first in installments of our Falco Builders Letter, and now in a book format that
you can download from the Sequoia Aircraft web site at www.SeqAir.com. There are
nine chapters in all, and this is our progress to date. We will be updating our web site aswe make further progress.
Alfred P. Scott

The Glider

Introduction
Among the many types of flying machines that helped conquer our airways, from the
most modest and delicate to the huge, rugged Flying Fortress with thousands of
horsepower, there is one category of aircraft that does entirely without engines: the
gliders.
The glider was developed in Germany after the first world war,and it found particular
acceptance among younger pilots. Even though many used it as a new form of sport and
excitement, others employed experimental gliders to advance their studies in
aerodynamics and to develop new methods of construction.
Today, aviation owes a great tribute to these last individuals. In fact, the glider has
taught a great deal to designers, builders and pilots. Torealize how much, we need only
look at how many ways our armed forces have used these vehicles in the recent conflict.
To build a glider, one needs no huge industrial facilities, complex technical equipment or
large financial backing—just pure creativity, a clear understanding of aerodynamic
phenomena, and a patient pursuit of perfection in design and construction. So even our
country, thanks tothe efforts and merits of the “Centro Studi ed Esperienze per il Volo a
Vela” at the Milan Polytechnic, was able to compete vigorously in this field.
The author of this book is, in fact, a young graduate of our Polytechnic who has already
tested his theories and practical notions by building several successful gliders.
In this volume, you will find in simple terminology all the necessary adviceand
information you’ll need to begin the project, complete the construction and fly your
glider.
Don’t be frightened if this book seems rather large for such a simple subject. It also
includes the specifications of a variety of gliders, so in addition to being a textbook, it is
also a reference manual.
To the new student generation, may this book be the incentive to further cultivate the...