Vertical Takeoff Rescue Amphibious Firefighting Tiltrotor
1
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Ryan Berg
Alex Carra
Michael Creaven
Joseph Diner
Meagan Hom
Ryan Paetzell
Jason Smith
Alan Steinert
James Tenney
Bryant Tomlin
2
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Purpose: Rescue Missions, and Aerial
Firefighting
Vertical Take Off and Landing (VTOL)
Amphibious Landing and Take Off
Range of 800 nm
50 passengers
Cruise of 300 kts
3
4
5
6
Weight
Quad-Rotor
Dual Fuselage
Conventional
8
7
6
5
4
3
1.82
1.41
2.1
2.52
1.15
1
1.16
1.07
1.11
1.1
1.09
2
1
1
1
1
1
2
6
12
8
6
4
3
57.23
2
3
3
3
3
3
39.29
3
1
1
1
2
1
36
1
3
2
1
1
2
111
168.23
55
94.29
74
110
Power Required (VTOL)
L/D (Cruise @ 10,000 ft)
Fuel Weight
Disk Loading
Max Bending Moment
CG Movement
Quantitative TOTAL
Ease of operation
Water stability
Rescue Operations
System complexity
Maintenance
Service Life
Qualitative TOTAL
OVERALL TOTAL
7
8
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Wing Span = 76.5 ft
Wing Area = 625 ft2
Cruise L/D = 12
Gross Takeoff Weight (VTOL) = 62,460 lb
Gross Takeoff Weight (short takeoff) = 70,000 lb
Fuel Weight = 10,175 lb
Max Power Available = 12300 shp
Max Speed = 333 kts
Rotor Diameter = 42 ft
Range = 800 nm
10
10000
4
Altitude (ft)
8000
10
3
5
6000
4000
2
2000
0
5
1
0
6
20
40
60
11
9
12
8
13
7
80
100
Time (min)
1 Vertical Takeoff (2100ft/min)
2 Transition(30sec)
3 Climb
4 Cruise
5 Glide down
6 Conversion
7 Landing
8 Vertical Takeoff (2100ft/min)
9 Transition
10 Climb
11 Cruise
12 Glide down
13 Conversion
14 Landing
120
140
14
160
180
11
Engine:
Rolls- Royce AE 1107C-Liberty Turboshaft
Shp
6150
Dimensions 78.1 by 43.2 in
Weight
971 lbs
14 stage compressor/2 stage high and 2 stage low pressure turbine
Self- lubricating system for VTOL operation
Maximum Thrust Produced: 77053 lb
Thrust Produced in VTOL: 6950 lb
(Rolls- Royce)
12
13
14
Airfoil
r/R
XN25
0.06
Radius
21 ft
XN18
0.12
Number of blades
6
XN12
0.5
Chord
2.97 ft
XN08
0.75
Twist
39 deg (-48 deg inboard/-30 deg outboard)
XN06
0.99
Material
Fibrous Composite with titanium alloy abrasion strip
Disk Loading
21.98 lb/ft2
Solidity
0.27
Figure of Merit
0.81
Propeller Efficiency
0.78
Coeff. Of Thrust
0.02
Tip Speed Ratio
1.78
Rotor airfoil sections and positions as
fraction of rotor length
(Romander)
15
•
•
NACA 65(216)-415 a =
0.5 airfoil was selected
for all three wings.
Airfoil Characteristics:
• High CL at 0 degrees AOA
• Maintains performance
characteristics even at low
Reynolds number
• Promotes laminar flow
over middle wing
Source: Raymer, Aircraft Design: A Conceptual
Approach
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Planform Area = 625 ft2
L/D in cruise was
calculated over a range of
wingspans using a
MATLAB drag estimation
program
Max obtainable L/D = 12
Corresponding wing span
= 76.5 ft
AR = 9.36
16
Speed = 300 knots
Altitude = 10000 ft
14
Design Point
L/D = 12
12
Lift to Drag Ratio

10
8
6
Maximum wing span based
on structural constraints
4
2
0
0
10
20
30
40
50
60
Wing Span (ft)
70
80
90
100
17
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A drag estimation
program provided by Dr.
Gur was used to verify
the calculated L/D for the
aircraft.
A basic VSP
representation of the
aircraft, as shown on the
right, was analyzed at
cruise conditions.
An L/D value of 12.5 was
calculated by the
program.
18
18
16000
16
14000
14
Power Available
12000
Rotor Tip Speed Limit
10000
Power (hp)
Lift to Drag Ratio
12
10
8
Altitude = Sea Level
Stall Speed
8000
6000
Power Required
6
Altitude = 10000 ft
4000
4
Altitude = 20000 ft
2000
2
0
Altitude = 30000 ft
0
50
100
150
200
250
Cruising Speed (knots)
300
350
400
0
50
100
150
200
250
Cruising Speed (knots)
300
350
400
19
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Roll rate 3.0o/sec per inch of
stick
Yaw rate 3.0o/sec per inch of
stick
Pitch rate 4.5o/sec per inch of
stick
A total of 6 in of stick
Aircraft is Dynamically stable
 7%MAC static margin
Flaperons 35% chord and are
deflected
The rudder is a symmetrical
airfoil (NACA-0012) and the
rudder is located at 25% chord
The horizontal tail is at an
incidence angle of -1.2o, and
the elevator is located at 35%
chord
Structural design of a
rib with the Flaperon
20
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Angle of Attack -8o to 12o
4
3
1
Lower
Control Limit 
 Maximum Cl with
Flaperons
Deflected
 Upper
Control
Limit
0.8
0.6
 Upper
Control
Limit
Lower
Control Limit 
0.4
2
0.2
Cl without
Flaperons 
Cl 1
Cm 0
-0.2
0
-0.4
-2
-20
-0.6
 Minimum Cl with
Flaperons Deflected
-1
-15
-10
-5
0

5
10
-0.8
15
20
-1
-20
-15
-10
-5
0
5
10
15
20

21
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Nacelles rotate at 3o per second
◦ Due to excessive vibrations in transition
◦ Pilot Safety
Nacelle limits are 0o to 100o
Transition
3000
2500
2000
Altitude (ft)

1500
1000
500
0
0
0.2
0.4
0.6
0.8
Time (min)
1
1.2
1.4
22
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Capable of takeoff in a sea state of up to 4.
Sea State 4
◦ Waves of 5 to 8 ft and wind speeds of 17 to 27 kts
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Determined through static wave analysis
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Design for Multiple Loading Conditions
◦ Aerodynamic Loading
◦ Vertical Takeoff/Helicopter Loads
◦ Water Loads
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Lightest Possible Structure
◦ Strut Braced Wing
◦ Composite Materials
◦ Wing Skin Tapering
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Simple Mediation of Aeroelastic Effects
◦ Static Wing Tip Deflection Constraints
24
4
Maneuver Envelope
3
Gust Envelope
Cruise Speed: 300 kts
Dive Speed: 405 kts
CLmax= 1.5
CLmin= -1.0
2
Load Factor, n
Maximum Load Factor: 3
Minimum Load Factor: -1
Dive Speed
Cruise Point
1
0
-1
-2
0
50
100
150
200
250
Velocity, V knots
300
350
400
450
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With resulting shear and moment diagrams for traditional wing
Shear-Vertical Takeoff
4
x 10
6
6
4
4
2
0
x 10
2
0
-2
-2
-4
-4
-6
-6
-30
-20
-10
0
10
Shear-Aerodynamic Loading
4
8
Shear, lb
Shear, lb
8
20
-30
30
-20
-10
Moment-Vertical Takeoff
5
x 10
10
5
10
20
30
20
30
Moment-Aerodynamic Loading
5
15
Moment, ft-lb
Moment, ft-lb
15
0
Wing Location, ft
Wing Location, ft
x 10
10
5
0
0
-30
-30
-20
-10
0
10
20
30
-20
-10
0
10
Wing Location, ft
Wing Location, ft
27
Vertical Takeoff
6
Moment, ft-lb
2
x 10
1.5
1
0.5
0
0
5
10
15
20
25
30
35
28
Vertical Takeoff
6
Moment, ft-lb
2
x 10
1.5
1
0.5
0
0
5
10
15
20
25
30
35
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Strut Braced wing divided into two sections due to
large stresses imparted on the center wing
Weight reduction from strut minimal due to center
wing stresses
Total SBW Weight: 5569 lb
Weight Reduction: 170 lb
Traditional Wing
Thickness Flange
Thickness Web
Area Wing Box
Wing Spar Weight
# of Stringers
Rib Spacing
Area Stringer
0.0475 ft
0.0390 ft
0.4191 ft2
5739 lb
4
2 ft
0.0035 ft2
Strut Braced
Wing (Outboard)
0.019 ft
0.018 ft
0.1812 ft2
1836 lb
4
2 ft
0.001 ft2
Strut Braced
Wing (Inboard)
0.095 ft
0.021 ft
0.7951 ft2
2835 lb
9
1.83 ft
0.0025 ft2
Strut
N/A
N/A
0.1 ft2
454 lb
N/A
N/A
N/A
30
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Wingbox idealized as rectangle
◦ Rear Spar placed at 54.3% chord
◦ Front Spar at 16.6% chord
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MATLAB routine written to vary size of structural
components
Combination of structural components yielding
the lightest structure selected
Wing skin thickness tapered linearly from
outboard wing root to tip
◦ Wing tip skin thickness 0.005 ft
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Materials◦ PEEK/IM Carbon Fiber (0°, 90°, ±45°)- Spars
◦ Cyanate Ester/HM Carbon Fiber (0°, 90°, ±45°)
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Wing Skin tapering
0.5 ft maximum tip
deflection constraint
Moments of inertia
for each
configuration
checked versus
contour plot
Weight Reduction:
327 lb
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Cross Sectional Area of Wingbox
◦ Root 0.3156 ft2
◦ Tip 0.2036 ft2
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Weight of Wingbox 2161 lb
Maximum Tip Deflection :
◦ 0.44772 ft (5.37 in)
Number of Stringers
Rib Spacing
Area of Stringers
Spar Thickness
Root Skin Thickness
Tip Skin Thickness
6
2.0 ft
2
0.01 ft
0.0075 ft
0.0233 ft
0.005 ft
33
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Structural Solidworks
CAD Model of
outboard wing
structure created
Finite Element
Analysis conducted
using ANSYS v.12
FEA results for tip
deflection compared
to MATLAB results
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35
Loading Conditions
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Aerodynamic Loading
◦ All weights assumed to be
equally distributed or a
point force
◦ Fuselage pinned at the
center of lift
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Water Landing
◦ Fuselage must have a zero
moment around the center
of gravity
◦ Buoyancy Force must
counteract the moment
force around the center of
gravity caused by the
weight distribution
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Water Landing
0.5
0
-0.5
-1
-1.5
0
10
20
30
Length (ft)
40
50
60
Bending Moment Diagram
4
0
3
Longeron Width (in)
3
0.0629
0.05
Bending Moment (ft-lb)
Bulkhead Spacing (ft)
Skin Thickness (in)
Aerodynamic Loading
1
x 10
-2
Final Calculated Values
Longeron Thickness (in)
x 10
1.5
Shear Force (lb)
Results
 Aerodynamic loading
caused much larger
moments
 Aero Load Factor=4.5
 Water Load Factor=8.34
 Aerodynamic loading case
turned out to be the
limiting case
Shear Force Diagram
4
2
-4
Water Landing
-6
Aerodynamic Loading
-8
-10
0
10
20
30
Length (ft)
40
50
60
37
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Can hold 50 passengers and 6
crew
Two side doors
Can carry standard 40x48 in
pallet
Uses new seats in V-22 from
Golan Industries/Army Division
Winches for cargo loading and
rescue
38
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Cockpit
 Utilizes electronic
controls
 Features HUD
Landing Gear
 Bicycle design
 66.3% TOGW on main
wheels at 35° off CG
Size
Front tire
Main tire
21 x 7.25-10
27.75 x 8.7514.5
Speed
(mph)
Max Load
(lb)
Max
Pressur
e (psi)
Max
width
(in)
Max
diam. (in)
Wheel
diam. (in)
PLY
Rating
210
6400
166
7.2
21.25
10.0
12
225
21500
320
8.75
27.75
14.5
24
1
2
3
4
5
6
7
8
9
10
11
12
Multifunctional Displays
HUD
Misc. Switches
Standby Flight Display
Flight director
Altimeter and Airspeed
Throttle Controls
Control Pedals
Control Stick
Engine Instrument Alert Sys.
ECS and Landing Gear Controls
Lights, Icing and Radio Controls
39
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Flight Control Sys.
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Electrical Control Sys.
◦ Triple redundant FCCs
◦ FADEC and AFCS
◦ Four Honeywell 90 kVA generators
◦ Hamilton Sundstrand Power System
T-62T-46-2 APU
◦ Single lead acid battery, which provides 24
VDC
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Hydraulic Control Sys.
Environmental Control Sys.
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Fuel System
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◦ Oxygen-enriched air for crew breathing is
provided at 6 stations
◦ GKN Aerospace deicing sys.
◦ 1000 gal of fuel in 18 tanks
◦ Fuel transfered between tanks to maintain
balance
◦ Aerial and ground capabilities
40
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Rescue
◦ Goodrich 42305 rescue winch 600 lb of lift and
200 ft of useable cable length
◦ Can carry 36 litters
◦ Aeromedical bay in left fuselage
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Firefighting
◦
◦
◦
◦
In water or hovering at 10 ft
1500 gal (750 gal in each fuselage)
American Turbine AT-309 pumps
released through a 20 x 35 in door
41
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Water Tank Tests
◦ Water Ingestion
◦ Sea State Tests
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H-V Diagram
Wind Tunnel Tests
◦ Aeroelastic Effects
◦ Interference Drag
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Downwash Verification
42
43
44
45
46
Cost
RDT&E +
Flyaway
$ 52,603,400
Operation and Maintenance (per
year)
Fuel Cost
$ 792,947
Crew Cost
$ 770,964
Maintenance
Costs
$ 1,277,213
TOTAL
$ 2,841,125
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Methods described in
Raymer
Based mainly off empty
weight, maximum
speed, the desired
production output in
five years, number of
flight test aircraft,
cruise velocity and take
off gross weight
49
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Addition of a strut can reduce structural
weight but also increases aerodynamic drag
Traditional and Strut Braced wings were
designed to satisfy the loading conditions
specified
Weights for each design compared to judge
the benefits
51