A fighter pilot is a military aviator trained to engage in air-to-air, and often air-to-ground combat while in the cockpit of a fighter aircraft. Fighter pilots undergo specialized training in aerial warfare and dogfighting (close range aerial combat). A fighter pilot with at least five air-to-air kills becomes known as an ace. Not all fighter pilots have experienced actual aerial combat mainly due to the decline of conventional warfare, with many countries cutting the budgets of their air forces and shifting their focus to research and development of unmanned aerial vehicles for possible future combat roles, which may replace the need for new fighter pilots entirely.