Table Of ContentAIRCRAFT DESIGN
Aerospace Series List
Introduction to UAV Systems 4e
Fahlstrom and Gleason
August 2012
Theory of Lift: Introductory
Computational Aerodynamics with MATLAB/
Octave
McBain
August 2012
Sense and Avoid in UAS: Research and Applications
Angelov
April 2012
Morphing Aerospace Vehicles and Structures
Valasek
April 2012
Gas Turbine Propulsion Systems
MacIsaac and Langton
July 2011
Basic Helicopter Aerodynamics, 3rd Edition
Seddon and Newman
July 2011
Advanced Control of Aircraft, Spacecraft and Rockets
Tewari
July 2011
Cooperative Path Planning of Unmanned Aerial
Vehicles
Tsourdos et al
November 2010
Principles of Flight for Pilots
Swatton
October 2010
Air Travel and Health: A Systems Perspective
Seabridge et al
September 2010
Design and Analysis of Composite Structures: With
applications to aerospace Structures
Kassapoglou
September 2010
Unmanned Aircraft Systems: UAVS Design,
Development and Deployment
Austin
April 2010
Introduction to Antenna Placement & Installations
Macnamara
April 2010
Principles of Flight Simulation
Allerton
October 2009
Aircraft Fuel Systems
Langton et al
May 2009
The Global Airline Industry
Belobaba
April 2009
Computational Modelling and Simulation of Aircraft
and the Environment:
Volume 1 – Platform Kinematics and Synthetic
Environment
Diston
April 2009
Handbook of Space Technology
Ley, Wittmann Hallmann
April 2009
Aircraft Performance Theory and Practice for Pilots
Swatton
August 2008
Surrogate Modelling in Engineering Design: A
Practical Guide
Forrester, Sobester, Keane August 2008
Aircraft Systems, 3rd Edition
Moir & Seabridge
March 2008
Introduction to Aircraft Aeroelasticity And Loads
Wright & Cooper
December 2007
Stability and Control of Aircraft Systems
Langton
September 2006
Military Avionics Systems
Moir & Seabridge
February 2006
Design and Development of Aircraft Systems
Moir & Seabridge
June 2004
Aircraft Loading and Structural Layout
Howe
May 2004
Aircraft Display Systems
Jukes
December 2003
Civil Avionics Systems
Moir & Seabridge
December 2002
AIRCRAFT DESIGN
A Systems Engineering Approach
Mohammad H. Sadraey
Daniel Webster College, New Hampshire, USA
A John Wiley & Sons, Ltd., Publication
This edition first published 2013
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Library of Congress Cataloging-in-Publication Data
Sadraey, Mohammad H.
Aircraft design : a systems engineering approach / Mohammad H. Sadraey.
pages cm
Includes bibliographical references and index.
ISBN 978-1-119-95340-1 (hardback)
1. Airplanes–Design and construction.
I. Title.
TL671.2.S3136 2012
629.134′1–dc23
2012009907
A catalogue record for this book is available from the British Library.
Print ISBN: 9781119953401
Set in 10/12pt Times by Laserwords Private Limited, Chennai, India.
To Fatemeh Zafarani, Ahmad, and Atieh
For all their love and understanding
Contents
Preface
xv
Series Preface
xix
Acknowledgments
xxi
Symbols and Acronyms
xxiii
1
Aircraft Design Fundamentals
1
1.1
Introduction to Design
1
1.2
Engineering Design
4
1.3
Design Project Planning
8
1.4
Decision Making
10
1.5
Feasibility Analysis
12
1.6
Tort of Negligence
15
References
17
2
Systems Engineering Approach
19
2.1
Introduction
19
2.2
Fundamentals of Systems Engineering
20
2.3
Conceptual System Design
23
2.3.1
Definition
23
2.3.2
Conceptual Design Flowchart
24
2.3.3
Technical Performance Measures
25
2.3.4
Functional Analysis
26
2.3.5
System Trade-Off Analysis
27
2.3.6
Conceptual Design Review
28
2.4
Preliminary System Design
29
2.5
Detail System Design
30
2.6
Design Requirements
33
2.7
Design Review, Evaluation, and Feedback
34
2.8
Systems Engineering Approach in Aircraft Design
37
2.8.1
Implementation of Systems Engineering
37
viii
Contents
2.8.2
Design Phases
38
2.8.3
Design Flowchart
39
2.8.4
Design Groups
41
2.8.5
Design Steps
43
References
47
3
Aircraft Conceptual Design
49
3.1
Introduction
49
3.2
Primary Functions of Aircraft Components
50
3.3
Aircraft Configuration Alternatives
52
3.3.1
Wing Configuration
53
3.3.2
Tail Configuration
55
3.3.3
Propulsion System Configuration
55
3.3.4
Landing Gear Configuration
56
3.3.5
Fuselage Configuration
58
3.3.6
Manufacturing-Related Items Configuration
58
3.3.7
Subsystems Configuration
59
3.4
Aircraft Classification and Design Constraints
62
3.5
Configuration Selection Process and Trade-Off Analysis
68
3.6
Conceptual Design Optimization
74
3.6.1
Mathematical Tools
74
3.6.2
Methodology
76
Problems
86
References
92
4
Preliminary Design
93
4.1
Introduction
93
4.2
Maximum Take-Off Weight Estimation
94
4.2.1
The General Technique
94
4.2.2
Weight Build-up
95
4.2.3
Payload Weight
96
4.2.4
Crew Weight
97
4.2.5
Fuel Weight
100
4.2.6
Empty Weight
108
4.2.7
Practical Steps of the Technique
112
4.3
Wing Area and Engine Sizing
113
4.3.1
Summary of the Technique
113
4.3.2
Stall Speed
118
4.3.3
Maximum Speed
120
4.3.4
Take-Off Run
131
4.3.5
Rate of Climb
136
4.3.6
Ceiling
140
4.4
Design Examples
145
Problems
155
References
158
Contents
ix
5
Wing Design
161
5.1
Introduction
161
5.2
Number of Wings
164
5.3
Wing Vertical Location
165
5.3.1
High Wing
165
5.3.2
Low Wing
168
5.3.3
Mid-Wing
169
5.3.4
Parasol Wing
169
5.3.5
The Selection Process
169
5.4
Airfoil Section
170
5.4.1
Airfoil Design or Airfoil Selection
171
5.4.2
General Features of an Airfoil
173
5.4.3
Characteristic Graphs of an Airfoil
176
5.4.4
Airfoil Selection Criteria
182
5.4.5
NACA Airfoils
183
5.4.6
Practical Steps for Wing Airfoil Section Selection
188
5.5
Wing Incidence
195
5.6
Aspect Ratio
198
5.7
Taper Ratio
203
5.8
The Significance of Lift and Load Distributions
206
5.9
Sweep Angle
209
5.10
Twist Angle
223
5.11
Dihedral Angle
226
5.12
High-Lift Device
230
5.12.1
The Functions of a High-Lift Device
230
5.12.2
High-Lift Device Classification
232
5.12.3
Design Technique
235
5.13
Aileron
241
5.14
Lifting-Line Theory
242
5.15
Accessories
246
5.15.1
Strake
247
5.15.2
Fence
247
5.15.3
Vortex Generator
248
5.15.4
Winglet
248
5.16
Wing Design Steps
249
5.17
Wing Design Example
250
Problems
259
References
264
6
Tail Design
265
6.1
Introduction
265
6.2
Aircraft Trim Requirements
268
6.2.1
Longitudinal Trim
270
6.2.2
Directional and Lateral Trim
276
6.3
A Review on Stability and Control
278
x
Contents
6.3.1
Stability
278
6.3.2
Control
282
6.3.3
Handling Qualities
284
6.4
Tail Configuration
285
6.4.1
Basic Tail Configuration
285
6.4.2
Aft Tail Configuration
288
6.5
Canard or Aft Tail
294
6.6
Optimum Tail Arm
298
6.7
Horizontal Tail Parameters
301
6.7.1
Horizontal Tail Design Fundamental Governing Equation
301
6.7.2
Fixed, All-Moving, or Adjustable
304
6.7.3
Airfoil Section
306
6.7.4
Tail Incidence
308
6.7.5
Aspect Ratio
311
6.7.6
Taper Ratio
312
6.7.7
Sweep Angle
313
6.7.8
Dihedral Angle
313
6.7.9
Tail Vertical Location
314
6.7.10
Other Tail Geometries
315
6.7.11
Control Provision
316
6.7.12
Final Check
316
6.8
Vertical Tail Design
317
6.8.1
Vertical Tail Design Requirements
317
6.8.2
Vertical Tail Parameters
319
6.9
Practical Design Steps
329
6.10
Tail Design Example
331
Problems
336
References
340
7
Fuselage Design
341
7.1
Introduction
341
7.2
Functional Analysis and Design Flowchart
341
7.3
Fuselage Configuration Design and Internal Arrangement
345
7.4
Ergonomics
346
7.4.1
Definitions
346
7.4.2
Human Dimensions and Limits
348
7.5
Cockpit Design
350
7.5.1
Number of Pilots and Crew Members
351
7.5.2
Pilot/Crew Mission
353
7.5.3
Pilot/Crew Comfort/Hardship Level
353
7.5.4
Pilot Personal Equipment
354
7.5.5
Control Equipment
355
7.5.6
Measurement Equipment
356
7.5.7
Level of Automation
357
7.5.8
External Constraints
359
Contents
xi
7.5.9
Cockpit Integration
359
7.6
Passenger Cabin Design
360
7.7
Cargo Section Design
368
7.8
Optimum Length-to-Diameter Ratio
372
7.8.1
Optimum Slenderness Ratio for Lowest fLD
372
7.8.2
Optimum Slenderness Ratio for Lowest Fuselage Wetted Area
378
7.8.3
Optimum Slenderness Ratio for the Lightest Fuselage
380
7.9
Other Fuselage Internal Segments
380
7.9.1
Fuel Tanks
381
7.9.2
Radar Dish
385
7.9.3
Wing Box
386
7.9.4
Power Transmission Systems
387
7.10
Lofting
388
7.10.1
Aerodynamics Considerations
388
7.10.2
Area Ruling
390
7.10.3
Radar Detectability
392
7.10.4
Fuselage Rear Section
392
7.11
Fuselage Design Steps
394
7.12
Design Example
395
Problems
406
References
410
8
Propulsion System Design
413
8.1
Introduction
413
8.2
Functional Analysis and Design Requirements
414
8.3
Engine Type Selection
416
8.3.1
Aircraft Engine Classification
417
8.3.2
Selection of Engine Type
428
8.4
Number of Engines
436
8.4.1
Flight Safety
437
8.4.2
Other Influential Parameters
438
8.5
Engine Location
439
8.5.1
Design Requirements
439
8.5.2
General Guidelines
441
8.5.3
Podded versus Buried
443
8.5.4
Pusher versus Tractor
444
8.5.5
Twin-Jet Engine: Under-Wing versus Rear Fuselage
446
8.6
Engine Installation
448
8.6.1
Prop-Driven Engine
450
8.6.2
Jet Engine
452
8.7
Propeller Sizing
456
8.8
Engine Performance
461
8.8.1
Prop-Driven Engine
461
8.8.2
Jet Engine
462
8.9
Engine Selection
462
xii
Contents
8.10
Propulsion System Design Steps
464
8.11
Design Example
467
Problems
471
References
478
9
Landing Gear Design
479
9.1
Introduction
479
9.2
Functional Analysis and Design Requirements
481
9.3
Landing Gear Configuration
484
9.3.1
Single Main
484
9.3.2
Bicycle
485
9.3.3
Tail-Gear
487
9.3.4
Tricycle
487
9.3.5
Quadricycle
488
9.3.6
Multi-Bogey
489
9.3.7
Releasable Rail
489
9.3.8
Skid
489
9.3.9
Seaplane Landing Device
490
9.3.10
Human Leg
491
9.3.11
Landing Gear Configuration Selection Process
492
9.3.12
Landing Gear Attachment
493
9.4
Fixed, Retractable, or Separable Landing Gear
494
9.5
Landing Gear Geometry
497
9.5.1
Landing Gear Height
498
9.5.2
Wheel Base
503
9.5.3
Wheel Track
508
9.6
Landing Gear and Aircraft Center of Gravity
516
9.6.1
Tipback and Tipforward Angle Requirements
516
9.6.2
Take-Off Rotation Requirement
518
9.7
Landing Gear Mechanical Subsystems/Parameters
524
9.7.1
Tire Sizing
524
9.7.2
Shock Absorber
525
9.7.3
Strut Sizing
526
9.7.4
Steering Subsystem
527
9.7.5
Landing Gear Retraction System
527
9.8
Landing Gear Design Steps
528
9.9
Landing Gear Design Example
529
Problems
539
References
544
10
Weight of Components
547
10.1
Introduction
547
10.2
Sensitivity of Weight Calculation
549
10.3
Aircraft Major Components
553
10.4
Weight Calculation Technique
556
10.4.1
Wing Weight
559
Contents
xiii
10.4.2
Horizontal Tail Weight
561
10.4.3
Vertical Tail Weight
561
10.4.4
Fuselage Weight
562
10.4.5
Landing Gear Weight
563
10.4.6
Installed Engine Weight
564
10.4.7
Fuel System Weight
564
10.4.8
Weight of Other Equipment and Subsystems
565
10.5
Chapter Examples
565
Problems
570
References
573
11
Aircraft Weight Distribution
575
11.1
Introduction
575
11.2
Aircraft Center of Gravity Calculation
578
11.3
Center of Gravity Range
585
11.3.1
Fixed or Variable Center of Gravity
585
11.3.2
Center of Gravity Range Definition
586
11.3.3
Ideal Center of Gravity Location
587
11.4
Longitudinal Center of Gravity Location
590
11.5
Technique to Determine the Aircraft Forward and Aft Center of Gravity
598
11.6
Weight Distribution Technique
606
11.6.1
Fundamentals of Weight Distribution
607
11.6.2
Longitudinal Stability Requirements
609
11.6.3
Longitudinal Controllability Requirements
611
11.6.4
Longitudinal Handling Quality Requirements
613
11.7
Aircraft Mass Moment of Inertia
615
11.8
Chapter Example
620
Problems
624
References
630
12
Design of Control Surfaces
631
12.1
Introduction
631
12.2
Configuration Selection of Control Surfaces
637
12.3
Handling Qualities
638
12.3.1
Definitions
640
12.3.2
Longitudinal Handling Qualities
643
12.3.3
Lateral-Directional Handling Qualities
647
12.4
Aileron Design
654
12.4.1
Introduction
654
12.4.2
Principles of Aileron Design
656
12.4.3
Aileron Design Constraints
664
12.4.4
Steps in Aileron Design
669
12.5
Elevator Design
670
12.5.1
Introduction
670
12.5.2
Principles of Elevator Design
672
12.5.3
Take-Off Rotation Requirement
676
xiv
Contents
12.5.4
Longitudinal Trim Requirement
680
12.5.5
Elevator Design Procedure
683
12.6
Rudder Design
685
12.6.1
Introduction to Rudder Design
685
12.6.2
Fundamentals of Rudder Design
688
12.6.3
Rudder Design Steps
709
12.7
Aerodynamic Balance and Mass Balance
713
12.7.1
Aerodynamic Balance
715
12.7.2
Mass Balance
722
12.8
Chapter Examples
723
12.8.1
Aileron Design Example
723
12.8.2
Elevator Design Example
729
12.8.3
Rudder Design Example
738
Problems
745
References
752
Appendices
755
Appendix A: Standard Atmosphere, SI Units
755
Appendix B: Standard Atmosphere, British Units
756
Index
757
Preface
Objectives
The objective of this book is to provide a basic text for courses in the design of heavier-
than-air vehicles at both the upper division undergraduate and beginning graduate levels.
Aircraft design is a special topic in the aeronautical/aerospace engineering discipline.
The academic major of aeronautical/aerospace engineering traditionally tends to have
four main areas of expertise: aerodynamics, flight dynamics, propulsion, and structure.
A qualified aircraft designer employs all these four scientific concepts and principles and
integrates them using special design techniques to design a coordinated unique system;
an aircraft. Design is a combination of science, art, and techniques. A designer not only
must have sufficient level of knowledge in these four areas, but also needs to employ
mathematics, skills, experiences, creativity, art, and system design techniques. It is true
that aircraft design is not completely teachable in classrooms, but combining class lectures
with a semester-long aircraft design project provides the best opportunity for students to
learn and experience aircraft design.
Every aeronautical engineering discipline offers at least one course in aircraft
design or aerospace system design. The lack of an aircraft design textbook with
academic features – such as full coverage of all aspects of an air vehicle, aeronautical
concepts, design methods, design flowcharts, design examples, and end-of-chapter
problems – combined with the newly developed systems engineering techniques was the
main motivation to write this book.
In the past several years, I have talked to various aircraft design instructors and stu-
dents at conferences and AIAA Design/Build/Fly design competitions. I came to the
conclusion that the great design books published by such pioneers as Roskam, Toren-
beek, Nicolai, Stinton, and Raymer need more development and expansion. This is to
meet the ever-increasing need of universities and colleges for aircraft design education,
and of industries for design implementation. The new text should possess significant
features such as systems engineering approaches, design procedures, solved examples,
and end-of-chapter problems. This book was written with the aim of filling the gap for
aeronautical/aerospace engineering students and also for practicing engineers.
