SE 019 338 Theory of Aircraft Flight. Aerospace Education II. Air Univ., Maxwell AFB, Ala. Junioi

142 Pages·2007·2.89 MB·English

.a
DOCUMENT RESUME
ED 111 638
SE 019 338
JAL
AUTHOR
Elmer,
D.
TITLE
Theory of Aircraft Flight. Aerospace Education II.
INSTITUTION
Air Univ., Maxwell AFB, Ala. Junioi Reserve Office
Training Corps.
PUB DATE.
74
NOTE
142p.; Colored drawings may not reproduce clearly.
Fbr the accompanying Instructor Handbook,
see SE 019
339. This is a revised text for Rb 068 29,31
EDRS PRICE
MF-$0.76 HC -$6.91 Plus Postage
DESCRIPTORS
*Aerospace Education; *Aerospace Technology;
*Instructional Materials; *Physical Sciences;
*hysics; Secondary Education; Textbooks
IDENTIFIERS
*Air Force Junior ROTC
ABSTRACT
This revised textbook, one in the Aerospa
e Education
II series, provides, answers to many questions related
to
planes
and properties of air flight. The first chapter provides
a
description of aerodynamic forces and deals with concepts
such as
acceleration, velocity,' nd forces of flight. The_second
chapter is
-devoted to the discussion o properties of the atmosphere.
ow
different characteristics of the atmosphere help
make flight
possible, how man can harness the air for flight,
and several other
questions related -to balancing of,forces in the air
are discussed in
chapter two and three. The discussion in
the fourth and fifth
chapters centers on how aircraft move through the air
The next two
chapters discuss the aircraft structure
and various'Wfnds of
instruments used to_control flight. A_ brief description
of 'navigation
instruments is also included. The book is designed
for use in ,the Air,
Force, ROTC program. (PS)
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*
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*
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*
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.
.
Aerospace Education II
MINT OF HEALTH
U S
EDUCATION & WELFARE
NATIONAL INSTITUTE OF
EDUCATION
REPRO
THIS DOCUMENT HAS SEEN
FROM
OUCED EXACTLY AS RECEIVED
ORIGIN
ory
THE PERSON OR ORGANIZATION
OPINIONS
AT I pio IT POINTS OF VIEW OR
V REPRE
STATED DO NOT NECESSAR
UTE OF
SENT OFFICIAL NAT1ONAt, .NSTT
c
EDUCATION POSITION OR
ft
ht
v---1
-
-4
I
Air
Force Junor ROTC
Air University/ Maxwell Air
Force
Base!
Alabama
C.)
AEROSPACE EDUCATION II
c
Theory of Aircraft
t
o
LT COLONEL JAMES D ELMER
Chief, High School Curriculum Division
.
AIR FORCE JUNIOR ROTC
AIR UNIVERSITY
MAXWELL AIR FORCE BASE. ALABAMA
1974
This publication has been reviewed and approved by competent personnel of the prepay
mg command in accordance with currentifirectrves on doctrine, policy, essentiality, pro.
priety, and quality.
,
only in the Air Force ROTC program,
This book will not be offered for sale. It is for
to
e
.0*
11.
e
.
.1
l
4
f
.
ft
,
4
A
A
r
0
t..
preface.
,do not fly, airtra
READ abput aircraft which
WE OFTEN
ft
which have accidents, but how often do we think about why
aircraft fly? And how loften do we wond& about the nature
Of this science of aircraft flight, how does the aircraft get off
the growid in the first place, how does it stay iii the air, how
is it controlled in the air; how is it landed.
Many'
.
. .
more "how" que,stions might be added: hoW is a plane put
together; how -does one man control a complex modern
and on and on.
aircraft.
.
. .
This unit, Theory of Aircraft Flight, will provide answers
for some of these qtiestionsabout the complicated and
serious businesi of flying aircraft. Odd as it tnay
seem, the
-
Weight brothers relied on many of the same principles used
today when they built and,flew
tint &uslce§sfall htavitrt-
than-air craft in 1903. Because today's highspeed aircraft
use better propulsion systems, building material,s, and
designs from those of the early pioneers of aviation, they
can fly much higher, farther, and faster than those. early
"iron birds`' However,.certain principles of flight
are com-
mon to all aircraft, old and rpwl---
In one sease,the hisf:06 of aviation is the history of
civilization. It has been said ta.t advances in Iransportatiop
have ,paralleled advances in degree of civilization. For the
history of flight, this statement is certainly true. The
pur-
pose of this unit, however, is not to givse you a histOry of
aviation; rather, its purpose is to explain what enables
man
to fly. To do this it will be necessary to discuss some histori-
cal deitelopwts which have made flying an accepted
means of trWportation:
You will also learn about the air around you and what
its properties are. We'll then -move
on to examine the
balance of forces which hold an aircraft in the air and how
an aircraft moves through the air. Next, we'll look at
'1,
aircraft; the
aircraft itructure. theibaiic components of an
acctir
hows ma-Whys of aircraft design; and the stresses that
on the airframe.
Finally,'we'll examine aircraft instruments: what they
.
how. they work. It
are; what types there are; and, basically,
seems, wiser to presentjn overall ;view of the aircraft and,
o
how it works before. we ezcamine tie instruments which the
his aircraft is performing. In addition,,
pilot uses to tell how
and navigation will dis-
the booklets on propulsion systemi
more depth thanthis brief over-
ctiss certain knstruments.in
all treatment allows.
We might mention here that several writers on the sub-
tha( "theory of
is
ject Qf aerodynamics point ont
somethingof a misnomer: human flight is fatt.
Wee know
that an aircraft cash fly, we know that the atmospWre has
certain properties. Why, then, do we call it a theory? The
"theory" involved is the tying together of all these knowh
facts into an explainable package.,
\
ti
41.
-at
i
V
I IV
Contents
PREFACE
iii
Chapter 1
AERODYNAMIC FORCES
1
...
Man's Early Attempts to Fly
2
-Newton's Laws of Motion-
$
Acceleration, Velocity, Force, and Mass
7
,
The Forcie of Flight
'
9
.
,4#
Chapter 2 PROPE-RTI#S OF THE ATMOSPHERE
13'
,
.io
The Atmosphere: What is it?
.
13
Composition of the Atmosphere
14
I
Physical Properties of the Atmosphere
,
15
.
Chapter 3 AIRFOILS AND
FLIGHT
r
25
/
Airfoils
.26
,.
Airfoil Design
26
. Leading Edge
27
' Trailing Edge
27
Chord
27
Camber
27
Relative Wind
28
,
Angle of Attack
29
Lift
30
V
Lift Variables
33
Angle of Attack Again
33
.
Another Lift VariableVelodity
of
Relative Wind
,
36
;
Air Density and Lift
36
Airfoil Shape as a Variable
37
Wing Ar-: and Lift
37
Planform eta') Airfoil
38
,r
Flaps, Slots, and
ilers
39
araptfr
WEItHT, THRUSX,
AND DRAG
45
Weight
45
46
Thrust.
47
Drag
.
,
4
SuperbritiSal Wing
51
.
...
./----
52
elicopters
H
57
Chapter 5 1AIRCRAFT MOTION AND CONTROL
i
-)
58
The Axet of RotatioN
,
.
.
-;Stability
59.
---
?
LOngitudinal
6-1
,
63
Lateral Axis,'Stability
65
Directional Stability
67.
Control
c
..i.
Climbing Flight :
71.
'
.'
.,
4
Forces in Turns
13
*'
'
Aircraft Motion and Control
7&
85
AIRCRAFT STRUCTURE.
Chapter 6
.
!
87. '.
.
Power Plant
87,
Fuseraie,
G,
.
,
-,
92
..'
Wings
.1
.
4
95
Empennage
,
99
Hydraulic-and Electfical Systemi
99
Hydrplics.
,
,.
,.
I
101
Electrical-'Sy 40s
; ) . '
,
.
,
101
Landing Gear
.'
.
.
.
.
.
109
M
CRAFT INSTRUMENTS
,,
Chapter 7
111
"Early,Aircraft Instrwnents..r.
,
%.
. ....-.
..
Instrument Clissification..... ...
.
.111-2
, .
..
$
,
114
Engine Instruments
4....
/err
...
l 16
NiivigatiOn Instruments
C
7
1(7"
.
Flight Insti-uments
c,'
..
123
SUMMARY
1
I
125
GLOSSARY
135
)1,D EX
...
4
1
Chapter
Aerodynamic
Forces
THIS CHAPTER places
man's attempts to fly in historical
perspective. RV, you will briefly review
man's early attemptsitc;
fly. Then, you will examine
the physical laws which ,underlie
flight, particularly Newton's
Laws of Motion and Bernoulli's Thin-
cipla. finally; you 141 lot* at
an aircraft in flight andexamine the
balance of (on
which keeps it there, After
you have studied
thia-tiVer; You should be able
to: (1) outline the steps that led
tc) isuctalisful..co,ntrolled, poWared,
heavier- than -air aircraft
flight' (2)
ShbVihowtho
Wright Brothers applied Newton's
Laws
of MotiOn and SertiOullri Principle
to their aircraft; and (3) ex.
plalnwhy the torceiot lit, weight ihrust,
'and drag are essential
tdauccessful flight
,
.
WITH A ROAR and then a iteady hum,
your flight takes off. The
"Fasten Seat Belts" sign gods off, and yoii
relax, secure in the
knowledge that your aircraft is being flown welI
and safely But then you
look out the window and see those big
engines, representing hundreds
of horsepower, propelling
your 'aircraft through the air How do they
keep your plane in the air" Why doesn't
it fall out of the sky? How (and
maybe why) did you get
up where you are in the first place"
Srt back, relax, and don't
worry Something more than good luck
is
keeping your aircraft in the air' In
one sense, the last five or six hundred
years' experience of mankind is holding
up your plane. This chapter will
9
THEORY OF AIRCRAFT FLIGHT
which have led to the
take a brief look at aspects of the last five centuries
at-
history of man's
smodth and safe flight you're on right now The
birds is an important aid to
tempts to fly under his own power like the
of man's trials
understanding why man is now able to fly. A short review
of your own
and errors in his attempts to fly may well remove some
certainly, it will show you
misconceptions about the nature of flight,
how'earlier man attempted to fly
till' kIVIN 1(1 H
%R N'S F tRi 'I
the Greeks You have
Like so many other things, it all began with
Daedalus and Icarus In
probably heard of read about the legend of
Minos of Crete, Daedalus
order to escape from the labyrinth of King
feathers and a magic
made wilts for himself and his son Icarus from
labyrinth, but, so the legend goes, Icarus
wax Both escaped from the
wings, causing him to
flew too near the sun, and the sun melted his
probably has no
plunge to his death in the sea. Like ail legends, this one
that man could ex-
somethin
basis in fact, rather, it arose to explain
an ad tried, but his
does,po
plain no other way birds fly and man
succeed.
nature was such that he didn't
with water, but
Archimedes, meanwhile, was performing experiments
also to affect pre-Chris-
his conclusions about the nature of water were
Archimedes' experiments led him to this
tian man's notions of flight
of water,
conclusion a body will float if it is lighter than a like measure
this conclusion to one specific
but it will sink if it is heavier Extending
lighter than water will float on the sea,
case, he concluded ihir if things
atmosphere The problem,
then things lighter thin air will float "on" the
airship lighter than a like volume of
of course, was simply to build an
air
history, tq Chinese had solved
In this same pre-Christian period of
how to harness moving
the problem quite another way they figured out
records indicate that some of these early
air by means of the kite Old
Some of these man-bear-
Chinese kites were large enough to lift a man
Chthese
battle for obsetvation Because the
ing kites were even used in
their knowledge, it was not until
and Greeks were unable to combine
directed his efforts to solving the
much later that man- seriously
problems of flight
flight was the great
Another major thinker on the problem of manned
parachute and an early
Leonardo da Vinci Da Vinci designed both a
manpowered or-
form (a prototype) of the helicopter, as well as a
principles as birds)
nithopter (a flying machine which used the same
of flying the machine was
But he realized that a power source capable
his ideas remained in notebook form until
not available, and so many of