Why a carrier's air group needs depth

The modern carrier story includes the growth and diversification of an air group that must cover reconnaissance, strike, air defence, anti-submarine warfare, airborne early warning, search and rescue, and other duties. Eighteen fighters are presented as a traditional lower bound for a defensive group because that number supports aircraft in the air, on alert, in maintenance, and held as spares. A small, tailored air group can suit a planned mission, but changing it quickly becomes difficult when a conflict or humanitarian crisis alters the requirement. The useful measure is whether the embarked force retains options after sailing as well as how many aircraft fit on the deck.