Why Fulmars needed a standing combat air patrol

The Fulmar could not gain altitude as quickly as the fleet needed when enemy aircraft approached. Keeping a combat air patrol aloft put fighters in position before an attack developed. Newly launched alert aircraft could then replace the patrol while the fighters already at height intercepted the attackers. Illustrious helped develop this practice alongside Ark Royal, whose Skuas faced a similar problem. Carriers using Sea Gladiators had less difficulty getting their fighters to altitude.