Combat has been fought in the air since 1911. Zeppelins and airplanes were used in World War I, but zeppelins were abandoned and airplanes were used and have been used in a variety of forms.
Originally, planes were used for reconnisance and observation until somebody brought a rifle and took a potshot at another plane.
Guns have been used in planes until quite recently, when they were replaced by guided missiles such as the Sidewinder.
Even the US F/A-22 Raptor, due to enter service in 2005, has a gatling-style gun, but it only carries about 480 rounds of ammunition.
This article or section should be merged with History of aerial warfare
Aerial warfare is the use of military aircraft and other flying machines for the purposes of warfare.
Having developed from using unpowered observation hot air balloons in the 18th century, aerial warfare has become a high-technology affair that has led to many advances in techniques such as propulsion, radar, and carbon fibers.
This included the aerial support of ground forces, and expansion of the "Cannae Maneuver" from two dimensions (Encirclement) to one of Three Dimensions (Encirclement and Vertical Envelopment).