Land-based aircraft may reach a fleet after hours of flight and can refuel in the air, but tankers are scarce and cannot rearm or repair them. After an interception, a distant fighter force may leave the ships uncovered until the next scheduled group arrives. A carrier instead maintains a combat air patrol and alert fighters in the same moving force. When the patrol intercepts a threat, alert aircraft can launch to take its place. The returning fighters then land, refuel, rearm, receive maintenance, and become available for another sortie. This cycle, rather than simple aircraft range, is the reason organic naval aviation provides persistent air power at sea.
Chapter · 42:41-44:36
Carrier air groups sustain local air power
A carrier keeps fighters close enough to replace a combat air patrol immediately, then rearm, refuel, repair, and relaunch the aircraft that made the interception.