Introduction to Aerospace – Historical Perspective Dr. Doug Cairns

2-14 For the Next Few Slides Basic Physics of Flight What’s happening during a flight Rule of Thumb airplane design

2-15 Basic Forces Lift Weight Drag Thrust Trim

2-16 What’s in Weight? Lift Weight Drag Thrust Trim Payload Fuel Airplane Operating Empty Weight (OEW) Reserves Operating items Systems Propulsion Landing Gear Body Wing & Tails Food, Supplies Navigate, control and support life Generate force to move airplane Support airplane on the ground Enclose the payload Provide lift Paying Passengers and Cargo

2-17 Weight changes during the flight. Payload Fuel Reserves Operating items Systems Propulsion Landing Gear Body Wing & Tails Food, Supplies Navigate, control & support life Generate force to move airplane Support airplane on the ground Enclose the payload Provide lift Payload Fuel Operating empty weight End of flight Start of Flight Burn off fuel

2-18 Lift Weight Drag Thrust Trim How do you make Lift? Bernoulli: “The faster the air flows over the surface, the lower the pressure air exerts on the surface.”

2-19 How to Change Lift Since Lift is about the same as weight and weight changes, then must be able to change lift. –Increase lift by increasing the tilt of the wing increasing the speed of the airplane (actually speed squared) decreasing the altitude of the airplane above the ground.

2-20 But there are Limits to Lift Lift Airfoil Tilt Angle “Stall” The flow no longer can stay attached to the upper surface.

2-21 Ways around the Limits to Lift Lift Airfoil Tilt Angle “Slats” “Slats & Flaps”

2-22 Wings are made up of airfoils Airfoil Wing

2-23 Lift Weight Drag Thrust Trim A propeller produces thrust like a wing produces lift except: The propeller is a wing rotated 90 degrees The speed over the airfoil comes from rotating the prop. How to create Thrust

2-24 How does a jet engine produce thrust? Propeller (“compressors”) Propeller (“turbines”) Fuel Burned ( Generates high speed air) Thrust A jet engine “sucks, squeezes, burns and blows.”

2-25 What is “Drag”? Lift Weight Drag Thrust Trim Skin Friction Excrescence Induced “Pressure” Lift and Span Aerodynamic details Smoothness Outside surface area Due to the influence of an airfoil on those outboard of it Due to the rapid growth of the boundary layer Due to roughness, gaps & antennas Due to the friction in the boundary layer next to the skin to the air flowing over the skin.

2-26 What & Why Trim? Lift Weight Drag Thrust Trim Trim comes from a wing like surface mounted on the back of the airplane To change the tilt of the airplane –increase down load - airplane nose goes up –decrease down load - airplane nose goes down

2-27 Airplane Controls Flaps Spoilers Aileron Rudder Elevators Slats Fin Stabilizer (Tail)

2-28 Airplane Stability Lift Weight A stable systemA stable airplane Move the ball away from the bottom and it returns to the bottom Because ball’s center of gravity is above the bottom of the bucket Move the nose of the airplane up and the airplane’s nose will come back down. Because airplane’s center of lift is aft of the center of weight

2-29 How does an airplane turn? It banks. Lift Weight

2-30 Why do airplanes have rudders? To balance an inoperative engine and crosswinds.

2-31 Design Envelope Takeoff and Landing Distances Fatigue Brake Capability Engine out takeoff Stall Margins Pressurization Speed margins System redundancy Flutter Situation Awareness Structural Strength margins

The Plane that Taught America to Fly Note: Dr. Cairns has around 100 hrs in this make and type, over 200 hours in similar type aircraft

We will have an opportunity to crawl around one of These!

The Greatest Fighter Aircraft Ever (according to the Military Channel)

The Funny Looking X29 (forward swept wing for better maneuverability)