Air supremacy is a concept in warfare in which one nation's military gains complete control of the opposing enemy's airspace through destruction of the enemy's fighter wing capacity, the airfields and runways, and its air-defensive capability. Although not a war-winning concept in and of itself, gaining air supremacy can give ground forces a decisive advantage, as demonstrated during the 1991 Gulf War and the 2003 Operation Iraqi Freedom.
The first country to gain air supremacy over a large area was Japan, during World War II. The Mitsubishi Zero enabled top Japanese aces to claim dozens of victories in air-to-air combat.
- The Zero-Sen possessed complete mastery in the air over the Pacific until the Battle of Midway in June 1942, which became the actual turning point of the Pacific War, although very few knew it at the time. 
- Due to its light weight, large wing area, low wing loading and big ailerons, the Zero was more agile than any contemporary foreign fighter. The initial climb rate was very good and the Zero could climb at a very steep angle, unmatched by contemporary fighters. The sustained climb rate was good, better than the US fighters in service at the beginning of the war ...
This changed quickly with the deployment of the Grumman Hellcat.
- The F6F Hellcat was designed specifically to counter the earlier A6M2 Zero-sen, the strengths and weaknesses of which became fully understood by US designers after an undamaged example was recovered in the Aleutians.
- Grumman's successor to the pugnacious Wildcat, the Hellcat embodied many of the lessons learnt by F4F pilots in the opening months of the Pacific war. Introduced to the fleet in January 1943, and blooded in combat against the Japanese by VF-5 seven months later, the F6F served as the principal US Navy fighter on board carrier decks until VJ-Day. Despite its lethality in the air when ranged against the best Japanese fighters, it still retained docile handling qualities around the carrier deck. Pilots flying the Hellcat claimed nearly 5000 kills in the Pacific, and over 350 pilots achieved ace status on the type.