Combat box

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Combat box formation for a squadron of 12 B-17s1. Lead Element 2. High Element 3. Low Element 4. Low Low Element
Combat box formation for a squadron of 12 B-17s
1. Lead Element
2. High Element
3. Low Element
4. Low Low Element

The Combat box was a tactical formation used by U.S. Army Air Force heavy (strategic) bombers during World War II.

Creation of the concept is credited to General Curtis E. LeMay when he was a colonel commanding the 305th Bombardment Group in England. However the Eighth Air Force had been experimenting with different tactical formations since its first bombing mission on August 17, 1942, several of which were also known as "boxes." LeMay's group did create the "Javelin Down" combat box in December, 1942, and that formation became the basis for all combat boxes following. The formation was created in accordance with USAAF doctrine that heavy bomber formations would be able to defend themselves against enemy interceptors in the absence of escorting fighters, and was designed to provide interlocking fire for defensive machine guns equipping the bombers.

[edit] The evolution of Eighth Air Force formations

The combat box was also referred to as a "staggered formation". Between November 1942 and the end of the war various configurations of the combat box were adopted to meet changing conditions. Although the combat box was initially designed around a Group of airplanes, it was expanded to include a formation of three groups flying together as a "combat wing", all of which were based on the same triangular design of a leading bomber (or grouping of bombers) in the center, and two bombers (or groupings) immediately behind in a Vee shape, with one at an altitude above and one below the center in close proximity for mutual defense.

The earliest bombing missions of the Eighth Air Force were flown with escorts provided by the RAF, so that formations were kept simple for visibility and ease of control. 6-airplane squadrons were flown as much as two to four miles apart to prevent mid-air collisions by their inexperienced crews. However the interceptions by German fighters that did take place indicated immediately that a massing of guns would be necessary, and that the very loose formations being used were inadequate.

In October and November 1942, when the bomber command expanded from two to six groups (two B-24 and four B-17 Flying Fortress), formations of 18 and 36 aircraft were tested on combat missions but were found to be handicapped by poor visibility between airplanes at different altitudes and poor flexibility, especially in turns. The lead bomber in these formations had generally been at the lowermost altitude, but the Javelin Down combat box (an 18-aircraft formation) placed it in the center and staggered the other elements and squadrons either above and below it to open up fields of fire and aid in visibility and flexibility.

Combat boxes of 3rd Bomb Division B-17s
Combat boxes of 3rd Bomb Division B-17s

All the B-17 groups adopted the formation immediately (one of the B-24 groups had been sent to North Africa and the other flew missions separately because of different performance characteristics). By this time German fighters had begun head-on attacks against the bombers as the weakest point in their defensive fire. The new combat boxes continued to be used, but groups were placed in a horizontal column and stacked at increasing altitude to decrease their vulnerability to attack. This resulted in the rear formations lagging behind which impacted both defensive tactics and bombing performance.

The wing box, a 54-plane formation (basically three 18-plane boxes stacked in a similar fashion to the group box), evolved from a need to provide defensive fire against head-on attacks. The formations were stacked so that while squadrons were stacked away from the sun on missions (to reduce glare), groups were stacked in the opposite direction, making for a more compact wing box.

The most serious disadavantage of the wing box was that the lowermost and uppermost elements, trailing at the end of the formation, had the least mutual protection. A third element of three bombers was added to the 18-plane box, placed where it could support these exposed squadrons, resulting in the most common 21-plane configuration.

In the summer of 1943 the Eighth expanded in size to 16 groups of B-17s and 4 of B-24s, and by the following June would grow to 39 groups. The table of organization and equipment for heavy bombardment groups was increased from 35 to 70 planes with a huge influx of new bombers beginning in the autumn of 1943 and the use of composite groups was discontinued as many groups flew two group boxes on a single mission.

In October the first radar-guided Pathfinder group began operations, bringing about a need for a compact 36-plane formation to optimize bombing performance in adverse weather conditions. This was done intitially by simply doubling the number of three-plane elements in a squadron formation, and placing all three planes within the element at the same altitude to avoid collisions. This proved difficult to fly and increased the likelihood of a bomber flying at the bottom of the box being struck by bombs dropped from a higher plane. The box was reduced in size to 27 aircraft to lessen the possibility, although a diamond-shaped formation of four 9-or four 10-plane squadrons was developed for B-24s of both the Eighth and Fifteenth Air Force.

The 54-plane wing combat box used by the Eighth's B-17s was also cumbersome to fly and required both practice and discipline to maintain formation. Turbulence from leading bombers added to the difficulty of maintaining formation. The 54-plane box served as a defense against fighters, however, and as flak became the greater threat in May, 1944, the 36-plane box was resurrected in a much looser formation and became the standard through the remainder of the war except on days when significant fighter opposition was anticipated.

[edit] Fifteenth Air Force formations

The Fifteenth Air Force, consisting of a preponderance of B-24 groups flying at altitudes 5,000 or more feet lower than those flown by the B-17-dominated Eighth Air Force, employed a larger group box during the period of December 1943 to July 1944. Called the "six-box formation", it consisted of forty aircraft, with the group divided into two units of twenty B-24s, one behind the other, and each unit consisted of three squadron boxes. The center squadron (known as Able Box) of the first unit was a composite formation of six aircraft containing the group leader, with the deputy leader flying on its wing. The other four aircraft of Able Box were from the two squadrons assigned to the unit for that mission, with the six bombers formed in two vee formations in trail. On each side of the lead squadron were seven-bomber boxes called Baker Box (to the right) and Charlie Box (to the left), each box made up of bombers of one squadron, also in vees of three, with one additional bomber flying in the slot of the center rear of each squadron box, and known as "Tail-end Charlie." This position was usually flown by the least experienced crew in the squadron and was vulnerable to fighter attack. The second unit of the group formation was configured identically, except that its boxes were named Dog, Easy, and Fox. Each position within a box was numbered, so that the group leader flew the Able One position while the Tail-end Charlie of the leftmost rear squadron flew Fox Seven.

Because it was laterally wide, the six-box formation was not a compact formation, was cumbersome to fly, and thus was less efficient in bombing accuracy. The Fifteenth Air Force adopted the diamond formation during the summer of 1944 to increase its bombing accuracy, but this also had the negative consequences of increasing losses to flak.

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