Page 11 - Understanding Flight

FM_Anderson 11/14/00 12:41 PM Page xi

Introduction xi

describe lift using Newton’s three laws. But, unlike anyone to our
knowledge, we take this description and use it to derive almost all
aspects of flight. It allows us to intuitively explain aspects that most
aeronautical engineers can only explain mathematically. It will
become clear to the reader why one increases the angle of the wing
when the airplane slows down or why lift takes less power when the
airplane goes faster. It will be obvious why airplanes can have
symmetric wings or fly upside down.

The third chapter is “Wings.” Here we will explain why wings look
the way they do and what tradeoffs take place in their design. When
you fly on a commercial jet and see all the changes that are made to
the wing on landing, you will have a clear understanding of what is
going on and why. A natural follow-on to “Wings” is a chapter on
“Stability and Control.” Airplane stability is presented and the
distinction is made between stable and balanced flight. The concept of
fly-by-wire and the role of the computer are also discussed.

Among other things, the chapter on “Propulsion” explains how a
jet engine works and why they have gotten so large. Would you
believe that there is essentially a propeller in front of the jet engine on
that Boeing 777?

The following chapter on “High-Speed Flight” discusses the interesting
phenomena associated with flying faster than the speed of sound and
why these airplanes look as they do. Chapter 7, “Airplane Performance,”
discusses such aspects of flight as the climb, cruise, and landings.

The final chapter on “Aerodynamic Testing” addresses wind-tunnel
testing and flight testing. The principles of wind tunnels are presented
in some detail. Some examples of flight testing as it pertains to the
previously introduced concepts are presented.

This work is presented on two levels. The bulk of the material is
addressed to the general reader. Here a minimum of experience is