Theory of Flight Aircraft Design and Construction. References: FTGU pages 9-14, 27

Theory of Flight 6.01 Aircraft Design and Construction References: FTGU pages 9-14, 27

Main Teaching Points Parts of an Airplane Aircraft Construction Landing Gear Standard Terminology

Definition The airplane is defined as: A power-driven Heavier-than air aircraft Deriving its lift in flight from aerodynamic reactions On surfaces that remain fixed under given conditions of flight.

Parts of an Airplane

Fuselage The fuselage is the main body of the aircraft, where the passengers, cargo and crew go.

Fuselage The fuselage is normally classified according to the type of construction: -Truss Type -Monocoque -Semi-monocoque

Fuselage Truss Type

Fuselage Semi-Monocoque

Empennage The empennage is the rear portion of the airplane It is integral to control and stability during flight

Wing Construction Spars spanwise members wood or metal carry bending loads Ribs web or truss give wing its cambered shape

Wing Construction Edges Leading Edge Trailing Edge Strength & Shape Wires Internal / External Bracing for strength Covering Metal or Fabric Metal strength

Wing Layouts High Wing Mid Wing Low Wing Bi-Plane

Confirmation

Landing Gear Conventional (Tail-Dragger) - Two main wheels and a tail wheel Tricycle Two main wheels and a nose wheel Retractable - Wheels may be raised so that they are enclosed in wings or fuselage (reducing drag) Fixed - Landing gear is not designed to retract

Landing Gear

Landing Gear Retractable Landing Gear PROS Reduced drag at cruise Higher cruising speed CONS Added weight Added mechanical complexity Risk of Gear Up Landing (land based) Risk of Gear Down Landing (amphibious)

Landing Gear Shock Absorption Absorb the impact of landing, or the effect of bumps in runway. Spring steel Landing Gear Air/Oil oleos Rubber cords (bungee) or discs Low pressure tires

Main Landing Gear - Spring Steel Cantilever - Landing Gear

Nose Landing Gear - Air / Oil Oleo - Landing Gear

Landing Gear - Brakes Brakes Provide a means of stopping the aircraft Assist with steering on the ground

Confirmation How would you describe the aircraft to the left? -tail dragger? -tricycle gear? -retractable gear? -float plane? -high wing? -low wing? -mid wing? -biplane? Request the use of the tools to label the aircraft.

Wing Span Wingspan is the maximum distance from wing tip to wing tip

Chord Chord is the imaginary line between the leading edge and the trailing edge of the wing A measure of the width of a wing

Wing Area Wing Area Length of the wing multiplied by the average width of wing

Planform Planform Shape of the wing as seen from above

Aspect Ratio Aspect Ratio Ratio of the span to chord of the wing A measure of how SLENDER the wing is

A structure curved to produce lift Airfoil

Camber Camber A measure of the curvature of an airfoil Mean Camber is the line equidistant between the upper & lower surfaces

Angle of Incidence Angle of Incidence Angle between chord line and the longitudinal axis

Relative Airflow Relative Airflow Airflow over the wing Related to the forward motion of the aircraft through the air

Angle of Attack Angle of Attack The angle between the chord line and the relative airflow It is a measure of how much the wing bites into the air

Confirmation Check Confirmation

Confirmation What kind of landing gear is this?

Confirmation What is the angle of attack?

Confirmation What are some of the differences between powered aircraft and gliders?

Confirmation Reading: From the Ground Up, pages 9-14 The next Theory of Flight Class covers the basic flight controls (6.02)