HokieWorksPresents…

Ben Cheyne Mike ShermanJared Collins Amy TharpDrew Diefenderfer Nikolai VozzaMichael LaPierre Jason WallaceChris Legendre Jon Worrell

April 26, 2005 AOE 4066

Phoenix Gunship

Phoenix Gunship

Phoenix 3-View

Weapons Selection“A weapon for every target”

Target Weapon

Paveway II LaserGuided Bomb

Buildings

105mm CannonLight Armored Vehicles

40mm Cannon/105mm Cannon

Trucks

40mm Cannon/105mm Cannon

AAA

40mm CannonMANPADS/Personnel

40mm Cannon

Key Features:• 40mm M2A1 is located on a turret near the nose of the aircraft• Fires high explosive-plugged (HE-P) rounds ideal for personnel• Target Acquisition Designation Sight (TADS) i.e. “what you see is what

you get” (currently used in the AH-64 Apache)• Auto-feed loader feeds the 40mm shells into the gun via belt drive• All Light Level Television and Infrared Detection System provide for

target detection.

40mm GuidanceTarget Acquisition Designation Sight (TADS)

105 mm Cannon

“The most cost effective persistent firepower weapon”

- AC-130H pilot Col. Scott Stephens (ret.)

http://www.fas.org/man/dod-101/sys/ac/equip/m102.htm

Benefits:

•Large Coverage area

•Cannon concealed inside fuselageof aircraft – allowing cabinpressurization

•Advanced AAQ-26 InfraredDetection Set (IDS) – allows forsimultaneous target tracking

•Low cost - $500 per round

How the 105mm Works

Cannon Layout

Laser Guided Munitions

GBU-12 Paveway IITargets

•Mobile Hard

•Fixed Soft

•Fixed Hard (buildings)

Benefits

•Laser Guided – Increased Precision

•8 nm range

•Light at 500 lbs

•$19,000 unit cost – Cost Effective

Guidance System

•Pave Tack AN/AVQ-26

Viper Strike BAT Munitions

•Unpowered stable glider

•Autonomous Weapon

•Operates in adverse conditions dayand night

•Designed to be dropped directly ontotargets

•Perfect for loitering

Weight Analysis

Total Weight = 15,568 lbs

88 lbsViper Strike (2)

1,600 lbsPaveway II (2)

5,280 lbs105mm Ammo (120)

4,800 lbs105mm Cannon (1)

2,000 lbs40mm Ammo (400)

1,800 lbs40mm Cannon (1)

WeightItem (Quantity)

Survivability

• Plot shows the amountthat can be spent onsurvivabilityenhancements(systems/add-ons) asthe survivability (Pkincreases)

Assumptions:Lost aircraft are replaced at cost

Survivability

• Shows that as the number of planes boughtincreases the amount of money that can bespent on survivability decreases (becauselosing aircraft becomes less importantcompared to the increased costs due tosurvivability improvements)

• Around $2 million should be spent onimprovements based on our aircraft costpredictions

Survivability

< $500,000< 10002 x Fire Detection and Extinguishing Systems

$56,0002,000Titanium Armor under Ammunition Stores

$56,0002,000Titanium Armor under Pilot

< $30,000< 500Chaff and Flare

$73,000< 50Extra Flight Control System

$1,300,000< 50Large Aircraft Infrared Countermeasures (LAIRCM) system

Cost, $Weight, lbsEnhancements

Sizing

• Using equations from Raymer and requirementsfrom the RFP we created carpet plots andconstraints for those plots to size the aircraft.

• The landing distance requirement is dependenton two variables, Clmax and the wing loading,W/S.

• It was assumed that with one engine out, andone engine with a thrust reverser the the landingdistance would increase by a quarter.

Sizing

0

1000

2000

3000

4000

5000

6000

7000L

an

din

g D

ista

nce, f

t

Clmax

W/S, lb/ft^2

70

80

90

100110

120130

2 2.1 2.2 2.3 2.4 2.5 2.6

RFP, landing dist 5000 ft

Sizing

• A wing loading of 100 lb/ft2 and Clmax of2.1 are both reasonable values.

• Figure 2 shows the constraint lines for ourthe landing distance and the 1.5 gmaneuver at 20,000 ft (probably turning).

Sizing

Sizing

• Green dot represents sizing based on the givenconstraints, value normalized to take-offconditions

0.3

T/W

10069,250

W/S, lb/ft^2TOGW, lbs

StructuresMaterial Layout

Carbon/Epoxy

Titanium

Aluminum/Lithium

E-Glass/Epoxy

StructuresMaterial Layout

Corrosion resistant and highstrength

GrayTitaniumWing Joint Connections

SurvivabilityGray

TitaniumShielding below WeaponStores

Pilot protection/survivabilityGrayTitaniumShielding below Pilot

Other Considerations

BlackCarbon Fiber / EpoxyFuselage

BlackCarbon Fiber / EpoxyControl Surfaces

Lightweight, excellent electricalcharacteristics

GreenE-Glass / EpoxyNose / Radome

BlackCarbon Fiber / EpoxyHorizontal Tail

Heat resistant (near engines),lightweight, strong

GrayTitaniumVertical Tail & Fin Skin

Tough, lightweightBlue

Aluminum-lithiumLeading Edges (horizontaltail, wing, fin)

Lightweight, strong, fatigue/corrosionresistant

BlackCarbon Fiber / EpoxyWing (skin & spar)

ReasonsColorMaterialComponent

StructuresMember Layout

• Wing– 3 spar wing design for redundancy

– Ribs placed on each edge and middle of eachof the three control surfaces to providetorsional stiffness and connection points forpayload and control surfaces

StructuralMember Layout

• Horizontal Tail– 3 spar setup for

redundancy (like wing)

– Ribs placed every 2 ft

• Vertical Tail– 2 spars

– Titanium skin fortemperature resistancenear engines

StructuresMember Layout

• Fuselage– 3 bulkhead compartments separating pilot

area, 40 mm gun area and 105 mm gun areaproviding firewalls between sections andallowing individual pressurization of sections

– 11 transverse supports (including thebulkheads) placed in critical areas (around105 door opening, at door connections,wing/fuselage intersection)

StructuresComplete Layout

StructuresV-n Diagram

Vc Vd

StructuresLanding Gear

0.1090.24Outer Radius (ft)

0.1090.02Thickness (ft)

0.1500.1156Volume (ft3)

SolidHollow

• Making the members hollowcylinders reduces the amount ofmaterial needed, thus reducingmaterial costs and weight.

Landing Gear

Front Landing Gear

Back Landing Gear

Tip over Angles

Aerodynamics

• Take-off Lift Coefficient

Where TOP is take-off parameter at RFP constraint of 5000 ft and sigma isthe density ratio.

Calculated at sea level, lowest possible lift coefficient

= 1.333

= 1.613

Maximum take-off lift coefficient is 1.21 times the take-off lift coefficient

( ) ( )WTCTOPSW

TOLσ)(=

TOLC

MAXTOLC

Lift Coefficient

• Landing Lift Coefficient

Worst situation is stated in the RFP where the wing loading at landing is 80percent the maximum take-off wing loading. Therefore the landing wingloading is equal to 80.

Based on the landing distance of 5000 ft given in the RFP, the lowestmaximum lift coefficient is 1.45. The need for high lift devices are minimal.

( ) aL

Landing SCS

WS +⎟⎟⎠

⎞⎜⎜⎝

⎛=

max

1*80

σ

Flap Analysis

• Used both single-slotted flaps and Fowler flaps to analyze the increase inlift coefficient at take-off and landing

for two different flaps

• For take-off it is about 60%-80% of those at landing

1.51.05Fowler

1.30.91Single-slotted

For LandingFor Take-off

..cos9.0maxmax LH

ref

flappedlL S

SCC Λ⎟

⎟⎠

⎞⎜⎜⎝

⎛Δ=Δ

maxlCΔ

0.7120.496Fowler

0.6170.432Single-slotted

at landing at take-offmsxLCΔmsxLCΔ

t/c ratio based on Korn Equation

0

0.05

0.1

0.15

0.2

0.25

0.3

0 15 30 45 60

sweep, deg

max

imu

m t

/c r

atio

M = 0.85

M = 0.8

M = 0.75

M = 0.68M=0.7

• Sweep at quarter chord = 15. 9º•Using the RFP requirements to cruise at an altitude of at least 30,000 ftwith a speed no slower than 400 knots or Mach of 0.68•The thickness to chord ratio can be no greater than 0.22.

Λ−

Λ−

Λ=

32 cos10coscosLA

DD

CctK

M

Airfoil Selection

• Based on NASA SupercriticalAirfoils

– Design lift coefficient between 0.6 and0.7

– Thickness to chord ratio between 0.10and 0.14

• Supercritical airfoils which wereanalyzed in more depth

– SC(2)-0612 and SC(2)-0714

0 0.2 0.4 0.6 0.8 1

0 0.2 0.4 0.6 0.8 1

Pressure Distributions-1.5

-1

-0.5

0

0.5

1

1.5

2

0 0.2 0.4 0.6 0.8 1

Cp

-1.5

-1

-0.5

0

0.5

1

1.5

2

0 0.2 0.4 0.6 0.8 1

Cp

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

0 0.2 0.4 0.6 0.8 1

Cp

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

0 0.2 0.4 0.6 0.8 1Cp

Supercritial airfoils SC(2)-0612 and SC(2)-0714 respectively at angle of attack of 0degrees and Mach of 0.7

Supercritical airfoils SC(2)-0612 and SC(2)-0714 respectively at angle of attack of 2 degrees and Mach of 0.7

0.016730.01410.01679Total

0.0004900.00047Landing Gear

0.000260.000240.00025Pylons

0.0015100.00145Flaps

00.000310.00032Paveway II

00.000330.00035Viper strike

0.000880.000800.00085Vertical Tail

0.002010.001830.00193Horizontal Tail

0.006310.005760.00608Fuselage

0.005280.004830.00509Wing

LandingCruiseTake-Off

Drag Breakdown for Phoenix

Drag Polars

• Assuming a parabolic drag polar, using

Ae

CCC LDoD π

2

+=

0

0.5

1

1.5

2

0 0.05 0.1 0.15 0.2 0.25

CD

CL

L/D)max = 11.1 @ CL = 1.7

Drag polar for Take-off conditions

Drag polar at cruise conditions Drag polar at landing conditions

00.10.20.30.40.50.60.70.80.9

1

0 0.02 0.04 0.06 0.08 0.1

CD

CL

L/D)max = 19.3 @ CL = 0.6

2.19.33Landing

0.619.3Cruise

1.711.1Take-off

CLL/Dmax

Lift to Drag ratios:

0

0.5

1

1.5

2

2.5

0 0.1 0.2 0.3 0.4

CD

CL L/D)max = 9.33 @ CL = 2.1

Stability & Control

Main concerns:– T-tail sizing

– Control surface sizing

– Stable or Unstable?

– Engine out analysis

Tail and Controls Sizing

• T-tail selected in order toremove the elevatorsfrom the downwash of thewing

• Several iterations ofsizing resulted indramatically increasingtailspan well beyond thenacelles

8.914.01Ctip (ft)

9.908.91Croot (ft)

0.900.45Taper Ratio

45.023.6Sweep (deg)

1.555.5Aspect Ratio

7.2335.53Span (ft)

136.82229.55Area (ft)

Vertical TailHorizontal Tail

15.43075Rudder

34.13585Elevators

19.32530Ailerons

Area (ft2)% Chord% Span

Stability

VLMpc & JKayVLM

– Takeoff

– Cruise

– Loiter

– Landing

SM = 39% (fully loaded)

Very stable!

Will handle large 105mm recoilforce!

Engine Out

Engine Out – LDstab (takeoff)– 5º bank– 11.96º sideslip– 3.61º rudder deflection– 13.35º aileron deflection

Weights

Major Component Breakdown

• TOGW = 69,984 lbs– In range of currently used gun ships

• Fuel = 20,903 lbs

• Weapons = 15,000 lbs

• Crew = 1,000 lbs

Weights

Weights

Weights Savings

• Mix of composite materials and standardaircraft materials used

• Save more than 2,300 lbs by usingcomposites

Weights

Weight Savings

• Greatest weight reduction in fuselage andwings

Weights

CG Travel

• Placed fuel and weapons in ideal locationto reduce CG travel during mission– 40 mm cannon acts as counterbalance to

engines

– 105 mm cannon placed towards center ofaircraft

– Missiles and bombs on hard points on wings

Weights

CG Travel• 300 cubic feet of fuel in wings

– Placed around wing main wing strut

• 145 cubic feet located in two tanks oninside of fuselage as close as possible tocenter of plane

• CG moves only 0.4 ft or 4.37% MACduring mission

Weights

CG Travel Throughout Mission

-60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60

CG Location % MAC

Mis

sio

n P

oin

t

Fully Loaded

_ Fuel _ Weapons

No Fuel No Weapons

_ Fuel All Weapons

No Fuel All Weapons

_ Fuel Hard Points Empty

Propulsion

Engine Location• Two high bypass ratio turbofan engines

mounted on either side of vertical tailWhy?

– Places engines out of the line of fire– Reduces chances of ingesting debris from

runway during takeoff– Act as counterbalance to 40mm cannon in

front of aircraft

Propulsion

Engine Location Continued

• Allows for greatest variety of weaponssystems– Wing mounted and internally mounted

weapons

• Two engines for survivability reasons

Propulsion

Engine Type

• High bypass engines diffuse heat intoenvironment efficiently

• Produce more thrust and are more fuelefficient than lower bypass ratio engines

Propulsion

Engine Sizing

• Scaled down AIAA engine deck

• 4 ft inlet diameter, 7.8 ft long

• Weight = 865.3 lbs each

• Max sea level thrust = 22,000 lbs each

• Max thrust/weight = 0.63

• 5% loss due to installation losses andengine wear

Propulsion

Nacelle Sizing• 4.75 ft inlet diameter, 9.17 ft long• Weight = 369 lbs each• Inlet area larger than minimum area required

to produce shock at a maximum cruise machnumber of 0.7

• Access hatch on bottom for maximumaccessibility

• 12.5 ft from ground so cherry picker must be used

Propulsion

Thrust Reverser• Choose clam shell over cascading type

• Light weight

• Mechanically Simpler, less parts

• More compact

• Reverses both the bypass and jet exhaust

Propulsion

Nozzle Design• 3.5 ft nozzle exit diameter

• Mixing nozzle selected• Reduces noise

• Reduces engine exhaust temperature

Propulsion

Optimum Operating Thrust

• Optimum mach number determined foractivity and altitude

• Optimum power level was found from plotof thrust versus fuel flow at given speedand altitude

Propulsion

Propulsion

Thrust at Operating Conditions

0

5000

10000

15000

20000

0 10000 20000 30000 40000

Altitude, H, ft

Th

rust

, T, l

bs

Available Thrust

Optimal Thrust

Mission Requirements• Design Mission

– Takeoff BFL no greater than 5,000ft.

– Climb at max power– Cruise at best speed for at least

500 nm (speed > 400 kts)– Loiter at 20,000 ft for 4 hrs.– Descend to 10,000 ft and expend

payload– Climb at max power– Cruise at best speed and alt– Descent to sea level– Loiter at best endurance for 30 min– Land with 5 percent reserve fuel– Clear 50 ft. obstacle with one

engine out and land on wet runway– Landing distance no greater than

5,000 ft.

• Ferry Mission– Takeoff BFL no greater than 5,000

ft.– Cruise climb to best cruise speed

and altitude– Cruise at best cruise speed and

altitude for at least 2,600 nm(speed > 400 kts)

– Descent to sea level– Loiter at best endurance for 30

min– Land with 5 percent reserve fuel– Clear 50 ft. obstacle with one

engine out and land on wetrunway

– Landing distance no greater than5,000 ft.

Takeoff/Landing Analysis

TAKEOFF (BFL)• TO Velocity (1.2Vs): 219.6 fps (130.1 kts)

• TO Clmax: 2.109• TO Distance: 4,779 ft.

LANDING• Landing Velocity (1.15Vs): 206.3 fps (122.2 kts)

• Landing Clmax: 2.3• Landing Distance: 4,445 ft.

(Has to clear 50 ft obstacle with one engine out)

Cruise Performance

35,000 ft.

36,000 ft.

37,000 ft.

Optimal CruiseConditions:

Speed: ~Mach 0.7

Altitude: 36,000 ft

SR: 0.123 nm/lb

Primary Mission Summary

1,64019,753424TOTAL

------10. Land

35857301201119. Descend/Loiter

5002,867541036,0004638. Cruise

355348836,0003777. Climb to cruise

---510,0002756. Descend/Drop

4648,1972401220,0001655. Descend/Loiter

5004,112541036,0004634. Cruise

1061,67016736,0003163. Climb to cruise

-4382-0-2. Takeoff

-1,07820-0-1. Taxi

Distance (nm)Fuel (lb)Time (min.)L/DAltitude

(ft)Speed (kts)Mission Segment

Additional Mission Information

Service Ceiling: 37,500 ft.

Absolute Ceiling: 42,000 ft.

Climb Angle: 21.1 degrees

Time to Climb: 16.1 min

Range: 5,185 nm

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

0 1,000 2,000 3,000 4,000 5,000 6,000

Max Rate of Climb, ft/min

Alt

itu

de,

ft

Service Ceiling

Absolute Ceiling

Main Systems

• Electric System– Hamilton-Sundstrand– Exterior/Interior lighting– Ventilation– Cabin pressurization– Thrust Reverser deployment

• Flight Control System– Controls flaps, ailerons, rudder,

horizontal stabilizer– Fly-by-Light (FBL) system

• Larger bandwidth than FBW• Lighter than FBW• Immune to Electromagnetic

Interference (EMI)

• Hydraulic System– Eaton Aerospace– Canon movement– Weapons ejection– Landing gear– Steering/Braking

• Fuel System– Eaton Aerospace– Air refueling– Ground refueling– Fuel flow to engines

ForwardBattery

CurrentTransformer

Aft Battery

Left, Auxiliary,Right AC/DC

PowerDistributor

Secondary PowerDistributor

Integrated DriveGenerator

Aft Standby DCPower Distributor

Forward StandbyAC/DC PowerDistributor

Electric System

Torque Shafting

Rotary Actuator

Angle Gearbox

AMC-cPCI – 300Advanced MissionComputer

ElectronicControl Unit

Electro-hydrostaticPower Drive Unit

Yaw Damper LinearActuator

Fiber Optic Cable

Flight Control System

Rotary Motion ActuatingCylinder + Vicker'sHydraulic Motor

Stationary Piston-Moveable

Actuating Cylinder

Single Piston Double-Rod Actuating Cylinder

Hydraulic PumpWeapon Ejection System

Hydraulic System

Hydraulic Line

Air RefuelingPort

GroundRefueling Port

Fuel Line

Fuel Pump

Fuel System

Reseal-ableFuel Tanks

Inboard FuelTank

Secondary Systems

Hamilton-Sundstrand Air Management System

-Ventilation, Heating/Cooling, Pressurization

Environment

BAE Systems Radar Enhanced Vision System

- Ensures pilot visibility in 0/0 conditions

Pilot Visibility

BAE Systems AMC – cPCI – 3000

- Flight/information management, missioncomputing, display processing

Mission Computer

TRW Communication/Navigation/Identification (CNI)

- Enables air-ground communication, navigationprocessing, and friend-or-foe identification

Communication/Identification System

H-764 Adaptive Configurable EGI

- Uses GPS, INS, or blended GPS/INS

Navigation System

Large Aircraft Infrared Countermeasure (LAIRCM)

- Active system to defend against advanced IRmissiles and MANPADs

Countermeasure System

Cockpit Layout

Cost Analysis

• RDT&E Cost

• Manufacturing Cost

• Flyaway Cost and Price per Plane

RDT&E Cost

Category CostAirframe Engineering and Design $215.59Development Support and Testing $62.02Flight Test Airplanes $568.51Flight Test Operations $24.91Profit $113.12Financing $147.06Total RDTE Cost $1,131.21

Airframe Engineering and

Design19%

Development Support and

Testing5%

Flight Test Airplanes

51%

Flight Test Operations

2%

Profit10%

Financing13%

*All figures are in millions of 2005 USD

Manufacturing Cost

Category 100 Planes 200 Planes 500 PlanesAirframe Engineering and Design $149.04 $196.19 $250.63Airplane Production $1,638.93 $3,656.03 $6,169.19Production Flight Test Operations $20.00 $40.00 $80.00Financing $200.89 $432.47 $727.20Total Manufacturing Cost $2,008.86 $4,324.69 $7,272.02

*All figures are in millions of 2005 USD

Flyaway CostCategory 100 Planes 200 Planes 500 Planes

Manufacturing Cost $2,008.86 $4,324.47 $7,272.02Manufacturing Profit $200.89 $432.47 $727.20Total Flyaway Cost $2,209.75 $4,756.94 $7,999.22

0

5

10

15

20

25

30

35

40

100 planes 200 planes 400 planes

Pri

ce p

er p

lan

e, m

illi

on

s o

f U

SD

….resulting in a Price per Airplane of……

*All figures are in millions of 2005 USD

Questions?