1. Aircraft Conceptual Design
Izhar H Kazmi
Assistant professor
Kazmi_izhar@yahoo.com
Department of Aeronautics and Astronautics
Institute of space Technology
Islamabad, Pakistan
FEB 2019
2. 03/03/25 2
What You have to do to start with
List of Design Requirements ( mission profiles) will be provided to you
Each Aircraft to be designed is a separate Project
You will work in group of two/single(if you cant find or don’t want to work with a
partner)
Select an a/c from list
Select a reference aircraft which is close to your a/c
4. Engineering (Design) Isn’t Done For Its
Own Sake, It Is Practiced in a Context
The “Design Onion”
Engineering
(Design
&
Analysis)
Manufacturing
Customers
(Operational
Considerations)
Marketing
Societal
Needs &
Implications
Environmental
Impact &
Consequences
Politics
Resource
Availability
Theology
Philosophy
• Why are we here?
• Why are we doing
this ?
Economics
Business
&
Finance
Nationalism
Tribalism
Tastes
&
Fashion
History
“Everything in this world is connected to everything else”. Think “system of systems”.
5. Perspectives on Airplane System Design
(With the specific or implicit objective of improving the air transportation system.)
Traditional System View A “System of Systems” Approach
Airplane
System
Wing
Sub-system
High-Lift
Sub-system
Flaps
Flap
Actuators
Somewhere
down here is
a sub-system
an individual
designer can
deal with.
Design requirements,
objectives and
constraints
Life, the
Universe
And
Everything
World Economic
System
World Transportation
System
New Airplane
System ?
Alternative
System ?
A Suite of
Systems ?
If one doesn’t
consider the
whole system,
jumping to the
conclusion that a
particular sub-
system is the
best solution
may result in a
dumb or futile
design effort.
Design requirements, objectives, and constraints.
?
6. Your case Ref
aircraft in
combination
with concept
sketch if you
want to make
one
Technology:
Yesterday: heavy,
cheep, under
perform
Today
Future: light,
expensive, exceed
performance
Example : next
slide
How Your text Book is Organized;
DESIGN PROCESS YOU WILL FOLLOW
Requirements:
Provided to you
as mission
profiles
7. Chapter 2
Overview of Design Process
• Requirements
• Phases of Aircraft design
• Conceptual Design Process
12. The Conceptual/Preliminary “Design Process”
Design
Requirements
(“musts”)
&
Objectives
(“wants”)
“ A problem properly posed
is half solved”
Aerodynamics
Structures
Propulsion
Systems
Controls
Software
Manufacturing
Trade
Studies
&
Testing
Integration
What would
happen if:
• Requirements change
• Constraints change
• Change assumptions
Resources
Marketing
Other
external
factors
Meets
DR&Os ??
Yes !
No !
Reject ?
or
Proceed
The
Design
13. Your case Ref
aircraft in
combination
with concept
sketch if you
want to make
one
Technology:
Yesterday: heavy,
cheep, under
perform
Today
Future: light,
expensive, exceed
performance
Example : next
slide
DESIGN PROCESS YOU WILL FOLLOW
Requirements:
Provided to you
as mission
profiles
17. 03/03/25 17
What You have to do to start with
List of various aircraft provided with requirements
Select an a/c from list
Expression of interest (From my side) Ref end of your book
Quotation (From your side)
Select a reference aircraft which is close to your a/c
Show comparison of your a/c and reference a/c with % differences
19. A Good Aircraft
• Aerodynamically efficient, including propulsion integration (streamlining!)
• Must balance near stability level for minimum drag
• Landing gear must be located relative to cg to allow rotation at TO
• Adequate control authority must be available throughout flight envelope
• Design to build easily (cheaply) and have low maintenance costs
• Possibility of upgrades
• Today: quiet, low emissions, Fuel efficient, less structural weight
20. A Key Thought on Design
You may never design an airplane, but:
• “shaping up” the problem, figuring out the right questions
• collecting the key information
• making quantitative/qualitative trade studies
- pro/con tables with quantitative ranking
- carpet plots/parametric analysis
• using engineering-based analysis to make decisions
• recognizing social, legal and financial considerations
• selecting and refining the preferred concept
These are universally valuable, this is engineering
Typically taught only in design?
03/03/25 AE 281: Chapter 5 (Part A) 20
22. Some Basic “Laws” of Airplane Design
• Innovation for mere innovation’s sake can be a great
waste of time (and money) – never invent anything if you don’t
have to
• You never get something for nothing – someone,
somewhere always pays for lunch
– While the laws of economics are somewhat malleable, the
laws of physics are not; thus
– “If it looks good, it will fly good” is a myth that is sometime
true
• Simplicity is the essence of true elegance – it can
also save weight and/or cost
• If you can’t build it, you can’t sell or use it
• They who control the purse strings control the policy
– to avoid exercises in futility, learn how to close a business case
• Grand concepts are easy – The devil is always in the details !
23. A completed airplane in many ways is a compromise
of the knowledge, experience and desire of the many
engineers that make up the various design and
production groups of an airplane company.
It is only being human to understand why the
engineers of the various groups feel that their part in
the design of an airplane is of greater importance and
that the headaches in design are due to the
requirements of the other less important groups.
This cartoon “Dream Airplane” by Mr. C. W. Miller,
Design Engineer of the Vega Aircraft Corporation,
indicates what might happen if each design vs.
production group were allowed to take itself too
seriously.
Conflict Among Aircraft Design
Special Interest Groups
24. Dream Airplanes
(One Person’s Dream may be Another’s Nightmare)
..after dining with Airbus.. Boeing
Sauna Piano lounge
Payloads
Marketing
Weights
Manufacturing
Aft
Super
computer
Flight Controls
Aerodynamics
Structures
Noise
Propulsion
J.H. McMasters (circa 1985)
Schizophrenia
Fwd
Super
computer
The Boeing Company
Hecho en México y Chile
25. Messerschmitt Me 262 First operational jet fighter Arado Ar 234 First operational jet bomber
Heinkel He 162 Messerschmitt (Lippisch) Me 163
Junkers Ju 287 Swept-forward wing jet bomber
Messerschmitt P. 1101
Horton Ho 229
German Aeronautical Progress (1944-45)
Heinkel He 280
DFS 228
26. Focke-Achgelis Fa 269 Tilt Rotor
Blohm und Voss P. 188 W-wing bomber
Focke-Wulf Ta 183
Focke-Wulf Ta
283
Ramjet fighter
Lippisch P.13a Delta wing fighter
Sänger Antipodal Bomber
Blohm und Voss P.202
Oblique-wing fighter
Messerschmitt variable sweep fighter
German Aeronautical Progress to 1945
http://www.luft46.com/
28. Fokker’s Rule: “If it looks good, it will fly good”
is a myth that is sometime true…..
McDonnell XP-67 “Moonbat” Dornier Do 335 “Anteater”
A-10 “Warthog”
To disparage a camel as a “horse
designed by committee” is to completely
ignore the obvious advantages of the
camel over the horse in the environment
in which the camel is intended to operate.
Antonov An 2
(over 12,000 built since 1947)
Boeing F-32 “Angry Frog”
32. Airplane Design Taxonomy
• Conceptual Design
• Preliminary Design
• Detail Design
• Design Support
Design Objectives
• An optimized system, defined in
sufficient detail to
– Offer to customers for sale
– Allow performance, cost, etc. guarantees
to be written into legally binding contracts
• A complete design [the “drawings” ]
including manufacturing
requirements, etc. that meets
guarantees and allows production of
the required hardware
• Derivatives, modifications, up-
grades, in-service deficiency
corrections, etc.
• A “configuration concept” that
appears to meet requirements
and constraints – as a system.
![Airplane Design Taxonomy
• Conceptual Design
• Preliminary Design
• Detail Design
• Design Support
Design Objectives
• An optimized system, defined in
sufficient detail to
– Offer to customers for sale
– Allow performance, cost, etc. guarantees
to be written into legally binding contracts
• A complete design [the “drawings” ]
including manufacturing
requirements, etc. that meets
guarantees and allows production of
the required hardware
• Derivatives, modifications, up-
grades, in-service deficiency
corrections, etc.
• A “configuration concept” that
appears to meet requirements
and constraints – as a system.](https://image.slidesharecdn.com/chapter12-acdesignintro-250303151019-f1418e97/85/Chapter-1-2-Aircraft-Design-Intro-ppt-32-320.jpg)