The Texture of Airplane Design Theory
Robert J. Kolker
does not take into account the design and application of high thrust jet
engines which is a whole area unto itself. Take a look at the topics
just for the design of light airplanes.
Design of Light Aircraft
Richard D. Hiscocks ISBN: 0-9699809-0-6 Softbound 280 pgs 1995
This Book is of interest to aeroplane enthusiasts. The elements of
design are described in a historical context with many examples to
illustrate and explain the process.
Wing theory is examined together with the aerofoil selection process,
scale effect, performance as required for a flight envelope aspects of
stability and control, biplane theory, loads on components, structural
stiffness requirements, flutter, fatigue life, and factors of safety.
All are viewed in the light of practical requirements and good design
practice.
The Art that is required in design to balance the demands of
[rjk. Note this very carefully. The operative word is Art.]
performance, safety and cost is described. Often a highly precise
analysis is not justified when the limitations of the theory and
materials of construction are considered. In the design examples
provided all of the arithmetic can be performed on a pocket calculator.
Readers who do not have the time or inclination to study official
airworthiness standards and texts written for specialists in
aerodynamics and structures will find this book a useful design guide.
Extensive data is provided for those who do not have ready access to a
technical library.
TABLE OF CONTENTS:
1 Loads, General
1.1 Introduction
1.2 Symmetrical Maneuvers
1.3 Load Factors
1.4 Dynamic Pressure
1.5 Airspeed
1.6 Flight Envelope
1.7 Ultimate and Limit Loads
2 Wing Section Properties
2.1 Coefficients, General
2.2 Lift Coefficient, CL
2.3 Lift Curve Slope. a=Cl/a
2.4 Zero Lift Angle aL=o
2.5 Drag Coefficient, CD
2.6 Pitching Moment Coefficient, CM
2.7 Wing Flap Effects
2.8 Boundary Layer and Scale Effects
3 The Wing in Three Dimensions
3.1 Introduction
3.2 Slope of the Lift Curve
3.3 Induced Drag
3.4 The Drag Polar
3.5 Parasite Drag
4 Performance Considerations
4.0 General
4.1 Aircraft Drag Estimate, - Example DOX
4.2 Selecting a Powerplant
4.3 Climb Performance
4.3.1 Performance at Sea Level
4.3.2 Climb at Altitude
4.3.3 Power vs Speed
4.3.4 Reduction Gear
4.4 Wing Characteristics, DOX
4.5 Weight and Balance
5 Manoeuvring Flight Loads
5.1 Symmetrical Manoeuvres
5.2 Balancing Loads
5.2.1 Principal external Loads
5.2.2 Angle of Attack
5.2.3 Thrust
5.2.4 Inertia Factor
5.2.5 Total Drag
5.2.6 Pitching Moment M
5.2.7 General Observations
5.3 Application to Aircraft DOX
5.3.1 Balance Calculations, Aircraft DOX
5.4 Balance Loads, n = 1
5.5 Balance Loads at the Envelope Boundaries
5.5.1 Loads at Boundaries of the Flight Envelope
5.5.2 Points D, E, C
5.6 High Lift Devices
5.7 Simplified Criteria
6 Wing Loads, Forces at Aero-Centre
6.1 Distribution of Forces, Symmetrical Loads
6.2 Wing Panel Loads
6.3 Inertia Relief
6.4 Normal and Chordwise Components
6.5 Observations
6.6 Unsymmetrical Loads, Wing Torsion
6.6.1 Centre Section Shear Loads
6.6.2 Wing Pitching Moment due to Ailerons
6.7 Simplified Design Requirements
6.7.1 Flight Envelope
6.7.2 Arbitrary Loads
7 Gust Loads
7.1 Sharp Edged Gust
7.2 Gradient Gusts
7.3 Gust Envelope
7.4 Flaps
8 Spanwise Distribution of Wing Loads
8.1 Spanwise Load Distribution
8.2 Wing Shear Load
8.3 Wing Bending Moment
8.4 Twisted Wing
8.5 Wing with Flap
8.6 Wing with Aileron
8.7 Wing with Continuous Twist
9 Tail Design
9.0 Longitudinal Stability
9.1 Horizontal Tail Loads
9.1.1 Balance Load Pb
9.1.2 Manoeuvring Loads Pm
9.1.3 Combined Loads, Horizontal Tail
9.1.4 Gust Loads Pg
9.1.5 Tailplane Setting
9.1.6 Spanwise Distribution of Tail Load
9.2 Directional Stability
9.2.1 Vertical Tail Balancing Loads
9.2.2 Manoeuvring Loads
9.2.3 Arbitrary Loads, Vertical Tail
9.2.4 Gust Loads, Vertical Tail
9.3 Combined Loads, Horizontal and Vertical Tail
Surfac 9.4 Outboard Fins
9.5 V Tails
9.6 Comments
10 Pressures on Wing Sections
10.1 Approximate Method
10.1.1 Comparison with Tests, NACA 4415 and 64 Series Sections
10.1.2 Application to DOX
10.1.3 Reversed Flow
10.2 Flap Loads
10.3 Aileron Loads
I 10.4 Load Distribution on Horizontal Tail Surfaces
10.4.1 Thin Aerofoil Theory Applied to Control Surfaces
10.4.2 Application to DOX
10.5 Tailpiane Torsion Loads
10.6 Comparison with Official Design Standards
10.7 Aerodynamic and Mass Balance
10.8 Chordwise Load Distribution on Vertical Tail
10.9 Flap and Elevator Interaction
11 Landing Gear Loads
11.1 Introduction
11.2 Energy Requirements
11.3 Tire Energy Capacity
11.4 Shock-Strut Energy
11.5 Design Examples
11.5.1 Low Wing Cantilever Monoplane, Fig.11.5.1(a)
11.5.2 High Wing Light Aircraft, Fig. 11.5.2(a)
11.5.3 High Wing Monoplane with Cantilever Main Gear, Fig. 11.5.3(a)
v 11.5.4 Cantilever Spring Main Gear
11.6 Limit and Ultimate Factors
11.6.1 Drop Tests
11.7 Basic Landing Conditions
11.7.1 Level Landing
11.7.2 Tail-down Landing
11.7.3 One-wheel Landing
11.7.4 Level Landing with Yaw
11.7.5 Braked Roll condition
11.7.6 Tail Wheels, Supplementary Conditions .
11.7.7 Nose Wheels, Supplementary Conditions
11.8 Emergency Landings
11.9 Remarks
12 Biplane Lift
12.1 Introduction
12.2 Load distribution, Classic Biplane
12.3 Manoeuvring and Gust Loads
12.3.1 Lift Coefficients
12.3.2 Lift Curve Slope
12.3.3 Drag
12.3.4 Pitching Moment
12.4 Example, Biplane Balance
12.4.1 Data required for balance calculations
12.5 Wing Flaps
12.6 Remarks
13 Engine Mount and Control System
13.1 Engine Mount
13.1.1 Load Conditions on the Flight Envelope
13.1.2 Gyroscopic Forces
13.1.3 Tension Coefficients
13.1.4 DOX Engine Mount
13.2 Control System
13.2.1 Aerodynamic Forces
13.2.2 Pilot Forces
13.2.3 Secondary Control Systems
13.2.4 Control System Stiffness
13.2.5 Ground Gusts
14 Flutter and Stiffness
14.1 Introduction
14.2 Wing Bending Torsion Mode
14.3 Wing Tip Torsional Stiffness
14.4 Wing Bending - Aileron Mode
14.4.1 Aileron Mass Balance
14.4.2 Aileron Torsional Stiffness
14.4.3 Aileron Control Circuit Stiffness
14.5 Fuselage Stiffness
14.6 Tail Structural Stiffness
14.6.1 Torsion, Horizontal Stabilizer
14.6.2 Torsion. Rudder, Elevator
14.7 Centre of Gravity, Mass Balance, Rudder, Elevator
14.8 Control Tabs
14.9 Control Divergence
15 Fatigue
15.1 Introduction
15.2 Gust Load Spectrum
15.3 Manoeuvring Load Spectrum
15.4 Life Prediction
15.4.1 Compact D Nose Example
15.4.2 Stabilized Thin Skin Cell Example
15.5 Discussion and Conclusions
Symbols and Abbreviations
Specification, Aircraft CF DOX
References
Index
Compare this table of contents to a toc for a book in quantum field
theory and you will see the difference in abstraction level, texture,
and specificity.
All of the topics are based on classical mechanics (no relativity, no
quantum theory, no electrodynamics). Note the particularity of the
topics above versus the generality for the elements of fundamental
theories of physics. And this book just addresses moderate performance
requirements. The design for the "heavies" and the combat aircraft are
even more particular and more complicated. What airplane design does not
have is the a priori mathematical generality of basic physics. Bottom
line: Designing a good airplane is more complicated that figuring out
how the Kosmos works. Strange, isn't it?
Another thing about designing airplanes. Doing good design of the parts
does not imply good design of the whole. The interaction of the parts
are such that one cannot infer the goodness of the design of the whole
aircraft from the goodness of design of the components. The aircraft as
a whole must be tested and vetted. That same whole-part issue is equally
true of cars and ships (and even buildings). There is a holistic aspect
that is simply not captured in the theory. That is why design is more of
an art than a science.
But guys like Phredd and Ahnold don't want to concern themselves with
such details. They prefer their preconceived notions.
Bob Kolker
Fred Weiss
.223037$%_6.134599@attbi_s01>...
> I found a book on the design of light aircraft.
Gee.
> This Book is of interest to aeroplane enthusiasts.
I wonder why it would be of interest to them since according to you we
don't know how to fly. And we don't know how to fly because we don't
know how to fly in hurricanes. This is equivalent to saying we don't
know how to run because we can't run in a tornado - and since
apparently - see below - running doesn't involve quantum mechanics
that really proves we don't know to run.
> Compare this table of contents to a toc for a book in quantum field
> theory and you will see the difference in abstraction level, texture,
> and specificity.
>
> All of the topics are based on classical mechanics (no relativity, no
> quantum theory, no electrodynamics).
Since according to you classical mechanics is false, I guess that
proves your point - that we don't know how to fly. (Bob doesn't
mention that relativity, quantum theory, and electrodynamics are not
necessary for flying.)
Bob is going bonkers here and doing his usual snow job when he knows
that his position is utterly absurd. Otherwise he'd have to admit he's
wrong.
Btw, Bob, do you have any books for cow enthusiasts that covers the
subject of cows and their capacities regarding flights to the moon?
Just so everyone is clear what the issue here is: Bob's position is
that he could stand in a terminal at JFK and watch planes take off and
land from today till doomsday and all he could say is "this here plane
took off" and "this here plane landed" but none of it could lead him
to the conclusion, "Hey, mebbe we know how to fly".
Admit it, Bob, you're an ignoramabus. Not to mention a schmeggeggie.
Fred Weiss
Arnold
.223037$%_6.134599@attbi_s01>...
> does not take into account the design and application of high thrust jet
> engines which is a whole area unto itself. Take a look at the topics
> just for the design of light airplanes.
>
>
>
> Design of Light Aircraft
>
> Richard D. Hiscocks ISBN: 0-9699809-0-6 Softbound 280 pgs 1995
substitute for grasping a point.
> > But guys like Phredd and Ahnold don't want to concern themselves with
> such details. They prefer their preconceived notions.
You don't know what you are talking about, and totally misunderstand
me. (I too have a similar book; Design for Flying by David Thurston,
but I will spare you the contents pages.)
Arnold
Tom S.
"Arnold" <arnold...@hotmail.com> wrote in message
news:2362e284.04080...@posting.google.com...
> "Robert J. Kolker" <robert...@hotmail.com> wrote in message
news:<bxeRc
> .223037$%_6.134599@attbi_s01>...
> > I found a book on the design of light aircraft. This design discipline
> > does not take into account the design and application of high thrust jet
> > engines which is a whole area unto itself. Take a look at the topics
> > just for the design of light airplanes.
>
> substitute for grasping a point.
>
> > > But guys like Phredd and Ahnold don't want to concern themselves with
> > such details. They prefer their preconceived notions.
>
> You don't know what you are talking about, and totally misunderstand
> me. (I too have a similar book; Design for Flying by David Thurston,
> but I will spare you the contents pages.)
>
were you? You were just moving throttle, rudders, flaps, ailerons...that's
not FLYING.
No, we don't really fly, we just get in the planes and they show movies out
the windows, and movies from the airport terminal.
Tom
1990 F33A , TNIO-550
Arnold
swest.net>...
> >
> Gee, Arnold...and all those years in the cockpit, you weren't really flying,
> were you? You were just moving throttle, rudders, flaps, ailerons...that's
> not FLYING.
I'm beginning to wonder if we are being subject to a Turing test, and
"Bob Kolker" is actually a computer program. Others have also noticed
multple resets and missed interpretations, followed by long (although
informative) irrelevant dissertations. Misplaced "you're an asshole"
for a simple disagreement also seems like a program glitch.
Arnold
Tom S.
It's like talking to someone who isn't really listening. His responses so
often have absolutely no relevance to the points being made. No relevance at
all. It's all reminisant of having a discussion with my in-laws that have
forms of Alzheimer's and whom are not very literate on any subject other
than sports or religion. :~)
Tom
--
Real science doesn't work on consensus.
It works on contention. When a new fact
is announced, it is attacked voraciously
from all sides and corners. If it holds up,
and proves to be true, it is then, and only
then, accepted as a fact.
With real science, you don't need
consensus. Only facts.
Scott Stephens
> I found a book on the design of light aircraft.
>
> Design of Light Aircraft
Is it online somewhere? I like collecting information.
> Bottom
> line: Designing a good airplane is more complicated that figuring out
> how the Kosmos works. Strange, isn't it?
I don't think so. Trying to understand the cosmos is about crunching
general, simple principles out of complex circumstances. Trying to make
an airplane has all sorts of diverse requirements.
> That same whole-part issue is equally
> true of cars and ships (and even buildings). There is a holistic aspect
> that is simply not captured in the theory. That is why design is more of
> an art than a science.
I think any technology is more art than science. Its a very human thing,
applying abstract scientific theory to accomplish a human purpose.
--
Scott
**********************************
DIY Piezo-Gyro, PCB Drill Bot & More Soon!
http://home.comcast.net/~scottxs/
**********************************
Mark N
> I'm beginning to wonder if we are being subject to a Turing test, and
> "Bob Kolker" is actually a computer program.
Arnold, you mean you only just now realized this?? I believe
it was Charles Novins who first pointed out that "Bob" is
obviously a computer program, an instantiation of the
"Kolker Algorithm." The program's rather limited repertoire
of canned responses is a dead giveaway!
Mark
P.S. Just kidding, Bob! I know you're a real person! ;-)
cantueso
.223037$%_6.134599@attbi_s01>...
> that is simply not captured in the theory. That is why design is more of
> an art than a science.
but why, why! did you call it "texture"?!
what a terrible word. it is only used in the presentation of modern
oil paintings where they mix in some plaster, sawdust, and also a
little grated aspirin to relieve boredom.
I am sure you will have a great time reading that book.
when it gets too detailed, it is no longer about airplanes.
I once had to translate a patent for some security valve of a high
speed airplane. there was nothing about the plane.
and once I had to do something about material fatigue (cracks in the
fuselage, the same as in ocean liners). there was nothing about the
plane.
maybe that is just the sad part of the story: some 80 years ago (or
when?) a man would have drawn a hundred airplanes. now ten thousand
men design one, everybody doing secretarial work looking after the
data.
Fred Weiss
2@trndny01>...
There's an element also of Bob just enjoying being contrary. Or saying
outrageous things just for the effect. He's an "enfant terrible".
There are times when he can be very sensible and rational. Especially
if he thinks you're not watching. I peak over at apo from time to time
and I'll sometimes say "Wow. Did Bob say that? I can't believe it". He
literally could be saying virtually the exact opposite thing on hpo at
the very same time!
However the element underneath it all is that he doesn't think
anything really adds up to a rationally consistent view of the
universe. It's all just B.S. to him. It doesn't really matter what it
is, good or bad, he'll attack it. Hence his radical empiricist
reductionism - "all that I believe is just what I can see with my own
eyes". He doesn't really believe that either, but then he doesn't
really believe anything.
Essentially he's a thoroughgoing nihilist with the totally malevolent
sense of life which goes along with it.
Fred Weiss
Robert J. Kolker
Fred Weiss wrote:
> However the element underneath it all is that he doesn't think
> anything really adds up to a rationally consistent view of the
> universe.
Yes I do. The Law of Non Contradiction holds.
When are you going to wake to the fact that our best physical theories
are highly educated guesses which are well supported by physical
experiment. Science runs on hypothesis, not guaranteed Truth.
Many hypotheses are useful and produce usefull results (technology) but
that is not guarantee that a condition underwhich they do not hold does
not exist. No matter how many time a theory is right it is no guarantee
that it will be right under conditions not yet tested for.
Bob Kolker