Thanks to the wiki we have some info on the "combat box" as used by the B-17 bomber in missions over Germany during World War Two [WW2].
"The Combat box was a tactical formation used by heavy (strategic) bombers of the U.S. Army Air Forces during World War II. The combat box was also referred to as a "staggered formation". Its defensive purpose was in massing the firepower of the bombers' guns, while offensively it concentrated the release of bombs on a target."
The box having both an offensive and defensive nature:
1. Offensive - - "concentrated the release of bombs on a target"
2. Defensive - - "massing the firepower of the bombers' guns"
The B-17 referred to as the Flying Fortress from all the defensive armaments, the three turrets of dual fifty [.50] caliber machine guns and the two single fifty caliber waist gunners. Additional guns added with that chine turret belatedly.
Strategic bombers were felt capable of more than adequate defense, organic firepower [all those fifty caliber machine guns when organized in a combat box] deemed sufficient!
"massed bombers could attack and destroy targets in daylight without fighter escort, relying on interlocking fire from their defensive machine guns, almost exclusively the Browning M2 .50-calibre gun"
"The practice of referring to a concentrated formation as a 'box' was the result of diagramming formations in plan, profile and front elevation views, positioning each individual bomber in an invisible boxlike area."
And again thanks to the wiki here is an image of the box:
"Combat box of a 12-plane B-17 squadron developed in October 1943.
Three such boxes completed a 36-plane group box."
Each box consisting of a:
1. Lead Element
2. High Element
3. Low Element
4. Low Low Element
That image of the combat box a basic formation, variations on the same theme occurring from time to time. The basic still worthy of note.
One picture worth ten thousand words? That box also mitigating against mid-air collision? Massed aircraft in the same formation but having room for maneuver in emergency situations without the threat of running into another friendly?