Combat air patrol endurance and layered fleet defence

Prewar navies doubted that fighters could launch, climb, and intercept an attack in time, so endurance aloft mattered more than the climb rate prized by land-based interceptor forces. Carrier fighters waited at altitude in a combat air patrol while deck aircraft prepared to replace or reinforce them. An 18-aircraft group might keep four aloft and four ready, then cycle further groups through maintenance and the flight deck as the attack developed. The patrol's main job was to split a strike formation into smaller groups rather than remain in prolonged dogfights. Heavy anti-aircraft fire could then disperse those groups further before medium and light weapons engaged individual attackers.