Flight Theory Notes
Introduction - Key Topics for the Course:
Aircraft Categories
Lighter Than Air
Rotorcraft
Airplane
Glider
Airplane Class
Single-Engine Land
Single-Engine Sea
Multi-Engine Land
Multi-Engine Sea
International Civil Aviation Organization (ICAO) : specialized UN agency that was established by the US in 1944 to manage the administration and governance of the Convention on International Civil Aviation (Chicago Convention)
Works with the Convention’s 193 Member States and industry groups to reach a common understanding on the international civil aviation standards and recommended practices (SARPs) and policies in support of a safe, efficient, secure, economically sustainable, and environmentally responsible civil aviation sector
Establishes aviation standards and recommended practices on an international level
Phonetic Alphabet
A Notice to Airmen (NOTAM) : contains information that is the establishment, condition or change in any aeronautical facility, service, procedure or hazard, the timely knowledge of which is essential to personnel concerned with flight operations
Contains time-sensitive information that allows for safer flight operations
Lesson One - AIrcraft Structure:
Lift and Basic Aerodynamics
Lift: produced by the dynamic effect of air acting on the wing
Thrust: The forward force produced by the powerplant/propeller
Weight: The combined load of the airplane itself that combats life (crew, fuel, cargo, baggage, weapons, etc.)
Drag: A rearward, retarding force caused by disruption of airflow by the wing, fuselage, and other protruding objects that opposes thrust
Aircraft Three Axes
Lateral Axis
Extends from wingtip to wingtip
Aviation term for rotation: Pitch
Controlled with Elevator - Pull back on yoke
Longitudinal Axis
Extends from nose of the aircraft to the tail
Aviation term for rotation: Roll
Controlled with Ailerons - Move yoke to left/right
Vertical Axis
Extends through the aircraft vertically
Aviation term for rotation: Yaw
Controlled with Rudder - Moving rudder pedals left/right
Center of Gravity: Specific point where the mass or weight is at the center
The point if the aircraft was suspended or balanced where it would be balanced
Helps determine
Stability
Loading operations
Flight performance
Major Aircraft Components
Fuselage: body of the plane
Wings: airfoils attached to each side of the fuselage
Empennage: entire tail group
Landing Gear: supports the aircraft when not flying
Powerplant: provides power and thrust to aircraft
Instrumentation
Old School
Ergonomics: science that deals with designing and arranging things so that its more accessible to people
Each instrument had a specific purpose but often had to be combined with another to give defined information
Pros: Simple to use and analyze
Cons: Scattered information all over cockpit (lots of cross checking)
Modern Cockpit
Utilizes Multi-Function Displays
Pros: More info all in one place, easy to identify problems
Cons: Requires extensive knowledge to operate effectively
Control Instruments
Display immediate attitude and power changes
Minimum information to safely fly
Normally:
Manifold Pressure
Attitude Indicator
Tachometer
Performance Instruments
Indicated the aircrafts actual performance
Provide the polit with awareness building information
Normally:
Altimeter
Airspeed
Vertical Speed Indicator
Heading Indicator
Turn and Slip Indicator
Others
Navigation Instruments
Indicate the position of the aircraft in relation to a selected navigation facility or fix
Normally
GPS (satellites)
VOR (very high frequency omni-directional radio range)
NDB (non-directional beacon)
ILS (instrument landing system)
Lesson Two - Principles of Flight
Atmosphere
Envelope that0e earth
Composed of:
78% Nitrogen
21% Oxygen
1% Other Gasses (argon, helium, etc.)
Atmospheric Pressure: pressure of the atmosphere at a given altitude and temperature
Constantly changing
Standard Day (Sea Level)
Pressure = 14.7 PSI
29.92 Inches of Mercury
59°F or 15° C
Lapse Rates in Standard Atmospheric Conditions
Pressure
-1” of mercury for every 1000’ altitude gain
-2°C or 3.5°F for every 1000’ of altitude gain
Pressure Altitude
Height above a Standard Datum Plane (SDP)
Can be found by
The altitude when the altimeter is set to 29.92
Applying a correction factor to the indicated altimeter setting
Density Altitude: The vertical distance above sea level in the standard atmosphere at which a given density is to be found
Dramatically effects aircraft performance (Density Alt. Charts)
Power: Less dense air = reduction
Thrust: Less efficient in thin air
Lift: Thin air = Less force on airfoil (less force = less lift)
Theories in Lift Production
Newton’s Basic Laws of Motion
Newton’s First Law:
“Every object persists in its state of rest or uniform motion in a straight line unless it is compelled to change that state by forces impressed on it”
An object at rest, stays at rest; an object in motion, stays in motion
How does this apply to aviation?
Newton’s Second Law
Force is equal to the change in momentum per change in time. For a constant mass, force = mass x acceleration
The greater the mass of an object, the more force required to accelerate
How does this apply to aviation?
Newton’s Third Law
FOr every action, there is an equal and opposite reaction
How does this apply to aviation?
Principles of Flight
Magnus Effect: Airflow over a cylinder
Studied effects of:
Rotating Cylinder
Moving Flow
Bernoulli’s Principle of DIfferential Pressure
Venturi Tube
Pressure and Velocity changes
Airfoil Design
Chord Line: Straight line from the leading edge to the trailing edge
Camber: Distance from the chord line to the upper and lower surfaces
Mean Camber Line: Mean line between the upper and lower surfaces (camber)
Airfoil Design Continued
Early Designs: Generate lift by traditional Bernoulli’s
Later Designs: Higher performance = Higher Demands
Inverted flight?
How does a modern symmetrical airfoil generate lift?
Angle of attack: The angle between the Chord Line and Relative Wind
Increased AoA = Increased Lift
Critical AoA = Stall (No lift being generated)