Stability And Flight Controls • Categories Of Aircraft o Lighter Than Air - Weight Of The Fluid Displaced Is The Weight Of The Object Buoyed . Hot Air Balloon . Gas . Dirigible . Blimp o Heavier Than Air - Lift Caused By Aerodynamics; Downthrust - Air Displaced Downward . Glider . Rotorcraft . Helicopter . Gyrocopter . Airplane • Sel • Ses • Mel • Mes • Amphibian • Engines o Rotary o In-Line 1 o Radial o V-Type o Opposed o Axial Jet Turbine o Centrifugal Jet Turbine o Fan Jet Turbine • Aircraft Vocabulary o Fuselage o Empennage o Landing Gear o Cowling o Nacelle o Canard o Cabane o Wing Placement . High Wing . Low Wing . Mid- Wing (½ Way Between Low Wing And High Wing) o Number Of Wings . Mono-Plane . Bi-Plane . Tri-Plane 2 • Stability o State Of Equilibrium – Sum Of All The Forces Acting On An Aircraft And All The Moments Equal Zero (Experiences No Acceleration) . Static Stability = No Motion • Positive: Tendency To Return To Neutral Position • Neutral: Stays Displaced • Negative: Keeps Going In Direction Of Displacement . Dynamic Stability • Positive: Turbulence Corrects Over Time • Neutral: Turbulence Stays The Same • Negative: Gets Worse o Axis Of An Airplane . Longitudinal Axis - Imaginary Line That Passes From Nose To Tail . Lateral Axis - Imaginary Line That Passes From Wingtip To Wingtip . Vertical Axis - Imaginary Line That Passes From Top To Bottom o Axis Of Stability . Longitudinal Stability - Pitch Stability . Lateral Stability - Roll Stability . Directional Stability - Yaw Stability 3 • Flight Control Surfaces = Hinged Or Movable Airfoils Designed To Change The Attitude Of The Aircraft During Flight. o Primary Control Surfaces : Ailerons, Elevator, Rudder o Secondary Control Surfaces : Trim Tabs o Auxiliary Control Surfaces : May Be Lift Augmenting Or Lift Decreasing . Lift Augmenting - Trailing Edge Flaps, Leading Edge Flaps (“Slats”), Slots . Lift Decreasing - Spoilers, Speed Brakes o Primary Flight Control = Used To Control Pitch, Roll, Or Yaw . Ailerons - Control Roll • Simple Aileron • Differential Aileron • Frieze Aileron . Elevator - Controls Pitch . Rudder – Controls Yaw • Ruddervator o Secondary Flight Control . Ground-Adjustable Tabs . Trim Tabs . Balance Tab . Servo Tab . Anti-Servo Tab 4 o Auxiliary Flight Control . Flaps • Simple Flap (Plain Flap) • Plain Split Flap (Split Edge Flap) • Slotted Flap • Fowler Flap • Zap Flap • Leading Edge Flap . Other Aux Devices • Speed Brakes • Spoilers o Roll Control (When Used Individually) o Glideslope Control W/O Pitch Change (When Deflected Together) o Braking (When Deflected Together) • Slot • Slat • Stall Strip (Fixed Spoiler) • Vortex Generators • Fences • Wash-In • Wash-Out • Other Terms 5 o Canard o Forward Swept Wing o Flying Wing o Biplane Wings o Interplane Interference o Gap/Chord Ratio o Decalage 6 .