Anything that flies with wings and stays aloft through aerodynamic lift counts as an aircraft. That covers gliders, airliners, military jets, helicopters, and balloons. Each type solves the same basic problem in a different way.

Fixed-wing aircraft generate lift from forward motion over a shaped wing. Rotary-wing aircraft spin their lifting surfaces and can hover. Lighter-than-air craft rely on buoyancy rather than aerodynamic force.

Basic components

• Fuselage, the main body
• Wings for lift
• Empennage for stability and control
• Powerplant for thrust
• Landing gear for ground operations

Weight and balance govern everything. Load an aircraft incorrectly and it may refuse to rotate on takeoff or become uncontrollable in flight. Pilots compute these figures before every departure.