|Glider Polars and
Speed-To-Fly ...Made Easy!
A User-Friendly Guide to Glider Performance Polar Analysis
Author: Bob Wander
From Bob Wander's "Gliding ...Made Easy" series
Paperback, many illustrations and black and white photos, 32 pages,
Dimensions: 8.31 x 11.0 inches
(211 x 280 mm)
Table of Contents
About the Author
User-friendly, non-technical polar analysis
and speed-to-fly decision-making.
Step-by-step analysis of glider polars, speed-to-fly and final glide.
Works for any glider performance polar under any weather conditions. No
During his lifetime Albert Einstein was regarded not only as a great
theoretical physicist but also as an exceptional teacher. Einstein was
able to explain the fundamentals of his complex Theory of Relativity
with clarity and style. One day, a colleague asked Einstein how he
managed to make complex physics so accessible to people without formal
training in math or physics. Einstein's witty reply showed that he
possessed a droll sense of humor (as well as great intelligence): "A
good teacher makes things as simple as possible - but not simpler!"
This volume makes it easy for you to learn the fundamentals of glider
performance polar analysis and speed-to-fly decisionmaking. The
step-by-step approach employed to illustrate glider performance is
user-friendly and non-technical. You do not need to know algebra, or
geometry, or calculus. In fact, the only math you will be asked to
perform is simple arithmetic - addition, subtraction, and division.
In short, I have made things as simple as possible - but not simpler.
Glider Polars And Speed-To-Fly Made Easy deals with several concepts. We
begin with an examination of the performance polar characteristics of a
particular glider. The principal performance speeds, how they are
discovered, and how to select optimum speed as you cruise between
thermals are all covered. These concepts are known by the curiously
descriptive phrase speed-to-fly. Speed-to-fly concerns itself with the
selection of the optimum airspeed to fly in the presence of calm air,
rising air, or subsiding air.
We also examine the problem of selecting the cruise airspeed that will
maximize your glide over the ground (a fundamentally different problem
than trying to maximize arrival altitude at the next thermal). Racing
pilots call this part of gliding the final glide because the last
portion of a successful racing flight is a glide to the finish gate.
During final glide the racing pilot seeks to minimize time spent on this
last portion of the flight. For that reason, stopping to circle in
thermals is not done (unless the pilot is too low to make the finish
gate, in which case another climb must be accomplished, then the final
glide begun anew). Since the final glide has as its objective the
attainment of an objective on the ground (the finish gate), the pilot
must factor in the effect of the wind on the track and groundspeed of
the glider during the final glide. After all, the glider is flying
through an ocean of air that is usually moving both horizontally (wind)
and vertically (convection). It follows that the speed of the glider
over the ground is actually the sum of two motions: the glider motion
through the airmass, and the airmass motion over the ground. We will
investigate why we adjust airspeed during final glide to account for any
wind and convection present. Then we will discover just how much to
adjust airspeed during final glide.
Finally, a word about the importance of selecting optimum airspeeds.
Some glider pilots think that only racing pilots need to be concerned
with selection of optimum airspeeds. Nothing could be further from the
truth. For safety's sake, every soaring pilot needs to know how to
extract maximum performance and maximum glide from the glider. This has
long been recognized by experienced glider flight instructors and by the
FAA, which rightly demands thorough knowledge of glider performance
airspeeds on both the Private Pilot Glider Practical Test and the
Commercial Pilot Glider Practical Test.