THE
TEXTBOOK
OF THE
CENTURY
You should not go
wave flying until
you have read
this book!
Reviewed by
Maurice Weaver
T
here have been a number of
exceptional gliding books
written and published in
the last ten years. They have
specifically targeted the racing pilot and
improving performance and increasing
the efficiency of soaring to achieve a
better result. These books have generally
focused on thermal lift conditions, while
touching on mountain and wave flying
in a chapter or two. After reviewing
this book you could say the earlier
publications are general in nature in the
topics they cover.
“Dancing with the Wind” is very specific,
but detailed and focuses on dynamic lift,
lift generated by some physical structure
on the ground. It’s a very technical and
narrow study of this form of lift. For me
it brings back memories of university
text books on fluid mechanics, structural
design and amino acids in the brain.
The last one being a lecture I accidently
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walked into and was unable to leave
until the end.
This book, written by Jean-Marie
Clement, is a must have for anyone
wishing to understand and exploit
mountains, wave and altitude gliding.
It’s a guide to the beginner trying to
understand how it all works, to the more
experienced pilot trying to understand
what just happened or why a certain
situation occurred, the way it did and
why, and to the very experienced pilot
wanting that specific edge or new angle
on high performance flying in these
often very challenging conditions.
Jean started flying in 1959. He studied
and specialised in Hydraulics,
sometimes referred to as Fluid
Mechanics and wrote his thesis on
Speed to Fly Technics and Total
Energy. Jean left gliding for a time
in 1975 and co- founded the Italian
Hang Gliding Federation, competed in
and designed and built hang gliders.
In 1982 he returned to gliding and
flew for the French gliding team and
ultimately came fourth in the World
championships in 1990. In 1992 he
refocused his attention on long distance
flying and improving performance by
optimal used of dynamic lift. He has
held various distance speed records
and completed the first out and return
declared 2000 km. Jean has 6,000 hrs in
gliders, 550 hours in power planes, has
27 French records and six World records.
Before you read a single word of
Dancing with the Wind, you can
only be impressed by its quality. The
photography is exceptional and the
charts, graphs and diagrams used to
explained theory and practice are of the
highest standard. Although very narrow
in context, it covers its chosen topic to a
level of detail only a few other books on
gliding have tried to do.
Gliding International
Just take slope soaring techniques and
tips for example.
Topics covered are:•
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•
•
•
•
•
The verticality of the wall, the horizontal component of wind
Wind gradient along the slope
How fast to fly along the slope
Ridge relative to the wind
Accelerators of flow
Right of way
Phase opposition
This is followed by a chapter on the
dangers of slope soaring and eleven
separate sub chapters on specific issues
to be aware of or avoid. This is one of
the many stand out aspects of this book.
The real story of this book however
is wave flying and flying at altitude.
What is covered is everything you need
to know to fly in wave or at altitude
to your best advantage, safely and
relatively comfortably.
There is a whole chapter on the theories
on the formation of waves and then
atypical waves such as shear waves and
wake waves (a new one for me).
Chapter 7 discusses in detail the
Hydraulic Jump or breaking waves.
Hydraulic jump is a new term for me
in respect to gliding. Wave formations
have a great deal of similarity with
rapids in a stream. Hydraulic jumps are
often induced into a spillway from a
dam to reduce the energy of the water
travelling down stream. As you steepen
the slope of a spillway eventually
that slope of the flow will break and
significant turbulence and white water is
generated. The concept that this occurs
in the atmosphere particularly is quite
intimidating.
However the author covers this topic
very well with some exceptional photos,
diagrams and descriptions.
He comments that,”I deeply hope
that every pilot awakens his scientific
curiosity and tries to decode the sky in
order to make the decisions outlined
above confidently and without qualms.”
Yes, you do need to read this chapter,
again and again.
Chapter 8 is - Identification and specific
techniques to use lee waves. The author
covers nine special wave cases that
are not typical as the author assumes
the reader has covered this general
type of wave formation in previous
publications. The topics include :• Wave in the presence of thermal, isolated downwind cumulus
July - August 2015
•
•
•
•
•
•
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Isolated downwind cumulus
Cumulus aligned along the crest
A layer of cumulus
Cumulus at two bases (confluence, convergence)
Flying downwind of ridges not perpendicular to the wind.
When the slope is not in phase with the lee-wave rebound
Negative wind gradient, rotors appearing to turn backwards
Migratory rotors
Steepness of the downwind wall
The ninth chapter again is very detailed
and covers the very specific topic of
speed to fly and limiting speeds and
loads. The author covers optimisation of
speed taking into consideration all those
issues related to mountains, wave and
altitude. Wind loading, ballast, altitude,
high velocity winds and structural
limitations including speed limiting,
flaps and airbrakes. Jean also discusses
instrumentation errors particularly the
vario and indicated airspeed. Although
I had the mis-conception that speed
to fly in wave was simple (as fast as
you can within the airframe limits) the
author believes speed to fly in wave is
much more complex than thermal flight.
One of the outstanding aspects of
this book is the extent to which
identification of issues and solutions
are offered and discussed in detail.
Flight planning and problem solving
is the next chapter. This covers issues
such as anti freeze, task planning, C of
G, preflight checks, post flight checks,
time and daylight, icing of the wings
and the canopy. The list goes on, but
to neglect these aspects of particularly
attitude flying can result in catastrophic
consequences which the author refers to
with examples throughout this amazing
volume.
A good example is the reference to the
closing in of cloud. The author covers
four levels of safety in dealing with this
possibility which is often beyond the
control of the pilot. They are:•
•
•
•
Have two gyros on two separate circuits
Know how to use those instruments i.e. training and practice
Have a moving map navigation system
And finally always have a downwind strip
Not surprisingly in a book of
this type the author covers the
much neglected area of the effects
of altitude and temperature on
the aircraft itself and the gelcoat
specifically but also the battery and
electrical system.
important topics, that of the pilot, his
or her health and wellbeing at altitude
and flying for long periods. The final
chapter covers oxygen and as I’ve come
to expect from this book, it covers the
topic in significant greater detail than
previous manuals I have read. The
Author reviews oxygen systems and
details applied research of the various
types and the results and effect on the
human body. A must read chapter.
In fact I think every pilot needs this
book as a guide and reference to flying
at altitude and the use of dynamic lift.
Most of the examples are in regard to the
northern hemisphere but is not entirely
devoid of southern hemisphere details
and examples. Either way I don’t believe
it matters.
In some respects I don’t believe this
review does this book justice as I had a
limited time to review it. At times I did
have trouble understanding it as I sense
it has been translated from French. For
the few times I did have some difficulty
I simply reread this section until I
understood the point being made. But
that minor comment aside this is an
exceptional volume.
To misquote a famous quote regarding
flying in Omarama, New Zealand. “You
must buy this book, sell whatever it
takes, but buy it“.
DANCING WITH THE WIND
This Book is a treasure, well printed
and 304 pages extremely well
illustrated - it is very heavy
(1.5 kg plus packing)
Including postage and packing
the price is
EUR 56.00
GBP 40.50
US$ 64.00
AUST $ 83.50
NZ $89.00
Ortder through our web site
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Janice Armstrang
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<[email protected]>
or phone 0064 7 571 4161
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The final chapters cover two very
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