Preliminary Design Review
Miguel Alanis
Tim Block
Becca Dale
Joseph Fallon
Purdue University
AAE 451 Senior Design Team 1
Aaron Mayne
Jason Olmstead
Adeel Soyfoo
Sarah Weise
1
Review of Concept and Market
Multi-functional, Rugged, Non- petroleum fueled Airplane
to serve:
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Air charters, governments (surveying, mail), medical transport, or
supplies delivery companies
Operates in rural, developing areas of the world such as
Australia, South America, or even rural parts of Canada
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AAE 451 Senior Design Team 1
2
Design Requirements
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Payload:
 2000 lbs, or
 10 passengers
Range: 1200 nm
 One-way full load
Takeoff Field Length: 2000 ft
Service ceiling: 25000 ft
Max speed: 250 kn
Weight: ≤ 12,500 lbs
Acquisition Cost: < $2.5 million
Alternate Fuel Source
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AAE 451 Senior Design Team 1
3
Design Concept
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Main Features:
•
•
•
•
•
•
•
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Tapered Wing
High Wing with Strut
Support
T-Tail
Non Pressurized Cabin
Fixed Landing Gear
66” Cargo Door
4 ft Ground Clearance
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4
Design Concept
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AAE 451 Senior Design Team 1
5
Concept Configurations
1
4
2
1. 10 seats
3
2. Executive
3. Combination seats/shipping container
4. 3 shipping containers (LD-3 Standard)
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AAE 451 Senior Design Team 1
6
Sizing of Aircraft
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TOGW: 12,432 lbs
W/S: 31.3 lb/ft2
P/W: 0.0875
AR: 9
λ = 0.3
Acquisition cost: $3.24 million
Operating cost: $424.64/hr
Sizing done using FLOPS Flight Optimization System,
Release 6.11(internal cost model not used)
Calibrated Using Cessna Grand Caravan

TOGW error ≈ 2%
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7
Constraint Analysis
Carpet Plot Design Points Summary
Aspect Ratio 9
0.09
AR
13000
0.095
12500
0.1
TOGW (lbs)
12000
W/S
P/W
T/W
GTOW
8
31.3
0.091
0.3140392
11360
9
31.3
0.0875
0.3019608
11317
10
31.3
0.086
0.2967843
11343
11
31.3
0.086
0.2967843
11448
0.105
11500
Stall
FAR 23 GTOW max
11000
Sea level Takeoff
10500
Climb Rate 5 ft/s, @
Sea Level, Takeoff
Flight
10000
15
25
35
45
Wing Loading (lbs./sq.ft)
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AAE 451 Senior Design Team 1
8
Compliance with Design Requirements
Goal
Threshold Value
Payload (lbs)
Range (nm)
2000
1200
≥ 1500
≥ 900
2000
1200
TO Field Length (ft)
≤ 2000
≤ 5000
3295
≤ 12,500
12,432
≥ 250
≥ 184
241
Acq. Cost ($US2006 millions) ≤ $2.5
≤ $3.5
$3.24
TOGW (lbs)
Max Speed (knots)
DOC ($US2006)
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≤ $500/hr
AAE 451 Senior Design Team 1
$424/hr
9
Structure - Wing and Tail
Main and Rear Spar
Rib Members
Stringers
Fuel tanks
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AAE 451 Senior Design Team 1
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Structure - Fuselage
Length = 38 ft
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Forward Section used for main payload/passengers
Aft Section for stability purposes
2 main keel beams running longitudinally in forward
section, used to support heavy payload
12 transverse square ribs/frames along fuselage length
16 longitudinal stringers/longerons
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Structure - Landing Gear
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50.76 deg
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Non-retractable
Tricycle Layout
2024-T6 Aluminum
Need to carefully choose
specific tires (depends on type
of runway landing)
Tread = 10.54 feet
Wheelbase = 17 feet
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AAE 451 Senior Design Team 1
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Structural Material Selection
Aircraft
Section
Material
Selection
Wing/Tail
Structure
(Spars, ribs,
stringers)
Aluminum
Alloy 7075
or 7150
Fuselage
Structure
(Keel beams,
ribs,
longerons)
Aluminum
Alloy 6061
or 7075
Wing/tail Skin
& Fuselage
skin
Aluminum
Alloy
2090-T83
~77,000
psi
Landing
gear
Aluminum
Alloy
2024-T6
60,000 –
70,000
psi
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Yield
Strength
~70,000
psi
~70,000
psi
Approximate
Cost
Advantages
Disadvantages
$4.00 –
5.00/lb
Strength, resists
corrosion.
commonly
used, low cost
Fatigue life
$4.00 –
5.00/lb
Strength, resists
corrosion.
commonly
used, low cost
Fatigue life
Up to
$10.00/lb
Very high
strength, resist
corrosion,
weight
reduction
$3.00/lb
Strength, resists
corrosion.
commonly
used, cheap
AAE 451 Senior Design Team 1
relatively new
material,
more
expensive
Fatigue life
13
Aerodynamics
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Airfoil NACA 4412 has the Highest cLmax
Slotted Flap on Entire Wing
CLcruse=0.4
CL@L/Dmax =0.6
CLmax=2.4
Wing Area=400 ft2
Taper Ratio=0.3
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Drag Polar
3
2.5
2
CL
1.5
Clean (whole aircraft)
Dirty (whole aircraft)
1
0.5
0
0
0.05
0.1
0.15
0.2
0.25
0.3
-0.5
-1
CD
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AAE 451 Senior Design Team 1
15
Weight & Balance
Center of Gravity Envelope Diagram
12000
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C.G. Location:18.5ft
Weight Breakdown:
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Gross Weight
11000
Payload: 2000 lbs
Crew: 410 lbs
Empty Weight: 6,113 lbs
Fuel Weigh: 3,903 lbs
10000
9000
8000
7000
6000
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0.55
0.6
0.65
c.g. location, %M.A.C. from datum
Green loading plane, Blue unloading plane
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Stability
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AAE 451 Senior Design Team 1
AC of wing
CG location
Neutral Point
AC of Vertical Tail
AC of Horizontal Tail
17
Stability
Wing
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Static Margin (SM): 16.1%
Neutral Point: 19.6 ft
Aerodynamic Center 15.0 ft
Leading Edge location 13.3 ft
Trailing Edge location 20.0 ft
Vertical Tail
distance from AC of v-tail to AC of wing
Horizontal Tail
32 ft
v-tail volume coefficient 0.0665
distance from AC of h-tail to AC of wing
h-tail volume coefficient 0.69
Area of vertical tail 49.4 ft2
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34 ft
AAE 451 Senior Design Team 1
Area of horizontal tail 53.5 ft2
18
Performance
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Optimal Performance
Values
Parameter
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Value Units
Vcruise
170
knots
Vstall
61
knots
Vmaxgliderange
148
knots
γmaxclimb
15.3
deg
46
ft/s
Climb
ratemax
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V-n Diagram
gust
normal
AAE 451 Senior Design Team 1
19
Performance
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Operating Envelope
Constant
energy
heights
Stall limit
Ps=0
q limit
Cruise
Height
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AAE 451 Senior Design Team 1
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Engine
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Pratt & Whitney Canada PT6A-67D
Delivers up to 1271 hp (1250 hp required)
High power to weight ratio
High reliability
Low fuel consumption (sfc at full power: 0.546 lb/hp/h)
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21
Propeller & Thrust produced
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4-bladed aluminum propeller
Integrated design lift coefficient cL = 0.500
Activity factor 140
Diameter 110 in
Rotational speed 1700 rpm
Blade Tip Speed Ma = 0.78
flight condition
static
take-off
climb
cruise
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thrust available [lbf] thrust required [lbf]
3462.20
3001.10
1360
2482.70
750
1840.10
810
AAE 451 Senior Design Team 1
22
Cost
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Acquisition cost
Our Aircraft:
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Grand Caravan: PC-12:
Acquisition Cost:
$3.24 million
$1.75 million
$3.4 million
RDT&E:
$415 million
$226 million
$421 million
Flyaway Cost:
$1.17 million
$618,000.00
$1.3 million
DOC
Our Aircraft:
DOC ($/hr):
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$424.64
Grand Caravan: PC-12:
$332.95
AAE 451 Senior Design Team 1
$370.00
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Conclusion
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Will concept be successful?
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Feasible design
New concept will give market advantage
Derived versions could offer more cabin space but
shorter range
Competition from remodeled petrol fueled aircraft
Significant “open” issues
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Stall characteristics (T-tail)
Finalize wing design (flap size)
Improve Takeoff and Landing Performance
Develop Bio-fuel kit for PT6A turbine
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Questions?
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Acquisition Cost Breakdown:
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Power series function
Depends on wing span, AR, GTOW, thrust, cruise
speed, and range
ln(cost)= {constants}*{vector of ln(parameters)}
Real Cost:
Caravan 675
Beech King Air C90GT
Beech 1900D
Avanti II
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Our Cost Model:
$1.8 million
$1.9 million
$2.95 million
$2.86 million
$5.4 million
$5.59 million
$6 million
$6.1 million
AAE 451 Senior Design Team 1
26
RDT&E and Flyaway Costs:
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DAPCA model outlined in Raymer’s text
Did not give an accurate acquisition cost
Did give accurate percentages for the RDT&E
and Flyaway cost break down
RDT&E = 0.64*(Acquisition Cost)
Flyaway = 0.36*(Acquisition Cost)
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AAE 451 Senior Design Team 1
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DOC:
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DAPCA model outlined in Raymer’s text
Did not give an accurate DOC, but calculated
value was off by a consistent percentage
Calculated our DOC at current fuel prices
Adjust DOC according to:
real DOC = 0.64*(calculated DOC) 
Added in addition costs due to increased fuel
price
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AAE 451 Senior Design Team 1
28
Cost Assumptions:
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RDT&E and Flyaway Costs:
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200 aircraft to break even
2 flight test aircraft
Avionics are 7% of the flyaway cost
DOC:
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1000 FH/year
1 MMH/FH
Properties of our fuel are the same as kerosene
Current fuel: $2.40 1/gal, FT: $7.40 1/gal
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Constraint Analysis
0.25
Sealevel Takeo ff
5000ft altitude Takeo ff o n a Ho t Day
Power to Weight Ratio (hp/lb)
0.2
Sealevel Cruise
10000 ft altitude cruise
0.15
Sealevel Climb
10000 ft altitude climb
0.1
15000 ft cruise
Emergency Landing at 5000ft altitude o n an Icy Runway
0.05
Emergency Landing at 5000ft altitude o n an Icy
Runway With Fuel Dump Optio n
Emergency Landing at 5000ft altitude o n a Ho t Day
0
0
10
20
30
40
50
60
70
Wing Loading (lb/ft^2)
80
Co mpariso n A ircraft Design P o ints
Desing P o int
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Sizing
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Method
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FLOPS
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Input parameters
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T/W, converted from P/W with prop numbers
Geometric Characteristics
Mission and Performance Constraints
Engine Definition
Wing Definition
Calibration
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Cessna Grand Caravan
 TOGW error aprrox. 2%
AAE 451 Senior Design Team 1
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