The Big Wing, also known as a Balbo, was a tactic proposed during the Battle of Britain by 12th Group commander Air Vice-Marshal Trafford Leigh-Mallory and Acting Squadron Leader Douglas Bader. The basic premise was to meet incoming Luftwaffe bombers in strength with between three and five squadrons. Squadrons under Bader's command employed this tactic, dubbed the Duxford Wing. In its initial deployment, they claimed 11 enemy aircraft for the loss of one fighter.
Though the "Big Wing" did not enjoy many deployments defensively, it sharply demonstrated the mantra of safety in numbers, as aircraft losses diminished significantly when they were deployed in this fashion.
Scramble the "Big Wing" in Blood Red Skies. This bundle gives you 4 squadrons of Supermarine Spitfires, for a total of 24 aircraft.