Wednesday, September 30, 2009
Aircraft Structure Lift and Basic Aerodynamics
Weight is the combined load of the airplane itself, the crew, the fuel, and the cargo or baggage. Weight pulls the airplane downward because of the force of gravity. It opposes lift, and acts vertically downward through the airplane’s center of gravity (CG).
Lift opposes the downward force of weight, is produced by the dynamic effect of the air acting on the wing, and acts perpendicular to the flightpath through the wing’s center of lift.
Drag is a rearward, retarding force, and is caused by disruption of airflow by the wing, fuselage, and other protruding objects. Drag opposes thrust, and acts rearward parallel to the relative wind. Aircraft becomes unstable. [Figure 2-3] The CG is computed during initial design and construction, and is further affected by the installation of onboard equipment, aircraft loading, and other factors.