Bird flight
An airship flies up because the upward force is equal or greater than the force of gravity.

Flight or flying is a process of movement of the object in a gaseous environment or a vacuum without contact with the surface of another environment, as is possible with the use of jet thrust, or other means of propulsion, and without it (by inertia). Best adapted for long controlled powered flight are flying birds and insects, and mammals of the order Chiroptera and extinct reptiles of the order pterosaurs. All of these animals use the aerodynamic principles of flight, using the load-bearing properties of the wing. There are also many animals that make gliding and parachute flight, such as spiders web, aeroplankton flying clams and flying fish, intending to use the ear or leather folds, mammals and reptiles. The fastest flying animal is the peregrine falcon. The speed of its dive is over 370 kilometres per hour (230 miles per hour).

Types of flight

Floating flight

Humans have managed to construct lighter than air vehicles that raise off the ground and fly, due to their floating in air and water.

An aerostat is a system that remains in the air primarily through the use of floating to give an aircraft that has the same overall density as air. Aerostats include free balloons, airships, and moored balloons. An aerostat's main structural component is its envelope, a lightweight skin containing a lifting gas to provide floating, to which other components are attached.

Aerostats are so named because they use "aerostatic" lift, a buoyant force that does not require lateral movement through the surrounding air mass. By contrast, aerodynes primarily use aerodynamic lift, which requires the side movement of at least some part of the aircraft through the surrounding air mass.