What I am writing now is from historical sources and I will try also to make some propositions about how to use this tactics but at a smaller scale, because we don?t have that many planes.
The Heavy Bomber ?Combat Box?
A key to the success of the American daytime strategic bombing campaign against Germany was the evolving bomber formation called the ?combat box? Designed to maximize defensive firepower and concentrate the group?s bomb load, variations of the combat box included 18, 27, 36, or 54 heavy bombers. Devised at the end of 1942, the basic 18-plane formation, called the Group Javelin Down, consisted of high, middle, and low six-plane squadrons stepped diagonally downward toward the sun.
Originally USAAF planners had hoped that 200-plus .50-caliber machine guns mounted in 18 Flying Fortresses would produce an impenetrable screen of fire around the formation. Even when later formations expanded to include 54 aircraft, their nearly 700 guns could not ensure that the majority of the bombers would reach their target, let alone survive the return trip. It took effective fighter escort, combined with the combat box, to make the ongoing strategic bombing campaign possible.
These large bomber formations provided distinct challenges to fighter pilots on both sides of the struggle. For Allied fighter pilots, the job of escorting the bombers to and from the target was an evolving task as the formations, enemy tactics, and the escort fighters? combat range changed over time. For German fighter pilots, the task of attacking massive streams of bombers flying in ever more effective formations and escorted by fighters with increasing range and freedom of action was a daunting one.
Escorting U.S. Bomber Formations
When it became clear early in the strategic bombing campaign that German fighters were making mincemeat of the heavy bomber formations, American fighter pilots were ordered to stick close-as close as 50-75 feet-to the slow-moving bombers. This very close escort robbed them of the advantages of altitude and speed, but provided opportunities to dive on enemy fighters below the formation. However, by early 1944 the American escort pilots were allowed greater freedom of movement, ranging out to the sides and front above the formation, sometimes scissoring to stay near the slower bombers. As described by Mike Spick in Luftwaffe Fighter Aces, the three squadrons in the fighter group escorting the bomber combat box usually arranged themselves as follows:
-One squadron would overtake the bombers and position above, dividing into two sections, one some miles ahead of the other.
-A second squadron also divided into two sections and positioned above and about a mile out from the bombers on each side of their box.
-The third squadron acted as top cover some 4,000 feet above the bombers, one section directly above and the other about ten miles ahead towards the sun where it would be ready to intercept any attacks from this ?blind spot.?
Typical Close Escort Formation
The picture above shows a typical close escort formation, with flank escorts, rear escort, and a forward sweep. The latter is the group furthest away from the bombers, usually out of visual range, and is the group?s defense against the head-on pass.
This wider-ranging escort made it possible for the escorts to find trouble before trouble found the bombers. Attacking enemy fighters before they could form up for a coordinated attack reduced Allied bomber losses and increased German fighter losses. Fighter group leaders had to resist sending their entire group against enemy attacks, since a well-timed German feint could attract so many pursuing fighters that the bombers would be left vulnerable to attack from another direction.
Attacking U.S. Bomber Formations
While it may sound as if German fighter pilots had the advantage in their freedom to form up at a distance, then hit fast and hard from the most advantageous angle, leaving their opposition little time to react, in reality there was plenty of fear to go around-for the attackers, their intended victims, and the shepherding escort pilots. The combat box formation bristled with heavy machine guns, and in the course of the war gunners aboard the bombers shot down far more enemy fighters than their fighter escort did. As Luftwaffe pilot Hans Philipp noted, ? ?curve in toward 40 Fortresses and all your past sins flash before your eyes.?
The frontal attack promised the best chance of survival. The German fighters would fly alongside the bomber formation, out of range of the gunners tracking them. About three miles ahead of the formation they would turn 180 degrees and attack from out of the sun at 12 o?clock high, aiming for the big bombers? cockpits. Sometimes they flew so close to their target that they had to zoom at the last instant to avoid the towering tail of the B-17. A two-gun chin turret was added to the B-17G model specifically to counter this head-on attack.
When attacking bombers from behind, the idea was to concentrate the attack by hurling one four-plane Schwarm after another at the target aircraft, quickly firing and then flying over the formation. Whether attacking from in front or behind, the German fighters often finished their attack with a split-S, while taking fire from the bombers? dorsal, tail, and belly guns, to open up as much distance from those guns as quickly as possible.
Other Luftwaffe tricks made life difficult for the American escorts. For example, as Mike Spick notes in Luftwaffe Fighter Aces, ? ?one flight of ?FW 190s was sent down through the formation as a decoy; the remainder stayed above to fall on the Americans when they dove after the sacrificial flight.? In the sudden, violent and confusing world of aerial combat, it was hard to resist the urge to follow any fighter that flew through the formation.
While German weaponry and tactics improved, the German fighter force was being worn down, with fewer and fewer experienced pilots left to lead the attack against the bombers. Bf 110s and Fw 190s armed with rockets and cannon, accompanied by Bf 109s flying top cover, broke up bomber formations and fell on the stragglers like wolves. These tactics were effective, but it was finally attrition that decided the outcome.
The appearance of the Messerschmitt Me-262 jet fighter allowed circumvention of the defending escorts altogether. In a technique pioneered by Luftwaffe pilots of the Kommando Nowotny, a Me-262 would approach the rear of an American formation at top speed (nearly 600 mph), bypassing the fighter screen. The German jet would then dive to a position roughly a mile behind and a quarter mile below the bombers, pull up into a high-g climb to scrub off airspeed and level off when even with the enemy formation. Now inside the screen of escorts and with a relatively slow closing speed with the bombers, the interceptor pilot could select a target, trigger a short burst from his four 30 mm cannon, roll inverted and dive away.
-You want as much distance between you and the bomber stream as you can get and still be able to see ? and get to ? the bomber group. The more distance you have, the more time you have to interfere with bandits on their way to the bombers. Escorts shouldn?t hesitate to move beyond visual range of the bombers if they spot bandits further out.
-The escorts usually stay between 5,000 to 8,000 feet higher than the bombers, so as to have enough energy to turn into attacking fighters.
-The conventional wisdom is to stay with the bombers, to break off enemy fighters when they cease to be a threat, and especially not to follow enemy fighters to lower altitudes. This may or may not be the right response, depending upon the circumstances. In an event, where every downed pilot means one less enemy plane, it is often better to release some escorts to follow and kill known bandits, even if they are trying to leave. In an arena, where there are always more enemy planes to come, it is usually best to stay with the bombers rather than chase bandits.
-Maintain your position relative to the bombers by keeping your speed high and flying at angles to the bomber stream. You will be faster than the bombers, and the temptation is to throttle back and fly level with them. You can do this if you are sure no bandits are around, but otherwise, you want to keep your speed high so that when they do show up, you have the energy to deal with them. Stay in position by flying at angles to the bombers. For example, if the bombers are holding 90 degrees, fly 120 degrees for a while, then turn to 60 degrees until you?re back in position, then repeat.
-If you have bandits hitting the bombers in a head-on pass, fire your guns at them, even if there?s no hope of hitting them. A head-on pass is a tricky thing. It takes place at closure speeds of 500 mph or faster and aiming is very difficult. If the shooter flinches on the approach, it can mean the difference between a bomber kill and a clean miss. Fill the air with tracers, make him think he has to take evasive action or die.
Here are also 2 videos which can help you make an idea how it was back then.