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Four Seat Light Plane. Chris Hayes, Matt Mayo, Bryant Ramon. Table of Contents. Title Page Table of Contents Problem Statement / Description Requirements Three-Views / Isometrics (Cessna 172 Skyhawk) Three-Views / Isometrics (Cirrus SR22)
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Four Seat Light Plane Chris Hayes, Matt Mayo, Bryant Ramon
Table of Contents Title Page Table of Contents Problem Statement / Description Requirements Three-Views / Isometrics (Cessna 172 Skyhawk) Three-Views / Isometrics (Cirrus SR22) Three-Views / Isometrics (Cessna 172 Re-Design) Chapter 1 - Design Proposal Chapter 2 – Preliminary Estimate of Take-Off Weight Chapter 3 – Wing Loading Selection Chapter 4 – Main Wing Design Chapter 5 – Fuselage Design Chapter 6 – Horizontal and Vertical Tail Design Chapter 7 –Engine Selection Chapter 8 – Take-off and Landing Chapter 9 – Enhanced Lift Design Chapter 10 – Structural Design and Material Selection Chapter 11 – Static Stability and Control Chapter 12 – Cost Estimate Chapter 13 – Design Summary and Trade Study Regulatory Compliance Performance Quote Final Rendering of our model Final Rendering of our model (cont.) Conclusions
Problem Statement / Description Your team works for Cessna and you’ve been charged with proposing a new design to replace/complement the Skyhawk. Your team will propose a new design that can out perform Diamond/Cirrus designs all with the prestigious Cessna nameplate. Your proposal should include a recommendation on 172 retirement, launching a replacement design, upgrading the 172 only or leaving the 172 as is and launching a new design.
Three-Views / Isometrics Cessna 172 Skyhawk Source: http://www.the-blueprints.com/en/blueprints/modernplanes/cessna/18078/view/cessna_172_skyhawk/
Three-Views / Isometrics Cirrus SR22 Source: http://servicecenters.cirrusdesign.com/TechPubs/pdf/POH/sr22-002/pdf/20880-002InfoManual.pdf
Design Proposal Re-Designing the Cessna 172 Skyhawk Passenger allowance of 250 lbs/pax Cabin Dimensions of 12’/4’/4’ Design Range (with Max Payload) of 800 nm Faster cruise than Cirrus SR22
Preliminary Estimate of Take-off Weight Design Weight Summary Assumptions(using Corke atmosphere model) • SFACT: 0.5280 • Corke Table 2.3 • Lift-to-Drag ratio: 13.0 • Corke Figure 2.4 • SFC: 0.7713 • Updated with Engine Spreadsheet Benchmarking Design Problems
Wing Loading Selection Design Wing Loading Summary Assumptions(using Corke atmosphere model) • Cl,max: 2.314083922 • Chapter 4 spreadsheet • Cd0: 0.0161 • Chapter 7 spreadsheet • e: 0.8 • Accepted value given by Corke • Takeoff Max Thrust: 906lbs • Calculate to obtain climb rate Benchmarking Design Problems
Main Wing Design Main Wing Design Summary Assumptions(using Corke atmosphere model) • Aspect Ratio: 7.5 • JAWA 2013 • LE Sweepback: 0 • Not required for light airplanes • Airfoil: NACA 2412 • Same airfoil as the Cessna 172S based on wikipedia • Interference factor: 1 • Corke Table 4.2 Benchmarking Design Problems
Fuselage Design Fuselage Design Summary Assumptions(using Corke atmosphere model) • Inverse Fineness: 7.11 • Corke Table 5.11 • Max Diameter: 4.5 • Design Driver • Interference factor: 1 • Corkepage 107 • Fuselage shape: Elliptical Cylinder • subsonic Benchmarking Design Problems
Horizontal and Vertical Tail Design Tail Design Summary Assumptions(using Corke atmosphere model) • Aspect Ratio: 1.3 vertical, 3 horizontal • Corke Table 6.5 in range • Taper Ratio: 0.5, 0.5 • Corke Table 6.5 • LHT / LVT: 18 ft / 18 ft • Corke page 126 Benchmarking Design Problems
Engine Selection Engine Selection Summary Assumptions(using Corke atmosphere model) Benchmarking Design Problems
Take-off and Landing Takeoff and Landing Summary Assumptions(using Corke atmosphere model) Benchmarking Design Problems
Enhanced Lift Design Wing Platform Plot Assumptions(using Corke atmosphere model) Benchmarking Design Problems
Structural Design and Material Selection Wing Platform Plot V-n Diagram Structure Material Summary Design Problems
Static Stability and Control Static Stability & Control Summary Final Weight Breakdown Rudder Design Design Problems
Cost Estimate Pie Chart (1986 CER’s) Cost Estimate Summary Proposed Cost vs. Requirement Design Problems
Trade Summary • Trade Study • Wanted to see the effect of a more efficient engine or increased cruise Mach would have on range Design Summary Trade Study Results
Regulatory and Design compliance Your Design Regulatory ComplianceCorke ReferenceStatus Certification (FAR Part 23) Velocities V_TO>1.1Y_Stall Compliant Takeoff Climb Gradient 300 fpm @ sea level compliant Rolling Friction n/a n/a Obstacle Height 50 feet n/a Emergency Exits 1 type IV compliant Max Load Factor load factor <3.1 compliant Design Compliance Airfoil Cross Section, Taper, Sweep Sections 4.1-4.3 compliant Crew Sight Lines Table 5.8, page 95 compliant Fuselage Volume Section 5.1 compliant Tail Geometry Tables 6.1-6.6, pages 123-128 compliant Tail Geometry – Aft VT TE Sweep<20 degpage 136 compliant Tail Placement – Stall Control Figure 6.9, page 129 compliant Tail Placement – Spin Recovery Figure 6.10, page 131 compliant Propeller Tip Speed/Mach < 0.85 page 152 compliant Longitudinal Static Stability Equation 11.26 compliant Directional Static Stability Equation 11.45 compliant Trim Drag Equation 11.61 compliant
Performance Quote Requirements/ Proposed Performance ItemTargetsDesignDelta%Cessna 172Cirrus SR 22 -Design Payload (Non-Expendable) 1 Pilot / 3 pax 4 n/a 4 4 -Passenger Allowance 250 lbs/pax 250lbs/pax n/a 250 250 -Cabin Length/Width/Height 12’/4’/4’ (192 ft^3) 194 ft^3 1% 158 ft^3 184 ft^3 -Design Payload (Expendable) 0 0 n/a 0 0 -Design Range w/Max Payload 800 nm 800 nm 0% 640 nm 400 nm -Design Time-on-Station w/ Payload 0 0 n/a 0 0 -Stall Speed <45 nm/hr 47.6 ktas -5.7% 48 ktas 60 ktas -Max Cruise Speed = Max Mach >160 nm/hr 158.5 ktas -0.9% 124 ktas 183 ktas -AEO Takeoff Field Length <1,800 ft 2021.1 ft 1630 ft 1756 ft -OEI Takeoff Field Length (BFL) n/a n/a n/a n/a n/a -Landing Field Length <1,500 ft 1324.6 ft 11.7% 1335 ft 1178 ft -AEO Rate-of-Climb >900 ft/min 704 ft/min 730 ft/min 1270 ft/min -OEI Rate-of-Climb n/a n/a n/a n/a n/a -Glide Slope <3 deg 2.49 deg 17% 6.34 deg 5.95 deg -Max Sustained Turn Rate >2 deg/s 5.64 deg/s 182% 22.2 deg/s 17.6 deg/s -Max Instantaneous Turn Rate >2.5 deg/s 7.27 deg/s 190.8% 13.8 deg/s 11.11 deg/s -Service Ceiling >20,000 ft 36,900 ft 84.5% 14,000 ft 17,500 ft -Unit Cost <$350,000 $689,850 97.1% $364,000 $664,900 -Development Cost <$11M $113,900,000 -935.5% $68,200,000 $141,800,000