Aviation and Flight Principles

2.

The Four Fundamental Forces of Flight

2.1.

Overview of Flight Forces

2.1.1.

Definitions of Forces

2.1.1.1.

Lift Definition and Direction

2.1.1.2.

Weight Definition and Direction

2.1.1.3.

Thrust Definition and Direction

2.1.1.4.

Drag Definition and Direction

2.1.2.

Force Vector Representation

2.1.2.1.

Magnitude and Direction

2.1.2.2.

Vector Addition

2.1.2.3.

Resultant Forces

2.1.3.

Interaction of Forces in Flight

2.1.3.1.

2.1.3.2.

Moments and Torques

2.2.

Force Equilibrium in Flight

2.2.1.

Straight and Level Flight

2.2.1.1.

Balanced Force Conditions

2.2.1.2.

Lift Equals Weight

2.2.1.3.

Thrust Equals Drag

2.2.2.

Climbing Flight

2.2.2.1.

Unbalanced Force Analysis

2.2.2.2.

Thrust Greater Than Drag

2.2.2.3.

Weight Component Effects

2.2.3.

Descending Flight

2.2.3.1.

Thrust Less Than Drag

2.2.3.2.

Gravitational Assistance

2.2.4.

Accelerated Flight

2.2.4.1.

Changes in Force Relationships

2.2.4.2.

Acceleration Calculations

2.3.

2.3.1.

Physical Principles of Lift Generation

2.3.1.1.

Airfoil Shape Effects

2.3.1.2.

Angle of Attack Influence

2.3.1.3.

Pressure Differences

2.3.1.4.

Circulation Theory

2.3.2.

The Lift Equation

2.3.2.1.

Mathematical Expression

2.3.2.2.

Variables Affecting Lift

2.3.2.2.1.

2.3.2.2.2.

Velocity Squared

2.3.2.2.3.

2.3.2.2.4.

Coefficient of Lift

2.3.3.

Coefficient of Lift

2.3.3.1.

Definition and Units

2.3.3.2.

Factors Influencing Coefficient of Lift

2.3.3.2.1.

Angle of Attack

2.3.3.2.2.

2.3.3.2.3.

Reynolds Number

2.3.3.2.4.

2.3.3.3.

Lift Coefficient Curves

2.3.3.3.1.

2.3.3.3.2.

2.3.3.3.3.

Maximum Lift Coefficient

2.3.4.

Factors Affecting Lift Production

2.3.4.1.

Wing Design Parameters

2.3.4.2.

Flight Conditions

2.3.4.3.

Environmental Factors

2.4.

2.4.1.

Components of Aircraft Weight

2.4.1.1.

2.4.1.2.

2.4.1.3.

2.4.1.4.

Maximum Takeoff Weight

2.4.2.

Center of Gravity

2.4.2.1.

Definition and Importance

2.4.2.2.

CG Location Effects on Stability

2.4.2.3.

CG Range Limitations

2.4.2.4.

Forward CG Effects

2.4.2.5.

2.4.3.

Effects of Weight on Performance

2.4.3.1.

Takeoff Performance

2.4.3.1.1.

Takeoff Distance

2.4.3.1.2.

2.4.3.2.

Landing Performance

2.4.3.2.1.

Landing Distance

2.4.3.2.2.

2.4.3.3.

Climb Performance

2.4.3.3.1.

2.4.3.3.2.

2.4.3.4.

Cruise Performance

2.4.3.4.1.

Fuel Consumption

2.4.3.4.2.

Range and Endurance

2.4.4.

Weight and Balance Calculations

2.4.4.1.

Moment Calculations

2.4.4.2.

CG Determination

2.4.4.3.

Loading Diagrams

2.4.4.4.

Effects of Improper Loading

2.5.

2.5.1.

Principles of Thrust Generation

2.5.1.1.

Newton's Third Law Application

2.5.1.2.

Momentum Change

2.5.1.3.

Mass Flow and Velocity Change

2.5.2.

Propeller-Driven Aircraft Thrust

2.5.2.1.

Propeller Disk Theory

2.5.2.2.

Blade Element Theory

2.5.2.3.

Propeller Efficiency

2.5.3.

Jet-Propelled Aircraft Thrust

2.5.3.1.

Turbojet Thrust Production

2.5.3.2.

Turbofan Thrust Production

2.5.3.3.

Bypass Ratio Effects

2.5.4.

Thrust Required vs Thrust Available

2.5.4.1.

Power Required Curves

2.5.4.2.

Power Available Curves

2.5.4.3.

Performance Limitations

2.5.4.4.

Service Ceiling

2.5.5.

Effects of Altitude on Thrust

2.5.5.1.

Engine Performance Degradation

2.5.5.2.

Propeller Efficiency Changes

2.5.5.3.

Turbojet Performance

2.5.5.4.

Turbofan Performance

2.5.6.

Thrust Vectoring

2.5.6.1.

Variable Thrust Direction

2.5.6.2.

VTOL Applications

2.6.

2.6.1.

Physical Principles of Drag

2.6.1.1.

2.6.1.2.

2.6.1.3.

2.6.2.

The Drag Equation

2.6.2.1.

Mathematical Expression

2.6.2.2.

Variables Affecting Drag

2.6.2.2.1.

2.6.2.2.2.

Velocity Squared

2.6.2.2.3.

2.6.2.2.4.

Coefficient of Drag

2.6.3.

Coefficient of Drag

2.6.3.1.

Definition and Units

2.6.3.2.

Factors Influencing Coefficient of Drag

2.6.3.2.1.

2.6.3.2.2.

Surface Roughness

2.6.3.2.3.

Reynolds Number

2.6.3.2.4.

2.6.4.

2.6.4.1.

2.6.4.1.1.

2.6.4.1.1.1.

2.6.4.1.1.2.

2.6.4.1.2.

Skin Friction Drag

2.6.4.1.2.1.

Surface Area Effects

2.6.4.1.2.2.

Surface Roughness

2.6.4.1.3.

Interference Drag

2.6.4.1.3.1.

Component Interactions

2.6.4.1.3.2.

Junction Effects

2.6.4.2.

2.6.4.2.1.

Relationship to Lift Production

2.6.4.2.2.

Wingtip Vortices

2.6.4.2.3.

Aspect Ratio Effects

2.6.4.2.4.

Elliptical Lift Distribution

2.6.5.

Total Drag Characteristics

2.6.5.1.

Drag Polar Curves

2.6.5.2.

Minimum Drag Speed

2.6.5.3.

Drag Rise with Speed

2.6.6.

Lift-to-Drag Ratio

2.6.6.1.

Definition and Importance

2.6.6.2.

Maximum L/D Ratio

2.6.6.3.

Performance Implications

2.6.6.4.

Glide Ratio Relationship

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1. Introduction to Aviation and Flight

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3. Aerodynamics of Airfoils and Wings