Preliminary Detailed Design Review

Project Review Project Status Timekeeping and Setback Management Manufacturing techniques Drawing formats Design Features Phase Objectives Task Assignment Justification Preliminary Phase Wing Wingbox Fuselage Landing Gear Electrical System Final Phase Tail Control Surfaces Nose Cone Optimization and revision Design Philosophy Design for Manufacture Controllability, Durability, and Payload Capacity Full System Analysis and Theory System Level View Wing Design Wingbox Design Analysis Fuselage and Landing Gear Design Analysis Electrical System Design Schematic Bill of Materials Part Numbers Totals Subsystem Breakdown Manufacturing Considerations

Project Status, Timekeeping and Setback Management

Engineering Requirements unchanged Two subsystem changes Airfoil Landing Gear Two serious setbacks in the last week

Pro or Con S1223 Detail: + Higher C l + Designed for low Re + Cruise α more forgiving for stall characteristics - C mac very high - C D high - Manufacturing challenges Pro or Con E423 Detail: + C mac lower + Easier to trim + Smaller tail allows for more lifting area - Lower C l - Flight conditions outside of traditional flight regime + Thicker trailing edge is easier to manufacture + At a particular angle of attack E423 generates more lift and less drag

Previous situation We had originally intended to use a conventional tricycle gear However, we were exploring the option of switching to a tail dragger configuration to save vertical space Change Further design work revealed that the vertical space savings were minimal and that various complications presented themselves (Stall angle with eppler, Operational uncertainty) We have officially reverted to a tricycle design

Test fixture fabrication failure Weld work performed in the machine shop was not done as instructed by the drawing. Rework is needed Data loss Drive failure on the 16 th resulted in the loss of most of the CAD work done this cycle. Effort to recover have been mostly successful but we have not progressed as far as we had hoped to

Test fixture needed to verify thrust equations Welds not performed as indicated on drawing Part excessively heated: warped as a result Part not assembled properly prior to welding: holes do not line up correctly Weld not properly centered, access to an internal bolt hole is obstructed Assessment of feasibility of repairs vs. starting over delayed by other obligations

Efforts to recover the data were unsuccessful due to how dramatic the storage hardware failed. Edge remains unfriendly to solidworks assemblies Current plan is to make more effective backups We have remade what was lost and are now at 80% of where we had hoped to be at this time prior to the failure

Revised Gantt Chart In the light of recent setbacks and success ahead of schedule we have adjusted our schedule. Available on edge in better resolution.

Structural analysis and optimization of existing parts Design remaining parts and analyze their structure. Now that the fuselage and landing gear are complete the final aerodynamic iteration can be completed. Results are promising and control surfaces will be sized soon.

Long Term Testing Plan At the present we have identified 5 tests that will need to be performed. Three are in place to satisfy the engineering requirements. The other two are to verify the analysis.

Overview of objectives for content covered in this review and that upcoming goals

The major objective was to design as much of the aircraft as possible to leave time for revision in the next phase. Priority was given to structures which would influence other structures.

Finish first round design Control surfaces and tail Revise design work from preliminary phase and correct known problems Reduce weight and takes steps to balance the aircraft

Discussion of methodology and design decisions not related to analysis

Laser cut wood parts and waterjet cut aluminum Accurate and quick operations to manufacture Assembly not substantially easier or harder Requires that we make flat parts Minimize welding Experiences with welded parts in the machine shop do not inspire confidence in the quality of our parts, so we are attempting to avoid using the process as much as possible. Tongue and groove construction is a good way to do this

1. Controllability: Uncontrollable aircraft is a safety risk and a threat to the airframe. 2. Robustness: Pilot error is a risk that we cannot control, so we must make the airframe as able to survive an error as possible. We will have numerous flights over the testing cycle and it would be unfeasible financially to make substantial repairs. 3. Payload Capacity: Seems counterintuitive to place this as our lowest design directive, but failure to meet the others first represents a more serious form of failure than simply not doing well in the competition.

Manufacturing techniques and considerations as well as the drawing format

Laser cut balsa and basswood: All parts not part of the direct payload support Waterjet cut 6061T0 and T6 Aluminum: Parts which directly support the payload Prof. Bonzo suggests that parts thicker than 0.125 will not get good results on the water jet without finishing machining work Jet is Ø.040 and round- limiting our smallest radius Unsatisfactory results producing round holes less than Ø0.100- such holes need to be drilled

We have several drawing formats that we need to operate around. Despite internal debate, we have chosen Solidworks as our CAD suite. Solidworks drawings are acceptable for our purposes. Laser cutter requires autocad style.dwg files. Solidwork drawings use the.dwg extension but they are different. The water jet also requires autocad style.dwg files and paper drawings. It is acceptable for the paper drawings to be made in Solidworks.

The model broken down into its smaller components and analyzed

Most of this semester so far has been devoted to aerodynamic analysis of the system. Our structural design constraints come from the aerodynamic analysis.

Aerodynamic Design and Sizing: Final Iteration Frozen as of October 5 th, 2015 Optimized for lift generation Maintain static stability in accordance with cargo-transport aircraft criteria Overall dimensions drive structural design

Final Sizing Diagram This is the master sizing document. Requirements of this document and several auxiliary documents drove the structural design efforts.

Final Wing Design

Final Horizontal Stabilizer Design

Final Vertical Stabilizer Design

XFLR5 Aerodynamic Model

Fuselage Sizing

Aircraft Longitudinal and Directional Static Stability

Zero-Lift Parasite Drag Calculations

Overall Aircraft Aerodynamics (From XFLR5 Convergence)

Aircraft Performance

Partial System View Not seen: port wing, wing sheathing, motor, monokote, tail, control surfaces

Side View of System Bolting not shown.

Top View Of particular note is the wingboxwing spar interface which will be elaborated on more later

Control surfaces are not included in this iteration of the design as their sizing is sensitive to these designs The complete wing In order to prevent the monokote from shrinking too much and distorting the shape we intend to sheath it in balsa. Sheathing not shown for clarity.

Main Spars Foam Wing Tip Top View of Wing Tip Present in image is the transition between all three wing profiles as well and other areas of interest

Main Spars Outer Spars Lightening/Wiring Holes Side View of Wing Demonstrating tendency of wing ribs to migrate down and backward as a result of decreasing rib size

The Wingbox Interfaces wings, tail and fuselage. Accommodates the wiring that will run from the electronics bay to the control surfaces.

Spar interfaces Bolt holes to interface with fuselage Side View of Wingbox 1 x0.5 rectangular aluminum spars connect each wing to the wing box. Each will be pinned in place through the bottom of the box.

Likely Pin Locations Top View of Wingbox showing servos and spar connections Aluminum plates will run on above and below the spars. This will provide for stability of the wingbox even when the wings are not present and help to secure the spars after assembly.

Detail of tail boom interface and tail servos The tail boom will be rectangular and will be bolted to the wingbox.

Outer Wingbox Bracket

Inner Wingbox Bracket

Cross Strips

Stress Analysis

Payload Bay Electronics Bay Motor Mount Detail View of the Fuselage The electronics bay is located forward of the payload bay. Fuselage area aft of payload bay is simply present to support the arming plug and for aerodynamic reasons.

Aeronautical Landing Gear Design

Aeronautical Landing Gear Design Cont.

Landing Gear Placement of gear is selected to ensure that the main gear (rear) support 80% of the load

Arming plug support Arming plug cable goes here Channel down the middle of the Platform The arming plug must be located aft of the payload bay. For this reason we will be running a high voltage line back through the middle of the floor to reach the arming plug

Rear View Track is wide enough to ensure ground stability

Stress Analysis

Electronic System Design Schematic Design is the standard for model aircraft modified only to accommodate the power limiter.

What we have, what we need, and how we plan to get it

We devised a simple part numbering scheme to assist in keeping track of our parts and files as they multiply Designations: A#### Assembly N#### Multi-use P#### Fasteners F#### Fuselage W#### Wing E#### Electrical C####- Control Surface G#### Landing Gear T#### Tail B#### - Wingbox

Budget is as of current bill of materials Not Included: Tail, Landing Gear, Fasteners Cost will increase as design progresses

Risk Assessment