Table of Contents:

1. Basic Concepts
2. The Atmosphere
3. The Airplane

The Atmosphere

• The composition of the atmosphere (the gaseous envelope surrounding the earth) is:
  
• 78% Nitrogen (N2)
  
• 21% Oxygen (O2)
  
• 1% Trace Gases (Ar, CO2, Others)
  
• Water Vapor (Highly Variable)
  
• At altitudes up to 90 km, gas composition is homogeneous (homosphere)
  
• Above 90 km, gases separate according to relative densities (O2, He, H2) (heterosphere)
  
• The atmosphere can also be separated into "shells" based on temperature distributions
  
• The troposphere is important for most aeronautics research
  

The Real Atmosphere

• Another atmospheric effect is moisture (precipitation, water vapor changes air density)
  
• Pressure is used to calibrate altimeters
  

The Aircraft
Basics of Airplane Design

• The basic components of an airplane are:
  
• Fuselage - The body of an airplane. Many other components are attached 
  to the fuselage. Designs vary according to the mission of the airplane.
  
• Wing - The pricipal lifting surface of an airplane. Some variables are the 
  cross-section of the wing (airfoil section), chord, planform shape, and placement 
  on the fuselage.
  
• Tail Assembly - The tail assembly (empennage) represents the control structures 
  at the rear of the airplane. Consists of:
  

• Landing Gear for support on the ground and during take-off and landing
  
• Power plants to initiate and sustain flight
  
• Control surfaces for yaw, pitch, roll, and lift control,
  

• Body forces (Weight) and Surface forces (Drag, Lift, and Thrust)

Information provided by: http://www.nas.nasa.gov