The term SERVING FEAT can be broken down into two parts: ACE, which is a 3 letter word, and SERVING FEAT. ACE stands for 'Air Combat Element', which is a unit of the United States Air Force that specializes in air-to-air combat. SERVING FEAT stands for 'Serving Fighter Aircraft Tactics', which is a set of tactics used by fighter aircraft to gain an advantage over their opponents. Together, these two terms refer to the tactics used by the Air Combat Element to gain an advantage in air-to-air combat.